Misconceptions about the Big Bang

Scientific American ^ | March 2005 | Charles H. Lineweaver and Tamara M. Davis

[furball4paws]

FOG Index.

There are two generally recognized FOG indices.

FOG1 is defined as the number of syllables divided by the number of words. Because of the large number of Anglo-Saxon monosyllables in English, a FOG1 index greater than 2 is thick. Scientists have high FOG1 indices, since the scientific style is designed to stuff as much crap into as few words as possible and there is a penchant for all those Latinized (and Greekized) words.

FOG2 is defined as the number of words divided by the number of significant thoughts in the verbage. Scientists have very low FOG2 indices because of the aforementioned scientific style. However, Deans and University Presidents have very high FOG2 indices. The FOG2 indices of politicians is undefined since dividing by zero is not allowed.

:^))

[NavyCanDo]

My favorite Big Band was Glenn Miller with Benny Goodman coming in a close 2nd. And don't forget Tommy Dorsey and Les Brown, Duke Ellington, and boy could that Harry James play a hard-singing riff.
Wait a minute - your talking "BIG BANG"?

Ahhhhhh NEVERMIND

[furball4paws]

PH - thank you for this ping. I liked it very much.

[Ichneumon]

Question: why aren't there greater consequences than the appearance of the light from these objects? Why is this motion, relative to ours, immune from the effects of special relativity?

Click on the link and read the whole article at Scientific American (and view all the sidebars, that's where most of the graphics are).

This article covers all those issues and more, and does it *very* well.

The short form is that while the distant galaxies are *separating* from us at over the speed of light, they are not *traveling* at/beyond the speed of light. "Travel" is velocity *through* space-time. But those galaxies are actually "sitting still" while space-time *itself* expands and just "carries" the galaxies with it. And Einstein's laws don't place a limit on the (relative) expansion velocity of space-time, only on the speeds of things *in* it.

For an analogy, consider a rubber sheet which has objects on it, and the rubber sheet has a high friction coefficient, so things on the sheet can't travel more than a certain speed across it because friction-based drag slows them to a crawl. But there's no limit on how fast the sheet *itself* can be stretched, separating the objects resting on it by any arbitrary velocity.

Here's one of the relevant sidebars -- the text of the article itself explains it in more detail:

And here's part of the relevant text from the body of the article (although it's best to read the whole article to get a real feel for all the interrelationships):

Notice that, according to Hubble's law, the universe does not expand at a single speed. Some galaxies recede from us at 1,000 kilometers per second, others (those twice as distant) at 2,000 km/s, and so on. In fact, Hubble's law predicts that galaxies beyond a certain distance, known as the Hubble distance, recede faster than the speed of light. For the measured value of the Hubble constant, this distance is about 14 billion light-years.

Does this prediction of faster-than-light galaxies mean that Hubble's law is wrong? Doesn't Einstein's special theory of relativity say that nothing can have a velocity exceeding that of light? This question has confused generations of students. The solution is that special relativity applies only to "normal" velocities--motion through space. The velocity in Hubble's law is a recession velocity caused by the expansion of space, not a motion through space. It is a general relativistic effect and is not bound by the special relativistic limit. Having a recession velocity greater than the speed of light does not violate special relativity. It is still true that nothing ever overtakes a light beam.

Another surprising result of this is that we can still "see" galaxies which are receding from us at well over the speed of light. One would think that the Hubble limit (the edge of the "observable universe" from where we are) would be at the point where galaxies are receding from us at the speed of light, but it's actually well *beyond* that. Again, the article explains all this in easily understandable terms if you read the whole thing.

It's well worth the time. I read it yesterday standing at the magazine rack while waiting for a prescription to be filled, and I'm glad someone posted it already -- I'd have done so myself otherwise, it's *that* good.

[PatrickHenry]

I think this means that things we can see now are going to wink out of sight as the universe expandes and ages. We will actually see things appear to recede from us and leave us alone in the dark. Makes me not want to stick around.

