Investors looking for a boom should first check out Playboy's busts.
The company, whose stock is trading at a five-year-low of less than $2 a share, announced last week that it's closing its DVD business. Late last month, it was reported by the British tabloid The Daily Star that Playboy founder Hugh Hefner is laying off some of his bunnies because of the souring economy.
And more trouble may await the Playboy empire and its shareholders. According to a study published last week by econometricians Terry Pettijohn II and Brian Jungeberg, men tend to look for bigger, more robust, women during a lean economy. The report -- titled Playboy Playmate Curves: Changes in Facial and Body Feature Preferences Across Social and Economic Conditions -- also noted that when times are prosperous, men prefer less grown-up, shorter women with narrower waists.
In a move that has rendered quaint the once risqué miniskirt index, the pair of academics achieved this breakthrough by comparing the measurements from 40 years of Playmates to the economic data of the times.
"When social and economic conditions were difficult, older, heavier, taller Playboy Playmates of the Year with larger waists, smaller eyes, larger waist-to-hip ratios, smaller bust-to-waist ratios, and smaller body mass index values were selected," says the study. "These results suggest that environmental security may influence perceptions and preferences for women with certain body and facial features."
Boiled down to plain English, the paper posits that men are less interested in viewing women purely for sex when the chips are down, preferring to focus on more mature women with the ability to care for them. In short, Playboy's sales may be headed for an even steeper decline.
Whether the good professors are onto something big is debatable. But Playboy's shareholders should heed the good professors' sage barometer as a centerfold for sell.
[Via The Street]
Saturday, October 25, 2008
Economy Rocks China Factories
SHAOXING, China — In the good old days — oh, three months ago — Tao Shoulong would prowl the streets of this ancient city in his Mercedes-Benz. His wife and partner, Yan Qi, would cruise around in her Toyota Land Cruiser. Together, they would drink into the night with clients, suppliers and creditors, hatching plans to expand their Zhejiang River Dragon Textile Printing & Dyeing Co.
Tao built River Dragon from a start-up with four employees into one of China's biggest textile printing firms in just five years. He had even grander dreams: He wanted to see his company's stock trade on Nasdaq alongside the likes of Microsoft and Intel.
The dreams are dead. River Dragon shut down on Oct. 7. Tao and Yan have vanished, leaving behind more than $290 million in debt and a lot of anger in this city 140 miles south of Shanghai in the Yangtze River Delta. The company's demise put 4,000 workers on the street and jilted hundreds of suppliers and creditors.
The speedy rise — and speedier fall — of River Dragon is a depressingly familiar story in China these days. Thousands of Chinese factories have shuttered in the past year, done in by:
•An export-killing global slowdown that began with the collapse of the U.S. housing market and the ensuing financial crisis. Local textile merchant Fang Xingquan, a River Dragon creditor, is among many who believe a sharp drop-off in exports was a key factor in the company's demise.
•Rising materials costs that have squeezed profit margins.
•A deliberate Chinese government campaign to regulate sweatshop factories out of business.
China's National Bureau of Statistics this week said the nation's economy grew at an annual rate of 9% in the quarter ended Sept. 30, the lowest since 2003. The state-run Xinhua news agency said the government is considering a series of actions to boost exports and stimulate home sales.
Many economists, including Yu Yongding of the Chinese Academy of Social Sciences, believe that China needs to keep annual economic growth of 8% or 9% to absorb the 24 million people entering the labor force every year or risk social instability.
Earlier this month, the International Monetary Fund predicted that Chinese economic growth would cool from 2007's sizzling 11.9% to 9.7% this year and 9.3% in 2009. Private forecasters are even more pessimistic. UBS Investment Research, for instance, forecasts 8% growth in 2009.
"China is being hit over the head by both the global crisis and the domestic slowdown," says Stephen Green, economist at Standard Chartered Bank in Shanghai.
Exports account for nearly 38% of China's economic output. JPMorgan Chase calculates that Chinese exports fall 5.7 percentage points every time global economic growth shrinks by a percentage point. And the IMF is predicting that global growth will drop 2 percentage points — from 5% last year to 3% in 2009. Chinese appliance maker Haier has already seen export growth drop to 10% the first three quarters of this year from 30% a year earlier, the official English-language China Daily newspaper reported.
What happens to China has big implications globally: China contributed 17% of world economic growth last year, the same as the United States, according to the United Nations.
Home prices collapsing
The Chinese economy is absorbing another blow beyond crumbling exports: collapsing home prices. Nicholas Lardy, senior fellow at the Peterson Institute for International Economics in Washington, D.C., reckons a slowdown in construction could shave another 1 to 2 percentage points off China's economic growth.
"The property bubble is already starting to burst," says Yan Yu, a business management scholar at Peking University, researching the export center of Dongguan in southern Guangdong province. "House prices here in Dongguan have fallen by up to 50% this year," leaving many homeowners owing more on their mortgages than their homes are worth.
"People have worked all their lives and believed the hype and bought overvalued properties, then saw their savings vanish," says independent economist Andy Xie in Shanghai. "That carries more political risk" than rising joblessness.
The good news: The forecast growth rates are still pretty impressive by any other economy's standards; Chinese exports have proved surprisingly resilient, growing nearly 22% in September from a year earlier; and the government in Beijing is sitting on enough cash — $1.8 trillion in foreign exchange reserves — to go on a spending spree if needed to rescue the Chinese economy from catastrophe.
"Chinese authorities appear to be well aware of the global economic situation," JPMorgan Chase reported this month. The bank expects government to turn the spigot on spending, quadrupling the budget deficit to the equivalent of 2% of economic output from 0.5% this year.
The authorities aren't going to save everyone. The Chinese government has put pressure on small firms that foul the environment, pay miserly wages and turn out cheap products. "Beijing no longer wants to be the world's sweatshop for junk," CLSA Asia-Pacific Markets says in a recent report.
First, China cut tax breaks for exporters and imposed new export taxes on polluters, even targeting producers of disposable chopsticks. Then it introduced a labor law in January, requiring companies to give workers written contracts and making it harder for them to lay off employees or to hire informal part-time help.
The combination of tougher regulations, weakening exports, rising costs and a stronger Chinese currency has hammered thousands of small factories. The pain has been especially agonizing in Guangdong, a low-cost manufacturing center across the border from Hong Kong in southern China.
Guangdong's exports rose just 14% the first seven months of 2008 after growing 27% a year earlier. Industrial profits were up just 4% this year through May, compared with 49% a year earlier and puny compared with 21% growth nationwide. "Guangdong's weak performance is a signal of the government's determination to restructure the low-value-added export process sector and to force out of business firms that abuse labor and the environment," CLSA concluded.
Trouble in toyland
Firms that were already struggling with narrow profit margins have been squeezed. More than half of all China's toy exporters — 3,631 firms — shut their doors the first half of the year, the official Xinhua news agency reported. "Many toy factories have gone bankrupt this year," says Luo Yunzhang, founder of toy exporter Guangzhou Sixiren Toy, which makes playground equipment for Ohio-based Little Tikes, among other products.
"We saw exports start to dip in May, when the government began restricting businessmen's visits ahead of the (August) Olympic Games. … Now the global crisis is causing problems. When people are in difficulties, they spend less on things like toys," Luo says. Luo predicts that Sixiren's export revenue will drop by half this year, to $500,000.
China's textile industry is also enduring a deep slump. Textile exports have been tumbling since March. More than 10,000 small textile manufacturers went out of business the first half of this year alone, the government says. "The global crisis is seriously affecting the local textile industry," says Yu Xin of the China Chemical Fibers and Textile Consultancy in Hangzhou.
China's 30-year economic boom has produced towns that specialize in one product. There are shoe towns, zipper towns, air conditioner towns and sock towns. Shaoxing — a city of 4.3 million long known in China for opera, rice wine and scenic river vistas — has sold itself as China's Textile City.
The textile sector has been "an easy market, as it is not complicated, has low entry barriers and is a big employer," says Standard Chartered's Green. The local government gives tax breaks, and the industry has benefited from having a large number of suppliers and trained workers close by.
For a while, River Dragon looked like one of the winners. After working as a clerk at another firm, Tao started the company in 2003 with his wife, Yan, and four colleagues. River Dragon went public in Singapore two years ago, and Tao bought another textile firm last year, hoping the acquisition would give River Dragon the heft to list on Nasdaq. In July, Yan, the company CEO, announced that River Dragon had landed a $10 million contract to supply apparel to 76 U.S. universities. But the deal proved a mirage. The end came quickly. A day after the factory stopped production, River Dragon stock was dropped from the Singapore exchange. Corporate documents are missing, and Tao and Yan are long gone.
"I think they are still on the run in China," says Fang, the supplier. He says he was stiffed for more than $860,000 when River Dragon went under.
Keeping society 'stable'
About 300 suppliers and creditors descended on the River Dragon complex, looting warehouses in the hopes of salvaging something. Hundreds of workers demonstrated in the streets, demanding back pay for August and September. Worried about the unrest, the local government coughed up cash. "The government paid the workers to keep society stable," textile analyst Yu says.
As their export orders dry up, Chinese manufacturers are likely to look for customers at home in China or in other emerging markets such as the Middle East and Africa. "Soon we will see vicious price competition between companies who have lost exports," Green says.
In Guangdong, toymaker Luo hopes to push domestic sales up to $1.5 million this year from $1 million in 2007.
"The situation in the U.S. and other countries will not turn around quickly," he says. "We must rely more on the domestic market, as Chinese consumers increasingly have money to spend on toys. Profits are very thin in the toy business, both in export and domestic sales. I prefer exports. … Domestic sales involve more work. There are more customers. But their orders are small."
Independent economist Xie says China became overly dependent on demand from the U.S. and Europe that was stoked by too much borrowed money and inflated asset values. "It's all coming to an end," he says. "You need to look elsewhere for livelihood. Americans cannot spend money anymore."
[Via USA Today]
Tao built River Dragon from a start-up with four employees into one of China's biggest textile printing firms in just five years. He had even grander dreams: He wanted to see his company's stock trade on Nasdaq alongside the likes of Microsoft and Intel.
The dreams are dead. River Dragon shut down on Oct. 7. Tao and Yan have vanished, leaving behind more than $290 million in debt and a lot of anger in this city 140 miles south of Shanghai in the Yangtze River Delta. The company's demise put 4,000 workers on the street and jilted hundreds of suppliers and creditors.
The speedy rise — and speedier fall — of River Dragon is a depressingly familiar story in China these days. Thousands of Chinese factories have shuttered in the past year, done in by:
•An export-killing global slowdown that began with the collapse of the U.S. housing market and the ensuing financial crisis. Local textile merchant Fang Xingquan, a River Dragon creditor, is among many who believe a sharp drop-off in exports was a key factor in the company's demise.
•Rising materials costs that have squeezed profit margins.
•A deliberate Chinese government campaign to regulate sweatshop factories out of business.
China's National Bureau of Statistics this week said the nation's economy grew at an annual rate of 9% in the quarter ended Sept. 30, the lowest since 2003. The state-run Xinhua news agency said the government is considering a series of actions to boost exports and stimulate home sales.
Many economists, including Yu Yongding of the Chinese Academy of Social Sciences, believe that China needs to keep annual economic growth of 8% or 9% to absorb the 24 million people entering the labor force every year or risk social instability.
