What is the meaning of Hubble’s Law, which says that all the galaxies in the universe are moving away from Earth at velocities that are proportional to their distances from Earth?

Hubble’s Law leads us directly to conclude that the universe is expanding and that it had a beginning – the Big Bang!

To understand this, consider a simpler, down-to-Earth example. Imagine that we were on the top of the Seattle Space Needle (on a clear day in Seattle) using a telescope to look at traffic leaving the city for a long weekend. Also imagine that we discover that every vehicle on the road happens to be moving away from us at a velocity proportional to their distance (Hubble’s Law v = H d). Thus if we see a minivan 75 miles away going 25 mph, we know H = 1/3. And if we see a sports car 150 miles away, it must be going 50 mph per Hubble’s Law. If none of the vehicles changed their velocities, then where were they 3 hours earlier? Since the minivan covers 75 miles in 3 hours (25 mph times 3 hours), and it is 75 miles away now, it must have been at the base of the Space Needle 3 hours ago. Similarly, the sports car covers 150 miles in 3 hours, so it too was at the Space Needle 3 hours ago. In fact, if every vehicle on the road is obeying Hubble’s Law, then every one of them must have been in the same place 3 hours ago (probably when everyone got off work). This must be true because we can rearrange Hubble’s Law to read d – v/H = 0.

What’s all that got to do with the universe? If all the galaxies are moving away from us at velocities proportional to their distances (Hubble’s Law), as we observe that they do indeed, then all the galaxies must have been in one place at one time long ago – we call that moment the Big Bang.

Hubble’s Law leads us directly to conclude that the universe is expanding and that it had a beginning – the Big Bang!

To understand this, consider a simpler, down-to-Earth example. Imagine that we were on the top of the Seattle Space Needle (on a clear day in Seattle) using a telescope to look at traffic leaving the city for a long weekend. Also imagine that we discover that every vehicle on the road happens to be moving away from us at a velocity proportional to their distance (Hubble’s Law v = H d). Thus if we see a minivan 75 miles away going 25 mph, we know H = 1/3. And if we see a sports car 150 miles away, it must be going 50 mph per Hubble’s Law. If none of the vehicles changed their velocities, then where were they 3 hours earlier? Since the minivan covers 75 miles in 3 hours (25 mph times 3 hours), and it is 75 miles away now, it must have been at the base of the Space Needle 3 hours ago. Similarly, the sports car covers 150 miles in 3 hours, so it too was at the Space Needle 3 hours ago. In fact, if every vehicle on the road is obeying Hubble’s Law, then every one of them must have been in the same place 3 hours ago (probably when everyone got off work). This must be true because we can rearrange Hubble’s Law to read d – v/H = 0.

What’s all that got to do with the universe? If all the galaxies are moving away from us at velocities proportional to their distances (Hubble’s Law), as we observe that they do indeed, then all the galaxies must have been in one place at one time long ago – we call that moment the Big Bang.

Have been unable to get your email address to subscribe for your newsletter; nor have I been able to find it elsewhere on Coast to Coast site to order a "radio" special for your books. You are on the show tonight! August 12, 2009.

ReplyDeleteI believe that dark energy is a cosmological constant, and I have second thoughts on Big Bang theory. Hunch.

Bill Kraham

Then because you can trace the car's origins to the Space Needle, couldn't you trace the motion of three or so galaxies the the approximate center of the universe (or starting point of the Big Bang)? I don't know why anyone would need to know it, but if this were possible I'd think I'd read someone talking about it more often than I do.

ReplyDeleteSorry to come to the post so late but I just found this site.

The observation of type Ia supernovae showed that the cosmological redshift of distant galaxies does not comply with the calculations on the basis of the Doppler effect (the Big Bang theory) and is subject to exponential law of damped oscillations, where the Hubble constant represents parameter of the attenuation electromagnetic oscillations. That is to say that Hubble constant - is quantum amount by which photon's frequency decreases in one period of oscillation. To determine by how much the frequency of the photon has decreased, the Hubble constant must be multiplied by the number of the committed oscillations that is completely consistent with the results obtained by the modern method of "standard candles" (Nobel Prize 2011).

ReplyDeleteA report in the MSU "Hubble's quantum law" (13.03.2013):

http://alemanow.narod.ru/hubbles.htm