70 Sextillion Stars! - Page 2

David Floyd · July 23, 2003, 13:21

Um, my limited knowledge of astronomy does not suggest that supernovae are as common as you are implying, but I could easily be wrong.

Sava · July 23, 2003, 13:23

Quote:

Um, my limited knowledge of astronomy does not suggest that supernovae are as common as you are implying, but I could easily be wrong.

I never mentioned supernovae...

Proteus_MST · July 23, 2003, 13:25

Quote:

Originally posted by Sava
And many are long dead and we can't see their light...

Imagine it like this... if you were to put a recording device in space, and record the stars from a single position over billions of years, but play it back in extreme fast forward, it would look like a night sky filled with fireflies.... blinking on and off all over.

Sounds ´like a great Idea.

We just have to find Storage Space large enough to store the Datas gathered by the Device.
Maybe we should ask the NSA, after all they must have a really large Storage Space, as they have to store all the Data gathered by Echelon

Az · July 23, 2003, 13:27

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Um, my limited knowledge of astronomy does not suggest that supernovae are as common as you are implying, but I could easily be wrong.

I think there is one going off in the known universe at any given moment.

DAVOUT · July 23, 2003, 13:27

Terminal state for stars is not always reached through supernovae process. Brown stars just becomes extint, I think.

David Floyd · July 23, 2003, 13:27

Ah. Yeah, that's probably right. I was only awake through half of my astronomy courses. Not that it wasn't interesting, just WAY too early.

Boris Godunov · July 23, 2003, 13:31

Sava, having read Hawking's ABHOT, in which he doesn't posit any infinite star theory, I'd have to ask you to provide some evidence.

Stars burning out is irrelevant--you're asserting that, right now, there are an infinite number of stars. If all matter in the universe emanated from the Big Bang, it is impossible for there to be an infinite number of stars, as you would also have to postulate the Big Bang happening an infinite number of years ago, which we know not to be the case.

Olber's Paradox still defies explanation:

"Think about the universe as stars evenly distributed on crystalline spheres surrounding us, much like the layers of an onion. Let's say stars appear nice and bright in the layer closest to us. The layer twice as distant would also contain stars, but each would appear four times fainter. The stars in the layer three times farther away would appear nine times fainter and so on.

It might be easy to conclude that because the most distant stars would be so terribly faint, there would be no way we could see them. But with the increase in layer size comes more stars. So, while stars in the layer twice as distant are four times fainter, there are four times as many of them. On the layer three times farther, there are nine times as many and so on.

In other words, each layer would contribute exactly the same amount of starlight to our sky, no matter how far away it is. And an infinite number of stars (and layers) would produce a nighttime sky as bright as the sun itself.

The paradox - known as Olber's Paradox - is named after Heinrich Olber, who tried to explain it in 1826. The paradox hasn't been totally explained even today."

Az · July 23, 2003, 13:33

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Terminal state for stars is not always reached through supernovae process. Brown stars just becomes extint, I think.

If you mean Brown Dwarves, they're proto-stars, that've never lit up. They lack some mass. It's quite tragic, really.

GePap · July 23, 2003, 13:37

Way to ruin a perfectly good sex thread with cosmology and astrophysics

Sava · July 23, 2003, 13:42

Boris: http://www.dcd.net/NBP/hawking_origins.html excerpts from the title I mentioned...

There isn't one single paragraph I can cut and paste... but Hawking says Steady-State probably isn't true, but that the general idea of the existence of the universe being infinite and the matter being infinite, is sound and most likely concurrently accurate in addition to the Big Bang theory. This was also supported by more recent findings that suggest there have been multiple (perhaps infinite) Big Bangs throughout history. I'll attempt to find these reports, as I recall reading them on the BBC Science page months ago.

yavoon · July 23, 2003, 13:50

infinite is a poor way to conceive of the universe. when a physicist sees an infinite it is usually a sign his theory has broken down at that point.

suchas the infinite density of black holes predicted by point particle physics.

Boris Godunov · July 23, 2003, 13:54

Quote:

Originally posted by Sava
Boris: http://www.dcd.net/NBP/hawking_origins.html excerpts from the title I mentioned...

There isn't one single paragraph I can cut and paste... but Hawking says Steady-State probably isn't true, but that the general idea of the existence of the universe being infinite and the matter being infinite, is sound and most likely concurrently accurate in addition to the Big Bang theory. This was also supported by more recent findings that suggest there have been multiple (perhaps infinite) Big Bangs throughout history. I'll attempt to find these reports, as I recall reading them on the BBC Science page months ago.

You must be reading a different essay than I am, because nowhere in there does he say anything about infinite matter. He does say that Steady State has been abandoned, yes.

Hawking's "no boundary" hypothesis does NOT stipulate an infinite number of stars in an infinite linear distance from every other point in the universe. It is postulating that the universe is infinite in the same way the area of the earth is infinite (only inverted, like being on the inside of the surface of a sphere). Notice how he makes tha analogy that one could travel all the way around the earth without falling off, and the same would hold true of the universe.

No where is he positing an infinite number of stars or amount of matter.

Odin · July 23, 2003, 14:24

Boris is right Sava.

I have A Brief History of Time, so I would know.