Wednesday, March 18, 2009

Sun calling it a day?

I would have guessed that Apple would acquire Sun, since their business lines and strategy complement each other.  IBM and Sun are long time competitors for the same market.  On the other hand, IBM's Cell and Sun's Niagra chip architectures may benefit from cross breeding.


Sun Shares Jump on I.B.M. Takeover Report - NYTimes.com
The Wall Street Journal, quoting “people familiar with the matter,” reported Wednesday that International Business Machines was in talks to buy Sun for at least $6.5 billion in cash, a premium of more than 100 percent over the company’s closing share price Tuesday. Officials of Sun and IBM could not immediately be reached for comment.


Thursday, March 5, 2009

Weber bars might not be lame after all.

LIGO should take note: it could be that a supernova explosion that isn't quite spherically symmetric amplifies gravitational waves amplitude by a factor of 10,000; making it possible to detect them using a much less sophisticated (and less expensive) equipment.   Something to remember the next time you feel tempted laugh at a guy with a Weber bar.


the physics arXiv blog » Blog Archive » Were gravitational waves first detected in 1987?
But get this: the assymetry can enhance the waves by a factor of 10^4.

He also points out that SN1987A is aspherical in exactly the way that might create this enhancement. So if SN1987A generated gravitational waves, Weber would have been perfectly able to detect them.

Qadir concludes: “The claim of Weber to have observed gravitational waves from [SN1987A] needs to be re-assessed”.

By all accounts, Weber was a careful experimenter who got something of a rough deal for his efforts


Wednesday, March 4, 2009

How are a thermometer and a stopwatch alike?

Here is a good review article about the nature of time. 

Is time an illusion? - physics-math - 19 January 2008 - New Scientist
With quantum mechanics rewritten in time-free form, combining it with general relativity seems less daunting, and a universe in which time is fundamental seems less likely. But if time doesn't exist, why do we experience it so relentlessly? Is it all an illusion?

Yes, says Rovelli, but there is a physical explanation for it. For more than a decade, he has been working with mathematician Alain Connes at the College de France in Paris to understand how a time-free reality could give rise to the appearance of time. Their idea, called the thermal time hypothesis, suggests that time emerges as a statistical effect, in the same way that temperature emerges from averaging the behaviour of large groups of molecules