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Do anyone understand this ?

I read science article about discover of galaxy that is 13 billion light years, then there is other galaxy 12 billion light years in other direction. The galaxys are 25 billion light years from each other. Nothing move faster than speed of light and universe is less than 15 billion years old so how galaxys are so far from each other.

The light we see is from 12 or 13 billions of years ago so they had to be that far apart then now it’s 13 billion years later so it seem the galaxys would be 50 billion year old but universe is less than 15 billion years old so can any of this be add up?

 

Thank you for any help in understanding. 

 May 13, 2015

Best Answer 

 #10
avatar+33661 
+10

It looks like nobody actually answered your question SquareRoot!  Here's an (admittedly oversimplified) explanation:

 

Suppose you switch on a torch and point it to your left.  At the same time you switch on another torch and point it to your right.  15 billion years later the light beams will be 30 billion light-years apart!

.

 Jun 28, 2015
 #1
avatar+1038 
+10

Start with Hubble's law. Space is continually increasing. That is, time-space is in a perpetual formation. The rate is 72 cubic kilometers per cubic Mparsec per second (± 11.1%) –i.e. give or take a few cubic millimeters.

 

Now, if I could only figure out how to increase this rate for my closet space.

 

 

Edited rate

 May 13, 2015
 #4
avatar+145 
+5

Ya Know why that's cool? Because the stars you see every night are real ghosts! That light you're seeing is from stars that might not even BE there any more! The stars are so far away, that even though that light travels so quickly, it doesn't hit you until billions of years later, after the star isn't even there anymore. You see ghosts every night.

 May 13, 2015
 #5
avatar+118687 
+5

That is a really good question square root  :/

 

Thanks you Nauseated but I think that your answer needs to be expanded upon.

 

Nauseated - it sounds like you need a tardis for a closet.  I thought only women were supposed to have closet problems :/

 

And yes GirlsNightOut the concepts here are very 'out there'    

 May 14, 2015
 #6
avatar+1038 
+10

One great thing about Hubble’s law is it e x p a n d s my a n s w e r, too – no need for me to do it. :)

 

Nauseated - it sounds like you need a tardis for a closet. I thought only women were supposed to have closet problems :/ 

 

Years ago, I often confused telephone booths for TARDISes. To keep it from becoming a total loss, I used the phone to call my feminine side. As you might expect I always got a busy signal -- and lost my dime, too. One time, the phone started ringing as I entered the booth. I answered, and, lo and behold, it was my feminine side calling. She wanted me to do something about Fibber McGee's closet.

 

https://www.youtube.com/watch?v=h9FGC68YcwM#t=13

 May 14, 2015
 #7
avatar+89 
+5

Thankyou for answer to question. I look at next term physics book and see large astro physics section in book. Not know about any thing of this.

I work on capstan equation problem now for many days and still not know how to do it and it is simple as to astro questions. Maybe I ask later and someone here know how to do it.

 

PS what is tardis?

 May 19, 2015
 #8
avatar+118687 
+10

WHAT IS A TARDIS YOU ASK !

 

https://www.youtube.com/watch?v=dUBxHd3bMhg

 

Also, the Tardis is female.  She has her own personality

 

Nauseated was mainly refering to the fact that a tardis is MUCH BIGGER on the inside than it is on the outside!

 May 20, 2015
 #9
avatar+89 
0

I am viewing all the “Doctor Who” videos I can find when I am on holiday. This is a great television program. I am glad you tell me about the program, Melody. I am learning to understand and speak much more English in watching this program. This is much more good than the soap operas.

 Jun 28, 2015
 #10
avatar+33661 
+10
Best Answer

It looks like nobody actually answered your question SquareRoot!  Here's an (admittedly oversimplified) explanation:

 

Suppose you switch on a torch and point it to your left.  At the same time you switch on another torch and point it to your right.  15 billion years later the light beams will be 30 billion light-years apart!

.

Alan Jun 28, 2015
 #11
avatar+118687 
+5

I am glad you enjoy these Squareroot.  I am also a fan of the newer Dr Who series.

 

The original series were from 1963 to 1989.  

They were somewhat more basic than the recent series are.

 Jun 28, 2015
 #12
avatar+89 
+5

Thank you Alan. I understand how that can be.

 

Let say the big bang happened near where Earth is. Then say the big bang blast the energy and matter out in to the universe as a sphere and say it moves at the speed of light for billions of years until it starts making stars and galaxies and still moves very fast while they are forming. Then it takes billions of years for the stars to make light and then the light travels for billions of years back to where the big bang happen.

 

So if the big bang happened near earth, and it takes 13 billions years to go out into space, and some billions of years to become stars and 13 billions of years for it to return the light to earth. This makes it seem the universe has to be 26 billions of years plus the billions of more years for the big bang energy to become stars.

 

If the big bang happen billions of light years from where Earth is now, it also seems the universe would be much more than the 15 billions of years. This would show the matter that made the Milkyway moved away from the big bang center as the matter that make the distant galaxies moved in a opposing direction.

 

This explains why the galaxies are 13 billions of light years distant after 6.5 billions of years, but not how the light have time to travel from a distant galaxies to the Milkyway and Earth, because this means 6.5 billions of years to go to where they are then 13 billions of years for the light to travel from there to here and that adds to 19.5 billions of years and that dose not count the billions of years for the stars to form.

 

I have not ask a question here but I explain why this is not easy for me to understand these concepts. The Hubble constant explain some of this, but it does not explain all of why this does not add up in a normal way. If you have more understanding of this or know a website that can explain more I would be appreciative. I have went to some sites on astrophysics but there are not many that much explain time of universe and distance from stars.

 Jun 28, 2015
 #13
avatar+33661 
+5

The following link might be of use: http://www.atlasoftheuniverse.com/bigbang.html 

 

I would just point out that the Earth (and everything else in our universe) came from within the big-bang.  The big-bang wasn't simply a big explosion in our nearby (or far-distant) space.

.

 Jun 29, 2015

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