Is the galaxy finite or infinite?

Question

I got into a discussion at school with a teacher about this and I was just curious to know what others thought.

Answer 1

Your use of words is maybe the problem...

We live on Earth which is a Planet.
The Earth circles the Sun along with some other planets forming one Solar System.
The Sun is a star just like other stars (some bigger, some smaller).

Our Sun's solar System is a part of the Milky Way Galaxy which consists of more than 200 Billion other Stars. This particular galaxy is in the shape of a disk and measures 1500 light years in width by about 1.5 light years in thickness.

The Milky Way Galaxy is only one of thousands and thousands of other galaxies in outer space.

This discussion of finite and infinite is pointless when you begin to consider the magnitude of the distances involved in discussing deep outer space. And, your use of the word galaxy in the question seems wrong. I think you meant the Universe. Galaxy sizes can be measured and are not infinite.
The Universe holds all of the galaxies, however, and cannot be measured at this time.

What we do know is that astronomers and scientists using the very best optical instruments available can see objects in deep space out to distances of 13 Billion Light Years in all directions. Further using Radio Telescopes, scientists can detect objects out as far as 40 Billion Light Years. That is not the end of outer space, it is just the limit of usefullness of our current best technology in "seeing" things.

Now, this thing about finite and infinite...Please take a moment and with a pencil and paper, please calculate the number of miles in 40 Billion Light Years. Write down the complete number, not some number to a power of ten. Remember that light travels at 186,000 Miles per Second, and we are talking about 40 Billion Years (not Days, Hours, or Minutes. So in this computation you will need to know the compute the number of seconds in a year.). When you succeed in writing down the actual number of miles (it is not hard, just a lot of zeros...) you will see that the number is incredibly large. It is so large in fact that there is no means of loking at it in relation to anything here on Earth. Since you were able to write down the number, it is not infinite, but it is so cotton picking big that it might as well be infinite. Why? Because no one will ever travel that far, or send radio messages that far, or get replies back, either. A radio message would take 40 Billion years to reach a space ship way out there, and 40 Billion more years to get an answer back. That is how far out there we can detect things, and that is still not the end of space.

If you are having trouble figuring out how to compute that distance in Miles the following will help you:

1 Light Year = 6 Trillion miles 6,000,000,000,000 Miles
1 year contains 365 X 24 X 60 X 60 Seconds

Compute the last number first.
Then multiply that number times 6 Trillion
and that answer gets multiplied by 40 Billion
to produce the number of Miles in 40 Billion Light Years.

I hope this gives you some idea of the vast distances involved in space.

Regards,
Zah

Answer 2

The galaxy is finite, otherwise the Milky Way would be all over the night sky. If you mean the universe, there are three possibilities. One it's infinite. Two it's finite. Three, it's circular, or something like that, which means that if you set off from one place and move in only one direction, you will eventually end up in the same place you started in

Answer 3

This galaxy, the one in which we live, the Milky Way, is finite. There seems to be some confusion on your part regarding the word galaxy, which is probably what led to the discussion with your teacher. I suggest you look it up, then apologize to the teacher, then the teacher should apologize to you for not recognizing the source of your confusion.

Answer 4

Nothing infinite has yet been observed. Therefor as long as you are using a logic system with an "excluded third" axiom as basis for your handling of knowledge (which you implicitly do because nobody has taught you that you don't have to :-)), the universe has to be assumed finite.

And if you are more confused now than you were before then you are actually closer to understanding reality.

Answer 5

The question of no rely if or no longer the universe is finite continues to be one being debated. The CMBR records gathered by way of the WMAP satellite tv for pc exhibits a flat curvature to area interior of 0.5%, a limiteless universe could require a flat curvature or a unfavorable curvature in spite of the undeniable fact that that 0.5% of errors ought to truly mean a effective curvature which may be a finite universe. yet another attitude grow to be the fundamental frequencies in the CMBR, in basic terms simply by fact the backside vibration of a string is set by way of that is length so is the backside vibration in the CMBR desperate by way of the dimensions of the universe and quite a number of the decrease frequencies are lacking which exhibits a finite universe, curiously, the harmonics in the CMBR additionally point out that the universe is a dodecahedron very equivalent to a soccer ball. in spite of the undeniable fact that, the a hundred,000,000 galaxies is predicated on the seen universe that's in basic terms out to the CMBR. that's as a results of the fact the further out we see the further back in time we are observing and the CMBR that's whilst the universe grow to be 380,000 years old grow to be whilst the universe cooled all the way down to 3,000 kelvin and grew to become clean, till now that factor it grow to be thoroughly opaque as a result we are able to in basic terms see to the CMBR no rely how large the universe rather is.

Answer 6

The Milky Way Galaxy is finite-------- along with the universe----- which current estimates place at about 156 billion light years wide.

Answer 7

The galaxy (which one?) is finite. The universe is infinite.

Answer 8

The galaxy is finite, everything has to end at some point

Answer 9

Galxaies are clumps of stars so they're all finite. The question is: is the number of galaxies finite?