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what is the universe expanding into?


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Sorry I cannot back up anything on this peculiar subject because it is cutting-edge. I am only exercising logical speculation.

Speculation goes in the speculations forum. This thread is located in the Astronomy and Cosmology forum, and it's not appropriate to derail discussions which fall under that discipline with pet hypotheses.

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MARTİN

All My Friends Say:the Big Bang created Space, Time, and Matter

right?

 

According to you, they say that. I don't know your friends.

If they say that then they are choosing to assert something ungrounded in science.

 

Probably they are just out of date---they are repeating what professional scientists used to say 5 or 10 years ago.

 

Suggest to your friends that they read recent writings (post 2005) by professionals. For an up-to-date popularized account, tell them to read the stuff at Einstein Online

http://www.einstein-online.info/en/spotlights/cosmology/index.html

 

There is no rational grounds for supposing that space time and matter were created at the moment of the Big Bang.

A particularly good popular article on this here:

http://www.einstein-online.info/en/spotlights/big_bangs/index.html

==quote==

A tale of two big bangs

In cosmology, "big bang" has two different meanings - and if you want to understand what's going on, you should be aware of that difference....

==endquote==

Edited by Martin
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everybody's saying the big bang definitely

happened but weres the evidence and I mean solid evidence not theory

 

As in things actually measured?

 

1) Hubble's law,

 

2) the CMBR,

 

3) nucleosynthesis and the abundance of light elements,

 

4) the large scale structure of the universe and galactic evolution.

 

If you include inflation we also explain

 

5) absence of relic monopoles,

 

6) near flatness of the universe,

 

7) the seeding galaxy formation via quantum fluctuations of the inflaton field. You can see evidence of this in the CMBR.

 

Hope these qualify as evidence for you.

 

Any other cosmological theory would need to explain these at least as well as BB cosmologies if they are to be taken as competitive theories. (I say nothing about quantum gravity theories and their cosmologies here )

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posted by airbrush

Space-time cannot exist without matter. Matter did not exist until the big bang, unless the big bang happened within an already existing universe, in which case the big bang erased a previous universe and introduced another.

 

what do you mean space-time cant exist without matter? why not?. that might be so with energy{ if that} but i see no reason for space-time not to exist without matter. it just wouldnt be curved much. and, ya, i know, matter is alot of energy compressed into itself, but, they still are two different things, just different "versions". matter is a result of energy compression.

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would it be possible to explain hubbles law a bit simpler and detailed and without the equations

 

 

http://en.wikipedia.org/wiki/Hubble's_law

"Hubble's law is the statement in physical cosmology that the redshift in light coming from distant galaxies is proportional to their distance."

 

It is often explained using a balloon with dots on it representing the galaxies. As the balloon expands, the distance between the dots increases no matter where you are on the surface of the balloon. The further away you are from a dot, the faster it is moving away from you. This expansion is from space expanding and not from the galaxies moving. Local gravitational forces keep galaxies and galaxy clusters from expanding.

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would it be possible to explain hubbles law a bit simpler and detailed and without the equations

 

Read the Wiki article.

 

However it is an oxymoron to say simpler and detailed and without the equations.

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would it be possible to explain hubbles law a bit simpler and detailed and without the equations

 

Jamey, you already got two sensible responses from NowThat and ajb, and I agree essentially.

 

There is a piece to the puzzle that people don't always mention (it may not even be in the WikiP article, I didn't look).

 

It might help you to think about this even tho you might not see at first what it has to do with Hubble law:

 

It is the idea of being at rest relative to the microwave background.

 

The solar system motion with respect to CMB (abbreviated wrt CMB) has been measured. Solar system is moving 370 km/second in direction of constellation Leo. The temperature map of the CMB is distorted by this. It is approximately uniform (with only tiny 1/1000 of one percent variation) except for the Doppler hotspot around Leo caused by our own motion in that direction. And the corresponding Doppler cold spot behind us.

 

To make the Hubble law precise, you take this 370 km/second motion out of the data. Adjust the data so it corresponds to what an observer would see if he was absolutely at rest, by universe standards. That is, at rest wrt CMB.

 

If you don't adjust for our own motion, then it will seem that distant galaxies ahead of us are receding slower than they should and those behind us are receding 370 km/s faster than they should.

 

Hubble himself detected this and figured out the cause (our own private motion relative to the expansion process or, if you like, the universe as a whole). He deduced the speed and direction many years before the CMB was discovered. And knew how to correct for it.

