Monday, March 31, 2014

Cosmos series continues with a journey to and inside a black hole

The National Geographic Series “Cosmos: A Spacetime Odyssey” has continued with “When Knowledge Conquered Fear” (March 23) and “A Sky Full of Ghosts” (March 30 on Fox and 31 on NatGeo).  Neil DeGrasse Tyson continues as host.
  
The first of these gave a biography of Isaac Newton, and also talked about the orbit of Haley’s Comet. But the real importance of the piece was the gradual replacement of knowledge passed down from religious authority to knowledge discovered by science and published in such a way that an ordinary person might be able to assess it without the supervision of political or religious “authorities”. Of course, this has implications for “social capital”, even the kind that Rick Santorum would want.

The second of these episodes was the more novel.  It explained the nature of gravity, and pointed out that when an object is moving, the velocity of the object is not added to the speed of the light that emanates from it.  Tyson briefly reviewed his calendar of time, and then took us on a thought experiment of visiting a black hole.  Time seems to slow down as we approach the event horizon.  (Maybe that’s what happens when we die, if of natural causes.)  If we could enter a black hole, we might find ourselves thrown into a different universe that the black hole “created” with its own “big bang”.

  
On YouTube there is another video where Tyson consider’s Disney’s 1979 film “The Black Hole”, by Gary Nelson, about a space ship perched near the event horizon of a black hole, and discovered by another ship.  I saw this in Dallas but it did not make a big impression. 


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