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#137 pgrmdave

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Posted 02 May 2005 - 07:52 AM

Damo, the problem with your idea that there is no motion is that we can measure acceleration. Acceleration occurs due to increased energy, so as long as we can measure the energy, we can measure acceleration. Cosmological motion caused by expansion does not add to energy, and so has no measureable acceleration, while the motions of the earth and moon do have energy, so we can know that they are moving.

#138 Queso

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Posted 02 May 2005 - 09:31 AM

all of the galaxies are moving away from each other. but i'm sure all of you already knew that.

#139 Buffy

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Posted 02 May 2005 - 10:13 AM

Forget it Buffy, I found an absurdity to your model and you can't even see it.

Actually, I've found a hole in your knowledge that is the source of your misunderstanding. It very clear you don't understand the meaning of local reference frame. It can be based on *whatever object you want to call stationary* what matters is relative motion. We can look solely at the Local Group of galaxies, and we can using red shifts *very precisely* measure their relative motion to us, and as a result we can build up a set of vectors for all of these objects. Since the Local Group *as a whole* is on a large enough scale to cancel out all these vectors on a cosmological scale, the group as a whole is "stationary" with respect to the expansion of the universe. When we use the vectors of the local group to define *our* vector *relative to the Local Group* we can use that vector to eliminate the blue shift seen in the raw data for the CMB. There is no absurdity here at all and it does not require any use of any "absolute" reference frame.

I hope this helps you understand the concept of local reference frames, but you should do some research on your own.

Cheers,
Buffy
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#140 bumab

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Posted 02 May 2005 - 11:29 AM

But by getting rid of absolute reference frames you are simultaneous making individual reference frames absolute.


Not quite true.

#141 Damo2600

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Posted 02 May 2005 - 12:02 PM

No I'm forgeting that the absolute reference frame is the CBR. Right?

So if we look at the universe through a microscope we see the galaxies like little sperm with their tails cut off all moving around with and against the CBR.

Josephine

#142 Buffy

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Posted 02 May 2005 - 02:28 PM

No I'm forgeting that the absolute reference frame is the CBR. Right?

Actually, no its not! It can be used as a calibration point to see if your movement with respect to the local reference frame aligns with the expansion of the universe, but it doesn't represent an absolute frame of reference because it looks the same from every point in the universe (once you've cancelled out your local reference frame motion).

So if we look at the universe through a microscope we see the galaxies like little sperm with their tails cut off all moving around with and against the CBR.

Well, they're being pulled by gravity and dark matter and being pushed by dark energy, they don't have their own locomotion and only barred spirals have tails, but they have two of them. :) They are moving around relative to one another, however as you increase the volume of the local reference frame you will eventually get to the point (argued to be about 20 million light years in diameter) at which expansion of the universe will start to dominate the relative motions.

Cheers,
Buffy

#143 Qfwfq

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Posted 03 May 2005 - 01:20 AM

We live inside one of the countless specks of the Cosmic Dust.

#144 Damo2600

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Posted 03 May 2005 - 03:47 AM

all of the galaxies are moving away from each other. but i'm sure all of you already knew that.


That's what I thought. If you use your vacuum cleaner it sucks the air out of the tube. Air is pulled into the vacuum and dust goes along with it. If the vacuum existed in all directions you could place a ball in the centre and it would be stationary. In a closed universe that was expanding all the galaxies would be pulled apart in an even fashion. They would be stationary.

However that's not what has been observed.

Apparently the galaxies have their own velocity. I'm gathering by my microscope looking at the sperm analogy with the tails cut off you would see the galaxies expanding. Although the sperm would be moving randomly with their own velocity. Like a psychedelic pattern.
Apparently Earth is moving at a velocity of 6000km/s against the CBR (which is a stationary standing wave) and we are going to crash into another galaxy in no time soon.

Josephine :)

#145 paultrr

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Posted 03 May 2005 - 03:51 AM

That's what I thought. If you use your vacuum cleaner it sucks the air out of the tube. Air is pulled into the vacuum and dust goes along with it. If the vacuum existed in all directions you could place a ball in the centre and it would be stationary. In a closed universe that was expanding all the galaxies would be pulled apart in an even fashion. They would be stationary.

