Standing in nothingness before the Big Bang

[Swimfit]

Hello, I have a question: let's say I was standing in nothingness before the Big Bang, then it happened! Would I first feel the pull of the gravity of the growing universe, then see it's light, and then feel the push of the gases. Or see the light, then the pull and the push because space hadn't gotten to me yet? Thanks for reading and answering my question.

 

[ShayanJ]

Maybe someone's going to answer your question,I don't know...but I just feel I should clarify something.
Even in well understood and well tested parts of modern physics,people can't imagine being in the middle of the system they're studying.And now you're asking us what would happen if we were standing at the middle of one of the most puzzling things in physics which is still an open theoretical question?!

 

[Nugatory]

Hello, I have a question: let's say I was standing in nothingness before the Big Bang, then it happened! Would I first feel the pull of the gravity of the growing universe, then see it's light, and then feel the push of the gases. Or see the light, then the pull and the push because space hadn't gotten to me yet? Thanks for reading and answering my question.��

If you can stand in it, it's not "nothingness", it's perfectly ordinary empty space like we find outside the Earth's atmosphere... So it didn't exist before the big bang. Thus, there's no good answer for your question as phrased... for roughly the same reason that I can't tell you what color the elephant in my living room is right now - the color of a non-existent elephant is not a meaningful concept.

I know that's not a very satisfying answer, and I'm sorry, but it wasn't a very satisfying question either . You may want to try poking around in some of the threads in the "Cosmology" forum here, that will get you started on a line of thinking that will go somewhere.

 

[Swimfit]

Thanks I know I can't stand in nothingness as a person. It was just a tumble of thought. I was listening to the fabric of the universe, and they use the visual of being on a river in a boat at high tide. When the moon suddenly disappeared they said we would notice the river receding before we saw the moon disappear. But that is in space, I thought things might change out of space in nothingness.

 

[ShayanJ]

To Swimfit:
About your comment on my post,Its OK to have strange thoughts,but the point is,when you enter physics,you should learn to think right and ask right...now people may tell this is going into boundaries which limits your creativity,blah blah blah...but there is always a law which induces some limit,its just possible to choose a broader limit than others'!
And for learning how to think like a physicist,you should study about other physicists' ideas until you're able to give some ideas yourself and then you can try thinking like a physicist and by practice,someday,you will become a physicist.

 

[Nugatory]

I was listening to the fabric of the universe...

OK, that's the problem right there...

 

[Swimfit]

Ok the way I understood the expanding universe, is the the universe is expanding faster than the speed of light. So I thought one might feel the effects of the expanding universe before actually seeing it. But I guess it is something we just can't know since we can't be there.

 

[Swimfit]

It is a book! The fabric of the universe. I was listening to while walking. Lol what is the color of your elephant in your living room? Any color you want it to be. It is imagination.

 

[Swimfit]

To Shyan: I'm sorry I'm not trying to be a smart ***. I hope you didn't take it like that I was just asking a question. I just Thought someone would have an answer. But I know that there is no way to know something when we can't be there. In space things may act a certian way but outside the universe we just can't know. Thanks for taking the time for your answers.

 

[Nugatory]

It is a book! The fabric of the universe. I was listening to while walking.

I know it's a book - it's just not a very good one

Search this forum for "Brian Greene" and you'll see what mean.

 

[Swimfit]

Thanks for reply. I will do the search.

 

[Swimfit]

Ok let's see if I can ask this question in the right way. Let's say a star went super nova would a very sensitive machine notice the gravitational effects first or light first? I hope I asked this in the proper manner.

 

[marcus]

Ok let's see if I can ask this question in the right way. Let's say a star went super nova would a very sensitive machine notice the gravitational effects first or light first? I hope I asked this in the proper manner.

The most common type of supernova is "core-collapse" type. In that case the gravitational collapse (and a huge release of neutrinos) happens well before the burst of light.

1. If one had a gravitational wave detector sensitive enough to feel the ripple from the core collapse then that would arrive, and be felt, BEFORE the burst of visible light

2. The neutrinos can be detected BEFORE the light. I believe this has actually happened. It would depend on how far away it was and on the speed the neutrinos were traveling. They travel ALMOST as fast as light, and they are generated in the core before the explosion shockwave has a chance to get out to the surface of the star and release visible light. Neutrinos pass effortlessly thru other matter so they can get out of the core and escape before the explosion shock, and they get a head start over the light.