Earlier this month, the International Monetary Fund predicted that Chinese economic growth would cool from 2007's sizzling 11.9% to 9.7% this year and 9.3% in 2009. Private forecasters are even more pessimistic. UBS Investment Research, for instance, forecasts 8% growth in 2009.
"China is being hit over the head by both the global crisis and the domestic slowdown," says Stephen Green, economist at Standard Chartered Bank in Shanghai.
Exports account for nearly 38% of China's economic output. JPMorgan Chase calculates that Chinese exports fall 5.7 percentage points every time global economic growth shrinks by a percentage point. And the IMF is predicting that global growth will drop 2 percentage points — from 5% last year to 3% in 2009. Chinese appliance maker Haier has already seen export growth drop to 10% the first three quarters of this year from 30% a year earlier, the official English-language China Daily newspaper reported.
What happens to China has big implications globally: China contributed 17% of world economic growth last year, the same as the United States, according to the United Nations.
Home prices collapsing
The Chinese economy is absorbing another blow beyond crumbling exports: collapsing home prices. Nicholas Lardy, senior fellow at the Peterson Institute for International Economics in Washington, D.C., reckons a slowdown in construction could shave another 1 to 2 percentage points off China's economic growth.
"The property bubble is already starting to burst," says Yan Yu, a business management scholar at Peking University, researching the export center of Dongguan in southern Guangdong province. "House prices here in Dongguan have fallen by up to 50% this year," leaving many homeowners owing more on their mortgages than their homes are worth.
"People have worked all their lives and believed the hype and bought overvalued properties, then saw their savings vanish," says independent economist Andy Xie in Shanghai. "That carries more political risk" than rising joblessness.
The good news: The forecast growth rates are still pretty impressive by any other economy's standards; Chinese exports have proved surprisingly resilient, growing nearly 22% in September from a year earlier; and the government in Beijing is sitting on enough cash — $1.8 trillion in foreign exchange reserves — to go on a spending spree if needed to rescue the Chinese economy from catastrophe.
"Chinese authorities appear to be well aware of the global economic situation," JPMorgan Chase reported this month. The bank expects government to turn the spigot on spending, quadrupling the budget deficit to the equivalent of 2% of economic output from 0.5% this year.
The authorities aren't going to save everyone. The Chinese government has put pressure on small firms that foul the environment, pay miserly wages and turn out cheap products. "Beijing no longer wants to be the world's sweatshop for junk," CLSA Asia-Pacific Markets says in a recent report.
First, China cut tax breaks for exporters and imposed new export taxes on polluters, even targeting producers of disposable chopsticks. Then it introduced a labor law in January, requiring companies to give workers written contracts and making it harder for them to lay off employees or to hire informal part-time help.
The combination of tougher regulations, weakening exports, rising costs and a stronger Chinese currency has hammered thousands of small factories. The pain has been especially agonizing in Guangdong, a low-cost manufacturing center across the border from Hong Kong in southern China.
Guangdong's exports rose just 14% the first seven months of 2008 after growing 27% a year earlier. Industrial profits were up just 4% this year through May, compared with 49% a year earlier and puny compared with 21% growth nationwide. "Guangdong's weak performance is a signal of the government's determination to restructure the low-value-added export process sector and to force out of business firms that abuse labor and the environment," CLSA concluded.
Trouble in toyland
Firms that were already struggling with narrow profit margins have been squeezed. More than half of all China's toy exporters — 3,631 firms — shut their doors the first half of the year, the official Xinhua news agency reported. "Many toy factories have gone bankrupt this year," says Luo Yunzhang, founder of toy exporter Guangzhou Sixiren Toy, which makes playground equipment for Ohio-based Little Tikes, among other products.
"We saw exports start to dip in May, when the government began restricting businessmen's visits ahead of the (August) Olympic Games. … Now the global crisis is causing problems. When people are in difficulties, they spend less on things like toys," Luo says. Luo predicts that Sixiren's export revenue will drop by half this year, to $500,000.
China's textile industry is also enduring a deep slump. Textile exports have been tumbling since March. More than 10,000 small textile manufacturers went out of business the first half of this year alone, the government says. "The global crisis is seriously affecting the local textile industry," says Yu Xin of the China Chemical Fibers and Textile Consultancy in Hangzhou.
China's 30-year economic boom has produced towns that specialize in one product. There are shoe towns, zipper towns, air conditioner towns and sock towns. Shaoxing — a city of 4.3 million long known in China for opera, rice wine and scenic river vistas — has sold itself as China's Textile City.
The textile sector has been "an easy market, as it is not complicated, has low entry barriers and is a big employer," says Standard Chartered's Green. The local government gives tax breaks, and the industry has benefited from having a large number of suppliers and trained workers close by.
For a while, River Dragon looked like one of the winners. After working as a clerk at another firm, Tao started the company in 2003 with his wife, Yan, and four colleagues. River Dragon went public in Singapore two years ago, and Tao bought another textile firm last year, hoping the acquisition would give River Dragon the heft to list on Nasdaq. In July, Yan, the company CEO, announced that River Dragon had landed a $10 million contract to supply apparel to 76 U.S. universities. But the deal proved a mirage. The end came quickly. A day after the factory stopped production, River Dragon stock was dropped from the Singapore exchange. Corporate documents are missing, and Tao and Yan are long gone.
"I think they are still on the run in China," says Fang, the supplier. He says he was stiffed for more than $860,000 when River Dragon went under.
Keeping society 'stable'
About 300 suppliers and creditors descended on the River Dragon complex, looting warehouses in the hopes of salvaging something. Hundreds of workers demonstrated in the streets, demanding back pay for August and September. Worried about the unrest, the local government coughed up cash. "The government paid the workers to keep society stable," textile analyst Yu says.
As their export orders dry up, Chinese manufacturers are likely to look for customers at home in China or in other emerging markets such as the Middle East and Africa. "Soon we will see vicious price competition between companies who have lost exports," Green says.
In Guangdong, toymaker Luo hopes to push domestic sales up to $1.5 million this year from $1 million in 2007.
"The situation in the U.S. and other countries will not turn around quickly," he says. "We must rely more on the domestic market, as Chinese consumers increasingly have money to spend on toys. Profits are very thin in the toy business, both in export and domestic sales. I prefer exports. … Domestic sales involve more work. There are more customers. But their orders are small."
Independent economist Xie says China became overly dependent on demand from the U.S. and Europe that was stoked by too much borrowed money and inflated asset values. "It's all coming to an end," he says. "You need to look elsewhere for livelihood. Americans cannot spend money anymore."
[Via USA Today]
Sunday, October 5, 2008
How Howard Hughes Avoided Taxes
As his empire grew, Hughes used every trick conceivable to avoid paying taxes to the government. In the early years of Hughes Aircraft, Hughes attempted to move his company from Southern California to Nevada in an effort to take advantage of Nevada's low tax rates. Ultimately, Hughes donated all his stock in Hughes Aircraft to the Howard Hughes Medical Institute, thereby turning the military contractor into a tax-exempt charity. In addition to avoiding income taxes, this had the effect of silencing the upper management in Hughes Aircraft, who for many years had clamored for stock in the company as part of their compensation.
Hughes was able to keep and maintain highly qualified managers in his companies by promising them large sums of money at the end of their careers. In order to be able to give them the most money without taxation, Hughes would make an arrangement whereby he would publicly criticize a certain manager that had recently left his company. Then, the manager would sue Hughes in court for public defamation. A settlement was given to this manager in court which was not subject to taxes. This happened with Noah Dietrich, Robert Maheu, and others. For example, Robert Maheu was awarded US$2.2 million in a defamation lawsuit shortly after leaving Hughes' employ.
Although Hughes lived in his own home in California for many years, he later came up with the idea of living in hotels as this enabled him not to have a legally declared residence in any state which would require him to pay personal income taxes. Shortly after Hughes began living in hotels with no state as his official residence, legislation was passed that any person living in a state 180 days or longer was subject to personal income tax during that time period in that state. Then, Hughes would live in a given hotel for just under 180 days, before moving to another hotel for just under 180 days, and so on. His extremely creative efforts to avoid taxes were successful; even after his death, the states of California and Texas were unable to collect inheritance taxes since it could not be proven that he was a legal resident of either state.
[Via Wikipedia]
Hughes was able to keep and maintain highly qualified managers in his companies by promising them large sums of money at the end of their careers. In order to be able to give them the most money without taxation, Hughes would make an arrangement whereby he would publicly criticize a certain manager that had recently left his company. Then, the manager would sue Hughes in court for public defamation. A settlement was given to this manager in court which was not subject to taxes. This happened with Noah Dietrich, Robert Maheu, and others. For example, Robert Maheu was awarded US$2.2 million in a defamation lawsuit shortly after leaving Hughes' employ.
Although Hughes lived in his own home in California for many years, he later came up with the idea of living in hotels as this enabled him not to have a legally declared residence in any state which would require him to pay personal income taxes. Shortly after Hughes began living in hotels with no state as his official residence, legislation was passed that any person living in a state 180 days or longer was subject to personal income tax during that time period in that state. Then, Hughes would live in a given hotel for just under 180 days, before moving to another hotel for just under 180 days, and so on. His extremely creative efforts to avoid taxes were successful; even after his death, the states of California and Texas were unable to collect inheritance taxes since it could not be proven that he was a legal resident of either state.
[Via Wikipedia]
Friday, September 26, 2008
How to Replace Expensive Software Packages
If you’ve downloaded and installed all of these, you’ve got access to all the productivity software you’ll likely need, clean and open and best of all free.
1. Firefox
http://www.getfirefox.com/
Replaces Internet Explorer
If you haven’t switched to Firefox for your web browsing needs, do it now. It stops annoying popups and it has tons of amazing plugins that can make surfing the web even better.
2. Thunderbird
http://www.mozilla.org/thunderbird/
Replaces Microsoft Outlook or Eudora
Thunderbird is an email client that has five big things going for it: it’s free, it’s full featured, it’s lightweight and runs quick, it has an unparalleled spam filter, and it protects you from those ridiculous phishing attacks by clearly indicating which emails send you to a bogus website. If you’re not already using a web-based email solution, Thunderbird should be your client.
3. Sunbird
http://www.mozilla.org/projects/calendar/sunbird/
Replaces Microsoft Outlook’s calendaring functions
Might as well get the Mozilla trifecta out of the way by mentioning Sunbird, which is the Mozilla Foundation’s calendaring program. It’s extremely easy to use and easy to share your calendar with others.
4. Abiword
http://www.abisource.com/
Replaces Microsoft Word
Want a good word processor but find Microsoft Word too expensive? AbiWord is excellent replacement for Word. It’s lightweight and includes pretty much every feature that everyone uses regularly in a word processor, plus it can save files in formats that you can exchange with Word and WordPerfect users, plus open any of their files, too.
5. OpenOffice
http://www.openoffice.org/
Replaces Microsoft Excel and Microsoft PowerPoint
If you want to replace the rest of the Office suite, your best bet is OpenOffice. It includes very nice replacements for Excel and PowerPoint (and workable replacements for Access and other Office elements).
6. ClamWin
http://www.clamwin.com/
Replaces Norton AntiVirus or McAfee
ClamWin is a slick anti-virus software that’s quite easy to manage and is unobtrusive while keep your system free of viruses.
