This conversation is closed.

Help! Are we really expanding?

how could all of the galaxies Hubble saw have been moving away from him in every direction?

If we look forward they should be moving away, but if we look back into the big bang, shouldn't they being moving toward us?

And if we are also moving at the same increasing speed how can there be redshift at all? wouldn't everything appear static, as if we were on an airplane ?

  • thumb
    Aug 8 2012: Take balloon and mark it with a lot of dots. Now blow it up and as it expands you'll see all the dots moving away from each other. This only happens with an expanding surface.

    Be careful, if you blow too much, there will be a big bang.
    • Aug 9 2012: so the fabric of space (balloon surface) is expanding and the galaxies are just along for the ride? does that mean there is a connection between the galaxies and balloon surface?
      • thumb
        Aug 9 2012: The balloon experiment is just an analogy which illustrates the increasing distance between galaxies etc. But here it stops.

        The problem with the Big Bang is that space itself was created and it is space itself that is expanding. For reasons I don't fully comprehend, and i'm not sure anyone does, the universe has no center nor does it have an edge. This is because we are not expanding in space but space it expanding itself.

        Add to this the little complexity of the size of the universe. It is so big that light from distant galaxies travels so far that we are not seeing these galaxies as they are today, but as they were when the light left them, sometimes billions of years ago. So, not only is space expanding, time is also a stretchy mess, at least from where we stand.

        Most physicists have stopped trying to visualize the cosmos, sub-atomic space and quantum mechanics. Instead they have models that are coherent within that context and they visualize those. The human brain is at present not really capable of visualizing 4+ dimensional space-time, which is what these extreme environments are made of. It's fun trying though :o)
        • Aug 10 2012: right, I got the analogy and I know about everything you said. I like you am just trying to comprehend where who and why we are.

          It's an addiction to say the least.. or an escape perhaps.
  • thumb
    Aug 8 2012: Simple trick for you to do to explain this.
    Get two thin pieces of paper, a ruler and a pen.
    Now on one piece of paper draw a 4x4 grid of dots each 1 or 2 centimeters apart from each other so there's a 1 or 2cm gap between all dots.
    Now on the second piece of paper draw the same 4x4 grid BUT double the distance between the dots, so if you chose 1cm now draw them 2cm apart, and if you chose 2 cm now do 4cm apart (I use 2cm and 4 cm shows up better)
    Now pick a dot on the first piece of paper, so for example say the 2nd dot from the left and 1 row down. Now match it up with it's corresponding dot on the other piece of paper by placing the sheets on top of each other so that you can see through them (hold them up to a light if you have to) and the magic begins.
    It will seem as though all the other dots have expanded away from the dot you picked, yet you know this not to be true. What's more is the fact that no matter what dots you pick the same thing will happen.
    this explains why we see red shift and in all directions and why do we see it? Because relative to the other galaxies we are in a fixed position from our perspective as mirrored by the dots you drew. So it appears that we are the centre of expansion, so these statements can be seemingly true at the same time, we are the centre of the universe and everywhere is the centre of the universe.
    Hope this helps.
  • Aug 8 2012: I don't know about the galaxies, but I do know for sure that, year after year, the floor is getting further and further away.
    • thumb
      Aug 9 2012: I am pretty sure that I am shrinking.
  • Aug 9 2012: Is there no retrograde motion?
  • thumb
    Aug 8 2012: Now if the airplane explodes, you, the pilot, the stewardess and the terrorist will all be moving away from each other.