I'm not an expert but I'm pretty sure the answer to your question is yes.That is, both disturbances in geometry (aka grav. waves) AND light travel at the same speed, namely c.
the collapse of the core of a massive star would probably cause some ripply disturbance in geometry and it happens before the release of visible light at the star surface.
We humans may never get to the point of building a grav. wave detector sensitive enough to feel the collapse of the core of a star (I can't predict) but in principle it should be detectable and the slight geometrical ripple should, in principle, get here before the visible light.

 

[Swimfit]

Marcus thank you so much for your answer! It was very informative. I tried asking the same question in let's say a more esoteric way which caused such and up roar, I think they knew very well what I was trying to ask but they were too busy tearing apart how I asked it. All they had to say is we don't know what happens outside the universe. And then tell me the answer to how it would happen within the universe as they understand it. Thanks again for taking the time to answer the question.

 

[marcus]

You are most welcome! My pleasure.

I'm glad you got some use from my response. I was thinking about your supernova question some more. You may have heard all you want about "which signal arrives here first?" and want to think about something else. But I'm curious about another aspect of that. Maybe someone else will see this and answer.

Earlier I only discussed what happens with CORE COLLAPSE type supernovas (read Wikipedia about the mechanism: the core stops fusing and gets so dense and heavy it cannot support itself, there is a neutronstar or black hole remnant).

That's the majority type. But there is also an important type of supernova called Type 1A (again read Wikipedia, it starts with a binary star where the smaller partner has, say, fused up to carbon and is not massive enough to fuse beyond that to still heavier elements, so it dies and begins cooling, but then the larger partner goes giant and dumps crud on it, till it reaches critical mass and fuses all its carbon at once in a thermonuclear explosion.)

Type 1A are wonderful supernovas because all of approximately the same intrinsic brightness determined by the critical mass for triggering a carbon fusion bomb . they leave no remnant! The whole star goes in the explosion. Not like core collapse, which usually leaves a neutron star remnant. It's very interesting. Do try the Wikipedia article on supernovas!

My question would be, if anybody knows, which signal would arrive first? The geometry ripple, or the flash of light?

The ripple of geometry would result from the disappearance of a star-sized mass. A whole lot of mass explodes to kingdom come and is removed from the picture. The larger partner of the binary pair now has nothing to orbit with, nothing pulling it. It suddenly takes off in some random direction. So spacetime geometry is radically disturbed. Clearly there will be ripples of geometry spreading out from that event! But isn't the flash of light SIMULTANEOUS with that, in this case?

No,some people will say. The mechanisms that produce the visible light are more complex and take more time… The light will arrive later in this case as well. But I wonder.

Well anyway, I'm curious about this. Maybe someone knowledgeable will respond.

 

[Swimfit]

Thanks again Marcus! Very interesting I will read that article on supernovas . Yes i think your right that we would feel the ripple before we saw the light from the massive explosion. Like the example i mention earlier with the moon disappearing, we would feel or see the effect of the tide before seeing the light of the moon blicking out. They say gravitational ripple is instantaneous at least that is the way i understood it. Of course I really don't know to really agree with you, but it seems like that is the order in which things would happen. So let's see if I have it right, if i was super sensitive and could feel all effects of every event I would feel the gravitational ripple first, then the light and then the force of the explosion. I'm glad that we are not that sensitive it would be overwhelming! But it would be interesting knowing all things as they happened. The way you discribe that super nova sounds like the way our sun will die. It will expand and envelope most of the planets and then explode. But will there be any rement left of our sun after? Another question! Lol thanks again for your answer.

 

[Swimfit]

I read the article on supernovae and then read about our sun to answer my question about how our sun would die. Sound like it would expand and contract until it finally explodes and we are left with a white drawf star until it peters out to nothing. But will there be any mass left? Go back and reread! Lol

 

[Chalnoth]

If our universe was born from another universe, then what you would see is a microscopic black hole popping into existence, then evaporating away into nothing almost instantaneously. If you could detect this microscopic black hole at all, you would have no way of knowing that it had resulted in the birth of a whole new universe.

