Comments on: FOLLOWUP: Leap seconds

By: 2008 teve um dia e um segundo a mais! Chega! « Comentários, Críticas, Dicas etc.

Mon, 05 Jan 2009 00:26:35 +0000

[...] Bad Astronmer FOLLOWUP [...]

By: Gary Ansorge

Gary Ansorge — Fri, 02 Jan 2009 17:08:53 +0000

Robert Gift: It’s actually a bit more complicated than that,,,ever bit of meteor that falls to earth has to impact the planet with some velocity and, depending on whether it impacts from a trailing direction(ie, coming up on the planet from behind, impacting against or with the planets rotation) or from head on(with the same caveats) they will impart their mass energy to our angular velocity. On average, it all cancels out. Besides, it took over 4 billion years and the ejection of a large mass into orbit(the moon) to slow our planetary rotation from a six hour day to the current 24. I expect life will be long gone due to solar expansion before the earths rotation stops. Too far in the future for even ME to worry about,,,

Gary 7

By: Jack Hagerty

Jack Hagerty — Fri, 02 Jan 2009 08:31:37 +0000

So why doesn’t the international standards committee that makes up the rules just redefine the length of day in atomic clock terms? Move the 1900 standard to 2000? That’s what astronomers did when shifting from the 1950 ephemeris to the 2000.

- Jack

PS – I belive “second” when refering to the unit of time is short for “second minute,” since it breaks the minute into the same number of pieces that a minute breaks an hour.

By: Mojo

Mojo — Fri, 02 Jan 2009 00:44:31 +0000

Phil, you said, “In fact, one is added almost every year now.” Why haven’t we had one since 2005?

By: Haxe

Haxe — Thu, 01 Jan 2009 23:41:31 +0000

There seems to be an error in this followup post. It says:

Imagine you have two clocks. One thinks there are 86,400 seconds in a day, the other thinks that there are 86,401, so the second clock runs a tad bit slower than the first.

Actually, the second clock will only count 86401 seconds per day if it runs _faster_ than the first clock, not slower.

Haxe

By: Robert Gift

Robert Gift — Thu, 01 Jan 2009 21:42:56 +0000

MASS from METEORS and SPACE DUST
is slowing the earth.
So if we launch more rockets to rid ourselves of some of the mass, and launch them in an easterly direction, we will speed up the earth.

Problem solved!

By: IBY

IBY — Thu, 01 Jan 2009 21:08:57 +0000

I wonder in what year will the Earth’s rotation be tidally locked with the moon’s. ^_^