Regarding the Big Bang...

[Arevalo]

Scientists can trace the age of the universe by measuring the current expansion of it. They can do this by measuring how quickly galaxies are moving away from us.

 

When they "rewind" this math, it leads them to the big bang. According to this theory, the universe before the Big Bang was an infinitely dense point.

 

So here's my question:

 

If black holes are created when the Schwartzchild Radius of an object is reached, wouldn't the universe before the Big Bang just me a super massive black hole? Surely the Schwartzchild radius of the universe is unfathomably larger than anything we can imagine.

 

Also:

 

If I am right, and the pre-bang universe was a super massive black hole, how would the Big Bang ever happen? All the energy making up the infinitely small point would be beyond the event horizon: meaning it would never leave.

Right?

 

Please correct me if I am wrong, or tell me what you think about this idea. Thanks!

[StringJunky]

What scientists are realising now about General Relativity is that the infinities given by it, with respect to the BB, signals to them that it is losing its applicability as an accurate description as they approach time zero in their studies of it...they need another theory which is as yet not forthcoming.

Edited June 28, 2013 by StringJunky

[ajb]

There are some similarities black holes and the observable universe. Both have horizons.

 

In fact the mathematical descritions of an expanding Universe and the gravitational collapse of bodies is very similar. Rewinding the Universe tells us that classically we must have a singularity at the begining of the Universe. The similarity with collapse lead to the Penrose–Hawking singularity theorems.

 

It seems that general relativity has singularities that are quite unavoidable.

 

As StringJunky points out, the usual interpretation of singularities in general relativity is that we have a situation that classical theory just cannot handle.

[Delbert]

"When they "rewind" this math, it leads them to the big bang. According to this theory, the universe before the Big Bang was an infinitely dense point."

 

That's assuming the contraction during such an imaginary rewind would go on to such tiny point. After all it was only relatively recently that they discovered that the universal expansion is increasing (dark energy and all that)! And an universe expanding faster now than in the past doesn't quite fit with the contracting down to a tiny point, me thinks.

Edited July 2, 2013 by Delbert

[Archimedes]

I believe this would bring up the question or whether or not you could have a singularity separately from a black hole. Can a singularity form and survive on its own? If it can, then still, it may or may not have been a black hole. We just don't know.

 

As for your question of IF it were a super-massive black hole, how would the big bang happen? I don't believe that question could be answered yet either, as we still don't understand black holes all that well, seeing as we can't just fly up to one to observe it. No, we have to observe it through many light years of distance, and through mathematical theories.

 

This is a good topic. I think it brings up some valid questions that have yet to be answered.

 

-Arch

[timo]

One of the not-so-well-known features of relativity is the paradoxical situation that to make statements about the structure of space time you have to make quite some assumptions about the structure of space time in advance. The assumptions/conditions for the Schwarzschild geometry and the cosmological models have significant differences and, in my opinion, don't compare well (or at all). Despite the mysterious word "singularity" appearing in both scenarios. One case assumes a time-invariant spacially located distribution of mass with surrounding vacuum and asymptotic Minkowski space, the other one a homogeneous non-locaed distribution of mass with no such thing as a surrounding.

[Delbert]

This universe business and associated big bang I find somewhat puzzling. Puzzling in terms of what we see - and experience - is only because of the position we're in. For example, this gas cloud reportedly entering a black hole (recent BBC Horizon prog), whereby I understand what we see will be the cloud dimming and slowing as it nears the even horizon, effectively hanging forever but never quite 'going in' due to time dilation (apparently contrary to the program saying 'swallowed').

 

Suppose then we took a ride on said gas cloud and flashed a light (say) once every second to someone on Earth, who did a similar flashing job to us. I understand the Earth bound flasher would see the time between our flashes getting ever longer, eventually ending up with an infinite time for the last flashes. But in contrast, we would see the time between flashing from Earth getting ever shorter, possibly to the point whereby it would be a continuous light.

 

So what would we on the gas cloud see of the rest of the universe? Presumably as per the flashing light everything would start to run faster. So how would this faster running universe fit with the laws of physics? For example, you can't have Earth whizzing round the Sun without it flying off into space! So, presumably the Earth, Sun, indeed the whole solar system, must be smaller - and continue to get ever smaller. And consequently the same to the whole universe?? That is, the whole universe running forward to its end and getting ever smaller as we approach the event horizon? Or expressed differently, our passing the event horizon would be coincident with the end of the universe.

 

Have I got it all wrong?

[David Levy]

So here's my question:

 

If black holes are created when the Schwartzchild Radius of an object is reached, wouldn't the universe before the Big Bang just me a super massive black hole? Surely the Schwartzchild radius of the universe is unfathomably larger than anything we can imagine.

 

 

Dear Arevalo

If we will stay at a spot which is 13 billions light years away from us we will surly see a similar view which we see from Earth.

The BB Theory is THE mainstream of the modern science.

The science try badly to explain how the universe had been created based on this theory – so far, without a real success.

We all must believe in it. We shouldn't criticize it.

If you want to be part of the science community, you must show your faith in this new god. One bad word on this lovely god and you will get a red ticket!!!

Never the less, I do believe that one day the science will have to open their eyes and see that the universe is based on a very simple mechanism. They just need to read the message from Sir Fred Hoyle http://en.wikipedia.org/wiki/Fred_Hoyle about the steady state theory.

" The theory tried to explain how the universe could be eternal and essentially unchanging while still having the galaxies we observe moving away from each other."

With some minor adaptation – this is the ultimate theory of what we see:

Edited July 6, 2013 by David Levy

[swansont]

Dear Arevalo

If we will stay at a spot which is 13 billions light years away from us we will surly see a similar view which we see from Earth.

The BB Theory is THE mainstream of the modern science.

The science try badly to explain how the universe had been created based on this theory – so far, without a real success.

We all must believe in it. We shouldn't criticize it.

If you want to be part of the science community, you must show your faith in this new god. One bad word on this lovely god and you will get a red ticket!!!

Never the less, I do believe that one day the science will have to open their eyes and see that the universe is based on a very simple mechanism. They just need to read the message from Sir Fred Hoyle http://en.wikipedia.org/wiki/Fred_Hoyle about the steady state theory.

" The theory tried to explain how the universe could be eternal and essentially unchanging while still having the galaxies we observe moving away from each other."

With some minor adaptation – this is the ultimate theory of what we see:

 

!

Moderator Note

It is inappropriate to discuss beefs with accepted physics in a discussion thread that is not on that topic. Cease and desist.

[doG]

If I am right, and the pre-bang universe was a super massive black hole, how would the Big Bang ever happen?

 

Perhaps a super massive black hole supernova, i.e. big bang? We haven't begun to understand the physics that would explain the life of such a black hole. If such a black hole did occur as the result of some universal sized big crunch then perhaps something similar to a supernova event could explain how the big bang occurred.

[Airbrush]

The difference between the Big Bang, before the bang, and a supergiant black hole is the Big Bang was in extreme inflationary motion from the beginning. Also, I think gravity behaved differently at such high density. If string theory is correct, and the Big Bang originated from a collision of higher dimensions, the Big Bang could have originated from a region of ANY size.

[Thinking]

I was thinking the same thing. Thats why i ended up here, searching the web.

The big bang was Always to short for me so it kept me thinking. This is my thought : There must be something that resulted in a big bang. There are some things needed. A way to harnest the energy, a place that results in actual change. I came across the prince rupert drop and that gave me the idear that a black hole could be like that. But than there has to be two different places or a change in the place. Imagine active space, there is time, distance, shapes etc and put inactive space next to it with no stable things exept the thing wich there both made of. In active space we see a Big machine, the black hole. It gathers and gathers, spit some out and moves. It harnest energie and go to other place. It gets bigger and bigger and finaly it comes to the edge of active space. It is so powerfull in its path that it easly slides over the edge(not realy edge but area of transision). Entering the unactive space. it has to change from the outside. No stable time, No stable distence, No stable shape etc will effect the outside and this changed outside will effect evry layer to the center. Its now a unstable black hole that cant react because there is active space needed for a stable reaction. The tail of that black hole is the fuse and is on the edge waiting for a push. Wen the tail gets the push it all start to collapse.and the active space in the center of the black hole is released and making new or wider active space.

I am just thinking, but thoughts like this realy give me a new view.

It also feels good to find a place where i can drop this.

[MigL]

They may be both possibly singularities central to a black hole and at the beginning of space tme, but they have vastly different properties.

If we draw a distance-time diagram ( y=time and x=distance ) we not that a black hole singularity is a timelike 'edge' to space-time. It is in effect a discontinuity on the left side of our diagram. The big bang singularity, on the other hand, is a spacelike edge to space-time. A discontinuity on the bottom side of our diagram and only in the past.

[Airbrush]

David: ".....If you want to be part of the science community, you must show your faith in this new god. One bad word on this lovely god and you will get a red ticket!!!"

 

No, all you need to do is ask questions about it, then find something wrong with the answers you get, or tell us WHY the Big Bang is wrong. So far you haven't. Fred Hoyle's theory is not good enough explanation, nor has any better theory been suggested.

 

From your Wiki article about Fred Hoyle:

"....In the end, mounting observational evidence convinced most cosmologists that the steady state model was incorrect and that the Big Bang was the theory that agreed best with observations, although Hoyle continued to support and develop his theory. In 1993, in an attempt to explain some of the evidence against the steady state theory, he presented a modified version called "quasi-steady state cosmology" (QSS), but the theory is not widely accepted.

 

The evidence that resulted in the Big Bang's victory over the steady state model, at least in the minds of most cosmologists, included the discovery of the cosmic microwave background radiation in the 1960s, the distribution of "young galaxies" and quasars throughout the Universe in the 1980s, a more consistent age estimate of the universe and most recently the observations of the COBE satellite in the 1990s and the Wilkinson Microwave Anisotropy Probe launched in 2001, which showed unevenness in the microwave background in the early universe, which corresponds to currently observed distributions of galaxies. Hoyle died in 2001 never accepting the expanding universe theory."

http://en.wikipedia.org/wiki/Fred_Hoyle

Edited August 1, 2013 by Airbrush

[krash661]

Sir Fred Hoyle[/font][/size][/b] http://en.wikipedia.org/wiki/Fred_Hoyle about the steady state theory.

did you know you can get an astronomy degree in six months online ?

was it also known that fred hoyle

coining the phrase 'Big Bang'

all in all, interesting papers this guy has.

Edited August 1, 2013 by krash661

[Iggy]

Suppose then we took a ride on said gas cloud and flashed a light (say) once every second to someone on Earth, who did a similar flashing job to us. I understand the Earth bound flasher would see the time between our flashes getting ever longer, eventually ending up with an infinite time for the last flashes. But in contrast, we would see the time between flashing from Earth getting ever shorter, possibly to the point whereby it would be a continuous light.

If you're falling into the black hole (like the gas cloud) then you would not see Earth's beacon super sped up. To see things super fast you would have to hover just outside the event horizon.

 

The closer you hover (static) to the horizon the faster Earth and the rest of the universe moves from your perspective. But, hovering static near an event horizon takes a lot of energy. Hovering infinitely close to the horizon means seeing the universe progress infinitely fast, and would require an infinite amount of energy to remain static against the pull of gravity.

 

On the other hand, if you're falling into the black hole -- if you aren't static -- then time dilation isn't reciprocal. Earth will see the black hole beacon slow indefinitely, but the person falling in the hole does not see the Earth beacon speed up indefinitely.

[a_lexios]

There are some similarities black holes and the observable universe. Both have horizons.

 

In fact the mathematical descritions of an expanding Universe and the gravitational collapse of bodies is very similar. Rewinding the Universe tells us that classically we must have a singularity at the begining of the Universe. The similarity with collapse lead to the Penrose–Hawking singularity theorems.

 

It seems that general relativity has singularities that are quite unavoidable.

 

As StringJunky points out, the usual interpretation of singularities in general relativity is that we have a situation that classical theory just cannot handle.

My understanding -please correct me if I am wrong- is that the definition of a black hole is strictly mathematical. A black hole is just the mathematical solution to formulas derived from General Relativity.That is the reason why their existence was factually determined a long time after their "discovery" as series of numbers in a piece of paper...(Exploiting the microlensing effect is currently one of the ways to detect the 'footprints' of a black hole)

The simplest black holes are spherically symmetric.(Non-rotating ones). For any spherically symmetric object one may define an imaginary sphere around it of radius rs = 2GM/c^2, where G is the universal gravitational constant, M the mass of the object and c the speed of light in vacuum. (Very peculiar, even though this formula is deriving from General Relativity, aren't you recognizing a pattern fitting right into Newtonian laws....?).

This formula tells us that the radius of the black hole is directly proportional to the mass of a black hole, i.e. the more massive the black hole the larger the radius.

The rs factor is called the Schwarzchild radius.

If the surface of ANY object is at a radius less than it's rs, then this imaginary sphere is called the event horizon and the object is called a black hole. Note that if the radius of the surface of ANY object is larger than rs then there is no event horizon and the object is not a black hole but something else instead...

Now as far as the observable universe is concerned:

At first, let us see what does "observing" or "seeing", really entails..?

Initially, there has to be light present (photons that is...)

Again -from what I've read- when light (photons) enter the eye, they reach the retina, which is the light-sensing structure of the eye, and by triggering it (coming in contact with the eye's photosensitive part) we are enabled to perceive our cosmos through the miracle of vision, right...?

Ok, now taking in consideration the fact that light travels at 300,000 kilometers per second for all observers (according to our predominant current theories) we can conclude that if the Universe were only one second old, an observer would not be able to see things which are more than 300,000 kilometers away because there would not have been sufficient time for this light to propagate that far...

So at each point in the history of our Universe there a distinct radius (a horizon) which is self-determined -pretty much- by the distance that light could have traveled since the birth of our Universe....As our Universe ages, the horizon expands outwards because there is more time for light to travel & on top of that our Universe itself is expanding with a slightly accelerating rate...

Logic states that if we cannot 'see' beyond the 'horizon', then neither can we be affected by any physical effect from beyond that horizon. Regions of space in the Universe which are separated in distance by more than the horizon, simply do not 'know' about each other, and cannot influence each other's physical conditions....

Therefore we choose to exclude those hypothetical 'parts' of our Universe (...?...or someone else's Universe) from our calculations and models and just say that we just don't care ! (very-very simplified...)

As a new member of your community, I hope I have slightly contributed to this thread with my post. Happy to be here.

Edited August 5, 2013 by a_lexios