 

[Swimfit]

Chalnoth, thank you for your post: my main question was would we feel the effects of the gravity from the black hole and then the lack of it, and then the gravity of the new universe before we saw its light? Assuming our senses were infinite. Thanks again for your post . I've always wondered if our universe is just recycling, forming then finally shrinking back to a singularity, and then reforming. I guess we really will never really know for sure.

 

[Naty1]

When the moon suddenly disappeared they said we would notice the river receding before we saw the moon disappear

That doesn't seem correct. What's the underlying explanation?

 

[Naty1]

Would I first feel the pull of the gravity of the growing universe, then see it's light,...

I'm guessing we need a theory of quantum gravity to be sure. Here is what I think I have learned, lots from discussions in these forums:

We have an FLRW model of the universe...On the front end we glue on, insert, an inflationary era that starts about 10^-36seconds after the big bang. But nobody knows just what the initial conditions were, why inflation started, and they are probably necessary to answer your question. Quantum vacuum fluctuations seem a popular possibility.

Very early on, all forces were unified...

Wiki describes subsequent theory:

In physical cosmology the electroweak epoch was the period in the evolution of the early universe when the temperature of the universe was high enough to merge electromagnetism and the weak interaction into a single electroweak interaction (> 100 GeV). The electroweak epoch began when the strong force separated from the electroweak interaction. Some cosmologists place this event at the start of the inflationary epoch, approximately 10^-36 seconds after the Big Bang.[1][2][3]

Anybody know if there are theories when gravity separated?? Is there 'light' during the electroweak epoch??


Penrose has written:

...'During the inflation stage we have a region of a false vacuum which represents a quantum mechanical phase transition to a vacuum different from the one we are familiar with today'...Lambda [the cosmological constant of expansion] was about 10¹¹⁰ times it's current density.

This transition is the 'slow roll' version described in Wikipedia. What goes on under such extreme conditions is not clear to me, but we have had discussions in these forums that the combination of a dynamic geometry [cosmic expansion, much slower now] and the presences of cosmological horizons [present then and still so] results in the production of particles. Which particles come first??

 

[Swimfit]

As far as I understood it that gravity is noticed immediately because of the fabric of space I think, and light must travel, so you would notice the water first then the moon blinking out. This is just what I read but I could be wrong. It is just the way I understood it. I'm not a physicist.

 

[Chalnoth]

Chalnoth, thank you for your post: my main question was would we feel the effects of the gravity from the black hole and then the lack of it, and then the gravity of the new universe before we saw its light? Assuming our senses were infinite. Thanks again for your post . I've always wondered if our universe is just recycling, forming then finally shrinking back to a singularity, and then reforming. I guess we really will never really know for sure.

That's not really what this is about. The fact that, from the outside, a new universe being born would look like a microscopic black hole that quickly evaporates means that that black hole is only a tiny shadow of the whole of the new universe. One way to think of it topologically would be if we imagine the fabric of space-time as an undulating flexible sheet that continually has bumps and ripples that occur spontaneously on a microscopic level. Every once in a while, one of these ripples will be so sharply-defined that instead of popping back flat, a bubble pops off this sheet. If you are sitting within the sheet, you see this event as a black hole that appears and then evaporates quickly. What you don't see is the new bubble that goes off to become a whole universe of its own.

Edit: Note that if this view is correct, most of the time when a bubble pops off, it won't actually produce a new universe. Most of the time the bubble will just collapse back in on itself.

 

[Swimfit]

So the first black hole is really just a shadow of the emerging new universe? Or the new universe is emerging from the black hole, which was the singlularty? If I'm understanding you right the first one is the right one. Kool god I love all this stuff! The universe is so amazing!

 

[Naty1]

Every once in a while, one of these ripples will be so sharply-defined that instead of popping back flat, a bubble pops off this sheet. If you are sitting within the sheet, you see this event as a black hole that appears and then evaporates quickly. What you don't see is the new bubble that goes off to become a whole universe of its own.

That's an interesting view I haven't read before. And you can't be 'off the sheet' because nothing is there...

What I have read is that in the formation of a black hole some matter collapses due to increasing spacetime curvature amid existing spacetime which remains. All existing matter within the horizon becomes hidden, unobservable. A new universe seems to spawn repulsive negative pressure gravity, which results in new rather flat space and curved spacetime amid incredibly fast, inflationary, expansion. Spacetime emerges. Such dynamic inflationary geometric expansion/evolution of spacetime together with vacuum fluctuations and a cosmological horizon spawns matter [particles] galore.


