Evidence for Universe Expansion Found

Yahoo (AP) ^ | 3/16/2006 | MATT CRENSON

[RadioAstronomer]

clearly flawed Inflationary Theory, you'd just divide the 17 Billion years that I used in the above post by the 123 AU result.

Arrrgggg.... Clearly flawed in your mind only.

[ThinkPlease]

H_0((Km/s)/Mpc * t (s) = ? (Km/Mpc) right?....

I think the answer is 42.

The context is the equation in this case. The Hubble constant is a constant in a very specific relation, the slope of this line:

That's it. Nothing else. Anyone that says otherwise is feeding you a line.

[Quark2005]

What do you think of the inflationary universe?

I found it 'upsetting' at first, until I learned to understand it a little better. (I'm not an expert at this stuff - Radio Astronomer is probably a better bet - I've had one grad level course in G.R. and a lot of particle physics, but that's about it.)

Apparently, in the inflationary model, there can be regions located outside our own observable 'bubble' as a result of the inflationary epoch, traveling away from us at (an apparent) 'faster' than light, but since we are forever causally disconnected from those regions, it doesn't really matter. Relativity's limit still holds from any observable point.

(One day, I'll understand this better myself, I hope.)

[RadioAstronomer]

and 382 do the correct math as well as show how a younger age for the Earth/Sun could be calculated under the clearly laughable proposition of Inflationary Theory actually being correct (which it is not).

Ummm.... You may want to do just a wee bit more research prior to posting this stuff anymore.

Just a suggestion.

[ThinkPlease]

So the warping of space in proximity to a large mass prevents/eliminates the expansion? Or does the warping just make it unmeasurable? Either way, I didn't know or expect that.

Do the math:

H_0=71(km/s)/megaparsec

d= 1 AU = 4 * 10^-12 Megaparsecs

v=128 *10 ^-12 km/s=1.28 *10^-10 km/s

that's a pretty small effect at that distance, and the effect of gravity pretty effectively overwhelms it.

[RadioAstronomer]

However, local regions bound by gravity, do not exhibit H.

[Doctor Stochastic]

That can always be done. One just sticks on an "extra" dimension. Sort of like combining electromagnetism and gravity into a 5 or 6 dimensional system. It's not very interesting because there's still no coupling between the systems. If one sticks a Fifth Dimension for the universise to "expand" into, it adds nothing to the actual physics. This contrasts with using time as a fourth dimension in relativity theory where new, observable physics results.

It's not wrong, it's just not particularly useful.

[ThinkPlease]

However, local regions bound by gravity, do not exhibit H

I always thought that's because the effect was so small no one would notice. Huh, I just double checked, and you are right. Thanks. You learn something new everyday!

[RadioAstronomer]

Interesting read:

http://en.wikipedia.org/wiki/Robertson-Walker_metric

I have to dash to work. :-(

Sigh.

[RadioAstronomer]

:-)

[RadioAstronomer]

So the warping of space in proximity to a large mass prevents/eliminates the expansion?

Indeed. Even at galactic scales. :-)

[The_Victor]

That's it. Nothing else. Anyone that says otherwise is feeding you a line.

At this point in the thread, I figured sci-fi fantasy interjection was appropriate.

But there you go getting us back on sound scientific footing. I'll bet this thread goes for another hundred posts as the attempt is made to defend previous fantasies. ;)

[PatrickHenry]

There's a spot-on article in Wikipedia here: Hubble's law. If you scroll down to the "Interpretation" section, it explains H₀ and it also shows all the relevant calculations. Because H₀ varies with the age of the universe, it can't be applied to two objects (earth and sun) for a long span of time -- even if they actually existed at the beginning.

[doc30]

Actually, I was thinking of it in terms of quantization of space. Yes, I know it's theoretical, but the checkerboard analogy is more in tune with that than making the squares bigger. If you make the squares bigger, then there is still the same number of squares between pieces. In checkers, you can have only one square per piece so adding squares is analogos to adding space, but the squares would have to be homogeneously added. The hard part for many people to get their heads around is that distance is measured in space, but it is not a measurement of space.

[Netheron]

Yes, I would agree that that is true. However, even if the expansion was going on, we couldn't detect it.

[Netheron]

Are you sure? It may give a common coordinate system to make the math easier.

If I measure positions on the Earth with lat/lon, I get funny coordinate singularities (North and South poles), but if I use quaternions (extra dimension) there are no singularity issues.

[The_Victor]

There's a spot-on article in Wikipedia here: Hubble's law. If you scroll down to the "Interpretation" section, it explains H0 and it also shows all the relevant calculations. Because H0 varies with the age of the universe, it can't be applied to two objects (earth and sun) for a long span of time -- even if they actually existed at the beginning.

How long before we get to the "it's only a theory," argument?

[PatrickHenry]

How long before we get to the "it's only a theory," argument?

That's for amateurs. The recommended challenge is: "Where you there?"

[AntiGuv]

my-subatomic-particles-were placemarker

[The_Victor]

That's for amateurs. The recommended challenge is: "Where you there?"

Do you suppose that an attempt by someone to observe the singularity could have caused the Big Bang?