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Author Topic:   Speed of Light
onifre
Member (Idle past 2950 days)
Posts: 4854
From: Dark Side of the Moon
Joined: 02-20-2008


Message 16 of 268 (472844)
06-25-2008 8:05 AM
Reply to: Message 14 by Libmr2bs
06-24-2008 8:57 PM


Re: speed of light
Would I be the first that someone thought was wrong? A stellar group of folks I would say.
Of course not.
I only suggest that Doppler should be confirmed by some other means before closing the book forever.
Sometimes one means is all you'll be able to have. If it as solid as something like the Doppler which can not only be tested for accuracy on galaxies but it can be tested here on Earth with something as simple as a car, I think you've got yourself a pretty good means for testing direction.
I do see your point though.
But don't forget that the metric space in between the galaxies is also measured and this further indicates that the space between them is expanding.

All great truths begin as blasphemies
I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your fuckin' mouth.

This message is a reply to:
 Message 14 by Libmr2bs, posted 06-24-2008 8:57 PM Libmr2bs has replied

Replies to this message:
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Agobot
Member (Idle past 5530 days)
Posts: 786
Joined: 12-16-2007


Message 17 of 268 (472848)
06-25-2008 8:38 AM


Dark energy
Why do we have to have Dark Energy to explain the expansion of the universe? If, for whatever reason, 10^-33 seconds after the BB, the universe started to expand very rapidly, what force could stop this expansion? Wouldn't all celestial bodies be moving through space almost indefinitely, unless a force that I can't think of, starts to slow them down(planets are rotating around our sun for this very same reason, right)?

Replies to this message:
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NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 18 of 268 (472849)
06-25-2008 8:46 AM
Reply to: Message 17 by Agobot
06-25-2008 8:38 AM


Re: Dark energy
Dark energy isn't used to talk about the expansion of the universe. The problem is that, in the last few years, measurements indicate that the rate of expansion is increasing.

This message is a reply to:
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ramoss
Member (Idle past 612 days)
Posts: 3228
Joined: 08-11-2004


Message 19 of 268 (472850)
06-25-2008 8:46 AM
Reply to: Message 17 by Agobot
06-25-2008 8:38 AM


Re: Dark energy
Well, the issue is that the rate at which the universe is expanding is increasing. Also, something that could potentially slow down the expansion of the universe is this little thing known as 'gravity'.

This message is a reply to:
 Message 17 by Agobot, posted 06-25-2008 8:38 AM Agobot has replied

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Agobot
Member (Idle past 5530 days)
Posts: 786
Joined: 12-16-2007


Message 20 of 268 (472851)
06-25-2008 8:56 AM
Reply to: Message 19 by ramoss
06-25-2008 8:46 AM


Re: Dark energy
ramoss writes:
Well, the issue is that the rate at which the universe is expanding is increasing. Also, something that could potentially slow down the expansion of the universe is this little thing known as 'gravity'.
I would think this little thing called gravity would decrease in strength with the ever expanding universe.

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onifre
Member (Idle past 2950 days)
Posts: 4854
From: Dark Side of the Moon
Joined: 02-20-2008


Message 21 of 268 (472859)
06-25-2008 1:03 PM
Reply to: Message 20 by Agobot
06-25-2008 8:56 AM


Re: Dark energy
I would think this little thing called gravity would decrease in strength with the ever expanding universe.
Thats the issue basically, that gravity seems to be lossing out to whatever it is thats expanding the Universe. If gravity was effecting the expantion then something like the Big Crunch...
Big Crunch - Wikipedia
...would happen.
However, the Universe is expanding and accelerating with no indication of regressing, so that is why the predicted outcome is now shifted more to a Big Freeze.
Heat death of the universe - Wikipedia

All great truths begin as blasphemies
I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your fuckin' mouth.

This message is a reply to:
 Message 20 by Agobot, posted 06-25-2008 8:56 AM Agobot has not replied

Replies to this message:
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ramoss
Member (Idle past 612 days)
Posts: 3228
Joined: 08-11-2004


Message 22 of 268 (472861)
06-25-2008 1:18 PM
Reply to: Message 21 by onifre
06-25-2008 1:03 PM


Re: Dark energy
That is exactly why 'Dark Energy' is a hypothesis right now , because of the observation.

This message is a reply to:
 Message 21 by onifre, posted 06-25-2008 1:03 PM onifre has replied

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Taz
Member (Idle past 3291 days)
Posts: 5069
From: Zerus
Joined: 07-18-2006


Message 23 of 268 (472863)
06-25-2008 1:30 PM


Wow, you guys are masters of the bleeding obvious.

Replies to this message:
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onifre
Member (Idle past 2950 days)
Posts: 4854
From: Dark Side of the Moon
Joined: 02-20-2008


Message 24 of 268 (472874)
06-25-2008 3:16 PM
Reply to: Message 18 by NosyNed
06-25-2008 8:46 AM


Re: Dark energy
Dark energy isn't used to talk about the expansion of the universe. The problem is that, in the last few years, measurements indicate that the rate of expansion is increasing.
Dark energy - Wikipedia

All great truths begin as blasphemies
I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your fuckin' mouth.

