Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Josh Monninger on 19/08/2009 14:30:02

Title: Is everything in the universe moving apart?
Post by: Josh Monninger on 19/08/2009 14:30:02

Josh Monninger asked the Naked Scientists:
   
I heard on "Ask The Naked Scientist (http://www.thenakedscientists.com/ask)" that everything is expanding, Universe-wise.

So, if everything is expanding, and moving away, then does that mean something that is, say, 100 light-years away is slowly becoming farther away?

This is something that has always messed with my mind ever since I was a small boy.

Thank you and I love the show (http://www.thenakedscientists.com/HTML/podcasts/).

Joshua Monninger
Elgin, IL, USA

What do you think?

Title: Is everything in the universe moving apart?
Post by: Ethos on 19/08/2009 16:21:55

Quote from: Josh Monninger on 19/08/2009 14:30:02

Josh Monninger asked the Naked Scientists:
   
I heard on "Ask The Naked Scientist (http://www.thenakedscientists.com/ask)" that everything is expanding, Universe-wise.

So, if everything is expanding, and moving away, then does that mean something that is, say, 100 light-years away is slowly becoming farther away?

The simple answer is yes. However, objects wihtin our local frame may not always appear that way. The reason for this is two fold; Firstly; Objects near to us have their own orbits and paths which may confuse the casual observer in to thinking that this expansion is a false concept. Secondly; Stray objects are also rare possibilities. But when we look at objects at greater distances, we see a universal expansion taking place. The scientific basis for this observation is grounded in the Doppler effect and can be measured by the red shift associated with distant stars and galaxies. Some scientists dispute these findings and suggest that the reason for the red shift is due to tired light. I don't think we have enough information yet to determine the final answer regarding these two opposing views.

Title: Is everything in the universe moving apart?
Post by: Vern on 19/08/2009 17:06:07

Yes; we don't have enough information to really judge between "tired light" theories and expanding universe theories. For most of my seven decades of life I subscribed to the Standard Model and Quantum Theory as it developed. However, of late I have begun to suspect that light really does age and as it ages it loses energy somehow.

Title: Is everything in the universe moving apart?
Post by: Don_1 on 19/08/2009 17:11:52

So it would seem, I tried an experiment on your behalf. I put a £10 note in my wallet, within a short period, it had moved away from my wallet into some politicians wallet.

Title: Is everything in the universe moving apart?
Post by: Ethos on 19/08/2009 21:52:56

Quote from: Don_1 on 19/08/2009 17:11:52

So it would seem, I tried an experiment on your behalf. I put a £10 note in my wallet, within a short period, it had moved away from my wallet into some politicians wallet.

Amazing, I seem to be having the same problem of late!