We'll always have the Local Group of galaxies. Just as Rick and Elsa will always have Paris.

[PatrickHenry]

The article says:
The solution is that special relativity applies only to "normal" velocities--motion through space. The velocity in Hubble's law is a recession velocity caused by the expansion of space, not a motion through space. It is a general relativistic effect and is not bound by the special relativistic limit. Having a recession velocity greater than the speed of light does not violate special relativity. It is still true that nothing ever overtakes a light beam.

Yes, I read that before I posted my question. I understand that it's due to the expansion of space. Still, those galaxies are moving (so to speak) faster than lightspeed with respect to us. Shouldn't their mass be rather ... large?

I understand that we're moving at that speed relative to them, and I assume we don't notice such a crushing mass because, locally, we're in free fall, so we wouldn't notice it. Nor would they, locally. But we should notice it as to them, and vice versa. Or so it seems to my limited understanding.

[Old Professer]

You mean it is Turtles all the way down?

[VadeRetro]

And Finch and Stifler's Mom will always have the pool table. (Sniff!) Thanks.

[TigersEye]

Even if you were correct -- and from what I know of biology, you aren't, ...

You don't know much about biology then.

Hint for the science-impaired: The "simplest one-celled organism" as we know it today is a *result* of evolution, not the *starting point* of it.

Life started with an organism of less than one cell? One fifth? One twentieth maybe?

[TigersEye]

...that still would make your comment a complete non sequitur to the material you were allegedly "responding" to.

[Like Darwinian evolution, cosmic expansion provides the context within which simple structures form and develop over time into complex structures. Without evolution and expansion, modern biology and cosmology make little sense.]

So, I say multi-cellular organisms are more complex in their basic design than the evolved mechanisms of multi-cellular organisms in comparison, yet that is non-sequitur to the statement "...the context within which simple structures form and develop over time into complex structures?" That's not logical.

The "simplest one-celled organism" as we know it today is a *result* of evolution, not the *starting point* of it.

What example, artifactual, experimental or theoretical, do you have of a one-celled organism that is more simple than the simplest known one-celled organism? Without one your refutation is empty.

[furball4paws]

"What example, artifactual, experimental or theoretical, do you have of a one-celled organism that is more simple than the simplest known one-celled organism? Without one your refutation is empty."

Because we have had 3.6-3.8 billion years of evolution. Evolutionary processes have touched all organisms, including single celled ones. Basically our Ichneumonoid friend is telling you that just because there is no 3.8 billion year old microbe in existence today and I can't show it to you under my microscope, doesn't mean that there never was one.

[TigersEye]

So you believe, on faith, that there must have been a simpler one-celled organism than exists today? You have no proof in any form. I don't believe things on faith.

[furball4paws]

No one said anything about faith. We have 3.6-3.8 billion year old fossil microbes. They existed - no faith. The fact that they no longer exist does not make them less real, just as the fact that Tyrannosaurus no longer exists makes it any less real. I also understand evolutionary processes and a 3.5 billion year old bug wouldn't stand a chance in today's more highly evolved and more highly competitive environments. Not to mention that the environments of today are much changed from those of 3.5 billion years ago.

Since we don't know the details of a 3.5 billion year old bug, your point as to the complexity of single celled bugs is meaningless. You may be right, but IMHO you are most likely wrong.

[longshadow]

Still, those galaxies are moving...

No; the galaxies are just sitting there minding their business; it's the expansion of the intervening space (between the distant galaxies and us) that creates the sense of movement.

Think of it this way; if no force acts on the mass in the galaxies, it's velocity hasn't changed, and thus there are no associated Special Relativistic effects, e.g. the effective mass of the galaxy doesn't get larger.

The relativistic effects that we DO see (redshift) are, as the article points out, due to General, not Special, Relativity, and are a consequence of the spatial expansion.

[doc30]

As in the Hindu (I think) description of the universe? Maybe it could be that strange.

[TigersEye]

...but IMHO you are most likely wrong

So it is on faith. As I said, you have no proof.