This message is a reply to:
 Message 18 by NosyNed, posted 06-25-2008 8:46 AM NosyNed has not replied

  
onifre
Member (Idle past 2950 days)
Posts: 4854
From: Dark Side of the Moon
Joined: 02-20-2008


Message 25 of 268 (472875)
06-25-2008 3:17 PM
Reply to: Message 22 by ramoss
06-25-2008 1:18 PM


Re: Dark energy
That is exactly why 'Dark Energy' is a hypothesis right now , because of the observation.
Huh?

All great truths begin as blasphemies
I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your fuckin' mouth.

This message is a reply to:
 Message 22 by ramoss, posted 06-25-2008 1:18 PM ramoss has not replied

  
onifre
Member (Idle past 2950 days)
Posts: 4854
From: Dark Side of the Moon
Joined: 02-20-2008


Message 26 of 268 (472876)
06-25-2008 3:18 PM
Reply to: Message 23 by Taz
06-25-2008 1:30 PM


Wow, you guys are masters of the bleeding obvious.
How so?

All great truths begin as blasphemies
I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your fuckin' mouth.

This message is a reply to:
 Message 23 by Taz, posted 06-25-2008 1:30 PM Taz has not replied

  
Libmr2bs
Member (Idle past 5726 days)
Posts: 45
Joined: 05-15-2008


Message 27 of 268 (472923)
06-25-2008 9:10 PM
Reply to: Message 16 by onifre
06-25-2008 8:05 AM


Re: speed of light
If galaxies are shrinking then the space between them would be expanding.
We can't see the center of our galaxy which would imply that we most probably can't see the far side of another galaxy. This would prevent us from seeing if the far side is moving away or toward the observer. It would seem that this is the real test of whether the universe is expanding and its rate of expansion.
I've researched this matter but can't find a reference where this situation has been explored.

This message is a reply to:
 Message 16 by onifre, posted 06-25-2008 8:05 AM onifre has replied

Replies to this message:
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lyx2no
Member (Idle past 4716 days)
Posts: 1277
From: A vast, undifferentiated plane.
Joined: 02-28-2008


Message 28 of 268 (472936)
06-25-2008 10:14 PM
Reply to: Message 27 by Libmr2bs
06-25-2008 9:10 PM


Re: speed of light
Why would galaxies that are farther away be shrinking faster?
We know they are farther because they subtend a lesser arc, have smaller, dimmer globular clusters, have cute, little, teeny-tiny super nova and appear closer together. The same way those Texas town look when you're still twenty miles away on a night run.
We don't have much of a choice in seeing our Milky Way edge on, but the majority of galaxies are not edge on to us (or even spirals). And having several billion of them to choose from we could ignore any that weren't straight on, clockwise spirals and still have plenty to spare.
Heck, let's ignore the centers of galaxies altogether. Let's just measure the red shift of the the high side of vertically oriented , edge on galaxies. Some will have peculiar motions toward us and some away. Again, with billions to choose from we'll still have plenty.
There are about a jillion ways to overcome your difficulties that a thoughtful man can come up with on a slow night. If someone did research this I'd bet his next research project was to determine if the lens caps should be left on or take off during observations.
Edited by lyx2no, : No reason given.

Kindly
There is a spider by the water pipe.

This message is a reply to:
 Message 27 by Libmr2bs, posted 06-25-2008 9:10 PM Libmr2bs has not replied

  
onifre
Member (Idle past 2950 days)
Posts: 4854
From: Dark Side of the Moon
Joined: 02-20-2008


Message 29 of 268 (472987)
06-26-2008 9:54 AM
Reply to: Message 27 by Libmr2bs
06-25-2008 9:10 PM


Re: speed of light
If galaxies are shrinking then the space between them would be expanding.
If galaxies were shrinking, then they would all appear to be moving away from us at the same rate. But we observe that farther objects are moving away from us faster than near objects (some of which are actually getting closer to us) which is consistent with the Big Bang.
If galaxies were shrinking then stars in our own galaxy would be blue shifted toward us, which we don't observe.
Edited by onifre, : No reason given.

All great truths begin as blasphemies
I smoke pot. If this bothers anyone, I suggest you look around at the world in which we live and shut your fuckin' mouth.

This message is a reply to:
 Message 27 by Libmr2bs, posted 06-25-2008 9:10 PM Libmr2bs has not replied

Replies to this message:
 Message 31 by Taz, posted 06-27-2008 12:35 AM onifre has replied
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Taz
Member (Idle past 3291 days)
Posts: 5069
From: Zerus
Joined: 07-18-2006


Message 30 of 268 (473095)
06-27-2008 12:28 AM
Reply to: Message 17 by Agobot
06-25-2008 8:38 AM


Re: Dark energy
Agobot writes:
Why do we have to have Dark Energy to explain the expansion of the universe?
I don't think anyone has given you a clear enough answer yet.
First of all, you need to know a couple bleedingly obvious facts.
(1) The universe is expanding at an accelerated rate.
(2) There isn't any force that we know of that could account for such a universal acceleration.
In order for all the matter in the universe to accelerate like that despite the force of gravity being present, there needs to be some kind of energy responsible for it. Hence, we call it dark energy. It's sort of like dark matter. We don't know what the hell it is but we sure as hell could see what it's doing to our universe.
The best suggestion I've heard is that perhaps the universal accelerated expansion of the universe is caused by the virtual particles popping in and out of existence. The total combination of all this causes an outward "pressure" that is enough to cause everything to expand.

I'm trying to see things your way, but I can't put my head that far up my ass.

This message is a reply to:
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