Author Archives: Ravi Narasimhan

An Impey Trifecta: Dark matter, strange correlations, and observing time

The online astronomy office hours from the UofA continue apace.  Every week  Prof. Chris Impey answers  ex tempore a mix of questions from planetary science to the fate of the universe from a thirsty audience across the globe.  A large Indian contingent stays up until the wee small hours of their morning to join in.   Part of the fun is pausing the video and trying to figure out the answer  from basic considerations before resuming.  It is fun to be right but more  instructive to be wrong.  I’ve been moved to send in three questions over the past couple of sessions and all have been answered.

  1. When in relation to the Big Bang did dark matter originate?
  2. There is a surprising correlation between supermassive galactic black hole size and the population of old stars in a galaxy. Can telescopes now resolve individual stars in distant galaxies well enough to distinguish old from new to establish this connection?
  3. Observational results come from the successful.  How do astronomers get precious telescope time?

Youtube Channel: Astronomy State of the Art

 

Backyard history: Southern California’s impact on astronomy

Silicon Valley has reshaped the earth, Hollywood has driven our perceptions of it, and not always for the better.  Less well known is the outsized role California has played in understanding our universe.   Mt. Wilson, Mt. Palomar, and their astronomers have had a Copernican impact on where we stand in the grand scheme of things.  The word ‘vision’ gets bandied about a lot these days but George Ellery Hale had it in spades.  Here’s how the two observatories that housed Hubble, Humason, Shapley,  Zwicky, Baade, Rubin, and Schmidt came to be.

The third video from Corning’s Museum of Glass shows that the path to science is not always smooth and that learning from mistakes is the norm.  The original 200 inch pyrex disk for the Palomar primary did not go according to plan and had to be recast.  The second attempt succeeded and even so, it took ten years of painstaking grinding and polishing at Caltech before it was ready for use.

Youtube Channel: Palomar Observatory

Youtube Channel: Irish Astronomy

https://www.youtube.com/watch?v=BL0ZGjF6DrA

Youtube Channel: Corning Museum of Glass

 

Fella of the Royal Society: Q&A with Keith Moore

I have always imagined that Paradise will be a kind of library
— J.L. Borges

No, I haven’t read any Borges but this is one of those quotes that is very popular with my ilk.  But, libraries are indeed wonderful things and I remember hanging out a lot – and later volunteering – at the old Albany (California) Public Library on Solano Avenue in the late 1970s.  Don’t look for it there now, it is a youth center affiliated with the YMCA.  I spent as much time at the Doe and Bancroft as any science major at Cal could.  The specialty books and journals were in Hildebrand Hall but the atmosphere in the general purpose stacks was unbeatable.  The Internet has obliterated what little attention span I once had so sitting down and reading a physical book is next to impossible and yet the lure, the promise, and the perfume of endless shelves of books is still strong.

“Objectivity” is one of Brady Haran‘s strongest and most addicting channels.  Most of the episodes are filmed at the Royal Society‘s Library in London and feature Keith Moore, the hypnotic and wildly popular head librarian who pulls from a bottomless collection of manuscripts, paintings, sculptures, and  instruments from Newton to the present.  The Brits were pieces of work for several hundred years but there can be no denying that they made a few positive contributions to somewhat offset their spherical bastardy.

Visiting the Society’s collections may just be sufficient to deal with the rigors of travel in whatever a post-COVID landscape may look like as well as London’s notoriously high prices.

Enjoy the long-requested Q&A with The Man which includes a very candid answer to a probing viewer question.  Be sure to check out the rest of the channel – some selections below.

Youtube Channel: Objectivity

Nick on ‘brick: Another look at 2001

/tap /tap

Is this thing still on?

Apparently.

I’ve posted previously of CinemaTyler’s excellent but breathless exploration of 2001: A Space Odyssey.  ParallaxNick takes a more leisurely and historical look at the same film. It is less about the filmmaking process and more on its origins, development, context, and implications.  Nick’s videos about astronomy are well worth the watch.

Youtube Channel: ParallaxNick

The time is out of joint: Chris Impey on the tick-tick-tock of the stately clock

Steven Weinberg wrote a famous book, “The First Three Minutes” on the early stages of the universe.  The same universe became transparent to light some 370,000 years later.  There are other landmarks in post-Big Bang time going down to bewildering fractions of a second.

But the early universe was very hot, very dense, and gravitationally very different from the comfortable-to-us 1 g we experience today on the surface of the earth.  Einstein has convincingly shown that spacetime is accordingly divorced from that human experience.   Clocks, for example, are affected by gravity and satnav constellations have to take this into account.  Did the first three minutes flow the same way three minutes flow in the here and now?  I sent that question to Chris Impey’s online office hour and he kindly answered.  It is a tantalizing response and one that will require substantial further study to fully appreciate – perhaps finally diving into the guts of GR.   It makes me wonder even more intensely why we anthropomorphize those intervals the way we do.

Youtube Channel: Astronomy State of the Art

Composer Toru Takemitsu has set the general idea to music.

Youtube Channel: Orquesta Sinfónica de Xalapa