7. Gaim
http://gaim.sourceforge.net/
Replaces AIM, Windows Messenger, etc.
This is a very clean instant messaging program that allows you to be on AOL Instant Messenger, Windows (MSN) Messenger, and Yahoo Messenger simultaneously with one program. There are other free packages that do this, but Gaim is stable and clean and simple.
8. GIMPShop
http://www.gimpshop.net/
Replaces Adobe Photoshop
This is a version of the GNU Image Manipulation Program that does a pretty solid job of imitating Adobe Photoshop - a regular user of Photoshop can adapt to it quite quickly. It’s very richly featured and runs quite well.
9. VLC Media Player
http://www.videolan.org/vlc/
Replaces Windows Media Player, Quicktime, RealPlayer, etc.
If you get tired of having tons of media players on your computer, get this package that runs pretty much every media type you’ll run across without breaking a sweat.
10. Filezilla
http://filezilla.sourceforge.net/
Replaces WinFTP
Many people occasionally have a need to FTP files to other computers; if you ever have the need to transfer files in such a fashion, FileZilla will do the job slickly and quickly.
11. MusikCube
http://www.musikcube.com/
Replaces iTunes
If you’re not already committed to downloaded music from the iTunes Music Store, then MusikCube is the best choice available for a music organizer and player. It organizes your mp3s, makes it really easy and really fast to find them, and allows you to make some incredibly clever smart playlists.
12. X-Chat 2
http://www.silverex.org/
Replaces mIRC
X-Chat is a free IRC client. For those unfamiliar with IRC, it’s a place for technical people (and, as my wife loves to point out, nerds) to meet and discuss topics in an open environment. I often find it very useful when piecing through difficult technical issues.
13. PDFCreator
http://sourceforge.net/projects/pdfcreator/
Replaces Adobe Acrobat
PDFCreator creates a virtual printer on your computer that, if you print a document to it from any program, creates a PDF of that document that can be read on any computer with Acrobat Reader on it. After installing PDFCreator, all you have to do is print like normal and out comes a PDF!
14. Notepad2
http://www.flos-freeware.ch/notepad2.html
Replaces Notepad
Notepad2 is a replacement for the traditional Windows Notepad that just adds a few sweet little features: multiple documents; line, word, and character counts; and some highlighting of tags.
15. GanttPV
http://www.pureviolet.net/ganttpv/
Replaces Microsoft Project
If you do any project management, GanttPV does a brilliant job of managing the task quickly, easily, and freely. If you need to move to MS Project later, you can export from GanttPV to Project, but once you start digging into GanttPV, you’ll likely have no reason to use Project.
16. GnuCash
http://www.gnucash.org/
Replaces Microsoft Money or Quicken
GnuCash is a slimmed-down version of the bloated Microsoft Money and Quicken packages. The interfaces are incredibly simple - it functions much like a checkbook ledger on your computer - but there’s a lot of meat hidden throughout the software.
17. True Combat: Elite
http://www.truecombatelite.net/
Replaces Quake IV, Halo, etc.
After all this downloading, you’re going to need to blow off a little steam. It’s basically a third person combat game, but the graphics are spectacular and the game is quite engrossing.
1. Firefox
http://www.getfirefox.com/
Replaces Internet Explorer
If you haven’t switched to Firefox for your web browsing needs, do it now. It stops annoying popups and it has tons of amazing plugins that can make surfing the web even better.
2. Thunderbird
http://www.mozilla.org/thunderbird/
Replaces Microsoft Outlook or Eudora
Thunderbird is an email client that has five big things going for it: it’s free, it’s full featured, it’s lightweight and runs quick, it has an unparalleled spam filter, and it protects you from those ridiculous phishing attacks by clearly indicating which emails send you to a bogus website. If you’re not already using a web-based email solution, Thunderbird should be your client.
3. Sunbird
http://www.mozilla.org/projects/calendar/sunbird/
Replaces Microsoft Outlook’s calendaring functions
Might as well get the Mozilla trifecta out of the way by mentioning Sunbird, which is the Mozilla Foundation’s calendaring program. It’s extremely easy to use and easy to share your calendar with others.
4. Abiword
http://www.abisource.com/
Replaces Microsoft Word
Want a good word processor but find Microsoft Word too expensive? AbiWord is excellent replacement for Word. It’s lightweight and includes pretty much every feature that everyone uses regularly in a word processor, plus it can save files in formats that you can exchange with Word and WordPerfect users, plus open any of their files, too.
5. OpenOffice
http://www.openoffice.org/
Replaces Microsoft Excel and Microsoft PowerPoint
If you want to replace the rest of the Office suite, your best bet is OpenOffice. It includes very nice replacements for Excel and PowerPoint (and workable replacements for Access and other Office elements).
6. ClamWin
http://www.clamwin.com/
Replaces Norton AntiVirus or McAfee
ClamWin is a slick anti-virus software that’s quite easy to manage and is unobtrusive while keep your system free of viruses.
7. Gaim
http://gaim.sourceforge.net/
Replaces AIM, Windows Messenger, etc.
This is a very clean instant messaging program that allows you to be on AOL Instant Messenger, Windows (MSN) Messenger, and Yahoo Messenger simultaneously with one program. There are other free packages that do this, but Gaim is stable and clean and simple.
8. GIMPShop
http://www.gimpshop.net/
Replaces Adobe Photoshop
This is a version of the GNU Image Manipulation Program that does a pretty solid job of imitating Adobe Photoshop - a regular user of Photoshop can adapt to it quite quickly. It’s very richly featured and runs quite well.
9. VLC Media Player
http://www.videolan.org/vlc/
Replaces Windows Media Player, Quicktime, RealPlayer, etc.
If you get tired of having tons of media players on your computer, get this package that runs pretty much every media type you’ll run across without breaking a sweat.
10. Filezilla
http://filezilla.sourceforge.net/
Replaces WinFTP
Many people occasionally have a need to FTP files to other computers; if you ever have the need to transfer files in such a fashion, FileZilla will do the job slickly and quickly.
11. MusikCube
http://www.musikcube.com/
Replaces iTunes
If you’re not already committed to downloaded music from the iTunes Music Store, then MusikCube is the best choice available for a music organizer and player. It organizes your mp3s, makes it really easy and really fast to find them, and allows you to make some incredibly clever smart playlists.
12. X-Chat 2
http://www.silverex.org/
Replaces mIRC
X-Chat is a free IRC client. For those unfamiliar with IRC, it’s a place for technical people (and, as my wife loves to point out, nerds) to meet and discuss topics in an open environment. I often find it very useful when piecing through difficult technical issues.
13. PDFCreator
http://sourceforge.net/projects/pdfcreator/
Replaces Adobe Acrobat
PDFCreator creates a virtual printer on your computer that, if you print a document to it from any program, creates a PDF of that document that can be read on any computer with Acrobat Reader on it. After installing PDFCreator, all you have to do is print like normal and out comes a PDF!
14. Notepad2
http://www.flos-freeware.ch/notepad2.html
Replaces Notepad
Notepad2 is a replacement for the traditional Windows Notepad that just adds a few sweet little features: multiple documents; line, word, and character counts; and some highlighting of tags.
15. GanttPV
http://www.pureviolet.net/ganttpv/
Replaces Microsoft Project
If you do any project management, GanttPV does a brilliant job of managing the task quickly, easily, and freely. If you need to move to MS Project later, you can export from GanttPV to Project, but once you start digging into GanttPV, you’ll likely have no reason to use Project.
16. GnuCash
http://www.gnucash.org/
Replaces Microsoft Money or Quicken
GnuCash is a slimmed-down version of the bloated Microsoft Money and Quicken packages. The interfaces are incredibly simple - it functions much like a checkbook ledger on your computer - but there’s a lot of meat hidden throughout the software.
17. True Combat: Elite
http://www.truecombatelite.net/
Replaces Quake IV, Halo, etc.
After all this downloading, you’re going to need to blow off a little steam. It’s basically a third person combat game, but the graphics are spectacular and the game is quite engrossing.
Monday, September 22, 2008
9 Mental Math Tricks
Math can be terrifying for many people. This list will hopefully improve your general knowledge of mathematical tricks and your speed when you need to do math in your head.
1. Multiplying by 9, or 99, or 999
Multiplying by 9 is really multiplying by 10-1.
So, 9×9 is just 9x(10-1) which is 9×10-9 which is 90-9 or 81.
Let’s try a harder example: 46×9 = 46×10-46 = 460-46 = 414.
One more example: 68×9 = 680-68 = 612.
To multiply by 99, you multiply by 100-1.
So, 46×99 = 46x(100-1) = 4600-46 = 4554.
Multiplying by 999 is similar to multiplying by 9 and by 99.
38×999 = 38x(1000-1) = 38000-38 = 37962.
2. Multiplying by 11
To multiply a number by 11 you add pairs of numbers next to each other, except for the numbers on the edges.
Let me illustrate:
To multiply 436 by 11 go from right to left.
First write down the 6 then add 6 to its neighbor on the left, 3, to get 9.
Write down 9 to the left of 6.
Then add 4 to 3 to get 7. Write down 7.
Then, write down the leftmost digit, 4.
So, 436×11 = is 4796.
Let’s do another example: 3254×11.
The answer comes from these sums and edge numbers: (3)(3+2)(2+5)(5+4)(4) = 35794.
One more example, this one involving carrying: 4657×11.
Write down the sums and edge numbers: (4)(4+6)(6+5)(5+7)(7).
Going from right to left we write down 7.
Then we notice that 5+7=12.
So we write down 2 and carry the 1.
6+5 = 11, plus the 1 we carried = 12.
So, we write down the 2 and carry the 1.
4+6 = 10, plus the 1 we carried = 11.
So, we write down the 1 and carry the 1.
To the leftmost digit, 4, we add the 1 we carried.
So, 4657×11 = 51227 .
3. Multiplying by 5, 25, or 125
Multiplying by 5 is just multiplying by 10 and then dividing by 2. Note: To multiply by 10 just add a 0 to the end of the number.
12×5 = (12×10)/2 = 120/2 = 60.
Another example: 64×5 = 640/2 = 320.
And, 4286×5 = 42860/2 = 21430.
To multiply by 25 you multiply by 100 (just add two 0’s to the end of the number) then divide by 4, since 100 = 25×4. Note: to divide by 4 your can just divide by 2 twice, since 2×2 = 4.
64×25 = 6400/4 = 3200/2 = 1600.
58×25 = 5800/4 = 2900/2 = 1450.
To multiply by 125, you multipy by 1000 then divide by 8 since 8×125 = 1000. Notice that 8 = 2×2x2. So, to divide by 1000 add three 0’s to the number and divide by 2 three times.
32×125 = 32000/8 = 16000/4 = 8000/2 = 4000.
48×125 = 48000/8 = 24000/4 = 12000/2 = 6000.
4. Multiplying together two numbers that differ by a small even number
This trick only works if you’ve memorized or can quickly calculate the squares of numbers. If you’re able to memorize some squares and use the tricks described later for some kinds of numbers you’ll be able to quickly multiply together many pairs of numbers that differ by 2, or 4, or 6.
Let’s say you want to calculate 12×14.
When two numbers differ by two their product is always the square of the number in between them minus 1.
12×14 = (13×13)-1 = 168.
16×18 = (17×17)-1 = 288.
