There already was a space that we know of but empty? I thought it (and time) didn't exist.
An interesting view of the gravitational forces at work within the universe.
https://www.forbes.com/sites/starts...mething-far-more-interesting/?sh=2c9677687ec2
https://www.forbes.com/sites/starts...mething-far-more-interesting/?sh=2c9677687ec2
You'll be aware that "empty" space is actually full of quantum fluctuations - virtual particle/antiparticle pairs are continually popping in-and-out of existence from the quantum vacuum, but on low energy scales and short timescales.
Ethan Siegel says that, during cosmic inflation, these fluctuations were much, much larger in energy - about 100 orders of magnitude larger - than they are today.
So the original fabric of space from which the Universe emerged was far from empty - it was chock-a-bloc full of energy.
It's only a hypothesis. You or I don't have to accept it. No one really understands exactly what happened before the Big Bang, but we're trying!!
Hi Galu,
I agree the current thinking changes.
When I refer to pre-universe, I recall the thinking that scientists postulated that there were 2 expanses separated by a membrane matter antimatter barrier. Some pre- time, pre universe event caused the membrane to fail.
None of which can be proven, an astrophysical philosophical debate - doesn't seem like much has changed 🤣
Estimations or pre-time events are a little...well they're guesses.
I guess this slight change in theory is mostly because we have not yet been able to see far enough back in time, by observation of the universe to prove the big bang - so another theory is cooked up, because we can't prove big bang, then we must be wrong.
because look far enough away, and far enough back in time, and we can see the earlier universe-but never the beginning.
Besides...I always like the rubber band theory better, it matches nature more - we see oscillation in nature, equilibrium etc
The real question, if my opinion is asked, would be:
How can any scientist assert that events occurred before the creation of universe, time and matter; the existence of energy can not even be asserted.
Moreover, without the reference of time, noone can prove it either, in a meaningful way
I agree the current thinking changes.
When I refer to pre-universe, I recall the thinking that scientists postulated that there were 2 expanses separated by a membrane matter antimatter barrier. Some pre- time, pre universe event caused the membrane to fail.
None of which can be proven, an astrophysical philosophical debate - doesn't seem like much has changed 🤣
Estimations or pre-time events are a little...well they're guesses.
I guess this slight change in theory is mostly because we have not yet been able to see far enough back in time, by observation of the universe to prove the big bang - so another theory is cooked up, because we can't prove big bang, then we must be wrong.
because look far enough away, and far enough back in time, and we can see the earlier universe-but never the beginning.
Besides...I always like the rubber band theory better, it matches nature more - we see oscillation in nature, equilibrium etc
The real question, if my opinion is asked, would be:
How can any scientist assert that events occurred before the creation of universe, time and matter; the existence of energy can not even be asserted.
Moreover, without the reference of time, noone can prove it either, in a meaningful way
Meaning starting with a Big Bang and ending with a Big Crunch?
At least the rubber band theory is not too big a 'stretch' of the imagination! 🙂
Stephen Hawking wrote that, as far as we are concerned, events before the big bang can have no consequences and so should not form part of a scientific model of the universe.
Easy for him to say! 😀
(maybe a little OT due to the broad spectrum of topics covered in this book), but I just NEED to advertize the book "The fabric of the cosmos" by Brian Greene. One of the best introduction books into these topics by one of the brightest minds on earth! It is quite some work to get through the book, but well worth the effort. Possible even for beginners without advanced mathematics knowledge.
Disclaimer: I am not affiliated with Greene nor do I get any kickback from any bookshop selling this book (free of amazon stocks too!) . I just admire this bright guy! Also interesting to mention is the Lex Friedman series of interviews on youtube ond / or Spotify with the brightest minds on this planet (though it takes years to get through all of them! 😉
Disclaimer: I am not affiliated with Greene nor do I get any kickback from any bookshop selling this book (free of amazon stocks too!) . I just admire this bright guy! Also interesting to mention is the Lex Friedman series of interviews on youtube ond / or Spotify with the brightest minds on this planet (though it takes years to get through all of them! 😉
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He seems well worth checking out! https://en.wikipedia.org/wiki/The_Fabric_of_the_Cosmos
There are different forms of 'brightness' of course.
Physicists and mathematicians excel at theorising and problem solving.
In the grander scale I think it is not very important to separate the BB and Inflation. Its geeky and they where only separated by a very small fraction of a second. Naming is old and dated and perhaps leading in the wrong direction - as is the "black hole" name. We know more know. If I was to name the "creation" event phases I think the inflation stage is the bang bit really and what followed shortly is more the thunder of the lightning bang 🙂 But as you might have experienced, being really close to a lightning strike, you cant tell the bang and thunder apart really.
Also, the BB did more than create the "observable" universe as you wrote above. It did the whole universe.
The Siegel article I suppose is partly speculative. All he says is not proven facts or is it? I think it should state that in the beginning...
And as usual....
//
Also, the BB did more than create the "observable" universe as you wrote above. It did the whole universe.
The Siegel article I suppose is partly speculative. All he says is not proven facts or is it? I think it should state that in the beginning...
And as usual....
//
Has the terminology in cosmology changed over the decades? I read that article and clicked over to the on in the sentence "But the Big Bang wasn't the very beginning of the Universe." https://www.forbes.com/sites/startswithabang/2017/09/21/the-big-bang-wasnt-the-beginning-after-all
I read and heard about the inflationary period when I was first reading cosmology in the early 1980s. There certainly was an inflationary period, immediately after the Singularity (which decades ago was apparently "the" explanation of how everything started, but I'm willing to put aside whether a state of infinite energy density ever existed), and during this time (yes, I know, time "as we know it" didn't exist before this and it's questionable whether it existed "then") the universe expanded at faster than the speed of light (reiterating what I said about time and also applying it to space). At some infinitesimal time (maybe 10^-20 or 10^-40 second) the "universe" had blown up to the size of a beach ball, and of course kept on going for a while. It was (quite) some time later that whatever existed cooled down enough to create subatomic particles and such, and then later cool down enough to form helium.
But all of this was considered "The Big Bang." I'm a little tempted to see if I can remember the authors and books I read back then to verify this, but I consider that a lot of trouble, as I rarely reread books.
Reading up a little more online, I'm tempted to think the "inflationary period was BEFORE what we call the Big Bang" idea is mostly from that/those Forbes writers.
From https://en.wikipedia.org/wiki/Inflation_(cosmology)
"In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from 10−36 seconds after the conjectured Big Bang singularity to some time between 10−33 and 10−32 seconds after the singularity."
So this inflationary period was very, very, (VERY!) short. I haven't seen anything that says, but I'm guessing that the inflationary period ended when the expansion rate slowed down to the speed of light.
From https://en.wikipedia.org/wiki/Big_Bang :
"The Big Bang theory is the prevailing cosmological model explaining the existence of the observable universe from the earliest known periods through its subsequent large-scale evolution."
There's also this from the same page. It seems to be a little vague as to exactly what it's referring to:
"After its initial expansion, an event that is by itself often called "the Big Bang", the universe cooled sufficiently to allow the formation of subatomic particles, and later atoms."
So it's saying the initial expansion itself is what's often called the Big Bang?
To create heavier periodic table elements such as Iron etc on the periodic table, the more energy is required - typically supernova of more than one large star. The expelled elements then become available for another star/planet composition.
The interesting question I have is - if there's a sea of large stars going bang then typically they go supernova and a heavy star or a blackhole results.. If there's lots occurring in close proximity (in the early universe) then does that mean blackholes can be destroyed with enough energy? Or once the change in entropy from outside and inside got to a threshold that the laws of physics changed to enable stable singularities?
I say this without references. OK, a bit slack. But apparently our Solar system grew up in a cluster of light Hydrogen Gas and Heavy elemental debris from SuperNovas.
Where did the rest of it go?
Not far away it seems. Think 180 LY.
This is how Cosmic expansion works. James Webb is on it. We must know. We will know.
Where did the rest of it go?
Not far away it seems. Think 180 LY.
This is how Cosmic expansion works. James Webb is on it. We must know. We will know.
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First of all, let's not confuse cosmic inflation with the metric expansion of space.
The former preceded the big bang and the latter is occurring in our universe right now.
However, space is not expanding within our galaxy, as gravitational attraction between its constituents overcomes metric expansion.
Neither is space expanding between the galaxies in our local cluster, as their mutual gravitational attraction prevents it.
Where the metric expansion of space does occur is in the vast, empty voids between galactic clusters, where gravity cannot prevent it.
According to Stephen Hawking, inflation explains the bang in the big bang!
The expansion due to inflation was far more extreme than the expansion predicted by the traditional big bang theory of general relativity in the time period in which inflation occurred.