morningfoxnorth

What do you think this means? This phrase was invented by Maryn Smith, 10 years old in the 4th grade at Riverview Elementary School, RIverside Montana.

For super accurate purposes, better than 10 cm, how is the position of the geographic north pole defined?

Using the stars and pulsars will not do it -- they can only define the Earth's spin axis, which is NOT the same as geographic north pole. And besides, the spin axis wobbles around and the north pole does not.

Does anyone here know the official modern definition of the geographic north pole? Or more generally, the zero points of latitude and longitude? I'm looking for a definition good down to better than a centimeter.

Have you seen the new video from the Japanese satellite KAGUYA around the moon? Visit http://www.jaxa.jp/index_e.html

The International Telecommunication Union (ITU) plans to stop application of leap seconds to UTC. At a meeting in Geneva, 11-14 September 2007, it was proposed that:

o April 2008: study group to submit recommendation on stopping leap seconds

o During 2008, conduct a mail vote among member states

o 2011: If 70% of member states agree, World Radio Conference will approve the recommendation

o 2013: Application of leap seconds will stop and UTC will become a continuous time scale.

http://www.navcen.uscg.gov/cgsic/meetings/47thMeet...

==> It has been said that this will "break" many astronomical and navigation applications, in about 2 or 3 years, when the difference UTC - UT1 exceeds 1 second. Many countries laws still used "mean solar time" (UT1); there could be legal consequences when the difference gets to 1 minute. Also, in about 3000 years, the sun will be about an hour behind civil time.

When the core of a star runs out of hydrogen, the star contracts (due to a decrease in the core temperature) and this causes the core to heat up again and start fusing helium. Why doesn't the He start fusing smoothly as the H runs out? Why the bounce / oscillation?

News stories say the world's official kilogram is loosing mass -- or is it the other test mass that are gaining weight? What do you think should be the definition of the kilogram, and how would you make one in your multi-million dollar lab?

The "Explanatory Supplement to the Astronomical Almanac" is a great reference book, but it was last published in 1992. When will the next revision be out?

In the 4th century AD in the Roman world, the length of the year was thought to be 365 days, 5 hours, 55 minutes, and 25.4 seconds (in modern units). The modern estimate for the vernal equinox year back then is 365d 5h 48m, 45.9s. How did the ancient philosopher / scientists figure the year with an error of less than 9 minutes?

How did western (Greek and European) astronomers in the fourth century, determine the length of the year so accurately?

http://en.wikipedia.org/wiki/hebrew_cale...

http://www.angelfire.com/pa2/passover/je...

Not just in Yahoo!Answers -- I can count those. But in general, in your experience.