 

Being at rest relative to CMB is like being at rest with respect to the collective matter in the early universe (when it was all spread out, before stars and galaxies began to condense and gather it into clumps.)

Because it is that nearly uniform hot gas filling the early universe that we are seeing when we look at the CMB.

 

An observer who sees no Doppler distortion in the temperature map of the CMB is essentially at rest relative to that ancient cloud of matter. Except of course the cloud as such no longer exists. It has expanded and cooled and condensed and become us and everything else.

 

The Hubble law is about objects and observers which are at rest wrt CMB.

It tells the rate that distances between objects at rest are increasing.

This is so basic that it is good to think about it and have it clearly in mind---it can help you understand the Hubble law better.

Edited by Martin
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Martin, usually at least in special relativity we use the fundamental construction that regardless of relatively speeding frames of motion, physics is experienced the same in any frame. This is a curious turn where we find the CMB is a blackbody radiation field, which actually refers to equilibrium it once had with the average distribution of masses. Does this present a challenge to relativity?

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Martin, usually at least in special relativity we use the fundamental construction that regardless of relatively speeding frames of motion, physics is experienced the same in any frame. This is a curious turn where we find the CMB is a blackbody radiation field, which actually refers to equilibrium it once had with the average distribution of masses. Does this present a challenge to relativity?

 

It almost sounds like Martin is a closet ether person, waiting for the right definition of ether. :D

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That's a bit strong, though I am still looking for a Phlogiston Society. It is consistent that we distinguish between a space vacuum which is the same regardless of Lorentz frame, or motion, and the CMB. The latter was tied to the mass field and that, on a fairly large scale, has both uniformity and locally definable "rest frames". On a mathematical level I am seeking to understand what is means that, when we establish the Robertson-Walker metric, which is the "expanding universe" GR form, we have abandoned covariance.

Edited by Norman Albers
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Does this present a challenge to relativity?

 

I think not, Norman, it just means there was some matter in the early universe, remarkably evenly distributed, and that one can say what it means to be at rest wrt that matter. GR is perfectly comfortable with that.

 

It almost sounds like Martin is a closet ether person, waiting for the right definition of ether. :D

:D

 

But seriously, why did people invent ether, what good did it ever do?

 

I didn't get enough sleep last night and I'm thinking of taking a nap. I can't think what ether is good for.

 

I'm pretty WYSIWYG and not closety. My streak of mysticism is probably about geometry, not ether.

 

Geometry seems to exist without it being the geometry of anything. This autonomous geometry even changes and evolves dynamically and responds to matter. How that could be is a question that one has to put on hold and keep submerged in order to get anything done. Maybe that's what I'm waiting for the right explanation for.

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The ether, which is an intuitive construct, may just be too subtle to be detected, like the program for existence.

 

I like that stuff about geometry existing without being the geometry of anything. Maybe Geometry is what people really mean by "God" (without knowing it).

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neither space nor time created matter

 

but space allows matter ( or really energy ) to manifest ( time is irrelevent )

 

Prove it, or stop making posts about it anywhere outside of the Speculations forum.

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posted by airbrush

 

Space-time cannot exist without matter. Matter did not exist until the big bang, unless the big bang happened within an already existing universe, in which case the big bang erased a previous universe and introduced another.

 

unfortunately that is just blather

 

 

what do you mean space-time cant exist without matter?

 

well lets try to define both

 

space=room

 

time= the measurement of movement of any kind . time is not a property of energy/matter but consequence of movement

 

nothing more nothing less

 

 

 

why not?.

 

why not indeed

 

that might be so with energy{ if that} but i see no reason for space-time not to exist without matter.

 

if space has no matter in it what then is time based on though ?

 

 

it just wouldnt be curved much. and, ya, i know, matter is alot of energy compressed into itself, but, they still are two different things, just different "versions". matter is a result of energy compression.

 

or you can look at matter being at a lower energy state than energy its self


Merged post follows:

Consecutive posts merged
Originally Posted by north

neither space nor time created matter

 

but space allows matter ( or really energy ) to manifest ( time is irrelevent )

 

 

Prove it, or stop making posts about it anywhere outside of the Speculations forum.

 

does space have any , unto its self , any fundamental properties associated to space ? that can influence any energy/matter object ?

 

no

 

 

does time unto its self have any properties that can influence energy/matter ?

 

no

 

 

does the introduction of time , unto its self change the speed of an object in either a positive or negative direction ?

 

no

Edited by north
Consecutive posts merged.
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