99×101 = (100×100)-1 = 10000-1 = 9999
If two numbers differ by 4 then their product is the square of the number in the middle (the average of the two numbers) minus 4.
11×15 = (13×13)-4 = 169-4 = 165.
13×17 = (15×15)-4 = 225-4 = 221.
If the two numbers differ by 6 then their product is the square of their average minus 9.
12×18 = (15×15)-9 = 216.
17×23 = (20×20)-9 = 391.
5. Squaring 2-digit numbers that end in 5
If a number ends in 5 then its square always ends in 25. To get the rest of the product take the left digit and multiply it by one more than itself.
35×35 ends in 25. We get the rest of the product by multiplying 3 by one more than 3. So, 3×4 = 12 and that’s the rest of the product. Thus, 35×35 = 1225.
To calculate 65×65, notice that 6×7 = 42 and write down 4225 as the answer.
85×85: Calculate 8×9 = 72 and write down 7225.
6. Multiplying together 2-digit numbers where the first digits are the same and the last digits sum to 10
Let’s say you want to multiply 42 by 48. You notice that the first digit is 4 in both cases. You also notice that the other digits, 2 and 8, sum to 10. You can then use this trick: multiply the first digit by one more than itself to get the first part of the answer and multiply the last digits together to get the second (right) part of the answer.
An illustration is in order:
To calculate 42×48: Multiply 4 by 4+1. So, 4×5 = 20. Write down 20.
Multiply together the last digits: 2×8 = 16. Write down 16.
The product of 42 and 48 is thus 2016.
Notice that for this particular example you could also have noticed that 42 and 48 differ by 6 and have applied technique number 4.
Another example: 64×66. 6×7 = 42. 4×6 = 24. The product is 4224.
A final example: 86×84. 8×9 = 72. 6×4 = 24. The product is 7224
7. Squaring other 2-digit numbers
Let’s say you want to square 58. Square each digit and write a partial answer. 5×5 = 25. 8×8 = 64. Write down 2564 to start. Then, multiply the two digits of the number you’re squaring together, 5×8=40.
Double this product: 40×2=80, then add a 0 to it, getting 800.
Add 800 to 2564 to get 3364.
This is pretty complicated so let’s do more examples.
32×32. The first part of the answer comes from squaring 3 and 2.
3×3=9. 2×2 = 4. Write down 0904. Notice the extra zeros. It’s important that every square in the partial product have two digits.
Multiply the digits, 2 and 3, together and double the whole thing. 2×3x2 = 12.
Add a zero to get 120. Add 120 to the partial product, 0904, and we get 1024.
56×56. The partial product comes from 5×5 and 6×6. Write down 2536.
5×6x2 = 60. Add a zero to get 600.
56×56 = 2536+600 = 3136.
One more example: 67×67. Write down 3649 as the partial product.
6×7x2 = 42×2 = 84. Add a zero to get 840.
67×67=3649+840 = 4489.
8. Multiplying by doubling and halving
There are cases when you’re multiplying two numbers together and one of the numbers is even. In this case you can divide that number by two and multiply the other number by 2. You can do this over and over until you get to multiplication this is easy for you to do.
Let’s say you want to multiply 14 by 16. You can do this:
14×16 = 28×8 = 56×4 = 112×2 = 224.
Another example: 12×15 = 6×30 = 6×3 with a 0 at the end so it’s 180.
48×17 = 24×34 = 12×68 = 6×136 = 3×272 = 816. (Being able to calculate that 3×27 = 81 in your head is very helpful for this problem.)
9. Multiplying by a power of 2
To multiply a number by 2, 4, 8, 16, 32, or some other power of 2 just keep doubling the product as many times as necessary. If you want to multiply by 16 then double the number 4 times since 16 = 2×2x2×2.
15×16: 15×2 = 30. 30×2 = 60. 60×2 = 120. 120×2 = 240.
23×8: 23×2 = 46. 46×2 = 92. 92×2 = 184.
54×8: 54×2 = 108. 108×2 = 216. 216×2 = 432.
I Never Said She Stole My Money: 7 Different Meanings
1. Multiplying by 9, or 99, or 999
Multiplying by 9 is really multiplying by 10-1.
So, 9×9 is just 9x(10-1) which is 9×10-9 which is 90-9 or 81.
Let’s try a harder example: 46×9 = 46×10-46 = 460-46 = 414.
One more example: 68×9 = 680-68 = 612.
To multiply by 99, you multiply by 100-1.
So, 46×99 = 46x(100-1) = 4600-46 = 4554.
Multiplying by 999 is similar to multiplying by 9 and by 99.
38×999 = 38x(1000-1) = 38000-38 = 37962.
2. Multiplying by 11
To multiply a number by 11 you add pairs of numbers next to each other, except for the numbers on the edges.
Let me illustrate:
To multiply 436 by 11 go from right to left.
First write down the 6 then add 6 to its neighbor on the left, 3, to get 9.
Write down 9 to the left of 6.
Then add 4 to 3 to get 7. Write down 7.
Then, write down the leftmost digit, 4.
So, 436×11 = is 4796.
Let’s do another example: 3254×11.
The answer comes from these sums and edge numbers: (3)(3+2)(2+5)(5+4)(4) = 35794.
One more example, this one involving carrying: 4657×11.
Write down the sums and edge numbers: (4)(4+6)(6+5)(5+7)(7).
Going from right to left we write down 7.
Then we notice that 5+7=12.
So we write down 2 and carry the 1.
6+5 = 11, plus the 1 we carried = 12.
So, we write down the 2 and carry the 1.
4+6 = 10, plus the 1 we carried = 11.
So, we write down the 1 and carry the 1.
To the leftmost digit, 4, we add the 1 we carried.
So, 4657×11 = 51227 .
3. Multiplying by 5, 25, or 125
Multiplying by 5 is just multiplying by 10 and then dividing by 2. Note: To multiply by 10 just add a 0 to the end of the number.
12×5 = (12×10)/2 = 120/2 = 60.
Another example: 64×5 = 640/2 = 320.
And, 4286×5 = 42860/2 = 21430.
To multiply by 25 you multiply by 100 (just add two 0’s to the end of the number) then divide by 4, since 100 = 25×4. Note: to divide by 4 your can just divide by 2 twice, since 2×2 = 4.
64×25 = 6400/4 = 3200/2 = 1600.
58×25 = 5800/4 = 2900/2 = 1450.
To multiply by 125, you multipy by 1000 then divide by 8 since 8×125 = 1000. Notice that 8 = 2×2x2. So, to divide by 1000 add three 0’s to the number and divide by 2 three times.
32×125 = 32000/8 = 16000/4 = 8000/2 = 4000.
48×125 = 48000/8 = 24000/4 = 12000/2 = 6000.
4. Multiplying together two numbers that differ by a small even number
This trick only works if you’ve memorized or can quickly calculate the squares of numbers. If you’re able to memorize some squares and use the tricks described later for some kinds of numbers you’ll be able to quickly multiply together many pairs of numbers that differ by 2, or 4, or 6.
Let’s say you want to calculate 12×14.
When two numbers differ by two their product is always the square of the number in between them minus 1.
12×14 = (13×13)-1 = 168.
16×18 = (17×17)-1 = 288.
99×101 = (100×100)-1 = 10000-1 = 9999
If two numbers differ by 4 then their product is the square of the number in the middle (the average of the two numbers) minus 4.
11×15 = (13×13)-4 = 169-4 = 165.
13×17 = (15×15)-4 = 225-4 = 221.
If the two numbers differ by 6 then their product is the square of their average minus 9.
12×18 = (15×15)-9 = 216.
17×23 = (20×20)-9 = 391.
5. Squaring 2-digit numbers that end in 5
If a number ends in 5 then its square always ends in 25. To get the rest of the product take the left digit and multiply it by one more than itself.
35×35 ends in 25. We get the rest of the product by multiplying 3 by one more than 3. So, 3×4 = 12 and that’s the rest of the product. Thus, 35×35 = 1225.
To calculate 65×65, notice that 6×7 = 42 and write down 4225 as the answer.
85×85: Calculate 8×9 = 72 and write down 7225.
6. Multiplying together 2-digit numbers where the first digits are the same and the last digits sum to 10
Let’s say you want to multiply 42 by 48. You notice that the first digit is 4 in both cases. You also notice that the other digits, 2 and 8, sum to 10. You can then use this trick: multiply the first digit by one more than itself to get the first part of the answer and multiply the last digits together to get the second (right) part of the answer.
An illustration is in order:
To calculate 42×48: Multiply 4 by 4+1. So, 4×5 = 20. Write down 20.
Multiply together the last digits: 2×8 = 16. Write down 16.
The product of 42 and 48 is thus 2016.
Notice that for this particular example you could also have noticed that 42 and 48 differ by 6 and have applied technique number 4.
Another example: 64×66. 6×7 = 42. 4×6 = 24. The product is 4224.
A final example: 86×84. 8×9 = 72. 6×4 = 24. The product is 7224
7. Squaring other 2-digit numbers
Let’s say you want to square 58. Square each digit and write a partial answer. 5×5 = 25. 8×8 = 64. Write down 2564 to start. Then, multiply the two digits of the number you’re squaring together, 5×8=40.
Double this product: 40×2=80, then add a 0 to it, getting 800.
Add 800 to 2564 to get 3364.
This is pretty complicated so let’s do more examples.
32×32. The first part of the answer comes from squaring 3 and 2.
3×3=9. 2×2 = 4. Write down 0904. Notice the extra zeros. It’s important that every square in the partial product have two digits.
Multiply the digits, 2 and 3, together and double the whole thing. 2×3x2 = 12.
Add a zero to get 120. Add 120 to the partial product, 0904, and we get 1024.
56×56. The partial product comes from 5×5 and 6×6. Write down 2536.
5×6x2 = 60. Add a zero to get 600.
56×56 = 2536+600 = 3136.
One more example: 67×67. Write down 3649 as the partial product.
6×7x2 = 42×2 = 84. Add a zero to get 840.
67×67=3649+840 = 4489.
8. Multiplying by doubling and halving
There are cases when you’re multiplying two numbers together and one of the numbers is even. In this case you can divide that number by two and multiply the other number by 2. You can do this over and over until you get to multiplication this is easy for you to do.
Let’s say you want to multiply 14 by 16. You can do this:
14×16 = 28×8 = 56×4 = 112×2 = 224.
Another example: 12×15 = 6×30 = 6×3 with a 0 at the end so it’s 180.
48×17 = 24×34 = 12×68 = 6×136 = 3×272 = 816. (Being able to calculate that 3×27 = 81 in your head is very helpful for this problem.)
9. Multiplying by a power of 2
To multiply a number by 2, 4, 8, 16, 32, or some other power of 2 just keep doubling the product as many times as necessary. If you want to multiply by 16 then double the number 4 times since 16 = 2×2x2×2.
15×16: 15×2 = 30. 30×2 = 60. 60×2 = 120. 120×2 = 240.
23×8: 23×2 = 46. 46×2 = 92. 92×2 = 184.
54×8: 54×2 = 108. 108×2 = 216. 216×2 = 432.
I Never Said She Stole My Money: 7 Different Meanings
The Most Beautiful Number
Sunday, September 14, 2008
Ten Things You Don’t Know About the Earth
1) The Earth is smoother than a billiard ball.
