Big Bang or Big Goof?

superluminal. While it could be ASSUMED that space can expand at any speed; matter, energy and gravity are limited to light speed.

Inflation relies on seemingly endless small areas expanding independently so they do not break the light barrier but can accomplish inflation. Why should this be? How did all these areas of space join up to form the universe? The moment they do, we are left with light speed being the limiting factor at the "rim" while everything inside will expand slower.

All matter and energy was apparently there from the first moment (so to speak). The second matter forms, everything will instantly collapse into a black hole, a state which it would still be in.

The BB idea talks of a four physical dimension hypersphere, with the universe being it's 3D skin, nothing actually moves. It is space that expands between everything so NO RED SHIFT. The 3D expansion is an actual expansion, with everything moving away from a central starting point. The BB seems to want the best of both worlds here and I cannot see inflation or expansion being possible.

I think the CMB is just slightly red shifted IR from stars over billions of years. Microwaves overlap IR and it would need little to redshift them over cosmic time. I don't believe photons are magic but believe that they do redshift after maybe trillions of interactions EACH, which explains their redshifting, and would be proportional with distance. (I noticed the talkorigins site quoted that awful tired light site as evidence against it).

It seems to me more like ever more unlikely fudges needed rather than predictions gained.

 

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There is no need to make it so complex. Space time is allowed to expand faster than light speed.

Thus was one more reason to invent superinflation....
(it is simpler to say that without the creation of mass energy there would be no inflation, and no spacetime - ie without hills there are no valleys)

i am confused as to what you are saying here. People invented this 4d Hyperballoon to as simplified way to explain the redshift. The 3d skin has to be growing. As you say, “3D expansion is an actual expansion, with everything moving away from a central starting point. “; (the central point is, confusingly, at every location in our universe, at the same time).....
(It is space that expands between everything so we have RED SHIFT.)

 

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kaneda,

You seem to be confusing cosmological red shift and Doppler shift. They are not the same thing, just as gravitational red shift is a separate model. Doppler shift is an observed frequency shift in electromagnetic radiation due to relative motion between the emitter and the reciever. Cosmological red shift is due the the stretching of the wavelength of em radiation while it is in flight from the emitter to the reciever. As that 'hypersphere' expands, the wavelength of the light inside it also expands.

 

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Correct.

How can I say this without offending you? With no intention other than simply informing you, this is wrong.

Inflation is theorized to have occurred uniformly, everywhere. The origin of the tiny anisotropies of the CMB and the general non-homogeneous nature of matter is due to quantum fluctuations in the tiny de Sitter space that was our observable universe, as magnified by inflation. Again, there is no "rim". You are not picturing the situation as it is thought to be. That is, there is no current reason to think that space is anything other than infinite in extent, and we only see an infinitesimal portion as our visible universe.

OK. Density is defined as mass per unit volume. If the density required to form a black hole is D in space as it is now, what happens if we run the clock backwards to nearly T=0?

A given unit volume of space gets exponentially smaller and smaller during our anti-inflationary period, leaving less room for M in what is a shrinking unit volume.

So, if the amount of mass that can occupy a given volume is assumed to be constant (not sure of that given a changing space metric) and that volume metric is decreasing, then the density must decrease, and at some point the density required to form a BH is not present. In a metrically shrunken space.

I haven't researched this. This is my "theory" alone. Give it a whirl.

It does? I don't know of this description.

Yes, there is. This is where the difference between doppler redshift and cosmological redshift is important. As space expands, the wavelength of light passing through this space is "stretched" (redshifted) along with the space. Cosmological redshift.

BB theory does not say this.

Well, many people cannot see evolution as being possible, time dilation (demonstrated every day in particle physics labs), or quantum tunneling (used every day in labs all over the world that have a TEM (Tunnelling Electron Microscope).

By what mechanism? Why is it "slightly" redshifted?

Little of what?

But why do you "believe" this? There is no evidence whatsoever for the "kaneda effect".

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Yes, it is awful.

 

blobrana. I've seen no evidence that anything can move at FTL speeds.

 

2Inquisitive. It is difficult to post when world war three is going on in the background, with dozens of Thai kids playing shoot-em-ups in internet cafes.

Space expanding we are told can stretch the frequency of light waves. From memory the figure is about 27 k/s per million light years. What's that? About the gravitational force of a dust mote on EMR? Why isn't light stongly red shifted when escaping from Earth?

There is no actual motion in the objects.

 

And just what makes you so sure that it isn't when viewed from a billion light years away?

 

superluminal. I think we are going to have to agree to disagree on space beyond what we can see and so only theorise about.

If we run the clock backwards, matter everywhere will have less space between it and whole galaxies will become super-massive black holes, and these will join with each other till we are left with a single SM BH which I would think would be stable (is there an upper limit on BH's?).

I can't really agree on this "units of space".

The BB expansion needs a 4D expansion as a 3D expansion does not work. But then you have to explain the hyperspehere away.

