Monthly Archive for October, 2007

Raw problems with Aperture

Published
by
grantkennedy
on 30 October 2007
in computing and photos
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Olympus raw files for exposures over 3.2s come up looking all blown out in Aperture. The files are bigger than usual, so I guess they have some noise reduction information within them that Aperture doesn’t know what to do with.

illustrating the problem

Hopefully someone has a suggestion… and they did!

A solution is to convert to DNG files using Adobe’s DNG converter. A possible advantage of doing this for all files is that the DNG is about half the size of the equivalent ORF, a potentially huge saving on disk space. There are further dicussions about this around the place (e.g.).

Nemesis

Published
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grantkennedy
on 16 October 2007
in news
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I commonly listen to Late Night Live on my way to and from school. It’s an Australian radio show hosted by Philip Adams, who interviews people from pretty much any field you can think of.

Today he was talking to Chalmers Johnson, who has written several books on how the USA has gotten itself into trouble of late. The latest is called “Nemesis,” which draws parallels between the current military overreach of the USA, and the collapse of the Roman empire. The interview was very interesting (get it here). Here’s a wee bit that Johnson said at one point during the interview:

“The world balance of power did not change one iota from September 11 to September 12. If the terrorists were to actually have a major impact upon the USA, it would have to be because we bungled the reaction, which is precisely what we did do. We started to declare something totally unprecedented and not needed, a war on terrorism, a war on the techniques, not a good idea. We refused to even contemplate serious police methods. We could have retained the support of virtually all of the world, including most of the Arab middle east, had we devoted ourselves to running down Osama Bin Laden and his associates in caves in Afghanistan. We knew where they were since we’d helped them build them in the 1980’s in the war with the Soviet Union. Had we done it seriously, not done it just with airplanes, but put serious ground forces into Afghanistan, it probably could have been handled quickly and fairly easily and coolly. Instead, it was seen as an opportunity for the neo-conservatives in the USA to expand presidential powers, to move the center of gravity of the operation of our foreign policy from the Department of State to the Department of Defence. The two old bureaucratic warriors were very skilled, namely Cheney and Rumsfeld, more or less made fools out of two attractive but not apparently terribly bright figures in our government, Colin Powell and Condeleezza Rice, and they also exploited a neophyte president who didn’t really know what he was doing, and was in over his head.”

Johnson was also on another podcast I listen to, Democracy Now, a while ago.

Cape Cod

Published
by
grantkennedy
on 15 October 2007
in photos and travel
. 1 Comment

Talk about your impromptu trips… Arriving home somewhat inebriated on Friday night, I booked a rental car for Sunday with vague plans of going somewhere, and sent a few invites. On Saturday I found that Fall isn’t really over yet, and decided Cape Cod would be a nice, near, new place to visit. Jill and Liz thought the same, so early Sunday we set off.

The car was a bit flasher than usual this time, with heated seats. Unfortunately the stereo was a little dated, not having an iPod jack. We managed to survive and overcome this deficiency by talking…

By the time we were on the Cape itself, it was getting a little ten o’clockish (as Pooh would say). We picked about the only place that looked open in Barnstable and wandered in for an excellent breakfast of eggs benedict. I’ve never been anywhere to eat where everyone got the same thing before.

Going in search of typical and interesting Cape Cod experiences, we first stopped at a beach. Being the time of year it is it was a little fresh out, and the water was pretty much as cold as it looked. We walked along it for a while anyway.

Jill and Liz at the beach

Next up was a more local experience, as we stopped at a road side barn sale. There was pretty much just junk for sale, and we pondered different means by which the purveyors of said junk had come to be in its possession. Perhaps by purchasing junk from the ubiquitous American “antique” shop? We didn’t think there was any way a person could acquire such a lamp collection by accident…

After passing a little lake in Nickerson State Park, we moved on to the Cape Cod National Seashore to tick off a lighthouse. We found it easily thanks to the excellent signage.

Lighthouse in national seashore

Continuing, and getting a little hungry, we went to the tip of the Cape to the lovely Provincetown. Being near the coast we had to have some seafood. I had fish and chips and a beer, yum. We walked off our late lunch by climbing to the top of the Pilgrim monument. The sign said a measly 112 steps, but I’m not sure that it explicitly said that most of the altitude is gained by walking up a big square spiral ramp.

BIG spiral ramp thing

The view from the top was nice, if a little breezy…

With the day nearly gone, we drove to the top end of the Cape for a quick photo before returning to the warmth of the car for the drive back to Boston.

Beach at the top of Cape Cod

We encountered some traffic at a few points, but nothing bad. Apparently the population of Provincetown grows from a few thousand, to something like 60,000 in summer, so I think we had it pretty easy. After a few glimpses of the sunset as we drove along random roads to avoid the traffic, we hit the highway proper.

The rest of the photos are here.

MIT Museum

Published
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grantkennedy
on 13 October 2007
in day to day
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With nothing planned today, I thought I’d go for a look at the MIT Museum. The museum has been in the news here lately, when they opened the Mark Epstein Innovation Gallery.

The “innovation gallery” is a room with some stuff related to current MIT research, like their City Car (which is really clever), and some submarine stuff. My favourite was a sensor thing that looked at a tray of beads, and then projected contours onto them from above. Nifty.

