Ok so the diameter of the observable universe is 93 billion light years. That means the distance from the center where the big bang occured to the outer edges of our (observable) universe is roughly 46,5 billion lightyears.
The fastest speed in the universe is the speed of light and the universe is 13,7 billion years old.
Doesn’t that mean that the farthest anything can be from the centre of the universe is 13,7 billion lightyears?
In: Planetary Science
big bang happened everywhere. there is no center.
expansion of space is faster than light, so no.
I appreciate these deep thoughts but Where are you trying to go Elon the beginning of time?
Space itself is expanding.
Think of an ant crawling on the surface of a balloon.
It starts off at a certain point on the surface and moves at a constant speed away from it. At the same time, the balloon is inflating. The distance between the ant and its starting point is increasing faster than it is moving, although it hasnt changed its speed.
> distance from the center where the big bang occurred…
There’s your mistake. There is no such center where the big bang occurred. The big bang occurred everywhere.
Don’t think of the big bang as a conventional explosion think of it as an expansion of the space of the universe. Imagine the universe is the surface of a balloon covered with glitter or dots. The dots/glitter represent all the stuff in the universe. The big bang, and the continued expansion since is like blowing up the balloon. As you blow it up, the surface stretches (space expands) and all the stuff gets further away from each other, with no “center” to the expansion.
I believe you are making the assumption that the stuff 46.5 billion light years must have traveled thru 46.5 billion light years of space in 13.7 billion years. But this is not how it works.
Back near the time of the big bang, there was less space in between things, so that distant stuff didn’t have to travel as far since the universe had not expanded much yet. Once some expansion happened and stuff spread out a little, further expansion of the space in-between the Earth and that distant stuff made that stuff more distant without it actually moving very much.
Sort of like putting two marks a short distance apart on a rubber band while it’s not stretched, then stretching out the rubber band. The marks will appear to move further apart, but they never moved along the rubber band. In this example, the rubber band is the universe, and the two marks are Earth and some distant example object.
* There is no such thing as the “center of the universe”.
* The “observable universe” is called that because it’s the only part we can ever observe. Our location in the universe is not special. We are in the center of a sphere around us simply because anything that exists is in the center of a sphere around it.
There is no center of the universe, all point in it was at the same location during the big bang.
So earth, the Andromeda galaxy and the farthest away galaxy we can observer all are equally the center of the universe. So you need to consider all point the center or no point the center, what you choose a question of what you consider a center to bee.
The big bang is not a explosion on space and stuff that move away in space. It is a rapid expansion of space. The name any typical visualisation in media is misleading. It is once again the expansion of space itself not moving of object in space.
What is at the edge of the observable universe have not traveled 46.5 billion lightyear from us. It is space in-between that have grown, the galaxis have not moved. The distance of two object will increase and neither is moving, that is the case of all object in the universe, it is only when other forcers are stronger like gravity for out galaxy or electromagnetic force for a single rock that distance between object do not get further apart.
There is of course motion of galaxies too, but its effect is minimal compared to the expansion. It is limited by the speed of light and c an be in the opposite direction of the expansion.
Because expansion of the universe it nos motion in the universe the distance between two object can grow faster then light can travel. With the expansion rate we see now is is only over distance of billion of light years that happen. The expansion on the scale of out solar system is in the order of 1 meter per year between the earth and the sun. That is if I correctly remember a calculation I have done.
the centre of the observable universe isn’t where the big bang happened. the centre of the observable universe is earth because it’s where we are observing from. the observable universe expands outwards from us because as time passes, more light from further away has had time to reach us so that we can observe it.
As already mentioned, space ins expanding. Everything in it expands as well. This effect does not affect small stuff like a solar system. Or it does, but the gravitational forces correct the small expansion. On a larger scale, two points in space can expand faster than light speed, if they are far enough away.
A second more strange thing is, that space itself expanded REALLY fast shortly after the big bang. This theory is called inflation theory. So in a fraction of a second the universe expanded from practical nothing to several light years.
So to sum this up, space expansion is not bound to light speeds. There does not seem to be a speed limit to it.
The center of the observable universe is Earth, or wherever your observer is located. The definition of the “observable universe” is a section of the entire universe that is possible to be observed due to physical limitations (mostly speed of light vs the age of the universe vs expansion rate) and it’s always going to be a sphere (of varying size) with the observer in the absolute center.
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