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баян от 2002 года :))) (+)

Автор: ГгГ
Дата: 29.10.05, @02:27

  1) Нет такого астрофизика.
2) Эта "новость" была разоблачена ещё в 2002 году.

http://curious.astro.cornell.edu/question.php?number=285

Will the sun go supernova in six years and destroy Earth (as seen on Yahoo)?
I recently read an article (link now expired on Yahoo Entertainment News) that I found initially disturbing, but after reading the information on this site regarding the sun, I feel much more calm. However, I am curious as to whether the article I read carries any merit whatsoever.

Is Dr. Piers Van der Meer an established astrophysicist? Is the European Space Agency a respectable organization? Do they have some sort of hidden agenda for promoting such an astonishing theory? Essentially, do these people know what they're talking about?

I hadn't seen this article before, so thanks for bringing it to my attention. You're right to be skeptical, for several reasons!

First, the sun is too small to ever go supernova, so the basic premise of the article is incorrect. There just isn't enough mass in our sun to cause it to explode and collapse to form a neutron star or black hole.

Also, I haven't been able to find out any information on this guy "Dr. Piers Van der Meer". There's an online database, called the Astrophysics Data System, that keeps records of Journal articles published in astronomy/astrophysics/planetary science. Even beginning graduate students will show up in the records because they've usually been to at least one conference, and as soon as you have a couple papers about your reaserch it's easy to find out what you're doing and where you work. But this person doesn't show up in the system at all! I looked him up using a search engine and he doesn't seem to have a web page affiliated with any organization. So if he's a serious astrophysicist, he hasn't published papers or appeared at conferences before, and isn't part of a major organization.

Also, the article claims he's associated with the European Space Agency (ESA) (which is a real, credible organization), but when you look at their website there's no mention of this press release at all. So it's not endorsed by them, apparently.

The article was also written for "Weekly World News", which is one of those papers that tends to publish fictional stories and half-truths, or distort the truth to get a sensationalistic story. And there are some truths to the story. For example, SOHO is a satellite that is run jointly by ESA and NASA, and it does take images of giant flares and prominences, which are like giant explosions on the sun. Flares and prominences happen all the time, and although they may cause aurorae or interfere with communications, they're really not a big deal. SOHO has lots of cool images; you can check them out at the SOHO website. Notice they don't say anything about the sun exploding either.

A few people have requested more information about the temperature of the sun. The temperature at the center of the sun is about 16 million degrees Kelvin (27 million degrees Fahrenheit), as stated in the article. As the sun burns up its hydrogen, helium builds up in the core, and the core contracts. This contraction causes heating, so the internal temperature of the sun is increasing over time. However, this temperature change in the hydrogen burning sun is very slow! In the book "The New Solar System", Kenneth Lang states that as a result of the core contraction and heating, the surface temperature has gone up 300 K over the past 4.5 billion years. When the sun exhausts its hydrogen supply (in a few billion years) the sun will become a red giant star, which has a much hotter, helium-burning, core but actually a lower surface temperature. (The Astro 201 website has a good webpage about the sun's evolution, if you want an explanation of the transition to red giants.) The current surface temperture of the sun is about 5780 Kelvins. Since surface temperature determines a star's color, the sun would actually appear blue if its surface temperature had doubled! Everyone would be able to notice that. Also, the Weekly World News article claims that people measured temperature trends "in recent years", which (besides being vague) is a very short time in the life of the sun. Temperature measurements over a few years really won't tell you anything about the long term behavior of the sun.

So, I think what happened is that Weekly World News pieced together some truths and found some person willing to add a few extra things to make the story exciting. It's certainly not credible astrophysics!

October 2002, Lynn Carter (more by Lynn Carter)

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