Physicists: My theory of obtaining lightspeed!

daz · 26 Oct 2006 at 13:45

It's dark because there is no light coming from there.

D.P. · 26 Oct 2006 at 13:47

daz said:
First we need a Heisenberg compensator.

But you dont need exact positions of electrons etc, approximations will work good enough, plus when you know the positions of the atoms you can infer stable elctron arrnagements and the atoms will stabalise into the correct organizations (I think)

Arcade Fire · 26 Oct 2006 at 13:52

SteveOBHave said:
I would be extraordinarily dubious accepting the idea the objects are moving away from us at light speed!?!?!?!? I would accept that some are moving away fast enough to state that due to 'rapid' movement the relative light wavelength is made longer (Doppler Effect) and thus drops it into red and beyond but def not moving at light speed.

It's possible - if space expands then the speed of an object relative to another object faraway could be greater than the speed of light, even though its speed relative to space is less than the speed of light. I think. It's been a while since I did any cosmology.

SteveOBHave · 26 Oct 2006 at 13:54

Alan! said:
It does sound strange but those stars aren't "moving" its the space in between thats expanding or stretching. This rate of expansion was faster than light. So the light hasn't reached us, and that part of the sky looks dark.

I'm sorry, it just doesn't stand to reason. How can the distance between two objects increase without one or both of the objects moving. I think you may have your astrophysics theory confused with dogma from the Flat Earth Society.

Shoseki · 26 Oct 2006 at 13:56

IMBA!

SteveOBHave · 26 Oct 2006 at 13:59

Arcade Fire said:
It's possible - if space expands then the speed of an object relative to another object faraway could be greater than the speed of light, even though its speed relative to space is less than the speed of light. I think. It's been a while since I did any cosmology.

OK - in the loosest possibly sense, there is a possibility that two objects could conceivably move away from each other at half the speed of light and therefore the distance between the two object would be increasing at the speed of light (relative). However the implications of this happening with every star that we can't 'see' IMO are too far fetched and the idea that this accounts for all the 'dark space' inbetween the stars we see in the sky is something that I just won't buy.

Alan! · 26 Oct 2006 at 13:59

daz · 26 Oct 2006 at 13:59

D.P. said:
But you dont need exact positions of electrons etc, approximations will work good enough, plus when you know the positions of the atoms you can infer stable elctron arrnagements and the atoms will stabalise into the correct organizations (I think)

I'm not sure I'd feel confident about moving organic matter in that way... but simple solids etc should be straight forward.

Visage · 26 Oct 2006 at 14:00

Alan! said:
No.
The universe is infinite so in any direction you travel you would eventually hit a star.

Firstly, its by no means certain that the universe is infinate.

Secondly, your hypothesis depends on an assumption that all poaths within an infinite surface will meet a star. This is not true - there are many intuitive counterexamples for this.

The reason you cant see these stars is because the universe is expanding and the space between you and the star is expanding faster than light, so the light from that star cant get to your eyes for you to see it. So the space looks dark.

Actually, its more that the energy flux from distant stars is so weak that its immeasurable. Even the energy from stars 1 light year away are spread over an area of the order of 10^33 square metres. Even for a star thats a hell of a lot of area to cover.

If the universe was to stop expanding, eventually the night sky would be full of light.

No it wouldnt.

I'd recommend Parallel Worlds: The Science of Alternative Universes and Our Future in the Cosmos by Michio Kaku it covers a lot of the stuff in this thread.

Interesting. Personally I'd recommend a decent introductory level astrophysics textbook.

SteveOBHave · 26 Oct 2006 at 14:01

Shoseki said:
IMBA!

huh?

SteveOBHave · 26 Oct 2006 at 14:04

Visage said:
Interesting. Personally I'd recommend a decent introductory level astrophysics textbook.

LOL

Shoseki · 26 Oct 2006 at 14:10

SteveOBHave said:
huh?

IMBA is slang for Imbalanced, as in amazing!

SteveOBHave · 26 Oct 2006 at 14:13

Alan! said:
Take an elastic band and draw two dots on it, then stretch the elastic band. The dots are now further apart but are still on the same part of the elastic you drew them on.

And your point is? The dots are still further apart than they were originally and in stretching the rubber you are moving the dots...

SteveOBHave · 26 Oct 2006 at 14:14

Shoseki said:
IMBA is slang for Imbalanced, as in amazing!

oh - I Googled it and looked it up on Wiki and both came up with International Mountain Bicycling Association LOL :rolleyes:

Alan! · 26 Oct 2006 at 14:18

Visage · 26 Oct 2006 at 14:31

Alan! said:
Then please recommend one, I have nothing to read at the moment.

'Universe' By Freedman et al, was the textbook of choice when I was doing my degree.

Not sure if anything has surpassed it since.

themistry · 26 Oct 2006 at 14:42

eXSBass said:
As you can see the solid mass is directly behind the space shuttles engines. This will not move! It's a solid still body (this can be obtained by attatching it to the moon so it doesn't fly of)

I didn't read your whole post, but it wont work for the reason above. You can't have a fixed object in space due to newtons second law (i think). The force against the object will push it backwards as much as it pushes you forwards. The moon will move. You could strap a rocket on the otherside to counter this but im sure it wouldnt work for some reason or other.

TM

Alan! · 26 Oct 2006 at 14:45

Visage · 26 Oct 2006 at 14:45

themistry said:
I didn't read your whole post, but it wont work for the reason above. You can't have a fixed object in space due to newtons second law (i think). The force against the object will push it backwards as much as it pushes you forwards. The moon will move. You could strap a rocket on the otherside to counter this but im sure it wouldnt work for some reason or other.

TM

You've got the right reasoning, but the wrong conclusion.

For example, you could apply the same logic to a space shuttle launch - namely that the force on the earth will push it backwards just as much as it pushes the shuttles forwards (or upwards, more precisely). The difference is, obviously, the different masses involved.

Visage · 26 Oct 2006 at 14:50

Alan! said:
Thanks.

So the whole warping space thing, compressing the space in front of you and stretching the space behind you, is theoretically possible?

Depends what you mean by 'compressing' and 'expanding'.

Intuitively, it sounds equivalent to standing at one end of a rug, pulling the far end of it towards you, taking a step, and then pushing the bit you've just stepped off backwards - thus getting you from one end of the rug to the other, while actually only taking a single step. If that is what you're envisaging then, while its theoretically possible, its a hell of a job. You're talking about some pretty strong bending of space time. And, from GR, the curvature of space time at a point is proportional to the energy density at that point, you're talking about incredible amounts of energy (or its mass equivalent).

But thats not why there are vast areas of darkness in the night sky, the universe isn't/hasn't expanded faster than the speed of light?

There is an 'inflationary hypothesis' of the universe - that the universe in its very early days expanded faster than light, but thats all it is, a hypothesis. The only real evidence ofr it is that it would explain a few anomolies. The problem is that, obviously, if this were true then relativity would be broken, so we'd need to fix it somehow.