New View of Doomed Star

Gilly · 22 Jun 2007 at 16:55

iCraig said:
I know.

Here's something else which is cool. Remember that the theory also applies to matter; because matter is limited to the speed of light. So, if you hypothetically got a massively long pole (I'm talking tens of millions of miles long here) and placed it between a point on Earth and a point on another planet thousands of light years away with intelligent life, normal logic would assume that if you pushed the pole upwards twice, to try and communicate with whoever is on the other end, nothing would happen to the other end of the pole until however many light years they are away. If they're 5000 light years away, their end of the pole won't move twice for 5000 years.

Wasn't there a theory on that regarding instantaneous communication?

Johnnytoxic · 22 Jun 2007 at 16:59

Yes it was a crazy thread with the OP getting shot down if I remember.

iCraig · 22 Jun 2007 at 17:01

GreenMint · 22 Jun 2007 at 17:32

johnnyfive said:
90% of people probably have no idea how the light your seeing from the stars at night are 1000's of years old. The stars you see at night probably don't exist anymore but your seeing the light from them years ago still.

Such a wierd but logical way to put things, i've been telling my gf and her little brother this over time every now & again but her bro never seems to get the fact that "Just because you can see a star, does not mean its now there" its such a bizarre thing that someone could literally look up at night, every night from aged 10 to aged 85, and see something in the sky, every night, constantly, that actually exploded 2000 years ago and was not even existent in thier lifetime!

dafloppyone · 22 Jun 2007 at 17:34

well those that thought that was bad...a couple of years ago we were hit by a gamma ray burst that left a 60mile dent in the ionosphere.... a wee bit stronger and we were cooked

SiD the Turtle · 22 Jun 2007 at 18:14

Clinkz said:
If you extend this theory to the very outer edges of the universe many many more light years away, for all we know time at these regions could already have ceased to exist and this extinction is making its way slowly towards us at the speed of light; hence explaining why there is a limit to the known observable universe.

That's the main idea behind the proof that the Universe hasn't always existed and isn't infinitely large, iirc. Correct me if I'm wrong space buffs but if the Universe was infinitely large and has always existed the entire sky would be jam packed with the light from stars. Correct?

pinkacidbootson · 22 Jun 2007 at 18:21

SiD the Turtle said:
That's the main idea behind the proof that the Universe hasn't always existed and isn't infinitely large, iirc. Correct me if I'm wrong space buffs but if the Universe was infinitely large and has always existed the entire sky would be jam packed with the light from stars. Correct?

Yes my physics tutor went over that a couple of months ago. If the universe was infinite, then there would be light coming from every point in the sky, so at night the sky would be totally bright.

Haircut · 22 Jun 2007 at 18:35

SiD the Turtle said:
That's the main idea behind the proof that the Universe hasn't always existed and isn't infinitely large, iirc. Correct me if I'm wrong space buffs but if the Universe was infinitely large and has always existed the entire sky would be jam packed with the light from stars. Correct?

That's known as Olber's Paradox
Link
One of the few things I remember from my relativity course at uni

Meridian · 22 Jun 2007 at 20:47

Haircut said:
That was just a minor explosion then,

A relative term - if our sun could and did do the same, all life on earth would be converted into a thin mist - along with most of the earth's crust.

M

Pumpkinstew · 22 Jun 2007 at 21:55

Clinkz said:
If you extend this theory to the very outer edges of the universe many many more light years away, for all we know time at these regions could already have ceased to exist and this extinction is making its way slowly towards us at the speed of light; hence explaining why there is a limit to the known observable universe.

If we're looking backwards in time surely matter would cease to exist here (ie heat death) before we could see it occurring at the edge of space. Or to put it another way in our frame of reference Earth is the oldest part of the Universe.

So wouldn't we perceive extinction making it's way away from us at the speed of light. (Assuming we survived to perceive it.) :confused: