"Negative Infinity"

[Uiler]

Isn't that like saying: prior to 1900 asking questions about particles smaller than protons, neutrons and electrons was a waste of time because even if such things existed, they couldn't matter?

Of course they mattered. Protons, neutrons and electrons mattered to atoms which then mattered to how your liver cells were formed which of course matters a lot to every human being pre-1900.

What people talk about about with respect to nothing "before" the Big Bang mattering is simply that. It can have no effect on anything whether we know about it or not. To put it another way, there is no cause and effect between anything "before" the big bang and anything after even if you allow for infinite time.

Of course this is just with the current standard Big Bang theory.

 

[Birdjaguar]

Of course they mattered. Protons, neutrons and electrons mattered to atoms which then mattered to how your liver cells were formed which of course matters a lot to every human being pre-1900.

What people talk about about with respect to nothing "before" the Big Bang mattering is simply that. It can have no effect on anything whether we know about it or not. To put it another way, there is no cause and effect between anything "before" the big bang and anything after even if you allow for infinite time.

I would have put it: If there is/was any effect of a pre big bang state on our universe, our current science is unable to explain what it might be.

 

[The Last Conformist]

I would have put it: If there is/was any effect of a pre big bang state on our universe, our current science is unable to explain what it might be.

That's why you aren't the physicist.

 

[C~G]

That's why you aren't the physicist.

So physicists can make with all their current scientific knowledge hypothetical scenarios about what ifs and what nots before the big bang but others cannot?

Are the physicists considered now by some as priests interpreting the God known as universum now or what?
Then I think we need new Luther for some reforming work.

 

[Sidhe]

That's why you aren't the physicist.

precisely, physisicists seem to have big ego's, they don't like admitting they don't know every aspect of their theories without at least being trumped by someone with a more specific PhD, or a nobel prize

So physicists can make with all their current scientific knowledge hypothetical scenarios about what ifs and what nots before the big bang but others cannot?

Are the physicists considered now by some as priests interpreting the God known as universum now or what?
Then I think we need new Luther for some reforming work.

When it comes to laymen like me yes they are perfectly entitled to claim whatever they like hoping the average person is too confused by long winded mathematical formulae to ask beyond that point, luckily I tend to ask someone with a PhD to explain it and then point out something in his name. It's very educational.

 

[Elrohir]

Right now, that's an unanswered question. Without the Universe, neither time nor space could exist, and without time or space to exist in, matter and energy could not exist. However, there is no satisfactory answer known right now as to how that could be true. Someday, someone will come with up with something revolutionary like Maxwell's Equations and all will become clear, but right now we don't know.

Technically, there was no hydrogen at the start of the Universe. Everything existed in a super-heated soup of quarks and anti-quarks, leptons and anti-leptons, photons and anti-photons and various other larger particles. The matter outnumbered the anti-matter for some unknown reason, and, as the Universe expanded, things cooled down enough that matter and anti-matter came in contact with each for long enough to cancel each other out. Once all of the anti-matter was gone, then quarks settled down into protons and neutrons, and those in turn became atoms of hydrogen, helium and lithium.

With that aside. Time isn't really separate from the stuff of the Universe. The concept of time has only to due with an object's speed relative to the speed of light. Time moves at a certain speed for those objects at rest that is based on the speed of light, and, as those objects speed up, time slows down for them in order to allow the relative speed of light to remain constant. That's what the Theory of Relativity explains.

It sounds to me like phyicists don't know nearly as much as they pretend. So why all the posturing? Why don't they all just say "We really don't have a clue how the Big Bang happened, or what, if anything, existed before it"? I think they would have a lot more credibility if they did. But I guess they're like every other human being, and can't stand the thought of acknowledging that their knowledge is finite.

 

[Uiler]

Ok so what your saying is essentially the laws of that particular singularity are totally different to the laws of an incredibly large mass condensed into a very small space, often labled as the heart of a blackhole? I'm confused here? So what's the subtle difference, sounds like we could apply the same theoretical principles here?

A singularity is NOT a very large mass condensed into a very small space. It is ANY non-zero mass condensed into ZERO space, well for graviational theories anyway. What people talk about is how dense a mass has to be before gravity is strong enough that there is no known force that can stop it from collapsing to a single point. A point by the way by definition occupies no space.

