Comments on: Questions Show: The Source of Atmospheres, the Vanishing Moon, and a Glow After Sunset

By: Dave

Dave — Sun, 30 Aug 2009 00:32:41 +0000

Concerning the question about the CMB radiation redshifting and blueshifting as one approaches the speed of light, did you forget about the relativistic *transverse* doppler effect?

By: SW Lenz

SW Lenz — Wed, 10 Jun 2009 04:47:04 +0000

Here is a cite for the Gegenschein http://en.wikipedia.org/wiki/Gegenschein

By: SW Lenz

SW Lenz — Wed, 10 Jun 2009 04:40:54 +0000

Should have added to my post that there is the Gegenschein, or Opposition light. It is similar to the zodiac lights. It is directy opposite the sun in the sky and is the perpendicular reflection of the sun off of dust along the plane of the solar system. It could and would provide a faint glow in the east immediately after sunset.

By: Steve in NC

Steve in NC — Thu, 04 Jun 2009 13:38:59 +0000

You say 'no effect if moon disappears' … but don't the Earth and Moon orbit a common center of mass that orbits the Sun? If the Moon went away the earth would shift its center of mass to the place that center of mass used to be … not a big change but probably somewhat violent!!!

By: Mike Wexler

Mike Wexler — Sat, 30 May 2009 17:50:20 +0000

Also you had a question about antimatter going backward in time being the same as matter going forward in time. I think they were referring to Richard Feynman and how he showed that the equations of Quantum Electrodynamics were the same for an electron going back in time and an anti-electron going forward in time. A reference can be found here (http://books.google.com/books?id=SoZhv5feNQ4C&pg=PA181&lpg=PA181&dq=antimatter+backward+in+time+feynman&source=bl&ots=-9KkO1JqI7&sig=7mMzVNU1qWFUX4e8lNoaXLg0vUc&hl=en&ei=DHEhSobwFpGatAOohMH4Aw&sa=X&oi=book_result&ct=result&resnum=1#PPA181,M1)