Maybe you’ve heard this statement: if the Earth were shrunk down to the size of a billiard ball, it would actually be smoother than one. When I was in third grade, my teacher said basketball, but it’s the same concept. But is it true? Let’s see. Strap in, there’s a wee bit of math (like, a really wee bit).
OK, first, how smooth is a billiard ball? According to the World Pool-Billiard Association, a pool ball is 2.25 inches in diameter, and has a tolerance of +/- 0.005 inches. In other words, it must have no pits or bumps more than 0.005 inches in height. That’s pretty smooth. The ratio of the size of an allowable bump to the size of the ball is 0.005/2.25 = about 0.002.
The Earth has a diameter of about 12,735 kilometers (on average, see below for more on this). Using the smoothness ratio from above, the Earth would be an acceptable pool ball if it had no bumps (mountains) or pits (trenches) more than 12,735 km x 0.00222 = about 28 km in size.
The highest point on Earth is the top of Mt. Everest, at 8.85 km. The deepest point on Earth is the Marianas Trench, at about 11 km deep.
Hey, those are within the tolerances! So for once, an urban legend is correct. If you shrank the Earth down to the size of a billiard ball, it would be smoother.
But would it be round enough to qualify?
2) The Earth is an oblate spheroid
The Earth is round! Despite common knowledge, people knew that the Earth was spherical thousands of years ago. Eratosthenes even calculated the circumference to very good accuracy!
But it’s not a perfect sphere. It spins, and because it spins, it bulges due to centrifugal force (yes, dagnappit, I said centrifugal). That is an outwards-directed force, the same thing that makes you lean to the right when turning left in a car. Since the Earth spins, there is a force outward that is a maximum at the Earth’s equator, making our Blue Marble bulge out, like a basketball with a guy sitting on it. This type of shape is called an oblate spheroid.
If you measure between the north and south poles, the Earth’s diameter is 12,713.6 km. If you measure across the Equator it’s 12,756.2 km, a difference of about 42.6 kilometers. Uh-oh! That’s more than our tolerance for a billiard ball. So the Earth is smooth enough, but not round enough, to qualify as a billiard ball.
Bummer. Of course, that’s assuming the tolerance for being out-of-round for a billiard ball is the same as it is for pits and bumps. The WPA site doesn’t say. I guess some things remain a mystery.
3) The Earth isn’t an oblate spheroid.
But we’re not done. The Earth is more complicated than an oblate spheroid. The Moon is out there too, and the Sun. They have gravity, and pull on us. The details are complicated (sate yourself here), but gravity (in the form of tides) raises bulges in the Earth’s surface as well. The tides from the Moon have an amplitude (height) of roughly a meter in the water, and maybe 30 cm in the solid Earth. The Sun is more massive than the Moon, but much farther away, and so its tides are only about half as high.
This is much smaller than the distortion due to the Earth’s spin, but it’s still there.
Other forces are at work as well, including pressure caused by the weight of the continents, upheaval due to tectonic forces, and so on. The Earth is actually a bit of a lumpy mess, but if you were to say it’s a sphere, you’d be pretty close. If you held the billiard-ball-sized Earth in your hand, I doubt you’d notice it isn’t a perfect sphere.
A professional pool player sure would though. I won’t tell Allison Fisher if you won’t.
4) OK, one more surfacey thing: the Earth is not exactly aligned with its geoid
If the Earth were infinitely elastic, then it would respond freely to all these different forces, and take on a weird, distorted shape called a geoid. For example, if the Earth’s surface were completely deluged with water (give it a few decades) then the surface shape would be a geoid. But the continents are not infinitely ductile, so the Earth’s surface is only approximately a geoid. It’s pretty close, though.
Precise measurements of the Earth’s surface are calibrated against this geoid, but the geoid itself is hard to measure. The best we can do right now is to model it using complicated mathematical functions. That’s why ESA is launching a satellite called GOCE (Gravity field and steady-state Ocean Circulation Explorer) in the next few months, to directly determine the geoid’s shape.
Who knew just getting the shape of the Earth would be such a pain?
5) Jumping into hole through the Earth is like orbiting it.
I grew up thinking that if you dug a hole through the Earth (for those in the US) you’d wind up in China. Turns out that’s not true; in fact note that the US and China are both entirely in the northern hemisphere which makes it impossible, so as a kid I guess I was pretty stupid.
You can prove it to yourself with this cool but otherwise worthless mapping tool.
But what if you did dig a hole through the Earth and jump in? What would happen?
Where my own hole through the Earth ends up.
Well, you’d die (see below). But if you had some magic material coating the walls of your 13,000 km deep well, you’d have quite a trip. You’d accelerate all the way down to the center, taking about 20 minutes to get there. Then, when you passed the center, you’d start falling up for another 20 minutes, slowing the whole way. You’d just reach the surface, then you’d fall again. Assuming you evacuated the air and compensated for Coriolis forces, you’d repeat the trip over and over again, much to your enjoyment and/or terror. Actually, this would go on forever, with you bouncing up and down. I hope you remember to pack a lunch.
Note that as you fell, you accelerate all the way down, but the acceleration itself would decrease as you fell: there is less mass between you and the center of the Earth as you head down, so the acceleration due to gravity decreases as you approach the center. However, the speed with which you pass the center is considerable: about 7.7 km/sec (5 miles/second).
In fact, the math driving your motion is the same as for an orbiting object. It takes the same amount of time to fall all the way through the Earth and back as it does to orbit it, if your orbit were right at the Earth’s surface (orbits slow down as the orbital radius increases). Even weirder, it doesn’t matter where your hole goes: a straight line through the Earth from any point to any other (shallow chord, through the diameter, or whatever) gives you the same travel time of 42 or so minutes.
Gravity is bizarre. But there you go. And if you do go take the long jump, well, your trip may be a wee bit unpleasant.
6) The Earth’s interior is hot due to impacts, shrinkage, sinkage, and radioactive decay.
A long time ago, you, me, and everything else on Earth was scattered in a disk around the Sun several billion kilometers across. Over time, this aggregated into tiny bodies called planetesimals, like dinky asteroids. These would smack together, and some would stick, forming a larger body. Eventually, this object got massive enough that its gravity actively drew in more bodies. As these impacted, they released their energy of motion (kinetic energy) as heat, and the young Earth became a molten ball. Ding! One source of heat.
As the gravity increased, its force tried to crush the Earth into a more compact ball. When you squeeze an object it heats up. Ding ding! The second heat source.
Since the Earth was mostly liquid, heavy stuff fell to the center and lighter stuff rose to the top. So the core of the Earth has lots of iron, nickel, osmium, and the like. As this stuff falls, heat is generated (ding ding ding!) because the potential energy is converted to kinetic energy, which in turn is converted to thermal energy due to friction.
And hey, some of those heavy elements are radioactive, like uranium. As they decay, they release heat (ding ding ding ding!). This accounts for probably more than half of the heat inside the planet.
So the Earth is hot in the inside due to at least four sources. But it’s still hot after all this time because the crust is a decent insulator. It prevents the heat from escaping efficiently, so even after 4.55 billion years, the Earth’s interior is still an unpleasantly warm place to be.
Incidentally, the amount of heat flowing out from the Earth’s surface due to internal sources is about 45 trillion Watts. That’s about three times the total global human energy consumption. If we could capture all that heat and convert it with 100% efficiency into electricity, it would literally power all of humanity. Too bad that’s an insurmountable if.
7) The Earth has at least five natural moons. But not really.
Most people think the Earth has one natural moon, which is why we call it the Moon. These people are right. But there are four other objects — at least — that stick near the Earth in the solar system. They’re not really moons, but they’re cool.
The biggest is called Cruithne (pronounced MRPH-mmmph-glug, or something similar). It’s about 5 kilometers across, and has an elliptical orbit that takes it inside and outside Earth’s solar orbit. The orbital period of Cruithne is about the same as the Earth’s, and due to the peculiarities of orbits, this means it is always on the same side of the Sun we are. From our perspective, it makes a weird bean-shaped orbit, sometimes closer, sometimes farther from the Earth, but never really far away.
That’s why some people say it’s a moon of the Earth. But it actually orbits the Sun, so it’s not a moon of ours. Same goes for the other three objects discovered, too.
Oh– these guys can’t hit the Earth. Although they stick near us, more or less, their orbits don’t physically cross ours. So we’re safe. From them.
8) The Earth is getting more massive.
Sure, we’re safe from Cruithne. But space is littered with detritus, and the Earth cuts a wide path (125 million square km in area, actually). As we plow through this material, we accumulate on average 20-40 tons of it per day! [Note: your mileage may vary; this number is difficult to determine, but it’s probably good within a factor of 2 or so.] Most of it is in the form of teeny dust particles which burn up in our atmosphere, what we call meteors (or shooting stars, but doesn’t "meteor" sound more sciencey?). These eventually fall to the ground (generally transported by rain drops) and pile up. They probably mostly wash down streams and rivers and then go into the oceans.
40 tons per day may sound like a lot, but it’s only 0.0000000000000000006% the mass of the Earth (in case I miscounted zeroes, that’s 2×10-26 6×10-21 times the Earth’s mass). It would take 140,000 million 450,000 trillion years to double the mass of the Earth this way, so again, you might want to pack a lunch. In a year, it’s enough cosmic junk to fill a six-story office building, if that’s a more palatable analogy.
I’ll note the Earth is losing mass, too: the atmosphere is leaking away due to a number of different processes. But this is far slower than the rate of mass accumulation, so the net affect is a gain of mass.
9) Mt. Everest isn’t the biggest mountain.
The height of a mountain may have an actual definition, but I think it’s fair to say that it should be measured from the base to the apex. Mt. Everest stretches 8850 meters above sea level, but it has a head start due to the general uplift from the Himalayas. The Hawaiian volcano Mauna Kea is 10,314 meters from stem to stern (um, OK, bad word usagement, but you get my point), so even though it only reaches to 4205 meters above sea level, it’s a bigger mountain than Everest.
Plus, Mauna Kea has telescopes on top of it, so that makes it cooler.
10) Destroying the Earth is hard.
Considering I wrote a book about destroying the Earth a dozen different ways (available for pre-order on amazon.com!), it turns out the phrase "destroying the Earth" is a bit misleading. I actually write about wiping out life, which is easy. Physically destroying the Earth is hard.
What would it take to vaporize the planet? Let’s define vaporization as blowing it up so hard that it disperses and cannot recollect due to gravity. How much energy would that take?
Think of it this way: take a rock. Throw it up so hard it escapes from the Earth. That takes quite a bit of energy! Now do it again. And again. Lather, rinse, repeat… a quadrillion times, until the Earth is gone. That’s a lot of energy! But we have one advantage: every rock we get rid of decreases the gravity of the Earth a little bit (because the mass of the Earth is smaller by the mass of the rock). As gravity decreases, it gets easier to remove rocks.
You can use math to calculate this; how much energy it takes to remove a rock and simultaneously account for the lowering of gravity. If you make some basic assumptions, it takes roughly 2 x 1032 Joules, or 200 million trillion trillion Joules. That’s a lot. For comparison, that’s the total amount of energy the Sun emits in a week. It’s also about a trillion times the destructive energy yield of detonating every nuclear weapon on Earth.
If you want to vaporize the Earth by nuking it, you’d better have quite an arsenal, and time on your hands. If you blew up every nuclear weapon on the planet once every second, it would take 160,000 years to turn the Earth into a cloud of expanding gas.
