Bright full moon tonight
 

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

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...

I snapped this with my 20x image stabilized zoom digicam.

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.

[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.

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

[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]

[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).

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

Paul

[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.

[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.

[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]

You are right, that one was of 2 days before the full moon. This one isn't quite as good but was last night on the full moon.

Jef.

[quote=Jeff Gilchrist;153229]You are right, that one was of 2 days before the full moon. This one isn't quite as good but was last night on the full moon.

Jef.[/quote]
As I just said - comparatively featureless.
Lighting can be critical in photography.

[QUOTE=Jeff Gilchrist;153229]You are right, that one was of 2 days before the full moon. This one isn't quite as good but was last night on the full moon.

Jef.[/QUOTE]If you look carefully, you'll see it's slightly after full moon. The craters on the leading limb of the moon are well defined; those on the other limb are not.

Paul

[URL]http://www.newscientist.com/article/dn16392-weekend-moon-will-be-biggest-of-the-year.html[/URL]

Perhaps some of us may have better viewing conditions than we did last month.

I was lucky enough to be at the Grand Canyon Saturday night for this full moon- See attached.

Norm

It reached perigee on Saturday night and was full on Sunday.
That may explain why your nice photo shows the moon before sunset.

Nice photo, Norm!

- - -

Photo also shows that the practically-full Moon near the horizon is actually of small angular size, not at all looming as seemingly large as it may appear to us when we view that situation first-hand. (Google "moon illusion".)

[quote=Spherical Cow;158514]I was lucky enough to be at the Grand Canyon Saturday night for this full moon- See attached.

Norm[/quote]
Nice photo! If you don't mind, I would like to print that out to put on our wall. If you have a larger resolution perhaps you could email it to r e s p o n s e - a t - t h e m i d d l e h o u s e dot co dot uk

(We have an area of wall reserved for nice photos like this.)

Thanks
Chris

[quote=davieddy;158532]That may explain why your nice photo shows the moon before sunset.[/quote]
The alternative/additional explanation is that the plane of the moon's
orbit is 5 degrees from the ecliptic (earth/sun orbit)

A few years ago I derived a formula for the precession of the
Earth's axis of rotation due to the torque exerted by the sun
on the oblate spheroid.
(Much more instructive than googling if you're up to it)
It involved the earth's moments of inertia,
and angular velocity. It came up with ~25000 years which is apparently
about right. I was was especially chuffed when I treated the moon's orbit
as a ring of radius 250,000 miles and the formula predicted that it
precessed in about 18 years.

I dont know where the intersection of the moon's orbit with the ecliptic
is wrt to the perigee ATM.

I have failed to calculate changes in the orientation of perigee however:(

David

[QUOTE=Flatlander;158540]Nice photo! If you don't mind, I would like to print that out to put on our wall. If you have a larger resolution perhaps you could email it to r e s p o n s e - a t - t h e m i d d l e h o u s e dot co dot uk

(We have an area of wall reserved for nice photos like this.)

Thanks
Chris[/QUOTE]

Sure- the high resolution version will be on its way in a couple of hours. The Canyon is a tremendous place for photography- it's good thing I had borrowed my son's nice digital camera, or I would have gone broke buying film.

Norm

[quote=Flatlander;158540]Nice photo! If you don't mind, I would like to print that out to put on our wall. If you have a larger resolution perhaps you could email it to r e s p o n s e - a t - t h e m i d d l e h o u s e dot co dot uk

(We have an area of wall reserved for nice photos like this.)

Thanks
Chris[/quote]

The Middle House? I thought that was a pub in Mayfield.

[quote=10metreh;159228]The Middle House? I thought that was a pub in Mayfield.[/quote]
I suppose that would make a good name for a pub.
We are the middle house in a row of five and I wanted an easy to remember email address.
When we moved in, the house was painted pink so I registered thepinkhouse.info. Then I realised it was similar to a gay website!
It's painted white now and thewhitehouse.com had already been registered. lol:smile: