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zuz
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I just heard that the universe inflated from the size of an atom to the size of our solar system in 100 seconds. Wouldn't that exceed the speed of light?
Let's say you have a beam of light being emitted from one edge of the initial atom-size universe, while it expands to the size of the solar system over 100 seconds. Imagine what happens as the light beam travels while the distances grow.zuz said:I just heard that the universe inflated from the size of an atom to the size of our solar system in 100 seconds.
Wouldn't that exceed the speed of light?
No, although I see where you are coming from. The point about nothing traveling faster than light is that nothing ever overtakes a pulse of light. And that is true during inflation too, because light isn't immune from the expansion of the universe. If a pulse of light is to the left of an atom and heading left, it will always be to the left of that atom.zuz said:I just heard that the universe inflated from the size of an atom to the size of our solar system in 100 seconds. Wouldn't that exceed the speed of light?
Too add to what others have already said, I would point out to you that you are using the word "universe" when you are actually talking about the OBSERVABLE universe. They are not the same thing and if you are interested in cosmology you'll want to learn the difference.zuz said:I just heard that the universe inflated from the size of an atom to the size of our solar system in 100 seconds. Wouldn't that exceed the speed of light?
I think it is helpful first to have a good notion what 'expansion of space' in general and then specifically what 'superluminal expansion' means. The former means that comoving objects get farther apart from each other, in our actual universe the galaxies which participate in the cosmological expansion. The latter (and the former) is shown very nicely in the recommendable article Expanding Confusion of Davis & Lineweaver, Fig 1, top panel "Proper distance, D, (Glyr)". This spacetime diagram(*) shows that the angle of the lightcone in the very early universe is much below 45° (it is 45° in not expanding flat spacetime). You can still imagine two neighboring comoving particles in this era. If one emits a photon it will not reach the other, because this recedes superluminal.zuz said:I just heard that the universe inflated from the size of an atom to the size of our solar system in 100 seconds. Wouldn't that exceed the speed of light?
The speed limit isn't about light - light travels at the speed limit for various reasons, but the speed limit is there whether there is light or not.zuz said:Actually, in the beginning, there was no "light" the universe was opaque.
Because when you feed various matter and radiation equations of state into the equations, that's what you get. You're bumping up against the limits of what anybody knows here.zuz said:How can the universe inflate to the size of the solar system in under two minutes?
Suppose you have a boat that has a maximum speed ot 30 mph. You put it on a river that's traveling at 70mp and then relative to the shore the boat ends up going 100mph. You are asking how the boat could possibly go 100mph when it is supposedly only capable of going 30mph.zuz said:So how did it get so big so fast?
zuz said:I just heard that the universe inflated from the size of an atom to the size of our solar system in 100 seconds.
Inflation is a period of rapid expansion in the very early universe.zuz said:The universe didn't expand, in inflated.
Thinking of the boat as light (or anything else) being carried along by expansion isn't a bad analogy. It isn't a completely satisfactory analogy, of course, but there isn't one. Really the only completely satisfactory answer is to learn the maths of cosmology. If you haven't done that, you'll just have to take our word for it at some point.zuz said:I don't know if this makes a difference or not, but I do know that light does not work that way in reference to the boat.
The Big Bang theory is the most widely accepted scientific explanation for the beginning of the universe. It states that around 13.8 billion years ago, all matter and energy in the universe was compressed into an incredibly dense and hot singularity. This singularity then expanded rapidly, leading to the formation of the universe as we know it.
Scientists determine the age of the universe by measuring the cosmic microwave background (CMB), which is the leftover radiation from the Big Bang. By studying the CMB, scientists can calculate the age of the universe to be around 13.8 billion years.
The concept of "before" the Big Bang is still a topic of debate and speculation among scientists. Some theories suggest that there was a previous universe that collapsed and led to the Big Bang, while others propose that time and space did not exist before the Big Bang.
After the initial expansion of the singularity, the universe continued to expand and cool. As it cooled, particles began to form and eventually combine to form atoms, which then clumped together to form stars and galaxies. Over billions of years, these structures continued to evolve and form the universe we see today.
Dark matter is a mysterious substance that makes up about 27% of the universe. It does not interact with light and cannot be directly observed, but its presence can be detected through its gravitational effects on visible matter. Scientists believe that dark matter played a crucial role in the formation and evolution of the universe, helping to shape the distribution of galaxies and large-scale structures.