“There was no time before big bang” – what does that mean?
In: Physics
It means literally what it sounds like. According to that theory, going into “the past” from the Big Bang would be like trying to go “north” from the North Pole. There simply isn’t anywhere left to go.
Space and time (really spacetime) itself was created at the big bang, according to current beliefs. So, like the other reply mentions, its like asking whats north of the north pole.
Time is the measurement of an object’s duration from one place to another and/or from one state of being to another. For example, you traveled from point A to point B in X amount of time or you are X years old. Because of the four fundamental forces of nature nothing is ever still and everything is always changing state within our concept of space. This is why in physics time cannot be separated from space and is in fact called space/time. Before the Big Bang there was no where to go because there was no distance between anything nor was there a change in a state of being because matter did not yet exist. While many scientists believe that everything was condensed to a single point before the Big Bang, the fact still remains. Whether nothing existed, or everything that does now exist existed at a single point, there was no where to go and nothing changed because matter as we know it did not exist. If there is no matter then there is nothing to measure. If there is nothing to measure then to have a duration of existence and travel from state of being A to state of being B did not exist and could not have existed. Either way, you need matter relative to space to have a duration of existence within and on that space therefore time could not have existed.
So this is beyond an ELI5, but then so is your question. There are theories that suggest at SOMETHING existed before the Big Bang, but string theory is beyond my comprehension and is still kind of an ongoing thing with no real answer about what, if anything, existed back then.
Outside of that, the most basic explanation of how there was no time before the Big Bang is that there was no matter (in the traditional sense) until the Big Bang happened. Time and energy cannot exist without each other. So if there’s no matter, there’s no energy, and there’s no time.
You can also get more philosophical about it – if there is no matter, then nothing exists to experience time. Therefore it cannot exist.
I’m going to try to add another layer to what others have already said
it’s important to keep in mind that we just don’t know some things. In the same way, people would have never comprehended computers 10,000 years ago, it’s likely that our understanding of it all will change drastically in another 10,000 years. It’s the same reason most of our science is based on “theories”. It’s what our theory is, based on our findings, but ultimately, most of science is about proving things wrong rather than proving they’re right. Because of that, it can be quite difficult to actually prove something past theory status.
I think a lot of confusion around this stems from the fact that we don’t have correct terminology to differentiate between the uses of the word ‘time’ (in addition to just being a hard to grasp concept, obviously, but beyond that).
In general, humans tend to use the word ‘time’ to describe a process behind the system that we use to measure the distance between events by a specific metric. We think about X happening and Y happening and time being a tool to describe the ‘distance’ between each event. In terms of describing the universe, ‘time’ is really just another coordinate, one directly tied to ‘space.’ It’s confusing, I think, because when you hear that there was ‘no time’ before the big bang, it’s easy to think about that in the terms that we use time to describe in a daily base; you might wonder, “Well, how long was there no time?” and quickly start to feel like that doesn’t make sense. But as a dimension, I think it starts to make sense. If you think about there not being space for events to occur in, you might think about how you can’t use a system to describe different states between events that never occurred. If one _instance_ (this is what I’m talking about, typically one would use the word ‘time’ here, but it only increases confusion because it’s not the same as the ‘time’ I’ve been talking about) is not any different than any other you compare it to, no entropy, no oscillation of any cesium atom, no change whatsoever on any level has occurred, is it actually different from any other instance? If you were to try to use it as a tool to describe the ‘space’ between events occurring, does it make sense to use it to describe two states that are exactly the same and nothing has occurred to differentiate one from the other? This is why thinking of it as a dimension rather than a descriptive tool makes sense, I think. There was no time, there was no up or down, and there was no left or right.
The Big Bang created both space and time.
The initial event went from essentially nothing to something very large in the tiniest fraction of a second. To be precise, it expanded its volume 10^78 times in 10^(-32) of a second.
We know that as things get more dense, time around it slows down. Rewinding the Big Bang, the Universe was so dense that time stopped and space itself did not exist. There was no ‘before’ because there was no anywhere for a ticking clock nor was there anywhen for a ticking clock to exist within.
“What is south of the south pole” ?
I’ll give an ELI5 that doesn’t include the concept of ‘nothing’ being, because that’s often when comprehension stops.
Consider ‘time’ as the word we give to cause-effect. Something happens, therefore something happens, therefore something happens, and so on. There is no ‘time’ without chains of causes and effects, and the same is true for ‘space’. We exist in permanent states of things affecting things, and that’s what we call spacetime.
But, so goes the (very well founded) theory, that isn’t how the universe always worked! All current causes and effects point back towards a single event where the very concept of ‘cause and effect / spacetime’ began.
We don’t know what ‘was’ before that. Whatever it was, it wasn’t based on cause and effect, and being fundamentally tethered to this state, it’s not likely we’ll ever be equipped to understand.
Tldr: Time is a word we use to describe the constantly changing state of everything, but this state has a clear ‘beginning’, ‘before’ which we lack the tools/minds to describe things.
The idea is that the big bang is everything and before that there was nothing. Which means time didn’t exist either. No universe, not even an empty blackness–true nothing.
Try to remember what it was like before you were born. I imagine that’s pretty close to what the universe was like “before” the Big Bang.
Latest Answers