In general, quantum mechanics spawns real particles from real numbers, antimatter from imaginary numbers, and virtual particles from complex numbers, aka a +bi. But whether these appear in an ordered sequence or simultaneously I don't know. For example, virtual particles can explain electriomagnetic effects and gravitons in QFT.

bapowell has posted in an earlier discussion:

... instead of particle production during inflation, cosmologists refer to the generation of perturbations. The formalism is the same -- but instead of quanta of the inflaton field, the inflationary expansion creates perturbations in the field value of the inflation across the universe.

The string theory view of this offers a nice physical insight I think: multidimensional spacetime sets the vibration patterns of strings...particle characteristics...so a dynamic inflationary geometry enables perturbations not seen so much in a static spacetime...and lots of particles emerge from the special vacuum during the expansion.

ok, I found a quote regarding 'particle production':

Particle creation and particle number in an expanding universe
Leonard Parker
Physics Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53200, USA

Abstract. I describe the logical basis of the method that I developed in 1962
and 1963 to define a quantum operator corresponding to the observable particle
number of a quantized free scalar field in a spatially-flat isotropically expanding
(and/or contracting) universe. This work also showed for the first time that particles
were created from the vacuum by the curved space-time of an expanding spatially-flat FLRW universe. The same process is responsible for creating the nearly scale-invariant spectrum of quantized perturbations of the inflaton scalar field during the inflationary stage of the expansion of the universe….

.

Note for swimfit if this appears too obtuse:
In quantum mechanics, certain 'operators' create observables, stuff we can detect in experiments, like a photon or electron blip on a detection screen. 'creation operations' increase particle numbers while 'annihilation operators' reduce particle number...so matter is born or dies.

 

[Swimfit]

Thanks Naty1 for your response! It was very deep I will need to reread several times to get it to sink in. I found it very interesting though! I was a little busy at work to be able to ponder on it. I've been listening the fabric of the Cosmos are there any other good books that are on audio books that are for the general public to read or listen to. It really helps the time go by during the walk. One guy was on here said that the book I'm listening really wasn't very good. I'm not sure if he meant it wasn't accurate or boring to Him. Sometimes while I'm walking and listening I'll get caught on one subject and thinking about that and the book it conditioning on! Lol I really do love all this stuff. Thanks again for response. swimfit

 

[Naty1]

The 'Fabric of the Cosmos' is not very popular in these forums because Brian Greene seems to lead many to a few incorrect interpretations. If you find it interesting, keep going!

I liked the book a lot because it discusses many ideas and concepts. In fact in his Chapterr 10, Deconstructing the Bang, he might even discuss a bit about particle production. In Chapter 3, Relatiity and the Absolute, he talks about spacetime loafs. I read that three times and never figured out what he was doing, and years after found out from these forums he uses flat Minkowski spacetime rather than the more general curved spacetime.

When you have read Chapter 10, and this thread has waned, check out this old discussion I started in these forums about three years ago...WHAT IS A PARTICLE... I think you will find the papers and posts very interesting. You may think you know what a particle is, but I bet you will find surprises galore.

https://www.physicsforums.com/showthread.php?t=386051

edit: One of the most fascinating things I discovered in these forums is the link between quantum mechanics, general relativity and cosmology. I think I spent several years in the forums before I realized there were cosmology discussions...who knew??

 

[Swimfit]

Question: in the above note to me it say's annihilation operators reduce the # of particles. Then the next quote is matter is born or dies. Now the annihilation operators do they completely destroy the particle or cause it to change form or change form like becoming pure energy. So since we are looking for particles and they have changed doesn't mean they ceased to exist or just changed form. Since we are looking for particles of course they would not be there. Could be they are there, but just not what we are looking for? Just like when we die do we cease to exist? I think not according to Einstein!

 

[Chalnoth]

Question: in the above note to me it say's annihilation operators reduce the # of particles. Then the next quote is matter is born or dies. Now the annihilation operators do they completely destroy the particle or cause it to change form or change form like becoming pure energy.

There's no such thing as pure energy. Energy is a property of some quantum mechanical field or other. It does not exist freely of its own accord.

