Scale of the universe

[Allen ★]

I found this to be cool.

How big does it go, how small does it get.  

https://htwins.net/scale2/

[Kzoo]

That was cool.

 

[jsharr ★]

Freaky if you just grab the slider and expand or contract as fast as it will let you.

[JerrySTL ★]

“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”

― Douglas Adams, The Hitchhiker's Guide to the Galaxy

[Bikeguy]

3 hours ago, Allen said:

I found this to be cool.

Yeah.. that that is cool.  (no pun about the red shift in universe)

I had to look up what is the HDF.   Hubble Deep Field

[MickinMD ★]

What's interesting is that if you try to go beyond the bubble that is the universe, there is no "beyond:" no empty space, nothing.

Yet the universe is currently expanding, creating new space.

So the big question is: Is there enough matter in the universe to slow down the expansion, which began around 16 billion years ago with the Big Bang, bring it to a stop and begin contracting?  If so, does that mean similar expansions and contractions have been going on forever?  Where did it all come from - was there or is there a deity aspect to all this?

But even more interesting, is that we may be able to live a second life backwards (we may not realize it's backwards) if the universe contracts.

Time is a strange property.  To almost everything in nature there is symmetry: left-right, up-down, backward-forward, positive and negative electricity, north and south magnetic pole, etc.

If we meant to pick up a pencil but forgot and moved to the right, we can move to the left and get it.

But, if we burn dinner because we cooked it too long, we can NOT go back in time and un-burn it.  That does NOT fit in with the properties of the universe.

The late, great Stephen Hawking said that Entropy is "the arrow of time."  Entropy is a measure of disorder and, as the universe expands and gets less ordered, the Entropy of the universe is always increasing.  In fact, that's the 3rd Law of Thermodynamics.  So we always see time moving forward.

But, if the universe begins to contract, Entropy will begin to decrease.  So does that mean time will run backwards.  If so, in another 50 billion years, we may all be doing this forum backward - though we may not realize it.  Of course, it may reverse and not do the exact same things in reverse. But it's fun to think about!

[Bikeguy]

2 hours ago, MickinMD said:

Entropy is a measure of disorder and, as the universe expands and gets less ordered, the Entropy of the universe is always increasing.  In fact, that's the 3rd Law of Thermodynamics

Then there is the question about the contradiction between entropy and life.  Life is incredibly ordered and structured.  Increasing entropy not so much.  

2 hours ago, MickinMD said:

Time is a strange property.  To almost everything in nature there is symmetry: left-right, up-down, backward-forward, positive and negative electricity, north and south magnetic pole, etc.

Maybe we just don't know how negative time can exist in our reality of the universe.  

[Dottleshead ★]

On 8/4/2020 at 1:55 PM, Kzoo said:

That was cool.

 

Seconded.