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PostPosted: Tue Sep 02, 2008 8:18 pm
by dids
Just read in a scientific magazine that the year 2008 will last one second more than 2007...
This has been announced in July by the International Earth Rotation Service (IERS) and Earth Orientation Parameters (EOP) head manager Daniel Gambis.
This will be to compensate difference between rotation time of the Earth and the atomic clocks...
It will be added to 31st of december, so this day will last 86401 seconds, and not 86400 as usual...

Reference:
ftp://hpiers.obspm.fr/iers/bul/bulc/bulletinc.dat
('last bulletin C' from this page: http://hpiers.obspm.fr/eop-pc/products/bulletins/bulletins.html)

PostPosted: Tue Sep 02, 2008 8:40 pm
by Killiney
I'm confused. Why will this year last longer?

PostPosted: Tue Sep 02, 2008 8:49 pm
by Macha
Killiney, this year we have a leap year (February has 29 days instead of 28 days). This happens every 4 years - next time this will be 2012. It's because of the time that the earth needs to go around the sun - it's not exactly 365 days, so every 4 years a day is "added" to the "normal" year, which has 365 days - then it has 366 days. Hope that helps.

PostPosted: Tue Sep 02, 2008 8:53 pm
by Killiney
Thanks. That kinda makes sense, but if the sun is equal in diameter, why then does it take the Earth longer to go round it?

PostPosted: Tue Sep 02, 2008 8:57 pm
by dids
Macha wrote:Killiney, this year we have a leap year (February has 29 days instead of 28 days). This happens every 4 years - next time this will be 2012. It's because of the time that the earth needs to go around the sun - it's not exactly 365 days, so every 4 years a day is "added" to the "normal" year, which has 365 days - then it has 366 days. Hope that helps.


Sorry Macha, this is not due to that, you are referring to the leap year, but what I reported is anything else; the details are in the links I submitted

PostPosted: Tue Sep 02, 2008 8:58 pm
by Killiney
I've read the links, Dids, merci bien, but I don't understand them. too sciency for me.

PostPosted: Tue Sep 02, 2008 8:59 pm
by dids
Killiney wrote:Thanks. That kinda makes sense, but if the sun is equal in diameter, why then does it take the Earth longer to go round it?


Earth's orbit is not circular, it varies constantly...

PostPosted: Tue Sep 02, 2008 9:01 pm
by dids
Killiney wrote:I've read the links, Dids, merci bien, but I don't understand them. too sciency for me.


no pb, Killiney... 8)

You'll just have to add one more second to the countdown to the next year on 31st december... :mrgreen:

PostPosted: Tue Sep 02, 2008 9:03 pm
by Killiney
lol I'll take your word for it :D I don't really understand why they've put another second onto it, that makes the last minute a minute and one second, so not a minute any more :lol:

PostPosted: Tue Sep 02, 2008 9:14 pm
by dids
to summarize, our clocks give time based on atomic clocks, which is supposed to match rotation of the Earth's itself, but this time there is a little difference...
If you want another astonishing news, in many millions of years the days will last 25 hours, because the Moon is (very) slowly moving away from the Earth... :roll: :wink:

PostPosted: Tue Sep 02, 2008 9:16 pm
by Killiney
WOW! that's a long day! presumably the night will last the same?

PostPosted: Tue Sep 02, 2008 9:48 pm
by dids
Killiney wrote:WOW! that's a long day! presumably the night will last the same?


In fact there will be one more hour in the whole day & night than today... I think I will be a bit old to see it by myself!!! :mrgreen:

PostPosted: Wed Sep 03, 2008 2:05 am
by Turlough
dids wrote:If you want another astonishing news, in many millions of years the days will last 25 hours, because the Moon is (very) slowly moving away from the Earth...


:| The Moon's orbit doesn't determine the length of the day, although it does set the length of the month. Day and night result from the Earth's rotation on its own axis.

PostPosted: Wed Sep 03, 2008 8:00 am
by dids
Turlough wrote:
dids wrote:If you want another astonishing news, in many millions of years the days will last 25 hours, because the Moon is (very) slowly moving away from the Earth...


:| The Moon's orbit doesn't determine the length of the day, although it does set the length of the month. Day and night result from the Earth's rotation on its own axis.


the Moon has an influence on Earth's rotation, as I've read there: http://www.nineplanets.org/luna.html
Also seen that in a documentary called Superscience, in the episode about the Moon

PostPosted: Wed Sep 03, 2008 8:09 am
by Killiney
dids wrote:
Killiney wrote:WOW! that's a long day! presumably the night will last the same?


In fact there will be one more hour in the whole day & night than today... I think I will be a bit old to see it by myself!!! :mrgreen:


Cool :D I wonder what the future'll be like :lol: