State of the Big Bang Theory - part 1

Hi S, good summary of Guth!

A few points where Guth is (necessarily, due to its date) out of date:

"The initial 'seed' weighed about an ounce (25 grams), and had a diameter more that a billion times smaller than a proton."

It is today accepted that the universe at large could be "flat", meaning it could have started out infinitely large, with infinite density. One can perhaps reconcile Guth's one ounce with the original seed of our present observable universe.

"If the mass density exceeds a critical value (that can be calculated from the expansion rate) then gravity will win out and the expansion will reverse and we will have the 'big crunch.' This is called a closed universe."

The accelerating expansion discovered around the publication time of the Guth book (that you quoted) threw this definition somewhat out of the window. One can now have a closed universe that expands forever, with a sort of 'mini-inflation' happening presently.

"At 300,000 years after the BB, the universe was transparent to light, allowing the Cosmic Background Explorer (COBE) to look around. The photons of the cosmic background radiation have been traveling in a straight line since that time. The horizon distance (the maximum distance that light could have traveled since the beginning of time) was 900,000 light-years."

I don't quite understand this passage. It reads as if light could only have traveled 900,000 light-years in the life of the universe until now! Actually, the CMB light has traveled just over 13 billion light-years since the BB.

I think what is meant is that due to the huge expansion rate at the very beginning (without inflation), only areas that is today 900,000 light-years apart could have interacted by means of radiation in the first 300,000 light-years after the BB. So without inflation, the CMB could not possibly have been so smooth in terms of temperature (as you explained).

My view on the "flatness problem" is that that's exactly what one would expect from nature. The problem is that the direct measurements of matter and other forms of energy do not fit this bill – hence the dark matter and dark energy requirements.

Or, perhaps, a different theory of gravity is required on large scales? Such theories do exist, e.g., MOND, but current evidence seems to point away from them and towards the pesky dark matter and dark energy.

-J

Thanks Jorrie. Actually it's only half my summary of Guth - Part 2 will be the 2nd half. Part of the reason for posting this series is to show how the BB theory is changing over time. I have no good references for older stuff. I showed the copyright date of the book to date this part of the theory and to try to ward off people telling me it was outdated. Part 3 will be a summary of another book dated 2000, and part 4 will be more recent data.

"It is today accepted that the universe at large could be "flat", meaning it could have started out infinitely large, with infinite density"

I would like to discuss this with you, but I think I would like to wait until after I post part 4.

"One can now have a closed universe that expands forever, with a sort of 'mini-inflation' happening presently."

That is what I think we have. It's the only thing that makes sense to me right now.

"I don't quite understand this passage. It reads as if light could only have traveled 900,000 light-years in the life of the universe until now!"

What he is saying is that the horizon distance was 900,000 years when the universe was 300,000 years old, which as you know was when the universe became transparent (BB theory). So when COBE looked at the CMB it was looking at a horizon distance of 900,000 years. I could have added "at that time" to the end of that line to make it more clear.

"So without inflation, the CMB could not possibly have been so smooth in terms of temperature"

I wouldn't say could not possibly. It's just that the classical BB theory has no explanation. I think there could be a better explanation than inflation for this.

First there was nothing, then it exploded!!!?

Even with all the "scientific justification" that tries to pass for an answer, it just doesn't make sense to me.

Hi checker33,

"First there was nothing, then it exploded!!!?"

Some versions start with nothing, but most with a small 'seed' of very dense matter which is far different than nothing. An explosion is a good description of very fast expansion. Reference the parable of the mustard seed in the Bible and my tag line.

regards,

S

StandardsGuy,

I'm very familiar with the parable of the mustard seed. But, this talking about any seed at all, concerning the Big Bang theory, is moot unless someone can figure out where that "seed" came from - it didn't come from nothing!!

Blessings,

33

prior to all the described activities and....maybe in spite of them ....it is still the

definition of nothing that is the bugaboo...maybe nothing does not exist....and never

has....but that's not logical.... is it...captain.

Why did the universe expand?

What was the trigger event?

Why did it have mass or volume at all?

These and many more unaswered questions?

The 'Big Bang' makes as much sense as the 'Flat Earth' (elephant, tortoise, etc.). That's not to say it didn't happen but to consider it the beginning of everything including time of all things (especially since time is such a local phenomena) borders on ludicrous.

This is not the only universe (but then the rest of them were not put there as 'parallel' universes either for the sake of 'free will' or to justify quantum theory).

Part 2, Part 3 and Part 4?

No Thanks!

Personally, I'm very curious what hoops the "scientific community" has gone through to try to justify their Big Bang Theory - I say "Bring on parts 2, 3, & 4!" Let's see what they've got!

Then why are you here? Why are you anywhere? Maybe you're nowhere. Maybe you're in the center of your visible universe (like the rest of us).

