Thanks Dad. Thinking of you.
Tonight Melbourne got to experience the tail end of a lunar eclipse as the moon rose in eclipse at 17:48. We took a friend on a trip up to the (apparently now closed) Olinda Golf Course to view the moon rise. It was nice and clear and after roaming around a bit to find a place where we should have been able to see the eclipsed moon we found a suitable spot but couldn’t see the moon itself. Mars was visible in the right area but of course the salient point of a lunar eclipse is that the moon is in the earths shadow and so wasn’t findable until it started to exit at third contact. Got a few photos, of which this was the best.
We had to head back down the hill as Donna had an appointment at 7pm but later on our friend called up and said excitedly “Have you seen the moon? Go and look!”. I went out to see but the hills were still in the way then, so later on I headed out with the camera once the moon was visible and got some more photos as the moon headed towards fourth contact (when it exits the shadow of the Earth).
It’d been a while since I’d last told Digikam to scan my collection for faces, and having just upgraded to 3.2.0 I thought it was about time to have another shot at it. However, I’d noticed it was taking an awful long time and seemed to only be using one of the eight cores on this system (Ivy Bridge i7-3770K running Kubuntu 13.04) so I thought I’d see if simply taking advantage of OpenMP could improve things with multithreading.
To do that I just started a new
konsole and (as a first step) told OpenMP to use all the cores with:
Running digikam from that session and starting a face scan showed that yes, it was using all 8 cores, but not really to a great amount. Running
iotop showed it doing about 5MB/s in reads and
latencytop showed that it was spending most of its time in fsync(). Now that’s good, because it’s making sure that the data has really hit the rust to ensure everything is consistent.
However, in this case I can rebuild the entire face database should I need to, and I have about 66GB of photos to scan, plus I wanted to see just how fast this could go. 😉 So now it’s time to get a little dangerous and try Stewart Smith’s wonderfully named “libeatmydata” library which gives you a library (surprise surprise) and helper program that lets you preload an fsync() function that really only does
return(0); (which, you may be interested to know, is still POSIX compliant).
So to test that out I just needed to do:
and suddenly I had 8 cores running flat out.
iotop showed that Digikam was now doing about 25-30MB/s reads and
latencytop showed most of its time waiting for things was now for user space lock contention, i.e. locks protecting shared data structures to stop threads from stomping on each other and going off into the weeds. Interestingly the disks are a lot quieter than before too. Oh, and it’s screaming through the photos now. 🙂
WARNING: Do not use eatmydata for anything you care about, it will do just what it says in the name should your power die, system hang, universe end, etc..
Well, OK, more a kitten than a cat.. 😉
We felt that our adult cat Mini needed a companion and a bit of research indicated that for an adult female a male kitten would give the best chance of a good match. So it was off down to the RSPCA to talk to them about what was possible, and we found they had 3 kittens of which one was male, and he had only just arrived after their internal quarantine and was lovely, so we picked him. Then we hit a hard question – we had to do the registration form for the council and that demanded a name! We were stuck, but then it occurred to us that given we had an adult called “Mini” the obvious choice was going to be “Maxi”.
So meet Maxi Samuel!
He’s remarkably well camouflaged in our house, though that’s not been a problem for him yet.. 😉
This morning was a partial solar eclipse in Melbourne. Back up where we saw the total solar eclipse last November they got an annular eclipse which would have been spectacular, but work is too frantic at the moment bringing up a new machine to even think about going up!
The first glimpse of it was from the train going into work with (of course) eclipse glasses (from Ice In Space) and by the time I got to Richmond I remembered I’d not taken a photo so had a go with my phone and the eclipse glasses and came up with this:
My plan though was to go to the playing fields at the University of Melbourne where I’d learnt before (via Twitter) that there would be some astro folks. There was a small group of people there with a telescope set up to project onto a screen at the rear who were having fun trying to keep it on target as it wouldn’t lock into place. The nice thing about projections like this is that you get a nice big image, like this:
I had a couple of left over eclipse glasses from the total eclipse so I passed them around and left them with them, they seemed to go down well!
Friday night I was at the Mount Burnett Observatory for the talk about the ASV’s New Astronomers Group (NAG), but we took a break from the talk shortly after sunset to look for the two comets in the southern sky that night, C/2011 PANSTARRS and C/2012 F6 Lemmon. It was a lovely clear night, though very windy, and we managed to see both of them. I’d brought my camera and tripod along and got these photographs:
Comet C/2011 PANSTARRS as seen from Mount Burnett Observatory
Comet C/2012 F6 Lemmon as seen from Mount Burnett Observatory
…and this time with a passing aircraft…
Then on Saturday night I got this photo of PANSTARRS from Upper Ferntree Gully, visible as a naked eye object.
Sadly PANSTARRS is heading off to the northern hemisphere so we may not get much more of it here in Australia.
It’s been 5 years now Dad.
My father was a sign writer and glass embosser by trade, working in the business started by his grandfather. He loved old mechanical things and one part of his work that gave him pride was hand painting museum acquisitions to their original standard. Here is a trailer for a steam road wagon originally operated by J.E. Thomas and Sons in Oswestry (and here’s a link to an advert for them, with a different livery).
One summer holiday (1988 I think) I helped him paint three coal railway trucks for the Maritime and Industrial Museum in Cardiff (part of the National Museum at the time), the museum is long gone but they now seem to have moved up to Big Pit museum at Blaenavon).
With just one sleep left to the annual celebration of Sir Isaac Newtons birth on the 25th December I’d like to take the opportunity to wish everyone a very Happy Newtonmas and may gravity not weigh you down too much in the coming new year. 🙂
This photo was taken this evening at Cardinia of the sun setting through grass, the choice of where the real horizontal lies is yours.