But yes, when real particles annihilate with one another, they generally release a series of other, lower-mass particles. The annihilations of more massive particles tend to result in more massive byproducts.

These annihilations can, in general, produce pretty much anything, for the reason that when you annihilate a particle with its anti-particle, the net quantum numbers all go to zero: all you're left with in the product is the energy, momentum, and angular momentum of the result. And any particle/anti-particle pair will meet the required conservation laws. What is produced from the annihilation then depends upon what those annihilating particles interact with. Electrons and protons, for example, interact mostly with the electromagnetic force, and as a result when they annihilate they usually only produce pairs of photons. When they come together to annihilate with a good amount of kinetic energy, they can also produce heavier leptons (muons and tauons). At higher energies still, they start to interact with the weak nuclear force, and produce neutrino/anti-neutrino pairs in greater numbers. They can also produce quark/anti-quark pairs, but not nearly as many as you'd get from proton/anti-proton annihilations, as leptons don't interact with the strong nuclear force.

 

[Swimfit]

Chalnoth Thanks for the reply I didn't even consider an anti- particle if it had been put that way I would have thought they might have balanced themselves out. But I guess what made on one side is also made on the other. And I didn't know there couldn't be pure energy! I thought that was the base of everything. Very interesting. Thanks again for the reply swimfit

 

[Swimfit]

I am so sorry I wrote the question badly! I hope everyone can get over it! Let me state I know that I can not stand in nothingness! I just posted it that way so I could witness the Big Bang and how I would feel the effects of the the Big Bang as far as Gravity, light, and force and in what order. That was the main Question in the post. I was realizing though that I wasn't in the fabric of space time if I was in nothingness would effects change because of that? But I soon realized that we really can't know the answer to that question because no one knows what nothingness is or if it is. So again I' m sorry that I wrote the question badly.

 

[jackmell]

I am so sorry I wrote the question badly! I hope everyone can get over it! Let me state I know that I can not stand in nothingness! I just posted it that way so I could witness the Big Bang and how I would feel the effects of the the Big Bang as far as Gravity, light, and force and in what order. That was the main Question in the post. I was realizing though that I wasn't in the fabric of space time if I was in nothingness would effects change because of that? But I soon realized that we really can't know the answer to that question because no one knows what nothingness is or if it is. So again I' m sorry that I wrote the question badly.

No need for that swimfit. If your comments are in reference to my deleted post, I just felt it would interfere with what you guys were discussing although you really can't swim in a block of ice. :)

 

[Swimfit]

No worries Jackmell : you were not the only one, so I thought I would make it clear I understood the error of my ways. And thanks for the reply it was interesting read about the phase- transitions. Others hinted at the too. Anything that anyone reply's is always interesting! If I could swim though a block of ice I would be a new world record holder! Lol thanks again for the reply

 

[Flatland]

Hello, I have a question: let's say I was standing in nothingness before the Big Bang, then it happened! Would I first feel the pull of the gravity of the growing universe, then see it's light, and then feel the push of the gases. Or see the light, then the pull and the push because space hadn't gotten to me yet? Thanks for reading and answering my question.

Space did not exist before the big bang. You couldn't stand anywhere because there was no space for you to stand in.

 

[Swimfit]

Jeeze flatland! You did not see the post I wrote just above this one to Jackmell! You might even try 1 that wrote just before that one!

 

[marcus]

Space did not exist before the big bang...

How do you know that? How can you be sure? We do not have a scientific consensus that space did not exist before the start of expansion. Older models break down right at the start and can't say anything meaningful---more recent ones do not suffer that kind of breakdown (don't have a "singularity").
The relevant field of research is called Quantum Cosmology. Here's a keyword search of recent professional journal articles on QC if anyone wants to get an idea of what models of start of expansion (no longer always referred to as "big bang") are like. Glancing at some of the titles and abstracts will give a general impression.
http://inspirehep.net/search?ln=en&...search=Search&sf=&so=d&rm=citation&rg=25&sc=0
The search gives 640 quantum cosmology research papers that appeared since 2009 but you can get a reasonable impression just by glancing at the short summaries of the first 10 or 20. In the first 100 or so papers, the most common model tends to be (nonsingular) big bounce.

Hello, I have a question:... Would I first feel the pull of the gravity of the growing universe, then see it's light,...