I've no doubt you'll cover this in due course, but every whoop (stet) that has been seen as "total supporting" the big bang theories has ultimately required a huge modifying term in order to keep it in place. For example, BB (not guns for burglars) includes the creation and destruction of energy during the expansion phase, and now requires both unidentified dark energy and dark matter to balance the books - these being problems that were originally major "nails in the coffin" of steady state theories. When the KOBE results first appeared, one of the principle results that was stated to support expansion theory was the fine directional structure of the radiation - but (at least to the uninitiated) the amounts of dark matter now being postulated would seem about right to cause these ripples. Similarly, it would seem that a low level of re-emission would be sufficient to provide a uniformity of radiation very similar to that observed by KOBE; and it would be perfectly possible for re-emission to match the black body spectrum to a level that is at least as close as measured by KOBE - even without postulating any strange properties for dark matter.

Don't get me wrong - I'm not pushing any particular theory*. I'm just expressing the feeling that it seems as if the vast bulk of funding is going to the BB models, when they are all suffering from precisely the problems that were thought to demolish the steady-staters. And, so long as no theory satisfactorily fits all the observations and predicts otherwise surprising ones, I regard a bit of competition as a great way to stimulate imaginations. (BTW, I take a similar view of string theory - where it seems to be a case of "if you put in enough variables, you can match any measurement you like").

My suspicion is that what is needed is a set of "new" constraints that will push everything into place - an equivalent to "the speed of light is the same for all inertial observers" and "gravitation being indistinguishable from acceleration" that drove what I regard as the last round of major theoretical progress. (Presumably if and when it emerges, it'll come from another young whipper-snapper)

*I'm nowhere near knowledgeable enough in these areas to even begin...

I look forward to parts 2-4...

Fyz

Hi Physicist?,

"I regard a bit of competition as a great way to stimulate imaginations."

How true, and that is why I post discussions like this.

Regards

S

This is really hard to grasp at times, but I do enjoy the effort to explain what the shape of an ice cube was from the melted puddle.

Are there not several more dimensions required (11 maybe) for the BB to worK? If so an attempt to explain an 11 dimension event with 4 dimension analogies might be a little tough. Can't wait for parts 2-4

Hi Yani,

"Are there not several more dimensions required (11 maybe) for the BB to worK?"

What I have heard of string theory is that there are 10 dimensions total. Stephen Weinberg called it philosophy and not science. I tend to agree because it can never be proven wrong, and little chance of proving it right!

Regards,

S

Theories are constantly changing and new theories are being invented in an attempt to explain everything without God. Where did the seed come from and how did life come from dead matter?

You either start with the one who is self existing, who exists outside of time and space, who always existed or you start with nothing.

If you want to leave God out of the theories then you must start with absolutely nothing not a very small seed.

Anything that STARTS to exist must have a CAUSE.

As Occam's Law states the fewer assumptions the more likely it is to be correct.

Occam's razor, also known as the law of parsimony, or the law of simplicity is often quoted in stronger forms as in the following statements...

"If you have two theories which both explain the observed facts then you should use the simplest until more evidence comes along"

"The simplest explanation for some phenomenon is more likely to be accurate than more complicated explanations."

"If you have two equally likely solutions to a problem, pick the simplest."

"The explanation requiring the fewest assumptions is most likely to be correct."

... or in the only form which takes its own advice...
"Keep things simple!"

Unfortunately, the addition of God does not add anything to accurate physics-based predictions. That has no bearing on God's existence - just that none of the "revealed" versions of God has any bearing on this particular study. Occam was right - bringing God into physics is merely an irrelevant distraction. (For what it is worth, the only time Einstein brought what he saw as God into the frame, it was to reject Quantum Mechanics, which is the best predictor of small-scale effects available to us).

Fyz

____________________________
"As simple as possible, and no simpler"

Hi Fyz, on your referring to Einstein: "... the only time Einstein brought what he saw as God into the frame, it was to reject Quantum Mechanics, ..."

I particularly like the exchange between Einstein and Bohr, where Einstein reportedly stated: "God does not not play dice with the Universe", whereupon Bohr replied: "stop telling God what he should do..."!

I feel that Einstein's "Old One" is chuckling at our feeble attempts to understand His works, but that He has given us this curiosity to at least try...

-J

That indeed was my reference. I rather suspect that Einstein may have sometimes quoted this himself.

Fyz

I believe it's a matter of time before someone proves:

A. It is a mathematical impossibility for the universe(s) to not exist.

B. There is a God.

C. They are the same thing.

(I vote for A)

I'm sure you can prove any or all of these things if you start from the "correct" axioms (assumptions). That doesn't mean that the proofs prove anything.