And yes, singularities, the ones we are talking about here, have nothing to do with Newton's laws. Newtonian singularities and GR singularities are both pathologies. However their physical meanings are completely different. Newtonian space is flat. GR space is curved. In GR the singularity represents where the curvature of space-time is infinitely curved. Newtonian physics has absolutely no concept of this. What a Newtonian singularity is physically? Who knows.

The behaviour close to the singularity then is completely different. In Newtonian physics a black hole of the type we are familiar with would never form because there is no maximum speed. Things like the infrared shift, time dilation seem as objects approach the black hole would not be seen.

Physically Newtonian singularities and GR singularities are completely different things.

Anyway Saying a bubble is all there is and causality is avoided by the singularity is still speculation however you want to look at it, with no more foundation than M theory. That much is self evident.

That's complete rubbish. The whole thing about causality has very good foundations. It is a direct result of applying GR. It can only be wrong if the whole theory of GR is wrong or needs correcting, which is entirely possible. GR may not be complete. But to say that the whole thing about causality is like M theory, which is a superstrring theory and is considered highly speculative and the butt of physics jokes, compared to a widely accepted theory that has strong experimental evidence just goes to show that you like throwing around technical terms without knowing what they mean. GR may NOT be complete but based on current exprimental evidence to put it on the same level as M theory is just plain ridiculous.

To be frank I'm not sure why we need to know or indeed if we ever will? But there you go some people tend to speculate when they see unanswerable questions, leaving unquestionable answers in the place of reason and logic. It's another it just does ok, get used to it. About as satisfying as spilt glass of lemonade on a hot day, at least to anyone who likes to invole himself in more than just established hypothesis.or to put it another way only with QM would hypothesis be accepted as fact.

Well better than trashing scientific theories without even knowing any science.

There is no reason why Newtons laws cannot be applied to particles though and in those laws we see the same infinities we see with Einsteins GR or QM. It just so happens that speculation on what would happen at very small particle differences came before QM.

Here's a clue. In quantum theory, particles are considered as waves. An electron is a wave. Two electrons are two waves. What is the distance between the two? And consider they overlap. Oh, oh, and they are in a quantum superposition. So neither of them have a clearly defined state. Classical mechanics breaks down once the wavelength of the particles is not minute compared to the size of the system i.e. once the wave like nature of the particles becomes important i.e. once quantum mechanics becomes important. For one thing classical mechanics including Newton's laws assumes that you are in a clearly defined state. Quantum mechanics doesn't. Let's say you have a Newtonian graviational well. In classical mechanics it doesn't have enough energy to get out, it's stuck. In quantum mechanics the particle has a non-zero chance of getting out (by this it means if we measure 10000 identical systems there will be a non-zero chance that you will find the atom outside the well in a few of them) even if its energy makes it impossible classically.

 

[Sidhe]

A singularity is NOT a very large mass condensed into a very small space. It is ANY non-zero mass condensed into ZERO space, well for graviational theories anyway. What people talk about is how dense a mass has to be before gravity is strong enough that there is no known force that can stop it from collapsing to a single point. A point by the way by definition occupies no space.

And yes, singularities, the ones we are talking about here, have nothing to do with Newton's laws. Newtonian singularities and GR singularities are both pathologies. However their physical meanings are completely different. Newtonian space is flat. GR space is curved. In GR the singularity represents where the curvature of space-time is infinitely curved. Newtonian physics has absolutely no concept of this. What a Newtonian singularity is physically? Who knows.

The behaviour close to the singularity then is completely different. In Newtonian physics a black hole of the type we are familiar with would never form because there is no maximum speed. Things like the infrared shift, time dilation seem as objects approach the black hole would not be seen.

Physically Newtonian singularities and GR singularities are completely different things.



That's complete rubbish. The whole thing about causality has very good foundations. It is a direct result of applying GR. It can only be wrong if the whole theory of GR is wrong or needs correcting, which is entirely possible. GR may not be complete. But to say that the whole thing about causality is like M theory, which is a superstrring theory and is considered highly speculative and the butt of physics jokes, compared to a widely accepted theory that has strong experimental evidence just goes to show that you like throwing around technical terms without knowing what they mean. GR may NOT be complete but based on current exprimental evidence to put it on the same level as M theory is just plain ridiculous.



Well better than trashing scientific theories without even knowing any science.



Here's a clue. In quantum theory, particles are considered as waves. An electron is a wave. Two electrons are two waves. What is the distance between the two? And consider they overlap. Oh, oh, and they are in a quantum superposition. So neither of them have a clearly defined state. Classical mechanics breaks down once the wavelength of the particles is not minute compared to the size of the system i.e. once the wave like nature of the particles becomes important i.e. once quantum mechanics becomes important. For one thing classical mechanics including Newton's laws assumes that you are in a clearly defined state. Quantum mechanics doesn't.

I know all this, last paragraph in particular, and kindly refrain from patronising me, I was only try to explain where the history of the singularity came from(believe it or not these ideas were bandied around before GR, but without a really good explanation of space/time) They tended to resort to Aether theories which were less controversial than now, it was replaced at that point by a better theory and I'm sorry but I'm not destroying anything, I'm merely saying that it cannot explain what it sets out to ascertain, what there is before the big bang, on this point it is no better than sheer speculation thus it equates to M theory as simply that. I'm sorry you didn't get the point but then you seem to think I was attacking the theory not a specific speculation based on the theory.

 

[Uiler]

It sounds to me like phyicists don't know nearly as much as they pretend. So why all the posturing? Why don't they all just say "We really don't have a clue how the Big Bang happened, or what, if anything, existed before it"? I think they would have a lot more credibility if they did. But I guess they're like every other human being, and can't stand the thought of acknowledging that their knowledge is finite.

Geez. That's what physicists *say*. Scientists are inherently conservative. They tend to couch every statement in case it gets turned against them by their peers. However newspapers and magazines like to sell stories and make up stories where none existed. I've stopped reading most popular science journals (Murdoch ones are pretty bad...) because they suck because of this. They present completely speculative stuff that has no acceptance as "the best thing since GR" and give the impression that everyone in physics thinks its correct when maybe a grand total of 3 people do. It may be correct but let's just say there's a reason why most Nobel Prizes in physics are given at least 20 years after the work is done. Physicists believe in "the test of time and evidence". In fact in the past scientists have been known to committ suicide because of rejection of their work by their peers (the work turned out to be correct later).

Don't blame scientists. Blame the media and those few publicity-seeking scientists. Actually I had a friend once working in experimental physics who was interviewed by a local paper. He was completely shocked by the tone of the article. It was rubbish he said and she twisted his words around entirely.

 

[Birdjaguar]

That's why you aren't the physicist.

Good point, but it does give me the freedom to ask different questions as I "stand on the shoulders of giants".

 

[Uiler]

I would have put it: If there is/was any effect of a pre big bang state on our universe, our current science is unable to explain what it might be.

Yeah, that's about right. So might as well say t=0 is at the Big Bang. Science might change. 200 years in the future who knows what the standard Big Bang theory is. But with current knowledge, that's the best we can do. That's all. Well actually that's not strictly correct. Current science doesn't say "We don't know so it doesn't matter". Current science says, "It has no effect, therefore it doesn't matter." That is even if we *did* know it wouldn't matter and we would still put t=0. Though how would we know about the previous universe if it doesn't have any impact on ours...? Now in the future physics might find a way to show it does have an effect, but I'd like to emphasis this subtle difference between "We don't know so it doesn't matter" and "It has no effect, therefore it doesn't matter." .

 

[Sidhe]

Geez. That's what physicists *say*. Scientists are inherently conservative. They tend to couch every statement in case it gets turned against them by their peers. However newspapers and magazines like to sell stories and make up stories where none existed. I've stopped reading most popular science journals (Murdoch ones are pretty bad...) because they suck because of this. They present completely speculative stuff that has no acceptance as "the best thing since GR" and give the impression that everyone in physics thinks its correct when maybe a grand total of 3 people do. It may be correct but let's just say there's a reason why most Nobel Prizes in physics are given at least 20 years after the work is done. Physicists believe in "the test of time and evidence". In fact in the past scientists have been known to committ suicide because of rejection of their work by their peers (the work turned out to be correct later).

Don't blame scientists. Blame the media and those few publicity-seeking scientists. Actually I had a friend once working in experimental physics who was interviewed by a local paper. He was completely shocked by the tone of the article. It was rubbish he said and she twisted his words around entirely.

It depends many physisicists are wary of making bold statements, but then saying we know what happened before the big band and it's nothing end of story is a pretty bold statement. There is a general trend towards asserting hypothesis based on mathematics, not theory based on evidence, in this case I mean actual direct proof that the theory explains the lack of causality in the big bang. So on the one hand your saying physicists are conservative and on the other they subject themselves to open speculation too?

I do know the "New scientist" phenomina, and no I don't accept fringe theories out of hand, I agree it's important to note that some publications that present theories are rather sensationalist and sometimes tend to bias there "breakthroughs" as accepted when in actuality they are not in any way mainstream.

 

[Souron]

I read an interesting explanation of what was before the big bang according to string theory that goes something like this. It assumes that there is enough mass in the universe for a Big Crunch:

Imagine the universe like the surface of a hose. The long dimension represents one of our everyday very large spatial dimensions. The dimension around the hose represents a small circular dimension about the circumference of the plank length. The universe consists of strings – little loops of different vibrations that we know to be fundamental particles. There are two ways to draw a string on such a hose. One is to draw a loop on the hose, such as you might on any flat plane. The other way is to draw a string that goes around the hose, like a donut. In fact, you could wind the string around the hose multiple times. String theory postulates that both of these string types must exist.

Each of these types of strings can be used to measure distance, but as it turns out, the two types of particles would yield reciprocal results. That is if you measure the distance with wound strings, the distance would be proportional to the radius, whereas the unwound distance would be proportional to the reciprocal of the radius. However the wound particles would have very high energy, and thus be unwieldy for human experiments. Thus all string interactions known to man are interactions of low energy strings.

One of the prerequisites of a Big Crunch is that the large special dimensions are also finite, however. The Big Crunch would then entail gravity shrinking that dimension to a tiny size. Going back to the garden hose analogy, it’s as if the garden hose was attached end to end and the rubber began to shrink along the length of the hose. When the length of the hose becomes small, the universe becomes more tightly packed and there is more energy in the unwound strings. But the wound strings would become wieldy. They would behave exactly like the unwound stings when the hose was long. The universe for them would seem to get larger. Much like the Big Bang!

The conclusion is that a Big Crunch would cause a corresponding Big Bang for these wound particles. And that Big Bang would be indifferent from our big band. In fact, what we think of as unwound particles today could just as easily be looked at as wound particles, although the math would look more complex. The resultant Big Bang would have enough mass to pull the universe ultimately back together into a Big Crunch, starting the cycle all over again.

So there was never a first day.

 

[Uiler]

No, they say, according to current model of the Big Bang and current standard GR blah blah blah blah. They will then say, "Hah, if you assume this however, which is not a standard theory but you know I like to see what happens if we do blah blah blah, this happens." There is no "end of story" as you say. People are actively working on it and have been for decades. Scientists don't like "end of story". Some of them even concern about "mathematical beauty". However modifying GR is not something you can do overnight. And make it accepted by the majority of the scientific community.

Look, the problem lies in the fact that people today are simply not taught science properly. And science as presented in magazines and newspapers suck. Every scientist knows deep down when he says something or someone else says something that there are implicitly 3 pages of disclaimers and PhD thesis length long collection of works about problems with it. If someone makes a too bold statement they pounce. "But, this theory only works if you make the assumption that the energy bandwidth of the wavepacket is much less than the energy gap..." "But you see, we found that even if the bandwidth is blah blah"

However, non-scientists don't carry this deeply embeded list of disclaimers. The way science is taught in school is a list of facts and equations which are set in stone. This could be because most science teachers in school don't understand science and it's easier for them just to get students to regurgitate a list. Maths is worse I think. High school maths teachers don't understand maths.

EDIT: As for evidence, this is the Big Bang. GR has experimental backing and the first thing physicists always do is to try to tackle the problem the simplest way. The whole, "let's assume it's a sphere" thing does have a basis in reality. Why can't you apply GR to the Big Bang? There is no current idea of what exactly the problems are so it's hard to get started. You can't exactly do a lab experiment for cosmology. Experimental evidence is hard and laborous to get. As far as I know none of the experimental evidence so far suggests that a straight application of GR is wrong. This could be more due to the sheer dearth of experimental evidence about the Big Bang - it's a difficult problem, but still, so far with what we know GR works OK. It's just that people really hate singularities. And what's fun about saying it's all over. That's no fun. No good for funding either. Funding does decrease as the decades go by without progress though. Quite simply the standard Big Bang theory is the best that widely accepted science can do and so far experimental evidence backs it and doesn't point out any major problems. But you know the whole situation could easily change. There's not exactly a wealth of experimental evidence in general for cosmology today. Often radical changes in theory occur because of some new advance in experimental physics that make people go, "Wow, our theory doesn't predict this. We may need to change it." So the experimentalists need to go and get more evidence first otherwise theorists are just theorising. But with cosmology it is difficult to get experimental data.

