The Big Rip?

Larspeart · 7th March 2003, 09:38 AM

Anyone care to explain this theory, and whether it holds much weight?

http://www.space.com/scienceastronom...ip_030306.html

SFB · 7th March 2003, 11:08 AM

Quote:

Originally posted by Larspeart
Anyone care to explain this theory, and whether it holds much weight?

http://www.space.com/scienceastronom...ip_030306.html

I certainly don't have the background to lend weight to the article but this sentence annoyed me:

"Scientifically it is just about the most repulsive notion ever conceived."

7th March 2003, 11:21 AM

"out-of-control phantom energy"

LOL.

That about covers it.

fishbob · 7th March 2003, 11:53 AM

It is not theory yet. It appears to be a hypothesis based on the output of computer models.

DanishDynamite · 7th March 2003, 12:18 PM

Interesting article, Larspeart.

While I'm no expert, it seems to be a straight forward consequence of tinkering with the cosmological constant. If it grows with time, the acceleration of space expanding will itself accelerate. Obviously, if an epansionary force (previously only significant at intergalactic scales) keeps growing, it will at some point start ripping up local stuff as well.

At the moment, however, it is just speculative tinkering, as far as I understand the article. Of course, as with any scientific hypothisis, it makes predictions which can then be tested.

7th March 2003, 02:32 PM

Interesting article. I wonder how an accelerating acceleration would allow for stable wormholes? (Since time travel is a direct consequence of stable wormholes, I won't bother asking about it.) Maybe something to do with negative energy...

Larspeart · 11th March 2003, 10:05 AM

Hmm, good points. I guess it 'could' happen. Interesting appraoch to the idea of expansion in the cosmos.

Anyway, there was a small update/addition to the original article on this.

http://www.space.com/astronotes/astronotes.html

It seems that a LOT of scienctists are puzzled and/or curious about this theory/hypo. Hell, even the responder at Space.com is at a loss for detailed answers to give on it.

What do you all think? Agree? Disagree? Curious? Skeptical?

DanishDynamite · 11th March 2003, 01:08 PM

Larspeart:

Quote:

What do you all think? Agree? Disagree? Curious? Skeptical?

Well, offhand I'm skeptical because this tinkering isn't a solution to any known problem. It is just fiddling with a "constant" and extrapolating.

It would be a bit like me postulating that the gravitational constant grows by one part in a trillion, every trillion years. Could that be true? Yes. Is there any reason to think so? No. Is there any evidence for or against? No.

7th March 2003, 09:38 AM	#1
Larspeart Muse Join Date: Feb 2003 Posts: 581	The Big Rip? Anyone care to explain this theory, and whether it holds much weight? http://www.space.com/scienceastronom...ip_030306.html
Larspeart Muse Join Date: Feb 2003 Posts: 581

7th March 2003, 11:08 AM	#2
SFB Critical Thinker Join Date: Dec 2001 Posts: 288	Re: The Big Rip? Quote: Originally posted by Larspeart Anyone care to explain this theory, and whether it holds much weight? http://www.space.com/scienceastronom...ip_030306.html I certainly don't have the background to lend weight to the article but this sentence annoyed me: "Scientifically it is just about the most repulsive notion ever conceived."
SFB Critical Thinker Join Date: Dec 2001 Posts: 288

7th March 2003, 11:21 AM	#3
Guest Posts: n/a	Re: Re: The Big Rip? "out-of-control phantom energy" LOL. That about covers it.
Guest Posts: n/a

7th March 2003, 11:53 AM	#4
fishbob Seasonally Disaffected Join Date: Jan 2003 Location: Chilly Undieville Posts: 5,667	It is not theory yet. It appears to be a hypothesis based on the output of computer models.
	__________________ When you believe in things you don't understand, then you suffer . . . " - Stevie Wonder "Stupidity - a callow indifference to facts or data" - Stuart Firestein -neuroscientist. I hate bigots.

7th March 2003, 02:32 PM	#6
rwald Guest Posts: n/a	Interesting article. I wonder how an accelerating acceleration would allow for stable wormholes? (Since time travel is a direct consequence of stable wormholes, I won't bother asking about it.) Maybe something to do with negative energy...
rwald Guest Posts: n/a

7th March 2003, 12:18 PM	#5
DanishDynamite Penultimate Amazing Join Date: Aug 2001 Location: In the cold Posts: 10,802	Interesting article, Larspeart. While I'm no expert, it seems to be a straight forward consequence of tinkering with the cosmological constant. If it grows with time, the acceleration of space expanding will itself accelerate. Obviously, if an epansionary force (previously only significant at intergalactic scales) keeps growing, it will at some point start ripping up local stuff as well. At the moment, however, it is just speculative tinkering, as far as I understand the article. Of course, as with any scientific hypothisis, it makes predictions which can then be tested.

11th March 2003, 10:05 AM	#7
Larspeart Muse Join Date: Feb 2003 Posts: 581	Hmm, good points. I guess it 'could' happen. Interesting appraoch to the idea of expansion in the cosmos. Anyway, there was a small update/addition to the original article on this. http://www.space.com/astronotes/astronotes.html It seems that a LOT of scienctists are puzzled and/or curious about this theory/hypo. Hell, even the responder at Space.com is at a loss for detailed answers to give on it. What do you all think? Agree? Disagree? Curious? Skeptical?
Larspeart Muse Join Date: Feb 2003 Posts: 581

11th March 2003, 01:08 PM	#8
DanishDynamite Penultimate Amazing Join Date: Aug 2001 Location: In the cold Posts: 10,802	Larspeart: Quote: What do you all think? Agree? Disagree? Curious? Skeptical? Well, offhand I'm skeptical because this tinkering isn't a solution to any known problem. It is just fiddling with a "constant" and extrapolating. It would be a bit like me postulating that the gravitational constant grows by one part in a trillion, every trillion years. Could that be true? Yes. Is there any reason to think so? No. Is there any evidence for or against? No.