I think it is perfectly OK how you asked the question. It's clear you are looking for a MENTAL IMAGE OF THE START OF EXPANSION.

Of course it's difficult to imagine actually being there---being in the universe when it was extremely dense and hot and super-packed with energy---and where else could anyone be since the universe is everything that exists? So people immediately start raising PHILOSOPHICAL objections, but all you wanted was a mental image so you could picture it concretely

No picture can be perfect, but here's one for starters. It corresponds to the main bulk of the first 50-100 research papers in that listing of keyword hits I linked.

The Inspire listing contains also contains various OTHER concepts of the start of expansion, but I don't happen to have graphic illustrations of them.

 

[Chalnoth]

The relevant field of research is called Quantum Cosmology.

This is not true. Quantum Cosmology is a subset of the work in this area, these days generally used to specifically talk about the application of the rather speculative Loop Quantum Gravity to a bounce in the early universe.

It's a term that is usually not used to refer to other proposed early universe models, such as the ekpyrotic universe, or the spontaneous inflation of the Carroll-Chen model.

Such models are extremely numerous and diverse, but there isn't a whole lot of active research in this area simply because there isn't very good data to point the way. If we get some significant improvements in data from the early universe (such as detections of primordial gravitational waves), we will probably have a lot more activity in this area.

 

[Swimfit]

Marcus thanks so much for your post it was very informative! Instead of all the critical comments made by others. All I was trying to do was find out in what order things might be felt. Gravity, light and the explosion. I really didn't mean that I could actually stand in nothingness or what ever it might be. But in reality I guess we really can't know. I just wish people would read beyond the original question and read all the treads before commenting. Thanks Marcus for your comment I will reread it and make sure I understand it. Thanks again swimfit

 

[marcus]

Good suggestion Chally! When I use the keyword "quantum cosmology" I get 640 papers (since 2009).
But when I add "ekpyrotic" I get 691 papers!

Actually if you actually look thru the list either way you will see a lot of Non-Loop papers, they just don't get cited so much, so you don't see as many in the top 20 or 30 of the listing. It is sorted by the number of citations.

So I will correct what I had to say.

Older models break down right at the start and can't say anything meaningful---more recent ones do not suffer that kind of breakdown (don't have a "singularity").
The relevant field of research is called Quantum Cosmology. Here's a keyword search of recent professional journal articles on QC if anyone wants to get an idea of what models of start of expansion (no longer always referred to as "big bang") are like. Glancing at some of the titles and abstracts will give a general impression.
http://inspirehep.net/search?ln=en&...search=Search&sf=&so=d&rm=citation&rg=25&sc=0
The search gives 691 quantum cosmology or ekpyrotic research papers that appeared since 2009 but you can get a reasonable impression just by glancing at the short summaries of the first 10 or 20. In the first 100 or so papers, the most common model tends to be (nonsingular) big bounce.

...
No picture can be perfect, but here's one for starters. It corresponds to the main bulk of the first 50-100 research papers in that listing of keyword hits I linked.

The Inspire listing contains also contains various OTHER concepts of the start of expansion, but I don't happen to have graphic illustrations of them.

 

[MathJakob]

Would I first feel the pull of the gravity of the growing universe, then see it's light

You would feel the pull of gravity before you saw light. Understandably people are right when they say your question does not make sense but cmon guys you know what he is asking... Imagine you was standing 100 light years away from the big bang, you're standing in nothingness and the big bang happened, you'd feel the pull of gravity first then 100 years later you'd see the universe.

My answer makes no sense I know as does the question, but it's obvious what the OP is trying to figure out. I think it's just more of a random question as apposed to anything meaningful.

 

[Chalnoth]

You would feel the pull of gravity before you saw light.

?

Gravity propagates at the speed of light.

Understandably people are right when they say your question does not make sense but cmon guys you know what he is asking... Imagine you was standing 100 light years away from the big bang, you're standing in nothingness and the big bang happened, you'd feel the pull of gravity first then 100 years later you'd see the universe.

Well, no. You probably wouldn't see (or feel) anything at all, because this event would look like a microscopic black hole that popped into existence and almost instantaneously decayed. In short, it'd just look like, from the outside, a normal quantum vacuum fluctation that happens regularly all around us all the time, and is therefore indistinguishable from the vacuum.

 

[MathJakob]

Gravity propagates at the speed of light.

Oh yeh! I forgot... but what about the inflation at the start of the big bang? So if gravity propagates at the speed of light and the universe is expanding faster than the speed of light, then are there some parts of space which do not have any gravity?

What would happen if you took the sun and put it in that part of space where there isn't any gravity? (hyperthetically)

 

[Swimfit]

So your saying that at the Big Bang gravity would move as fast as the light? And that gravity would only be felt or sensed first in the fabric of space time? Now the sun thing would the sun stay there without the fabric of space time or continue to move?

 

[Swimfit]

So is there gravity without mass? Or does the mass create the gravity?

 

[Drakkith]

So your saying that at the Big Bang gravity would move as fast as the light? And that gravity would only be felt or sensed first in the fabric of space time? Now the sun thing would the sun stay there without the fabric of space time or continue to move?��

Changes in the metric of spacetime move at the speed of light. A typical example is a gravitational wave. I'd prefer not to talk about what was felt or seen first, as the very early universe does not quite work the same way as it does now. Forces were unified and radiation was so energetic that it could create matter and antimatter. Not to mention that we don't even know how the origin of the universe happened.

Also, talk of what would happen without the fabric of spacetime makes no sense. Without spacetime there is nothing. No dimensions, no anything.

So is there gravity without mass? Or does the mass create the gravity?

Mass and energy cause spacetime to "bend", which usually manifests as an attractive force between objects, although there are other effects such as frame dragging to take into account. Without mass or energy there is no bending of spacetime and thus no gravity.

 

[Chronos]

It would be pointless to talk about being 100 light years, or any other 'distance' away from the big bang. There is no space or time in the absence of a gravitational field. See http://www.astronomycafe.net/gravity/gravity.html for discussion

 

[Flatland]

How do you know that? How can you be sure? We do not have a scientific consensus that space did not exist before the start of expansion.

No one knows it's just that this is the best answer we have right now. The Big Bang was the beginning of spacetime as we know it. Some type of spacetime might have existed before the Big Bang but it certainly wouldn't be the same type that existed after, otherwise our model wouldn't break down. It certainly wouldn't be something you can stand in. I'm not sure if there is any consensus on whether spacetime existed prior to the Big Bang but I'm willing to bet that most Physicist will tell you no.

 

[texasH53D]

OP, here's my two cents though it might be worth less than that ha.
First off, from what I understand, there is no "nothingness". We cannot understand "nothingness" because we have found that "nothingness" actually has physical value. In fact "empty space" is not so empty. It is a cauldron of particles.
So, here is what I understand: when the universe was bare from galaxies, stars, planets and what have you, there were still elementary particles flying around and eventually, when particles were traveling fast enough and collided, the big bang happened and the byproduct of that was a whole bunch of other particles.
I have no idea what you may have seen or felt first as there may have been more photons given off first, or maybe more (gravitons I think their called, what gives gravity... gravity?) were given off first.
S.N; If there are particles in "nothingness" then that means the higgs field is in there too because it's what gives particles their mass right ? And if protons were there too, than so was the strong and weak nuclear forces as well right ? I am just as lost.

 

[Drakkith]

Texas, your understanding is not correct. We don't know how the universe was created, we only know that the early universe was very dense, very hot, and consisted of a sea of very energetic particles and radiation. Before this point in time we know nothing, as the math in our theories breaks down and starts giving us infinities.

See here: http://en.wikipedia.org/wiki/Chronology_of_the_universe

 

[Chalnoth]

Oh yeh! I forgot... but what about the inflation at the start of the big bang? So if gravity propagates at the speed of light and the universe is expanding faster than the speed of light, then are there some parts of space which do not have any gravity?

Saying that the universe expands faster than light is a nonsensical statement. Expansion cannot possibly be faster (or slower) than the speed of light, because expansion isn't a speed! Expansion is a rate. It's like saying that your car's engine can't revolve at faster than 60 mph: that statement doesn't make sense, because engine revolutions are measured in RPM's, which are not a speed at all.

And just as matter cannot ever outpace a light ray, due to the speed of light limitation, matter also cannot outpace the gravity it produces. So it is fundamentally impossible for matter and gravity to become somehow separated.