And this is only if you account for gravity! There are chemical bonds holding the Earth’s matter together as well, so it takes even more energy.
This is why Star Wars is not science fiction, it’s fantasy. The Death Star wouldn’t be able to have a weapon that powerful. The energy storage alone is a bit much, even for the power of the Dark Side.
Even giant collisions can’t vaporize the planet. An object roughly the size of Mars impacted the Earth more than 4.5 billion years ago, and the ejected debris formed the Moon (the rest of the collider merged with the Earth). But the Earth wasn’t vaporized. Even smacking a whole planet into another one doesn’t destroy them!
Of course, the collision melted the Earth all the way down to the core, so the damage is, um, considerable. But the Earth is still around.
The Sun will eventually become a red giant (Chapter 7!), and while it probably won’t consume the Earth, it’ll put the hurt on us for sure. But even then, total vaporization is unlikely (though Mercury is doomed).
Planets tend to be sturdy. Good thing, too. We live on one.
[Via Discover Magazine]
Maybe you’ve heard this statement: if the Earth were shrunk down to the size of a billiard ball, it would actually be smoother than one. When I was in third grade, my teacher said basketball, but it’s the same concept. But is it true? Let’s see. Strap in, there’s a wee bit of math (like, a really wee bit).
OK, first, how smooth is a billiard ball? According to the World Pool-Billiard Association, a pool ball is 2.25 inches in diameter, and has a tolerance of +/- 0.005 inches. In other words, it must have no pits or bumps more than 0.005 inches in height. That’s pretty smooth. The ratio of the size of an allowable bump to the size of the ball is 0.005/2.25 = about 0.002.
The Earth has a diameter of about 12,735 kilometers (on average, see below for more on this). Using the smoothness ratio from above, the Earth would be an acceptable pool ball if it had no bumps (mountains) or pits (trenches) more than 12,735 km x 0.00222 = about 28 km in size.
The highest point on Earth is the top of Mt. Everest, at 8.85 km. The deepest point on Earth is the Marianas Trench, at about 11 km deep.
Hey, those are within the tolerances! So for once, an urban legend is correct. If you shrank the Earth down to the size of a billiard ball, it would be smoother.
But would it be round enough to qualify?
2) The Earth is an oblate spheroid
The Earth is round! Despite common knowledge, people knew that the Earth was spherical thousands of years ago. Eratosthenes even calculated the circumference to very good accuracy!
But it’s not a perfect sphere. It spins, and because it spins, it bulges due to centrifugal force (yes, dagnappit, I said centrifugal). That is an outwards-directed force, the same thing that makes you lean to the right when turning left in a car. Since the Earth spins, there is a force outward that is a maximum at the Earth’s equator, making our Blue Marble bulge out, like a basketball with a guy sitting on it. This type of shape is called an oblate spheroid.
If you measure between the north and south poles, the Earth’s diameter is 12,713.6 km. If you measure across the Equator it’s 12,756.2 km, a difference of about 42.6 kilometers. Uh-oh! That’s more than our tolerance for a billiard ball. So the Earth is smooth enough, but not round enough, to qualify as a billiard ball.
Bummer. Of course, that’s assuming the tolerance for being out-of-round for a billiard ball is the same as it is for pits and bumps. The WPA site doesn’t say. I guess some things remain a mystery.
3) The Earth isn’t an oblate spheroid.
But we’re not done. The Earth is more complicated than an oblate spheroid. The Moon is out there too, and the Sun. They have gravity, and pull on us. The details are complicated (sate yourself here), but gravity (in the form of tides) raises bulges in the Earth’s surface as well. The tides from the Moon have an amplitude (height) of roughly a meter in the water, and maybe 30 cm in the solid Earth. The Sun is more massive than the Moon, but much farther away, and so its tides are only about half as high.
This is much smaller than the distortion due to the Earth’s spin, but it’s still there.
Other forces are at work as well, including pressure caused by the weight of the continents, upheaval due to tectonic forces, and so on. The Earth is actually a bit of a lumpy mess, but if you were to say it’s a sphere, you’d be pretty close. If you held the billiard-ball-sized Earth in your hand, I doubt you’d notice it isn’t a perfect sphere.
A professional pool player sure would though. I won’t tell Allison Fisher if you won’t.
4) OK, one more surfacey thing: the Earth is not exactly aligned with its geoid
If the Earth were infinitely elastic, then it would respond freely to all these different forces, and take on a weird, distorted shape called a geoid. For example, if the Earth’s surface were completely deluged with water (give it a few decades) then the surface shape would be a geoid. But the continents are not infinitely ductile, so the Earth’s surface is only approximately a geoid. It’s pretty close, though.
Precise measurements of the Earth’s surface are calibrated against this geoid, but the geoid itself is hard to measure. The best we can do right now is to model it using complicated mathematical functions. That’s why ESA is launching a satellite called GOCE (Gravity field and steady-state Ocean Circulation Explorer) in the next few months, to directly determine the geoid’s shape.
Who knew just getting the shape of the Earth would be such a pain?
5) Jumping into hole through the Earth is like orbiting it.
I grew up thinking that if you dug a hole through the Earth (for those in the US) you’d wind up in China. Turns out that’s not true; in fact note that the US and China are both entirely in the northern hemisphere which makes it impossible, so as a kid I guess I was pretty stupid.
You can prove it to yourself with this cool but otherwise worthless mapping tool.
But what if you did dig a hole through the Earth and jump in? What would happen?
Where my own hole through the Earth ends up.
Well, you’d die (see below). But if you had some magic material coating the walls of your 13,000 km deep well, you’d have quite a trip. You’d accelerate all the way down to the center, taking about 20 minutes to get there. Then, when you passed the center, you’d start falling up for another 20 minutes, slowing the whole way. You’d just reach the surface, then you’d fall again. Assuming you evacuated the air and compensated for Coriolis forces, you’d repeat the trip over and over again, much to your enjoyment and/or terror. Actually, this would go on forever, with you bouncing up and down. I hope you remember to pack a lunch.
Note that as you fell, you accelerate all the way down, but the acceleration itself would decrease as you fell: there is less mass between you and the center of the Earth as you head down, so the acceleration due to gravity decreases as you approach the center. However, the speed with which you pass the center is considerable: about 7.7 km/sec (5 miles/second).
In fact, the math driving your motion is the same as for an orbiting object. It takes the same amount of time to fall all the way through the Earth and back as it does to orbit it, if your orbit were right at the Earth’s surface (orbits slow down as the orbital radius increases). Even weirder, it doesn’t matter where your hole goes: a straight line through the Earth from any point to any other (shallow chord, through the diameter, or whatever) gives you the same travel time of 42 or so minutes.
Gravity is bizarre. But there you go. And if you do go take the long jump, well, your trip may be a wee bit unpleasant.
6) The Earth’s interior is hot due to impacts, shrinkage, sinkage, and radioactive decay.
A long time ago, you, me, and everything else on Earth was scattered in a disk around the Sun several billion kilometers across. Over time, this aggregated into tiny bodies called planetesimals, like dinky asteroids. These would smack together, and some would stick, forming a larger body. Eventually, this object got massive enough that its gravity actively drew in more bodies. As these impacted, they released their energy of motion (kinetic energy) as heat, and the young Earth became a molten ball. Ding! One source of heat.
As the gravity increased, its force tried to crush the Earth into a more compact ball. When you squeeze an object it heats up. Ding ding! The second heat source.
Since the Earth was mostly liquid, heavy stuff fell to the center and lighter stuff rose to the top. So the core of the Earth has lots of iron, nickel, osmium, and the like. As this stuff falls, heat is generated (ding ding ding!) because the potential energy is converted to kinetic energy, which in turn is converted to thermal energy due to friction.
And hey, some of those heavy elements are radioactive, like uranium. As they decay, they release heat (ding ding ding ding!). This accounts for probably more than half of the heat inside the planet.
So the Earth is hot in the inside due to at least four sources. But it’s still hot after all this time because the crust is a decent insulator. It prevents the heat from escaping efficiently, so even after 4.55 billion years, the Earth’s interior is still an unpleasantly warm place to be.
Incidentally, the amount of heat flowing out from the Earth’s surface due to internal sources is about 45 trillion Watts. That’s about three times the total global human energy consumption. If we could capture all that heat and convert it with 100% efficiency into electricity, it would literally power all of humanity. Too bad that’s an insurmountable if.
7) The Earth has at least five natural moons. But not really.
Most people think the Earth has one natural moon, which is why we call it the Moon. These people are right. But there are four other objects — at least — that stick near the Earth in the solar system. They’re not really moons, but they’re cool.
The biggest is called Cruithne (pronounced MRPH-mmmph-glug, or something similar). It’s about 5 kilometers across, and has an elliptical orbit that takes it inside and outside Earth’s solar orbit. The orbital period of Cruithne is about the same as the Earth’s, and due to the peculiarities of orbits, this means it is always on the same side of the Sun we are. From our perspective, it makes a weird bean-shaped orbit, sometimes closer, sometimes farther from the Earth, but never really far away.
That’s why some people say it’s a moon of the Earth. But it actually orbits the Sun, so it’s not a moon of ours. Same goes for the other three objects discovered, too.
Oh– these guys can’t hit the Earth. Although they stick near us, more or less, their orbits don’t physically cross ours. So we’re safe. From them.
8) The Earth is getting more massive.
Sure, we’re safe from Cruithne. But space is littered with detritus, and the Earth cuts a wide path (125 million square km in area, actually). As we plow through this material, we accumulate on average 20-40 tons of it per day! [Note: your mileage may vary; this number is difficult to determine, but it’s probably good within a factor of 2 or so.] Most of it is in the form of teeny dust particles which burn up in our atmosphere, what we call meteors (or shooting stars, but doesn’t "meteor" sound more sciencey?). These eventually fall to the ground (generally transported by rain drops) and pile up. They probably mostly wash down streams and rivers and then go into the oceans.
40 tons per day may sound like a lot, but it’s only 0.0000000000000000006% the mass of the Earth (in case I miscounted zeroes, that’s 2×10-26 6×10-21 times the Earth’s mass). It would take 140,000 million 450,000 trillion years to double the mass of the Earth this way, so again, you might want to pack a lunch. In a year, it’s enough cosmic junk to fill a six-story office building, if that’s a more palatable analogy.
I’ll note the Earth is losing mass, too: the atmosphere is leaking away due to a number of different processes. But this is far slower than the rate of mass accumulation, so the net affect is a gain of mass.
9) Mt. Everest isn’t the biggest mountain.
The height of a mountain may have an actual definition, but I think it’s fair to say that it should be measured from the base to the apex. Mt. Everest stretches 8850 meters above sea level, but it has a head start due to the general uplift from the Himalayas. The Hawaiian volcano Mauna Kea is 10,314 meters from stem to stern (um, OK, bad word usagement, but you get my point), so even though it only reaches to 4205 meters above sea level, it’s a bigger mountain than Everest.
Plus, Mauna Kea has telescopes on top of it, so that makes it cooler.
10) Destroying the Earth is hard.
Considering I wrote a book about destroying the Earth a dozen different ways (available for pre-order on amazon.com!), it turns out the phrase "destroying the Earth" is a bit misleading. I actually write about wiping out life, which is easy. Physically destroying the Earth is hard.
What would it take to vaporize the planet? Let’s define vaporization as blowing it up so hard that it disperses and cannot recollect due to gravity. How much energy would that take?
Think of it this way: take a rock. Throw it up so hard it escapes from the Earth. That takes quite a bit of energy! Now do it again. And again. Lather, rinse, repeat… a quadrillion times, until the Earth is gone. That’s a lot of energy! But we have one advantage: every rock we get rid of decreases the gravity of the Earth a little bit (because the mass of the Earth is smaller by the mass of the rock). As gravity decreases, it gets easier to remove rocks.
You can use math to calculate this; how much energy it takes to remove a rock and simultaneously account for the lowering of gravity. If you make some basic assumptions, it takes roughly 2 x 1032 Joules, or 200 million trillion trillion Joules. That’s a lot. For comparison, that’s the total amount of energy the Sun emits in a week. It’s also about a trillion times the destructive energy yield of detonating every nuclear weapon on Earth.
If you want to vaporize the Earth by nuking it, you’d better have quite an arsenal, and time on your hands. If you blew up every nuclear weapon on the planet once every second, it would take 160,000 years to turn the Earth into a cloud of expanding gas.
And this is only if you account for gravity! There are chemical bonds holding the Earth’s matter together as well, so it takes even more energy.
This is why Star Wars is not science fiction, it’s fantasy. The Death Star wouldn’t be able to have a weapon that powerful. The energy storage alone is a bit much, even for the power of the Dark Side.
Even giant collisions can’t vaporize the planet. An object roughly the size of Mars impacted the Earth more than 4.5 billion years ago, and the ejected debris formed the Moon (the rest of the collider merged with the Earth). But the Earth wasn’t vaporized. Even smacking a whole planet into another one doesn’t destroy them!
Of course, the collision melted the Earth all the way down to the core, so the damage is, um, considerable. But the Earth is still around.
The Sun will eventually become a red giant (Chapter 7!), and while it probably won’t consume the Earth, it’ll put the hurt on us for sure. But even then, total vaporization is unlikely (though Mercury is doomed).
Planets tend to be sturdy. Good thing, too. We live on one.
[Via Discover Magazine]
Ten Lies About Microprocessors
Processor selection too often turns into a religious war. Debunking the dominant myths is the first step towards making a rational choice.
Talk about sports teams, politics, religion, or your favorite boy band and most bartenders won't raise an eyebrow. But get a group of engineers and programmers arguing over which microprocessor is best and you're liable to get eighty-sixed for trash-talking x86.
People get passionate about processors in a way they don't over DRAMs or decoders. Everyone has favorites, as well as horror stories about the one they'll never use again. Legend and lore surround microprocessors. Some is useful, but a lot is superstition ingrained by tradition.
Myth #1: Few processor choices
This is the most insidious misconception. If you're designing an embedded system, how many 32-bit processors can you choose from? 10? 20? In reality, there are more than 100 different 32-bit embedded processors for sale right now. (And that's not counting different packaging options or speed grades.) Dozens of companies make 32-bit processors, representing more than 15 different CPU architectures and instruction sets. Add in a few hundred more 16-bit processors and a few hundred 8-bit processors and you've got an embarrassment of riches.
#2: Intel rules the world
If you say "microprocessor," a lot of people think, "Pentium." The mainstream press is partly to blame. Newspapers proclaim that Intel has a 95% share of the microprocessor market. That's off by almost two orders of magnitude.
As we saw in the January issue, only about 2% of all microprocessors made drive PCs ("The Two Percent Solution," p. 29). Intel's Pentium has a dominant share of the PC business (the Federal Trade Commission stopped just short of declaring it a monopoly), but PCs are a tiny slice of the microprocessor pie. The other 98% is embedded CPUs; Intel's not even in the top five of that group.
Even if we weed out the enormous volume of 8-bit and 16-bit chips and focus on 32-bitters, Intel's name still appears well down the list. ARM vendors alone sell about three times more processors than Intel sells Pentiums.
#3: Instruction sets don't matter
Whether you program in C/C++, BASIC, Ada, or Java, your code ultimately boils down into the hardware instruction set of the processor it's running on. You may not need to know all the machine instructions your CPU provides, but the instruction set does affect your code. A few elegant lines of C may produce a hideous tangle of assembly instructions and vice versa.
Performance, predictability, and even power consumption all depend heavily on the underlying instruction set of the processor, and there's nothing a high-level language can do to change that.
Let's take a simple example of multiplying two numbers together. This is trivial in any language and hardly something programmers will worry over. Yet different chips handle multiplication in different ways. For a while, many RISC chips couldn't even do multiplication—it was considered "impure" and not part of the RISC canon. Many viewed multiplication as glorified adding and shifting, so early RISC compilers had to synthesize their own integer multiply functions. It worked, but it wasn't fast.
Now most (but not all) processors have a built-in multiply instruction. But not all multipliers are the same. Some chips can multiply two numbers much faster than other chips, and it has nothing to do with clock frequencies. As the chart in Figure 1 shows, some chips (such as Hitachi's SH7604 and SH7708) can multiply any two 32-bit numbers in four cycles or less. Other chips (notably Motorola's 68020 and '030) take more than 40 cycles to do the same math.
Stranger still, most chips are unpredictable. The minimum time for a multiplication might be less than half of the maximum time. What's the difference? Bigger numbers require longer calculations, and that takes more time.
Finally, the order of the numbers matters. In grade school we were taught that multiplication is commutative, that the order of the two numbers doesn't affect the answer. That's still true, but the order does affect the time required to do the math. On many chips, multiply time is determined by one of the two operands. Swap their order and you may cut your multiply time in half. Good luck guessing which way is better, though.
None of this is visible to high-level source code. Few C compilers are even aware of these differences because most customers—developers of embedded systems—never ask. Many processor users just don't know what's going on under the hood.
#4: RISC is better than CISC
We covered this one in March, so let's just say that RISC is different from CISC ("RISCy Business," p. 37); neither is necessarily better all the time, and both have their strengths. CISC chips provide better code density (smaller memory footprint) and more mature software tools, but RISC chips have higher clock rates and more glamorous marketing. Take your pick, but make it an informed one.
#5: Java chips are coming
So's Christmas. Actually, Christmas is a lot closer because it's going to be here this year. Java chips have more in common with Santa Claus than Christmas: a nice fable for nave young engineers who aren't yet old enough to know better.
Java is remarkable in a number of ways, most of them having to do with marketing. But it's also remarkably resistant to hardware implementation. A number of companies have tried to produce an all-Java microprocessor and every one has failed to some degree. This trend is likely to continue.
Apart from being hilariously ironic—wasn't the whole point of Java to be hardware independent?—Java processors run headfirst into the low doorway of logic. The Java language was never meant to be handled in hardware, and it shows. Garbage collection, threads, stack orientation, and object management take about a megabyte worth of Java virtual machine to translate into something that even today's fastest microprocessors struggle to execute. Decades of computer evolution and research at companies and universities around the world have failed to produce anything that looks like a Java machine. This is not a coincidence.
Today Java "accelerator" chips are available from Nazomi, Zucotto, inSilicon, Octera, and many others. Most execute 30% to 60% of Java's bytecodes in hardware. The rest they punt and handle in software because it's simply too awkward to do otherwise. Following the standard 80/20 rule, these chips accelerate the most used Java instructions to produce a noticeable speedup in overall Java performance. But they're a far cry from a 100% Java implementation.
After a few years of rapid improvement, Java chips seem to have plateaued at that 60% level. Sun itself canceled its Java chip development. We've reached the point of diminishing returns, where implementing the remaining Java instructions in hardware doesn't produce worthwhile benefits. If you're in the market for Java chips, this is about as good as it's going to get.
#6: Dhrystone MIPS is a useful benchmark
The term MIPS is bandied about more than any other in the microprocessor business. It's become utterly hollow, unless you interpret it as Meaningless Indicator of Performance for Salesmen.
As I explained earlier, instructions aren't the same from processor to processor, so counting and comparing them isn't useful. It's like saying the German word for windshield wipers (Windschutzscheibewischerbltter) is longer than the English equivalent. Duh.
MIPS is commonly derived from something called the Dhrystone benchmark, which is more than 30 years old, was written in PL/I, and was meant to compare the VAX 11/780 to other mainframes. It's also only about 4KB of code, fits easily into cache, and doesn't do any useful work. Because of its diminutive size but exaggerated importance, Dhrystone is subject to some, shall we say, creative optimization. There are C compilers with a -dhrystone switch that drastically improves reported results. Today's MIPS ratings are achieved by dividing Dhrystone scores by 1,757 because that's what the first VAX scored back in the 1970s. We're measuring VAX-equivalents using a 4KB snippet of PL/I code that's been translated to C and tweaked who-knows-how-many times to produce a score that Marketing "accidentally" misprints with an extra zero behind it. Now how useful is that?
#7: Price is proportional to performance
Microprocessors are now sold like perfume: the price on the label has no connection to the cost of the ingredients. It's tempting to assume some meaningful relationship between cost and price. Save your time—there isn't one. Cost is what it takes to build a chip; price is whatever the marketing department wants it to be. Happily, we work in an industry where market pressures drive up value and drive down price all the time. As chip consumers, we benefit from the cutthroat cost cutting and market-share horse trading.
The cost to make a silicon chip has little to do with the amount of silicon in it. Cost is mostly determined by overhead amortization and the depreciation of the fab. Price, however, is determined by market forces—good ol' supply and demand. If your chip runs Windows XP, you can charge an arm and a leg for it. If it doesn't, the same amount of silicon will command a much lower price.
Even within the embedded world, there are $15 processors that outperform $150 processors. Price is negotiable, malleable, and wholly unpredictable. Shop around.
#8: ARM is lowest power
There aren't many strong brand reputations in the microprocessor business but ARM enjoys one of the best. According to their reputation, ARM's chips are endowed with an almost magical ability to run on bright sunlight or the energy released by rubbing a cat. An ARM processor, two lemons, and some copper wire are all that's needed to build the latest PDA, it seems.
Like many myths, this one is rooted in reality, but that reality has changed and the myth has expanded. In the early '90s, ARM was one of the first 32-bit processors to be embedded into ASICs, rather than soldered alongside as a separate chip. Compared to the big 68030, 29000, and 486DX chips of the day, the wee ARM6 consumed less total energy than the others gave off as heat. That's because the ARM had no floating-point unit, no cache, no outside bus, no drivers, and not much of an instruction set.
Today there are plenty of 32-bit processors available as ASIC cores. Many are smaller than the ARM7, to say nothing of the newer ARM10 or ARM11. Many use less power, both in standby mode and when they're active. If power consumption is your primary consideration, by all means give ARM a call. But ten years of progress and competition have moved ARM to the middle of the pack when it comes to power efficiency.
#9: Second sourcing micros
Second sourcing used to be the watchword of purchasing departments everywhere. Hardware engineers often aren't allowed to specify any component unless it's available from two or more sources. That's fine for resistors—it reduces risk and dependency on any one supplier—but it's now impossible for microprocessors.
Sure, you can get MIPS chips from a dozen different sources, such as NEC, PMC-Sierra, IDT, and Intrinsity, but they aren't interchangeable each other. They all execute the same instruction set, but their buses, pin-outs, peripherals, speeds, and packages are all different. At best, the programmers can keep most of their code, but the hardware engineers will have to design an all-new system.
