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-   -   Bright full moon tonight (https://www.mersenneforum.org/showthread.php?t=11125)

davieddy 2008-12-12 19:31

Bright full moon tonight
 
[URL]http://www.newscientist.com/article/dn16266-tonights-moon-is-biggest-in-15-years.html[/URL]

mart_r 2008-12-12 20:52

Thanks for pointing that out. These small events mostly go by unnoticed.

I hope the sky is not too cloudy here in Germany. *takes a look outside* well...

Jeff Gilchrist 2008-12-12 23:24

1 Attachment(s)
I snapped this with my 20x image stabilized zoom digicam.

robert44444uk 2008-12-13 01:54

It was super beautiful here in Dhaka, having dinner outdoors. Moon hung high like a ceiling light. The major mare were crystal clear, even to my imperfect eyes.

cheesehead 2008-12-13 03:51

[quote=mart_r;153101]These small events mostly go by unnoticed.[/quote]Another small event that will go by unnoticed by most folks:

"2008 to be extended by one second"

[URL]http://www.newscientist.com/article/dn16232-2008-to-be-extended-by-one-second.html[/URL]

Yes, it's leap-second season again.

But this is not without controversy. (I know we discussed this before, but can't find the thread now.)

[url]http://www.cl.cam.ac.uk/~mgk25/time/metrologia-leapsecond.pdf[/url] explains a [i]lot[/i] of technical details.

As pointed out at [URL="http://www.cl.cam.ac.uk/%7Emgk25/time/leap/"]http://www.cl.cam.ac.uk/~mgk25/time/leap/[/URL],

[quote]Starting with a [URL="http://hpiers.obspm.fr/iers/info/gazette.48"]UTC Questionnaire[/URL] distributed by [URL="http://hpiers.obspm.fr/"]IERS[/URL] in late 1999, several international scientific organizations ([URL="http://www.itu.int/"]ITU[/URL], [URL="http://www.ursi.org/"]URSI[/URL], [URL="http://www.iau.org/"]IAU[/URL], etc.) have initiated a consultation process of whether the definition of UTC should be modified. In particular, it has been proposed to remove leap seconds from the international reference time (UTC) that is broadcast in radio time signals, which is the basis of almost all regional civilian time zones, thereby effectively decoupling civilian time keeping from the rotation of the Earth.

The main arguments in favour of abandoning leap seconds are:
[LIST][*]leap seconds could cause disruptions where computers are tightly synchronized with UTC;[*]leap seconds are a rare anomaly to deal with, which is a worry in particular with safety-critical real-time systems (e.g., new concepts for air-traffic control entirely based on satellite navigation);[*]exact astronomical time plays no significant role in most people’s daily lives, and those who need to know UT1 exactly know already where to look it up.[/LIST] The main arguments against abandoning leap seconds are:
[LIST][*]there is so far a lack of credible reports about serious problems caused by leap seconds;[*]the assumption that UTC and UT1 differ by no more than a second is hardwired into a huge number of deployed systems (e.g., antennas that track satellites), which cost a lot to modify;[*]system designers who worry about leap seconds simply should use TAI instead of UTC and all we need is more easy access to TAI references;[*]desktop computers and network servers can easily cope with leap seconds and all we need are standardized guidelines on how to steer a computer’s clock around them;[*]we must not give up the >5000 years old human practice of defining time through Earth’s rotation because of unfounded worries of some air-traffic control engineers;[*]abandoning leap seconds would break sundials.[/LIST] Most of the discussion on this proposal has taken place so far on the [URL="http://rom.usno.navy.mil/archives/leapsecs.html"]US Naval Observatory leap seconds mailing list (LEAPSECS)[/URL].[/quote]This page goes on to detail some discussion and proposals during 2003-2005, but nothing since then.

Note "there is so far a lack of credible reports about serious problems caused by leap seconds" -- it's going to take a plane crash to motivate some people to do anything.

10metreh 2008-12-13 08:05

It's such a shame that it was cloudy here in England. I only got one peep through a gap in the clouds.

davieddy 2008-12-13 14:48

[quote=10metreh;153142]It's such a shame that it was cloudy here in England. I only got one peep through a gap in the clouds.[/quote]
Indeed. Weather is even worse than usual ATM.
However it was especially clear for a spectacular lunar eclipse a year or
two ago.
[URL]http://mersenneforum.org/showthread.php?t=7247&highlight=Lunar+eclipse[/URL]

10metreh 2008-12-13 18:46

[quote=davieddy;153182]Indeed. Weather is even worse than usual ATM.
However it was especially clear for a spectacular lunar eclipse a year or
two ago.
[URL]http://mersenneforum.org/showthread.php?t=7247&highlight=Lunar+eclipse[/URL][/quote]

I remember that one (the eclipse, not the thread).

xilman 2008-12-13 19:24

[QUOTE=cheesehead;153131]abandoning leap seconds would break sundials.[/QUOTE]I love it!

Paul

philmoore 2008-12-13 21:01

[QUOTE=Jeff Gilchrist;153115]I snapped this with my 20x image stabilized zoom digicam.[/QUOTE]

Jeff, when did you take that picture? It looks like it was taken a couple of days before full. We got clouded out here in western Oregon last night, and we are getting snow at the moment. Unfortunately, tonight is also supposed to be the peak of the Geminid meteor shower.

davieddy 2008-12-13 22:01

[quote=philmoore;153216]Jeff, when did you take that picture? It looks like it was taken a couple of days before full. We got clouded out here in western Oregon last night, and we are getting snow at the moment. Unfortunately, tonight is also supposed to be the peak of the Geminid meteor shower.[/quote]
That's what I thought. Taking a photo at full moon
is not the best way to display "geo"graphical features.


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