So the way I’m reading this is … if I were there when the Big Bang … banged … it would be appear to me that in an instant the universe was all around me. Kind of like being in a pitch black void and then the lights come on and I see all the way to the horizon – which would already be 10 light-years away.
I would have seen no light … the first light didn’t happen for 380,000 years (according to the Discovery Channel.)
I would have heard nothing … would I?
I would have felt intense heat … tens of trillions of degrees.
Nothingness would have been replaced by the universe in an instant.
not to hijack, but I’ve heard various things on what existed at the beginning. Was all the energy in the universe just in a subatomic pinprick, or was all the energy of the universe non-existent and created from nothing?
We can say things about conditions at various times (or at least, attempt to-- There are still a lot of details we’re unsure of), but we can’t say what you would have experienced, because a human couldn’t have existed under those conditions. Or, if you posit some other sort of being that could have existed, then you have to describe what that being is like, before we can even attempt to say what it would have experienced.
In any event, whatever sort of being you were, you had to have, at all times, have been entirely contained within the Universe. And assuming, as seems plausible, that the Universe is infinite, then it must always, at all times, have been infinite. There wasn’t ever a “nothingness outside of the Universe”, because there isn’t any “outside of the Universe”.
But what about time dilation? If the universe were a point-like entity, would that not involve a different meaning to the passage of time? Would the first second be as we know a second or would it be more like millions of years as spacetime puffed out?
As I understand it, space can expand faster than the speed of light, so relativity does not apply, and there is no reason to include time dilation. There is almost certainly universe beyond our event horizon, for example.
The problem with the OP is that it infers someone standing “outside” the universe - but there is no outside the universe, and all space is contained within the horizon of the Big Bang, 10 light years in a second, assuming that is correct. Our everyday commonsense views of experience just don’t work in those conditions.
This is a topic that gets people really confused and there is several things
Firstly if you take the classical big bang model and run it back in time you get a point a finite time in the past where distances (betwen galaxiees, clusters, superclusters, etc) all go to zero. We call this point the big bang. However thinking of the Universe as being spatially pointlike at the big bang can lead you to problems, it isn’t anything really due its singular nature.
The big bang model has been refined to include inflation, which started a vanishingly small fraction of a second after the big bang and finished and vanishingly small fraction of a second later. In addition it is thought that all classical big bang models must fail an even vanishingly smaller fraction of a second before the big bang due to the dominance of quantum effects.We don’t usually include inflationary or quantum effects though when calculating the age or size of the. Universe, unless specifically looking at those effects.
After 1 second, ignoring inflation, etc, the observable universe would’ve been a bit bigger than 1 lightsecond, maybe several lightseconds in size. The article though is talking about the size of the current observable universe though after 1 second, which is the region of space in our current observable universe as it was after 1 second.
