Acceleration of the Expansion of the Universe

General physics and astronomy discussions not directly related to Celestia
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Sitting Duck
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Joined: 10.10.2005
With us: 19 years 6 months
Location: Antwerp, Belgium

Acceleration of the Expansion of the Universe

Post #1by Sitting Duck » 24.10.2005, 17:21

If the universe is accelerating its expansion, and the universe was expanding at a pace faster than the speed of light directly after the big bang (size of grapefruit to solar system in one second?), then how fast would it be expanding now??? or has there been a process of deceleration, followed by acceleration, like someone taking a breath in blowing up a balloon :?:
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Rocket started hissing, leak lead to a no-launch
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Leaked in fuelling stage

BrainDead
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Post #2by BrainDead » 24.10.2005, 23:52

Have a look HERE
for a better explanation of what scientists think they know now.
Brain-Dead Bob

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Topic author
Sitting Duck
Posts: 44
Joined: 10.10.2005
With us: 19 years 6 months
Location: Antwerp, Belgium

Post #3by Sitting Duck » 25.10.2005, 16:27

Thanks, but Im not sure if this entirely answers my question. If i have things staright here, the universe is expanding, more space is being added, at an ever increasing rate, but what would this rate be?
Notes

Unintentional launch, cork was too loose to sustain adequate pressure

Very succesful glide

Best launch so far

Rocket started hissing, leak lead to a no-launch

None

Leaked in fuelling stage

al'be:do
Posts: 2
Joined: 13.12.2005
With us: 19 years 4 months

Post #4by al'be:do » 14.12.2005, 00:55

The Hubble Term is the measure for the expansion speed. The last measurement in the "H0 Key Project" with the HubbleSpace Telescope lead to the value of

71 (+/- 6) km s-1 Mpc-1.

That means for every megaparsec (1 million parsecs, 3261633 lightyears) away from the spectator the expansion speed rises 71 (between 65 and 77) kilometers per second.

This is an "error" of around 9 percent. This is because we don't know the values of the so called "cepheides", stars used for distance calibration, precisely enough.

The inverse of the Hubble term is roughly the age of the universe, if the expansion is assumed to be constant.

al'be:do


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