It's the 100th Anniversary of the "VAR!" plate, when humanity first had physical proof to understand the scale of the Universe. Happy VARDay, everyone!
#Astronomy #Astrodon #HistoryOfScience #Science #Telescopes #MtWilson #VARDay

What's the VAR! plate, you ask? (I mean, I assume a few of you followed me because I'm an astronomer, right?)

So, did you ever see the #FatherTed clip about cows -- these ones are small, those are far away? Space is pretty much like that. In this case, though, the cow was the Andromeda Nebula. Was it small, but close to us? Or huge and really far away? If the Universe was just the Milky Way, it had to be the former. If the latter? Then the Universe is a whole lot bigger!

Part of the issue is that one guy -- Mt. Wilson astronomer Van Maanen -- claimed he saw galaxies rotating. For such rotation to be seen on human time scales, these would have to be small -- or the orbits would be faster than the speed of light!

Astronomers will tell you that, at this time, there was a great debate -- no, a The Great Debate -- between two leading scholars at the Smithsonian Natural History Museum. This debate ignited public interest and set the stage for what was to come.

(These astronomers are probably *vastly* overselling how important this debate was. People with niche hobbies tend to do that with minor events.)

@thomasconnor

It's only 100 yrs since that discovery. 100 yrs. (~3 generations), since we know, that we are living in an island galaxy - surrounded by billions of such galaxies.

The human race exists for at least 300.000 yrs. (~100.000 generations).

Not the only hint showing us, that we live in a very special time period...

Another hint in the grafic below!