There was a time when Motorola and Hitachi provided identical 68k processors, DMA controllers, and other chips. Intel and AMD used to second-source each other's processors as well (remember when AMD and Intel were friends?). Many low-end parts in the 8051 or 6805 family also used to be double- or even triple-sourced. Alas, competition has brought an end to those days. Now every processor chip is unique, even if its instruction set isn't.
#10: The great processor shakeout
With more than 100 different embedded 32-bit processors for sale, there must be too many choices for the market to support, right? Who's going to win and who's going to lose? Come the revolution, who will be first against the wall?
Probably none of them. In fact, the number of embedded processors is likely to grow, not shrink. Those hundred-odd chips are all in volume production with dozens of happy customers who wouldn't use anything else. Those chips are around for a reason, and the number of reasons keeps growing. MP3 players, digital-video cameras, automotive electronics, and other new toys are popping up all the time, and they each need a new and different kind of processor. There's no such thing as a typical embedded system and there's no such thing as a typical embedded processor. As long as embedded developers invent new devices, new embedded processors will be there to make them tick.
[Via Embedded.com]
Talk about sports teams, politics, religion, or your favorite boy band and most bartenders won't raise an eyebrow. But get a group of engineers and programmers arguing over which microprocessor is best and you're liable to get eighty-sixed for trash-talking x86.
People get passionate about processors in a way they don't over DRAMs or decoders. Everyone has favorites, as well as horror stories about the one they'll never use again. Legend and lore surround microprocessors. Some is useful, but a lot is superstition ingrained by tradition.
Myth #1: Few processor choices
This is the most insidious misconception. If you're designing an embedded system, how many 32-bit processors can you choose from? 10? 20? In reality, there are more than 100 different 32-bit embedded processors for sale right now. (And that's not counting different packaging options or speed grades.) Dozens of companies make 32-bit processors, representing more than 15 different CPU architectures and instruction sets. Add in a few hundred more 16-bit processors and a few hundred 8-bit processors and you've got an embarrassment of riches.
#2: Intel rules the world
If you say "microprocessor," a lot of people think, "Pentium." The mainstream press is partly to blame. Newspapers proclaim that Intel has a 95% share of the microprocessor market. That's off by almost two orders of magnitude.
As we saw in the January issue, only about 2% of all microprocessors made drive PCs ("The Two Percent Solution," p. 29). Intel's Pentium has a dominant share of the PC business (the Federal Trade Commission stopped just short of declaring it a monopoly), but PCs are a tiny slice of the microprocessor pie. The other 98% is embedded CPUs; Intel's not even in the top five of that group.
Even if we weed out the enormous volume of 8-bit and 16-bit chips and focus on 32-bitters, Intel's name still appears well down the list. ARM vendors alone sell about three times more processors than Intel sells Pentiums.
#3: Instruction sets don't matter
Whether you program in C/C++, BASIC, Ada, or Java, your code ultimately boils down into the hardware instruction set of the processor it's running on. You may not need to know all the machine instructions your CPU provides, but the instruction set does affect your code. A few elegant lines of C may produce a hideous tangle of assembly instructions and vice versa.
Performance, predictability, and even power consumption all depend heavily on the underlying instruction set of the processor, and there's nothing a high-level language can do to change that.
Let's take a simple example of multiplying two numbers together. This is trivial in any language and hardly something programmers will worry over. Yet different chips handle multiplication in different ways. For a while, many RISC chips couldn't even do multiplication—it was considered "impure" and not part of the RISC canon. Many viewed multiplication as glorified adding and shifting, so early RISC compilers had to synthesize their own integer multiply functions. It worked, but it wasn't fast.
Now most (but not all) processors have a built-in multiply instruction. But not all multipliers are the same. Some chips can multiply two numbers much faster than other chips, and it has nothing to do with clock frequencies. As the chart in Figure 1 shows, some chips (such as Hitachi's SH7604 and SH7708) can multiply any two 32-bit numbers in four cycles or less. Other chips (notably Motorola's 68020 and '030) take more than 40 cycles to do the same math.
Stranger still, most chips are unpredictable. The minimum time for a multiplication might be less than half of the maximum time. What's the difference? Bigger numbers require longer calculations, and that takes more time.
Finally, the order of the numbers matters. In grade school we were taught that multiplication is commutative, that the order of the two numbers doesn't affect the answer. That's still true, but the order does affect the time required to do the math. On many chips, multiply time is determined by one of the two operands. Swap their order and you may cut your multiply time in half. Good luck guessing which way is better, though.
None of this is visible to high-level source code. Few C compilers are even aware of these differences because most customers—developers of embedded systems—never ask. Many processor users just don't know what's going on under the hood.
#4: RISC is better than CISC
We covered this one in March, so let's just say that RISC is different from CISC ("RISCy Business," p. 37); neither is necessarily better all the time, and both have their strengths. CISC chips provide better code density (smaller memory footprint) and more mature software tools, but RISC chips have higher clock rates and more glamorous marketing. Take your pick, but make it an informed one.
#5: Java chips are coming
So's Christmas. Actually, Christmas is a lot closer because it's going to be here this year. Java chips have more in common with Santa Claus than Christmas: a nice fable for nave young engineers who aren't yet old enough to know better.
Java is remarkable in a number of ways, most of them having to do with marketing. But it's also remarkably resistant to hardware implementation. A number of companies have tried to produce an all-Java microprocessor and every one has failed to some degree. This trend is likely to continue.
Apart from being hilariously ironic—wasn't the whole point of Java to be hardware independent?—Java processors run headfirst into the low doorway of logic. The Java language was never meant to be handled in hardware, and it shows. Garbage collection, threads, stack orientation, and object management take about a megabyte worth of Java virtual machine to translate into something that even today's fastest microprocessors struggle to execute. Decades of computer evolution and research at companies and universities around the world have failed to produce anything that looks like a Java machine. This is not a coincidence.
Today Java "accelerator" chips are available from Nazomi, Zucotto, inSilicon, Octera, and many others. Most execute 30% to 60% of Java's bytecodes in hardware. The rest they punt and handle in software because it's simply too awkward to do otherwise. Following the standard 80/20 rule, these chips accelerate the most used Java instructions to produce a noticeable speedup in overall Java performance. But they're a far cry from a 100% Java implementation.
After a few years of rapid improvement, Java chips seem to have plateaued at that 60% level. Sun itself canceled its Java chip development. We've reached the point of diminishing returns, where implementing the remaining Java instructions in hardware doesn't produce worthwhile benefits. If you're in the market for Java chips, this is about as good as it's going to get.
#6: Dhrystone MIPS is a useful benchmark
The term MIPS is bandied about more than any other in the microprocessor business. It's become utterly hollow, unless you interpret it as Meaningless Indicator of Performance for Salesmen.
As I explained earlier, instructions aren't the same from processor to processor, so counting and comparing them isn't useful. It's like saying the German word for windshield wipers (Windschutzscheibewischerbltter) is longer than the English equivalent. Duh.
MIPS is commonly derived from something called the Dhrystone benchmark, which is more than 30 years old, was written in PL/I, and was meant to compare the VAX 11/780 to other mainframes. It's also only about 4KB of code, fits easily into cache, and doesn't do any useful work. Because of its diminutive size but exaggerated importance, Dhrystone is subject to some, shall we say, creative optimization. There are C compilers with a -dhrystone switch that drastically improves reported results. Today's MIPS ratings are achieved by dividing Dhrystone scores by 1,757 because that's what the first VAX scored back in the 1970s. We're measuring VAX-equivalents using a 4KB snippet of PL/I code that's been translated to C and tweaked who-knows-how-many times to produce a score that Marketing "accidentally" misprints with an extra zero behind it. Now how useful is that?
#7: Price is proportional to performance
Microprocessors are now sold like perfume: the price on the label has no connection to the cost of the ingredients. It's tempting to assume some meaningful relationship between cost and price. Save your time—there isn't one. Cost is what it takes to build a chip; price is whatever the marketing department wants it to be. Happily, we work in an industry where market pressures drive up value and drive down price all the time. As chip consumers, we benefit from the cutthroat cost cutting and market-share horse trading.
The cost to make a silicon chip has little to do with the amount of silicon in it. Cost is mostly determined by overhead amortization and the depreciation of the fab. Price, however, is determined by market forces—good ol' supply and demand. If your chip runs Windows XP, you can charge an arm and a leg for it. If it doesn't, the same amount of silicon will command a much lower price.
Even within the embedded world, there are $15 processors that outperform $150 processors. Price is negotiable, malleable, and wholly unpredictable. Shop around.
#8: ARM is lowest power
There aren't many strong brand reputations in the microprocessor business but ARM enjoys one of the best. According to their reputation, ARM's chips are endowed with an almost magical ability to run on bright sunlight or the energy released by rubbing a cat. An ARM processor, two lemons, and some copper wire are all that's needed to build the latest PDA, it seems.
Like many myths, this one is rooted in reality, but that reality has changed and the myth has expanded. In the early '90s, ARM was one of the first 32-bit processors to be embedded into ASICs, rather than soldered alongside as a separate chip. Compared to the big 68030, 29000, and 486DX chips of the day, the wee ARM6 consumed less total energy than the others gave off as heat. That's because the ARM had no floating-point unit, no cache, no outside bus, no drivers, and not much of an instruction set.
Today there are plenty of 32-bit processors available as ASIC cores. Many are smaller than the ARM7, to say nothing of the newer ARM10 or ARM11. Many use less power, both in standby mode and when they're active. If power consumption is your primary consideration, by all means give ARM a call. But ten years of progress and competition have moved ARM to the middle of the pack when it comes to power efficiency.
#9: Second sourcing micros
Second sourcing used to be the watchword of purchasing departments everywhere. Hardware engineers often aren't allowed to specify any component unless it's available from two or more sources. That's fine for resistors—it reduces risk and dependency on any one supplier—but it's now impossible for microprocessors.
Sure, you can get MIPS chips from a dozen different sources, such as NEC, PMC-Sierra, IDT, and Intrinsity, but they aren't interchangeable each other. They all execute the same instruction set, but their buses, pin-outs, peripherals, speeds, and packages are all different. At best, the programmers can keep most of their code, but the hardware engineers will have to design an all-new system.
There was a time when Motorola and Hitachi provided identical 68k processors, DMA controllers, and other chips. Intel and AMD used to second-source each other's processors as well (remember when AMD and Intel were friends?). Many low-end parts in the 8051 or 6805 family also used to be double- or even triple-sourced. Alas, competition has brought an end to those days. Now every processor chip is unique, even if its instruction set isn't.
#10: The great processor shakeout
With more than 100 different embedded 32-bit processors for sale, there must be too many choices for the market to support, right? Who's going to win and who's going to lose? Come the revolution, who will be first against the wall?
Probably none of them. In fact, the number of embedded processors is likely to grow, not shrink. Those hundred-odd chips are all in volume production with dozens of happy customers who wouldn't use anything else. Those chips are around for a reason, and the number of reasons keeps growing. MP3 players, digital-video cameras, automotive electronics, and other new toys are popping up all the time, and they each need a new and different kind of processor. There's no such thing as a typical embedded system and there's no such thing as a typical embedded processor. As long as embedded developers invent new devices, new embedded processors will be there to make them tick.
[Via Embedded.com]
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