Dr. Stephen Meyer
๐ค SpeakerAppearances Over Time
Podcast Appearances
And the first big shift takes place in cosmology.
It actually starts to happen about a century ago.
And it's partly a California story because in Southern California, Mount Wilson, the observatory, they start building these great big dome telescopes.
And because of that, they're able to resolve tiny points of light deep into the night sky.
And in the 1920s, there was still a debate about whether or not
there were any galaxies beyond our own Milky Way.
There were these little smudges that they could see on their photographic plates.
But as they got better and better resolution, better photographic technology, they realized the little smudges were galaxies, represented galaxies in their own right.
And one of the key figures there was Edwin Hubble,
who was able, in a number of my PowerPoint presentations, I actually have his black and white photographic images of the different galaxies, the spiral nebula and so forth.
And so the first thing they discover is we're not alone.
At least there are other galaxies besides ours.
But then they discovered that the light coming from those distant galaxies is being stretched out, which is indicated by the redness in the color
And they realize that if it's being stretched out, that must mean that the galaxies are moving away so that the wavelengths are stretching out.
Like, you probably remember from high school science class, the Doppler effect.
If a train is moving away, the pitch of the whistle goes, mmm, drops.
And so the light similarly lowers in, or lengthens in wavelength and lowers in frequency.
And so this was an indicator that the galaxies in every sector of the night sky were moving away from us, suggesting a universe that's actually expanding.
And then when that was coupled with Einstein's new ideas about gravity, they became aware that it wasn't just that the galaxies were moving away from us, but that space was expanding exponentially.
as the galaxies moved away, that it was the expansion of space that was carrying the galaxies away, and so that we had literally a picture of an expanding universe outward from a beginning point.