The first one, of course, is just common logic: based on the definition of the universe as everything that exists, the existence of mathematics implies the existence of the universe. However, as philosophers can still argue about the existence of mathematics it just changes the reference point for a futile discussion.

Fyz

N.B. So far as I am aware, there is no such thing as a "mathematical impossibility". If you can describe something, you can define a set of conditions under which it becomes possible or even necessary. There are significant branches of mathematics that are concerned with how much you can deduce without what are generally regarded as "basic principles of logic". For example, there is an interesting branch of logic in which "not untrue" does not necessarily mean "true". On a more utilitarian note, the idea that objects without separate identities do not follow the same statistics as objects with identity might seem a pure hypothetical mathematical construct - until you examine the behaviour of bosons.

First, I absolutely do not believe that energy cannot be created or destroyed. Just because mankind cannot do it or see it or even figure it out, doesn't mean it can't happen. Not only do I think it can happen, I think it does happen and is constantly happening, on a gigantic scale! In the scheme of intelligence of the universe, mankinds IQ is still less than 1.

Second, although there may have been a "big bang" in our neighborhood of the universe 13.7 billion years ago, and possibly even our own galaxy exploding, it certainly did NOT create the universe! The universe was then and is still now "being created". It is growing, living, dying and being reborn...forever.

The universe will not "crunch". It is creating it's own energy to continue growing.

Einstien was right. Everything is predictable, but just not by mankind.

There is a very simple answer that explains absolutely everything.

sorry I forgot to log in

DavidARheault

Hi David,

It's good to see you're still alive. Your post is very confused. I agree with some of it. Let me elaborate. My original statement about the law of conservation of energy has been in thousands or physics text book for years. It is now being refuted by modern big bang theory which you claim you don't believe in.

Setting that aside, it's a law "of this universe". Assuming for a minute that God created this universe from within a larger one, He would not have the restriction of that law - in fact He would have created that law for this universe.

"big bang...certainly did NOT create the universe! The universe was then and is still now "being created".

The word then from your quote seems to refer to the big bang, but it did not create the universe? When was then, then? The universe still being created is what my tag line is all about.

"It is growing, living, dying and being reborn...forever. The universe will not "crunch".

Here is a contradiction. If it doesn't "crunch", it doesn't die or get reborn.

"Everything is predictable, but just not by mankind. There is a very simple answer that explains absolutely everything."

Another contradiction. If mankind can't predict, then there will be no simple answer. You need to figure out what your beliefs are before you try to state them.

Regards,

S

Hi S

I'm curious about your avatar - is that a plater or a dewar or a whatsit (the picture is so small I can't tell - must be getting old)

Fyz

I also wondered about 33's avatar. My guess is that it's a F15 or similar, flying at high angle of attack in extremely cold, moist air. Or what?

-J

Jorrie,

You were close, it's an F-14 Tomcat.

Still waiting on Part 2!

Have a good day,

33

Part 2 has been posted. I thought it would come out last night, but it didn't. You don't have to wait for it on the list; you can go to the general forum and search for it. How far apart do you want the others?

S

Hi Fyz,

It's a helium dewar, as part of a Josephson Junction voltage standard.

S

Thanks. I believe that frequency and length are effectively defined w.r.t. a Caesium transition. I'm probably aeons out of date, but I believe that currently leaves mass relying on an historic standard. I would imagine that the Josephson Voltage standard could fill that gap - at least in principle; however, I've heard proposals for introducing a number of other standards as the primary reference for mass. I take it that this means the Josephson standard will remain as a secondary standard, with the Josephson constant subject to change. Would you care to comment on this - or even to introduce a new thread on the topic of standards?

Regards

Fyz

Hi Fyz,

I'm not very current on the current SI definitions. They have changed at times i.e. which units are defined by other units. The Josephson Junction (JJ) is considered an intrinsic standard, which is better than a primary standard for a calibration lab because it needs not be sent to NIST for calibration. NIST on occasion has been part of a 'round robin' to compare the several labs that own JJs to establish an uncertainty for their use. The constant that you mention could conceivably change. I will consider a thread for the JJ. Good suggestion.

Regards,

S

If we work on the suggested scale, where mankind's IQ is less than 1, the laws of physics could indeed be very simple and yet not understood by us.

However, the complexity also depends on what you mean by 'explains absolutely everything'. My suspicion is that any intelligence would want to understand the universe as far as possible; assuming they had once elucidated the laws, they'd wish to know the consequences. On the set-theory basis that a set always has more subsets than it has elements, and that 'understanding' means being able to see how everything of interest interacts, you inevitably need an intelligence out of proportion to what you are observing - so you need to be larger than the universe under study. => not simple to any intelligence contained within the universe.

Fyz

Which would certainly seem to rule out superior artificial intelligence.

StandardsGuy,

So, when can we expect parts 2, 3, & 4? I'm very curious to see where this is headed.

33