When Edwin Hubble observed that distant galaxies are speeding away from us in all directions, he discovered the reality that we live in an expanding Universe. Hubble worked to calculate exactly how fast this expansion is happening, creating the Hubble constant – which astronomers continue to refine and reference in their research.
Click here to download the episode.
Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.
“Hubble Constant” on the Astronomy Cast website, with shownotes and transcript.
And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout:
Wow! Everything is moving away from us and earth is at the center of the universe which is as big as how far our most powerfull telescopes can see. What are the odds?
Make a dot anywhere on the surface of a balloon. That dot is the Earth. Now inflate the balloon. Every other point on the balloon’s surface will recede from the dot that marks Earth. What’s more, the farther away another point is, the faster it will recede. Does that mean Earth is at the ‘center of the balloon’?
.
Doug, I’m very familiar with the balloon analogy. But reading it again, I was just thinking. The balloon represents a closed universe because it is finite in three dimensions but boundless in its surface’s two dimensions That universe would eventually stop expanding and contract to a big crunch. We now know that our universe’s expansion is accelerating, meaning it will never stop and contract (unless some universal constant(s) change). This universe is represented by a saddle shape. But a saddle shape does seem to have a center, at least the way it’s usually represented. Could it be that any point in the saddle looks like any other point and still like a saddle? From the pictures normally seen, the saddle point looks ‘special’.
Um, im pretty sure he was being sarcastic =P