However that's not what has been observed.

Apparently the galaxies have their own velocity. I'm gathering by my microscope looking at the sperm analogy with the tails cut off you would see the galaxies expanding. Although the sperm would be moving randomly with their own velocity. Like a psychedelic pattern.
Apparently Earth is moving at a velocity of 6000km/s against the CBR (which is a stationary standing wave) and we are going to crash into another galaxy in no time soon.

Josephine :)


No time soon is on the order of along time. If memory serves me try well after our sun has gone through its red giant stage. In short we have far more to worry about in the future.

Also, not everything is exactly even. Our own local group moves toward Virgo. Other groups move different. The distribution of galaxies themselves is well known to not be equal, the great wall, voids, etc. The CMB itself has a slight unevenness. Also back in the 90's during some of the study of the CMB there was a study which found that our own motion against the CMB and the hotspot associated with that motion are slightly offset. Never heard much come of that published article. But it was like we are moving one direction and yet the hotspot due to that motion is offset by a certain angle.

#146 Damo2600

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Posted 03 May 2005 - 11:06 AM

"In short we have far more to worry about in the future."

We do indeed. The future is a very important consideration in a great deal of aspects.

"Also, not everything is exactly even. Our own local group moves toward Virgo. Other groups move different. The distribution of galaxies themselves is well known to not be equal, the great wall, voids, etc. The CMB itself has a slight unevenness. Also back in the 90's during some of the study of the CMB there was a study which found that our own motion against the CMB and the hotspot associated with that motion are slightly offset. Never heard much come of that published article. But it was like we are moving one direction and yet the hotspot due to that motion is offset by a certain angle."

Thank you Paul. That is very interesting I will look into all of this. My personal sources simplified it all excessively suggesting to me that everything is 'perfectly' even. Sites I have seen suggest that there is an overall average eveness though. So we will see.

Josephine :)

#147 Damo2600

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Posted 06 May 2005 - 01:38 AM

Hi guys,

I have just found out that the mass measured within the universe is only 5% of the mass needed to close the universe. Which means that dark energy (which has not been found) even if it were to be 45% of the required mass we would still be missing 50%. Studies into neutrinos, a massive particle, is a possibilty that we will find the extra mass, but we would need to find a whole bunch of them. The other two models, still possible, were not even discussed in this thread.

The truth maybe out there.
Josephine

#148 Tormod

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Posted 06 May 2005 - 02:43 AM

I have just found out that the mass measured within the universe is only 5% of the mass needed to close the universe.


This is a different topic and has been discussed before.

We have some content about it on our main site, try this search for starters:
http://www.hypograph...ealm=Hypography

By the way, the hypography on "missing matter" needs a huge update since most of those links are dead.

#149 paultrr

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Posted 06 May 2005 - 04:25 AM

Thank you Paul. That is very interesting I will look into all of this. My personal sources simplified it all excessively suggesting to me that everything is 'perfectly' even. Sites I have seen suggest that there is an overall average eveness though. So we will see.

Josephine :xx:


There is an overall eveness. But that still a long way from total eveness. Hawking called the CMB shrunk back in time a wrinkled pea for a big reason in his book "The Universe in a Nutshell". Its held that it was the uneveness that helped form the structure we find in the universe.

#150 Damo2600

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Posted 06 May 2005 - 05:33 AM

Thanks for that Tormod,

Hey Paul,

The hotspot you were talking about made sense to me when you first told me but on thinking about I wondered how there would be a hotspot since the Earth is spinning. It would make some sense if it were nearer to the north or south pole. This is confusing to me.

Josephine

#151 IMAMONKEY!

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Posted 06 May 2005 - 05:56 AM

OK! many many many! and i stress that word... big words! I diddnt understand half of what was posted here... care to explain? anyone! i love to learn and light travel is my favorite subject!

#152 C1ay

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Posted 06 May 2005 - 02:46 PM

[quote name='IMAMONKEY!']OK! many many many! and i stress that word... big words! I diddnt understand half of what was posted here.QUOTE]
Have you ever used Dictionary.com? It might help you with some of the words. You might try looking some of it up in Wikipedia as well. Then ask specific questions about the material to help fill in the blanks.