Eli5: How is the size of the universe 95 billion lightyears if it’s only 13.7 billion years old?

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My partner asked me this but I’m hardly smart enough to understand the question. If the Big Bang was ~13.7 billion years ago and nothing can be faster than the speed of light then how is the size of the universe 95 billion light years across?

Please explain this to my like I’m 5. Thank you!

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14 Answers

Anonymous 0 Comments

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Anonymous 0 Comments

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Anonymous 0 Comments

Bard has made me a bit lazy.

The universe is expanding, and it has been expanding since the Big Bang. This means that the distance between two points in space can increase over time. So, even though the Big Bang happened 13.7 billion years ago, the universe is now much larger than 13.7 billion light years across.
In fact, the observable universe is about 93 billion light years across. This means that the light from the most distant objects we can see has been traveling for 13.7 billion years, but the objects themselves are now much farther away than that.
The reason for this is that the universe is expanding at an accelerating rate. This means that the farther away an object is, the faster it is moving away from us. So, even though the light from the most distant objects has been traveling for 13.7 billion years, those objects are now much farther away than that.

Anonymous 0 Comments

Bard has made me a bit lazy.

The universe is expanding, and it has been expanding since the Big Bang. This means that the distance between two points in space can increase over time. So, even though the Big Bang happened 13.7 billion years ago, the universe is now much larger than 13.7 billion light years across.
In fact, the observable universe is about 93 billion light years across. This means that the light from the most distant objects we can see has been traveling for 13.7 billion years, but the objects themselves are now much farther away than that.
The reason for this is that the universe is expanding at an accelerating rate. This means that the farther away an object is, the faster it is moving away from us. So, even though the light from the most distant objects has been traveling for 13.7 billion years, those objects are now much farther away than that.

Anonymous 0 Comments

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Anonymous 0 Comments

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Anonymous 0 Comments

I’m going for even simpler…

Imagine you live in London and a friend sends you a postcard from Paris telling you he is just getting on the train to Istanbul … when you receive the postcard how far away is he?

Does that work , or over simplify … I’m not sure.

Anonymous 0 Comments

I’m going for even simpler…

Imagine you live in London and a friend sends you a postcard from Paris telling you he is just getting on the train to Istanbul … when you receive the postcard how far away is he?

Does that work , or over simplify … I’m not sure.

Anonymous 0 Comments

The other answers are correct but seem to miss one fundamental fact, which is that the speed of light is only a speed limit for *objects* moving within space. Space *itself* is free to expand much faster than the speed of light.

Imagine matter in space as beads on a bungee cord. The beads can only move along the cord at the speed of light, but the bungee cord can stretch as fast as it wants. The space between the beads will expand without the beads themselves actually moving in space.

Anonymous 0 Comments

The other answers are correct but seem to miss one fundamental fact, which is that the speed of light is only a speed limit for *objects* moving within space. Space *itself* is free to expand much faster than the speed of light.

Imagine matter in space as beads on a bungee cord. The beads can only move along the cord at the speed of light, but the bungee cord can stretch as fast as it wants. The space between the beads will expand without the beads themselves actually moving in space.