3/9/2004: New Hubble deep field

[Pie]

Originally posted by lumberjim
If there was a local starfaring people, we would already have been enslaved or colonized.

... But we already have!

[Happy Monkey]

Originally posted by lumberjim
Beest, if there was acceleration on an object, and no resistance, ie. vaccuum, the object WOULD continue to incease it's speed until it collided with something, or came under gravity's pull.

Not quite. For accelleration, there needs to be a continual force. Velocity remains constant in the absence of outside forces, not acceleration.

[lumberjim]

i'm not a physics prof, but i thought that if an object in motion was not encountering any contrary action, then the motion would continue as it is. including a state of acceleration. if it's gaining speed, and there's nothing to slow it down, why would it stop gaining speed?

one of you bookworms has to know this.

on third thought, as i re-read my point, why would it continue to gain speed if there was nothing adding further impetus?

so, then, why ARE these galaxies increasing in speed?

[Beestie]

Not quite. For accelleration, there needs to be a continual force.

I think it needs to be an increasing force: constant force produces constant velocity and resistance is not relevant to the phenomenon itself but merely its magnitute. And that is what is a little unsettling to me. What force at that distance grows stronger?

[Beestie]

i'm not a physics prof, but i thought that if an object in motion was not encountering any contrary action, then the motion would continue as it is. including a state of acceleration.

Accelleration cannot occur in the absence of an outside force. The absence of resistance is not sufficient to create accelleration and would, in fact, violate Newton's 2nd law (inertia: objects at rest/motion tend to stay that way- motion being constant velocity in this case).

[Happy Monkey]

Originally posted by Beestie
I think it needs to be an increasing force: constant force produces constant velocity and resistance is not relevant to the phenomenon itself but merely its magnitute.

No, constant force produces constant accelleration. Zero force produces constant velocity.

If a spaceship in deep space stops firing its engine, it will not stop. It will just stop accelerating. To stop, it would need to fire the engine in the opposite direction.

[SteveDallas]

Originally posted by noodles
u click the button, and the space shuttle whistles off.

Then it whistles back, and with pictures.

And then everybody sees those pictures.

And no one challenges those pics, since they've never been there.

Are you saying they're faked?

[lumberjim]

Originally posted by Beestie
I think it needs to be an increasing force: constant force produces constant velocity and resistance is not relevant to the phenomenon itself but merely its magnitute. And that is what is a little unsettling to me. What force at that distance grows stronger?

PURE CONJECTURE:

suppose the object was moving through our local space, which, while relative to our atmoshpere is a vaccuum, is not a pure vaccuum. as these galaxies travel into deeper space, the vaccuum may be more PURE. therefore, the relative resistance to it's motion is less, causing a PERCEIVED acceleration as these objects encounter increasingly less resistance.

??

who's the physicist? belesteiri?

bruce probably knows. he knows EVERYTHING!

[tw]

Originally posted by lumberjim
so, then, why ARE these galaxies increasing in speed?

Many answers have been offered including dark matter. But to really understand this effect, we must better understand Quantum effects. Newtonian and Einstein physics have only taken us so far. Both were early attempts at explaining gravity. They don't explain the relationships between gravity and other universal forces. A unified theory is necessary to explain those other forces. Ten dimensional string theory may have recently gone farther to explain how the various forms of energy and matter interplay.

But currently, we don't know which way to look. Is the acceleration due to matter or energy we don't know about - the dark matter? Or do we first need to better learn quantum physics. In quantum physics, we are only about where Newton was in understanding Newtonian gravity - the stuff taught in high school physics. A not so veiled comment about (and again) why we needed the super collider.

[lumberjim]

was this just your fancy way of saying, "uh, i dunno?"

or are you saying that no-one knows?

[Happy Monkey]

suppose the object was moving through our local space, which, while relative to our atmoshpere is a vaccuum, is not a pure vaccuum. as these galaxies travel into deeper space, the vaccuum may be more PURE. therefore, the relative resistance to it's motion is less, causing a PERCEIVED acceleration as these objects encounter increasingly less resistance.

I'm a Comp-Sci major, math minor, but if I had a sub-minor, it would be physics.

There are several issues with that. First, the diminishment of resistance doesn't speed anything up unless there is a force pushing through the resistance. If something moving in space enters an area with zero resistance, it will continue moving at the speed at which it entered. Second, I greatly doubt that interstellar particles would produce a measurable effect on the acceleration of galaxies. Third, as far as I understand, galaxies aren't actually expanding into an area of empty space. Space itself is expanding, including the space between galaxies. I'm not well versed enough to explain it, so look here. Of course, this theory allows for a universe which curves back on itself, which would explain the seemingly infinite number of galaxies the further away we look.

[Pi]

What the fuck...
Can't we just look up to the stars and enjoy the feeling of being tiny and unimportant considering these enorm distances?
Come back to earth and see the world with better eyes, stop bothering and be happy?

That's what I think seing these pictures...

[lumberjim]

sure we could, pi, but that doesn;t leave much room for impressing each other with the profundity of our thoughts.

[lumberjim]

Originally posted by lumberjim
sure we could, pi, but that doesn;t leave much room for impressing each other with the profundity of our thoughts.

oh my god, i'm turning into xoxoxobruce!

[wolf]

No, you're still confusing the ; for the '

We know you're you.