Wow! Last night's Secret Science Club lecture by NYU's Dr David W. Hogg was attended by a standing room only crowd at the beautiful Bell House. An overflow crowd in the front room was able to hear the lecture... I think an expansion of the Bell House may be in order!
Speaking of expansion, the talk was about the Big Bang, the event about 13.7 billion years ago which kicked off this universe of ours. As large as that number may seem, it's generally thought that the "lifespan" of a proton is ten to the 33rd years (sorry, can't be arsed using superscripts for a better looking expression of scientific notation), while the universe is a mere 13.7 times ten to the ninth years old. Yeah, the universe is still pretty much a pup.
The universe has been determined to be expanding- light from distant stars shifts toward the red end of the spectrum due to the Doppler Effect, so those stars are moving away from us. The early universe was a lot denser and a lot hotter than it is now- go back far enough, and a lot of the gas in the universe would actually have been plasma... before the formation of protons and neutrons (as the universe expanded and cooled), the matter in the extremely young universe would have been a quark-gluon plasma. Approximately 300,000 years after the Big Bang, the formation of atoms would have been possible.
"The Big Bang" was originally a pejorative name coined by astronomer Fred Hoyle who believed that the universe was relatively unchanging, and that there were many sources of matter, rather than all matter originating at once in a, so to speak, big bang.
As an interesting aside, Charles Darwin noted that hundreds of millions of years would have been necessary for evolution by means of natural selection to have resulted in all of the modern life forms on the earth, but physicist Lord Kelvin determined that the sun was, at best, tens of millions of years old- Kelvin made his determination based on the assumption that the sun's energy was due to its contraction from a less dense state. Nuclear fusion hadn't been discovered at this time (for a good overview, this blog post is a great, and amusing, read. Think of it, Charles Darwin could have revolutionized physics as well as biology!
Dr Hogg also gave an overview of black holes, and mentioned the supermassive black hole at the heart of a typical galaxy.
The talk veered into a more speculative vein, as Dr Hogg opined that it may be possible that multiple universes were formed in Big Bang, each might have different "laws of physics", but laws of physics in observable universe seem to be constant. In a very funny aside, he mentioned a statement by another scientist who joked- just think how fucked we'd be if, instead of three spatial and one temporal dimension, there were two spatial dimenstions and two temporal dimensions.
The observable universe is homogenous and isotropic- there seems to be no observable center to it... wherever you are, you are the center of the universe. Well, last night, the center of the universe was in the Gowanus section of Brooklyn.
I apologize for not doing the lecture the justice it deserves- I'm a little rushed as I write this. It was another great talk, and Dr Hogg was a funny, engaging lecturer who seemed to be having a ball.