You talk of space stretching and so making light red shift. How does it endlessly stretch from point source (or whatever) to what it is today (maybe over a hundred billion light years across)? How can space "stretch"?

A trillion interactions on the way to Earth just might affect a photon? We know photons can be absorbed and emitted. Though very tiny and without charge (even more so than neutrinos), I would think they can suffer actual impacts over time. It sounds better to me than saying a comparatively non-existant stretching of space can somehow affect them. One second. That's a million light years of space stretched to one million light years and 27 metres. That is really going to have a lot of effect on a photon. Not.

Almost 6pm. I have to rush off now and see if they have fixed my laptop since it was not the hard drive as originally thought.

 

That's perfectly reasonable.

All I can say is that that's not what the hot big bang model predicts. Other than that, I'm tapped out on that aspect.

Fair enough.

I don't think that's the case. Unless someone has a reference that describes this?

That's just the thing. The model requires it, the model is currently fairly well supported by observational evidence, therefore we accept the 'expanding space' concept, until something radical changes it. Other than that, How can space "stretch"? I have not one fucking clue bub.

Well, again, we have no physics that hints that photons can redshift by interactions in the way you describe. Therefore, the redshift is explained as cosmological in origin. Can't really discuss much more than that, since I'd need to see some evidence that a radical new mechanism for redshift was present.

 

Hum,
Yeah,
what i meant was that the main stream view is that there is there is nothing to govern the speed limit for the expansion of time/space...(not `stuff` in space time)...
One piece of evidence come from the smoothness of the CBR; which is best explained by something like Superinflation, which expanded the size of the universe faster than light-speed. According to the simple bigbang model , this connected parts of the universe which could not possibly have had enough time (13 .7 billon years) to `communicate`.
(Because objects and `things` in that space time are limited by the velocity of light, etc).

 

superluminal. A photon always travels at a set speed. If something causes it to lose energy, like coming out of a gravity well, then it loses energy by red shifting since it cannot slow down. Possibly the wrong explanation but I think of it as that as it is losing energy, so it will lose frequency (vibrate slower for want of a better explanation). This gives it a longer wavelength as frequency and wavelength are proportional, so it is red shifted.

I prefer to think that maybe a trillion collisions/interactions over a billion light years causes a photon to lose energy, so red shifts them.

As to space, I think it is a material of some kind that we cannot at present recognise and the structure determines the speed of light, etc. I don't think space can stretch because it would affect so many other things if it could become (for want of a better term) "less dense". But I don't know either. Maybe more of it can be made, endlessly, that while this process is going on, there is a counter-process going on elsewhere that we also don't know about?

 

blobrana. Yes, that's inflation. However not as smooth as some claim. What I couldn't understand recently was that hot and cold spots in the early universe/the CMB were said to be proof of this when I thought their non-uniformity was the opposite.

 

But photons can slow down... They can even be stopped. It has been done...

 

Yes. You are correct.

Ok. Lets talk about this then. It is estimated that the average density of matter in the universe is 1 hydrogen atom per cubic meter. Now, this would place about 10^25 H atoms in a 1m square path over a billion light years. Lets's assume that most of this is ionized, i.e. just a proton.

First thing:

Blue light has a wavelength of ~450nm while a proton has a diameter of roughly 0.000001nm. Visible light will not interact with the interstellar medium in any significant way.

Second thing:

If it did interact (somehow, maybe the hydrogen is neutral? Or it's something else?), the odds of a given photon interacting with a lone hydrogen nuclei are small. Let's say that a photon interacted with some of them, say a few trillion, as you say. Well, as a photon passes through a 1 m block of glass, it encounters and interacts with trillions of silica atoms. No redshift.

So, you may prefer to think that particle interactions cause redshifting, but there is no known mechanism for this in physics as we know it. It's fundamental.

You might as well be arguing that wind is not necessecarily the motions of air molecules, but some other unknown mechanism, jsut because you don't like the air-molecule theory of wind.

I'm not trying to offend here at all. It's just that tossing such a fundamental bit of physics as part of your argument/debate leaves us not much room to do anything.

 

Under very special circumstances. This usually (!) dosen't happen in the universe at large.

 

You are correct.

The thing to keep in mind here is what takes place when a photon IS absorbed.

It kicks an electron to a higher energy level. And when the electron falls back down it emits another photon that contains the exact amount of energy that was contained in the original photon. There is no loss of energy and no change in wavelength/frequency. Therefore, no red shift or any other change.

 

Well, an atom can absorb a photon of a given wavelength and emit a photon of a different wavelength. This is called fluorescence. The rest of the energy goes into heating up the material.

But that's not redshift.

 

That is correct. But I was specificially addressing his idea of "tired light" and resticting what I said to the absorbtion and re-emitting of light of the same frequency. It doesn't reappear as slightly shifted down or up in frequency. A great deal of visible light is also absorbed and discharged in the IR bands - simple heat.

 

Yep.

 

Since I think space is responsible for the fact that no matter can move at light speed and that all EMR and gravity travels at light speed, I think that tells us that space itself is only capable of moving at light speed and no faster.