It is the *conservative* POV based on widely accepted theories and experimental evidence for this interpreation of the Big Bang. *You* are the one who is not satisfied with the most conservative POV and want to be speculative. It is not the scientific community that is being careless, but you. But being careless can be beneficial. Bohr's model was completely wrong but he somehow got the right answer and gave QM a big boost.

It depends many physisicists are wary of making bold statements, but then saying we know what happened before the big band and it's nothing end of story is a pretty bold statement. There is a general trend towards asserting hypothesis based on mathematics, not theory based on evidence, in this case I mean actual direct proof that the theory explains the lack of causality in the big bang. So on the one hand your saying physicists are conservative and on the other they subject themselves to open speculation too?

I do know the "New scientist" phenomina, and no I don't accept fringe theories out of hand, I agree it's important to note that some publications that present theories are rather sensationalist and sometimes tend to bias there "breakthroughs" as accepted when in actuality they are not in anyway mainstream.

 

[Sidhe]

I think we're on the same page now anyway. Agreed. Luckily my Maths teacher is myself atm and a text book, although I will say that this is far from perfect, it's very difficult to get feedback by email. I'm luckier than most in that I work in a med physics dept so I can in theory ask some of the staff there, although this is sometimes very difficult to do in work time.

I think if you get a good maths teacher then you end up getting involved with maths even excited by it, school teachers do the best with the material available, some have no passion for the subject others are only interested in regurgitation like you say, after all if your looking for real insight into maths, you do need to go to university to really get the finer points especially in physics, it's just a shame I supose that people are turned off the maths by lack lustre teachers.I know I detested the regurgitation aspect of school maths, doing endless examples is fine, but it becomes more interesting if they throw in a little applied maths especially at school, sadly I saw little of that when taking the GCSE exams at the end of schooling, I'm not sure how it goes now. I did take a physics GCSE and oddly it never inspired me much, again the teacher wasn't great.

 

[Uiler]

I'd just like to say. With science everything is up for grabs. Nothing is sacred. It's to our best current knowledge, assuming blah blah is correct and blah blah is isotropic and blah blah is a harmonic oscillator. This is what we can say. But you know if you want to be a bit wild, you *could* say...This simplification is not necessarily bad though. If you tried to model every single thing you would make no progress whatsoever. What makes a great scientist is his/her ability to work out what exactly is important for the problem. And of course what the problem really is. It's his/her ability to *ignore* and filter out things which are not essential to the phenomena you are studying. Does it really matter for the purpose of classical mechanics for bulk matter if we ignore individual atoms? No. Doesn't work in quantum mechanics though of course. It all boils down to "What can I throw out of this problem to make it simpler while still keeping the essential things?" KISS (Keep it Simple Stupid).

 

[The Last Conformist]

So physicists can make with all their current scientific knowledge hypothetical scenarios about what ifs and what nots before the big bang but others cannot?

I say that a physicist wouldn't say what he said, and you interpret this as me saying he isn't entitled to speculate? Have your English reading comprehension checked, dude.

 

[warpus]

You weren't speaking about "all of existence", but of "the entire Universe" (post 23, 3rd paragraph).

From wikipedia:

the universe is thought to be a finite or infinite space-time continuum in which all matter and energy exist. It has been hypothesized by some scientists that the universe may be part of a system of many other universes, known as the multiverse.

So I should have probably specified that I'm talking about the hypothetical multiverse instead.

 

[The Last Conformist]

So I should have probably specified that I'm talking about the hypothetical multiverse instead.

Yup. In cosmology, "the universe", for reasons good or bad, usually refers only to our 4D spacetime.

 

[Birdjaguar]

I say that a physicist wouldn't say what he said,

I saw it as a good natured poke at my science handicap.