What you are telling me is beside the point anyway. Evolution theory is based on the proposed increase in complexity of known organisms over time as evidenced by the fossil record. Yet the most advanced multi-celled org. known is far less complex in its additional design than the basics of cellular biology.

It seems counterintuitive to the "simple to complex" view that the latest designs contain nothing in them, structurally or functionally, that comes anywhere near the fantastic complexity of basic cellular function.

[TigerTale]

See post 34

Thanks. I've perused that page before, but to my untrained brain, it does not appear to explain the nature of the vacuum energy.

I apprehend that the Heisenberg Uncertainty Principle predicts fluctuations in the energy of a vacuum, even though the energy averages out to zero. Otherwise the vacuum energy would certainly be zero at all times, and this is not allowed by the HUP. Did I get that right?

Causality still seems to be a problem--what causes the virtual pairs to come into existance? Or, if the answer to this question is "a vacuum fluctuation," then what causes the fluctuation?

Does the energy of a vacuum consist entirely in the virtual particles, or does it consist in the vacuum's other attributes--such as the space the vacuum occupies? Space is a real "thing," isn't it? If space exists, then it would not seem proper to call the vacuum "nothing."

I believe I read or heard that energy can be contained in the curvature of space. Is this correct? Does the vacuum energy come from the curvature of the entire universe? Does the vacuum near a massive object contain more energy than the vacuum in inter-galactic space?

I hope I haven't pestered you with too many questions. Anyone who wishes to answer, feel free.

[PatrickHenry]

No; the galaxies are just sitting there minding their business; it's the expansion of the intervening space (between the distant galaxies and us) that creates the sense of movement.

Grumble, grumble ... maybe, but I donno. God not only doesn't play dice, he doesn't toss Frisbees either.

[stremba]

DISCLAIMER: I am not a physicist, so any of the following may not be entirely correct:
Vacuum energy is a result of the Heisneburg Uncertainty Principle. According to this principle, the energy of the vacuum can assume a nonzero level for some short amount of time, the amount of time depending on the amount by which the energy differs from zero, the more energy, the shorter the time. The end result is that a particle-antiparticle pair can form so long as they annihilate each other within some short time span. (I still fail to understand why we don't see gamma rays formed by this process. I understand that the energy must return to zero, but what happens to the gamma rays formed in a p-ap annihilation?)

As far as causality goes, it may seem counterintuitive, but quantum mechanics has shown that the idea of causality may not be particularly useful in describing the microscopic world. For example, in a sample of radioactive material, we can predict pretty precisely how many decay events will occur in a given time. However we cannot predict the amount of time that will pass before a GIVEN radioactive atom will decay. What is the cause that causes that atom to decay at the time it does and not some earlier or later time? There doesn't appear to be any causality behind such microscopic events.

As far as whether or not space is really a "something" and whether the curvature of space can contain energy, general relativity sure seems to me to treat space-time as a thing. It speaks of the curvature of space-time and postulates that gravity is caused by this curvature. Since there is energy associated with gravity, there is also energy associated with curvature of space-time. If I understand it correctly, that's one of the problems with a quantum theory of gravity. It would have gravitational interactions occurring via exchange of particles known as gravitons. However, the graviton, which would be a quantum of space curvature, would have an energy associated with it. This energy would tend to cause further curvature, according to GR. This would result in more gravitons and further curvature. This leads to the prediction of infinite energies from a quantum gravitational theory, which clearly is problematic for a theory in physics. Hopefully this helps some, and I of course am anxiously waiting for some of the resident physics experts to tear what I've said apart.

[TigerTale]

The end result is that a particle-antiparticle pair can form so long as they annihilate each other within some short time span.

Thank you for your reply.

So, does the vacuum energy consist entirely in the particle-antiparticle pairs? In other words, is the energy of a given volume of vacuum zero when there are no pairs present in that volume? Or are the paricle-antiparticle pairs the result of a non-zero energy state which subsequently manifests itself as virtual particles? Can the energy volume of a vacuum be non-zero when no virtual particles are present?