Big Bang

[Lord Of The Dragons]

The problem here is that string theory is not accepted by all physicsts, in fact far from it. Actually it isn't even a theory, more of a hypothesis. String theory is a nice attempt to unify the forces of nature and subatomic particles into one theory. However there is currently very little evidence to show whether string theory is correct. Even more problematically there are multiple (and sometimes mutually exclusive) interpretations of string theory. String theory requires more than the three spatial dimensions we are used to. The string theorists argue about how many are required and how they exist.

Then we have brane theory. This is an off shot of string theory. It is fairly new and is not yet widely accepted even by string theorists. It really is just a hypothesis with no evidence to support it... yet.

This at one of the cutting edges of physics. Brane theory and even string theory itself may become accepted or discarded in the next few years. Either way mankind's knowledge will have increased as a result.

I would disagree with what you said about String Theory being just a hypothesis. I think String Theory is as relevant a theory as Relativity was when it was in its infancy. And yes, String Theory is, basically, still in its infancy, especially compared to Relativity and Quantum mechanics. You also have to remember that String Theory was considered dead at one point and was hardly even thought of during the 70s, it wasn't until mid-way through the 80s that it was taken up again as a viable theory and there has been many significant advancements made in it in the years since then.

True, for String Theory to work properly, it has to exist in many dimensions and most of these dimensions are much smaller than the Planck length and, therefore, almost impossible to prove. However, taking these dimensions as a given, String Theory works remarkably well when applied to models of the universe. That's why it is still the best option as a grand unification theory to date imo.

[Waspie_Dwarf]

No, string theory has been unified, I believe it is called M theory.

I do not claim to be any kind of expert on the subject, but it is my understanding is that M theory is a branch of string theory which would unify them if correct. However, yet again, it is highly hypothetical. As there is no empirical evidence to support string theory there can, logically, be no empirical evidence to support M theory.

All theories are just models which rely on their predictive capacity and or / consistency with known observations as validity.

This is true but string theory has not yet reached that level, it remains purely hypothetical, a mathematical possibility but not yet backed up by observations in the same way that Relativity or Quantum Mechanics are. These have both been tested experimentally. The theories make specific predictions when where then tested and the results found to be excellent fits, Sting Theory has not been tested in the same way, that is why I believe it is only a working hypothesis and not yet theory. One day string theory may be experimentally verified, but not yet.

Do we know if the electrons are really spinning in electron spin ?.

Do we know if there are really quarks inside subatomic particles ?.

Do we know if a one legged duck really swims in a circle?.

I'm not sure about the duck, but the other two were predicted and then experimentally verified. We can take this discussion down to the philosophical level, do we really know that anything exists, but then it would no longer suitable for the science board. From a scientific point of view though the Standard Model has been tested time and time again and the experiments appear to confirm it. This is not true of string theory.

I advocate acceptance of M theory until it is either disproved by malprediction of violation of previously accepted facts.

Up until here you were making good scientific sense, sadly you ruined it with this one sentence. Science should never EVER be in the business of accepting as fact something for which there is little or no supporting evidence, that is the realm of superstition and religion. IM theory should neither be accepted nor rejected until such time as there is good evidence to make such a decision. It should be treated as what it is a hypothesis... a good but unproven working model.

If science cannot be wrong, if we can't change our minds, if we just dogmatically accept something as forever and eternally true irregardless of new insight and evidence , If we malign and mistreat everyone that does not share our opinion, then we would have to change our name to Religion.

I agree with you on this point (and have made this very same point many times on this science forum), but it also holds true that if we dogmatically accept a hypothesis arbitrarily, as you seem to have done above, we risk going down the same route. Acceptance of a hypothesis must be on the weight of evidence. If there is no evidence there can be no acceptance however good the hypothesis looks on paper.

I have no problem with string theory, my posts should in no way be considered an attack on it. My point is simply that it remains purely hypothetical and should not be considered fact... yet.

[--Mandalore--]

I have a question and maybe somebody can help me with it. I read in a high school textbook today(I collect them btw) and it said that when all the matter came together that it started spinning and exploded thus the Big Bang, the question I have is if this "infintesimile region" was spinning in one direction wouldn't all the galaxies, planets, etc. be spinning in the same direction? Thanks.

[Torgo]

I have a question and maybe somebody can help me with it. I read in a high school textbook today(I collect them btw) and it said that when all the matter came together that it started spinning and exploded thus the Big Bang, the question I have is if this "infintesimile region" was spinning in one direction wouldn't all the galaxies, planets, etc. be spinning in the same direction? Thanks.

Your textbook is wrong.

People (including the people who write the often oversimplified textbooks) have an odd conception that the big bang was directly responsible for every detail in the uinverse. As near as we can tell, what ACTUALLY happened is that the furthest back we can see (the microwave background radiation) the primordial gas was very nearly uniform with only small density differences. These lead large clouds to collapse into the filament-of-galaxies and void structure we see in the universe as a whole. As clouds collapsed further, you got places becoming dense enough for star formation. Depending on the details of that collapse you got galaxies with a lot of spin (spirals) or not much spin (ellipticals) and spin in all different directions. Within all these galaxies, the forces causing smaller clouds to collapse into stars and stellar systems are FAR stronger influences on the eventual orientation of the stars and planets than the galactic spin. Its basically chaotic stochastic steps all along the way causing all these things, not some kind of overall angular momentum of the universe.

Edited April 29, 2008 by Torgo

[--Mandalore--]

Your textbook is wrong.

People (including the people who write the often oversimplified textbooks) have an odd conception that the big bang was directly responsible for every detail in the uinverse. As near as we can tell, what ACTUALLY happened is that the furthest back we can see (the microwave background radiation) the primordial gas was very nearly uniform with only small density differences. These lead large clouds to collapse into the filament-of-galaxies and void structure we see in the universe as a whole. As clouds collapsed further, you got places becoming dense enough for star formation. Depending on the details of that collapse you got galaxies with a lot of spin (spirals) or not much spin (ellipticals) and spin in all different directions. Within all these galaxies, the forces causing smaller clouds to collapse into stars and stellar systems are FAR stronger influences on the eventual orientation of the stars and planets than the galactic spin. Its basically chaotic stochastic steps all along the way causing all these things, not some kind of overall angular momentum of the universe.

Thanks, I don't believe in the Big Bang, but I do like to study up on the subject of evolution and the Big Bang.

[laveticus666]

All anybody can do is guess. There simply no way of knowing anything at all that was before our universe. This is all we have. All our knowledge comes ffrom what we observe in our universe. Theres just no way to know anything about the physics or conditions of what was before. It would have completely no dimenstions. Thats impossible to even imagine.

Edited May 5, 2008 by laveticus666

[Admiral Danger]

family guy's version of it was really funny

god beat this guy at chess and he was farting and he uses a light next to his bottom then he farted and then the galaxies were created. but as we know thats not true but i still dont have a clue about how the big bang started. the next big question is what came before the universe became a super atom and how were the elements created =S

[turbonium]

MID what about the post 10, could it be we are all but a small atom sized event happening all inside a universe of atoms ?

Ah, yes....I believe that is the "Horton Hears A Who" theory, proposed by Dr. Seuss!!