The museum proper has a bunch of different exhibits, on things as diverse as proteins and robotics. Being a techy geeky kind of guy, the robotics was very interesting. I had no idea they had build robots that could run, and even do flips! Another highlight was the art of Arthur Ganson, very cool clockwork like sculptures.

Well worth a visit if you’re in Cambridge.

Olympus 50-200 zoom lens review

Published
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grantkennedy
on 12 October 2007
in photos
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Having just taken delivery of my brand spanking 14-54mm f2.8-3.5 lens to replace the factory one that came with my E-500, I realise I’ve never said anything more about the 50-200mm I got a while ago. So here’s a few comments from an amateur…

First off, the lens feels solid in the hand. It feels like a thousand bucks, which is good since that’s about what it’s worth. I just took it though Peru for three weeks and I think it survived all the dust admirably, especially since it used it more than the normal lens, and we went places like Cerro Blanco, which is a combination of sand dune and desert. I think photos like the one below speak volumes for what one can do with a lens like this…

Child at the llama farm

So what are the bad things? The first downside (though maybe this applies to all lenses, I don’t know) is some reflections when pointed directly at bright lights (e.g. the sun). The way around this is obvious I guess… though I do like sunsets.

sunset in NY, note massive reflection

Another thing is an unevenness in image brightness at medium zooms, like around 100mm. I’ve only noticed this recently in photos with even backgrounds, such as the sky. I guess there’s some vignetting going on or something…

dog nasca line with fading around the edges

Aside from those two things, I love this lens, and currently use it more than the normal 17-45mm (this may change with my new purchase however). I like that it feels solid, I like the sleeve tripod mount (which I use to carry it with sometimes. I don’t own a decent tripod yet, which you need for the weight of the lens), I like that I can get close to people without having to.

So go on, buy it! However, I’m not any more than someone who likes taking nice pictures, so if you want a proper review by someone who knows there are some out there (e.g. here here and here).

gmail POP accounts

Published
by
grantkennedy
on 10 October 2007
in computing
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So for a while I was using the gmail “check other POP accounts” feature, but no more. The last few days I’ve had emails arrive an hour after they were sent, and in one case this led to me missing cake. Apparently the checking frequency drops to an hour after a while. Not good enough I’m afraid…

Paper accepted!

Published
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grantkennedy
on 5 October 2007
in school
. 0 Comments

After four revisions and seven months of extra (part time) work, my second planet formation paper has been accepted, finally! To sum up the paper in a few sentences…

We think that the likelihood of a star forming at least one gas giant planet increases with the mass of the star. There are two reasons for this: Firstly, the mass of the disks surrounding these stars seems to increase with the mass of the star, and therefore so do the masses of protoplanets that form. Secondly, there is probably a threshold protoplanet mass at which gas accretion occurs and giant planets form. Higher mass stars can therefore form protoplanets above the gas giant forming threshold (and therefore gas giants) more easily, because on average they have more material to do so.

The preprint can be found here.

Aperture

Published
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grantkennedy
on 4 October 2007
in computing and photos
. 0 Comments

So being at Harvard I have access to various things at academic rates, so I went out and bought two academic versions of Aperture. I only meant to buy one but got confused along the way…

Anyway, combined with the extra memory I’ve equipped my macbook with, the software runs nicely. It looks pretty and I think I’m reaping the benefits already. It’s much easier to identify crap photos with the loupe, and the interface is just that bit more high tech.

Here is the first photo to come out of it. I came home last night and there were these cool dark clouds rolling over the city out my window.

Clouds out my window

There’s some reflection just above the Prudential center, and evidently 3s is enough to need the noise reduction, but I still loved the clouds.

MacBook Pro needs 2Gb

Published
by
grantkennedy
on 4 October 2007
in computing
. 4 Comments

Were you cheap like me, and bought the cheaper of the two MacBook Pro’s? the one with only 1Gb of ram? tsk tsk…

As long as I’ve had it, I’ve been slightly disappointed with the performance of this supposedly lightning fast notebook. Recently I actually stopped to look at how the memory was doing with the Activity Monitor, and not surprisingly it was sitting on about 1Gb constantly… obviously short of RAM. It only takes running my standard everyday things to do it: Mail, Firefox, iCal, iTunes, Terminal, Emacs, maybe X as well, and it’s all over. And that’s without using iPhoto, Maple, some Python plotting windows or other miscellaneous stuff like rsync’ing 100Gb to my external drive for a backup…

So yesterday I put another Gb in, and voila! It’s a whole new computer, and does things when I ask it. So if you were cheap like me, go spend the $60 or so dollars it costs for a whole new machine!

Planet formation around stars of various masses: The snow line and the frequency of gas giants

Published
by
grantkennedy
on 2 October 2007
in school
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This paper was just accepted to the Astrophysical Journal. It considers a simple disk and snow line model, and uses this to predict the likelihood of stars of different masses harbouring gas giants. We think gas giant frequency increases with stellar mass, which is consistent with observations at present.

In summary, observations indicate that disk mass changes roughly with stellar mass, with a wide distribution of masses at a given stellar mass. Therefore more massive stars on average have more material available for planet formation. In addition, there appears to be a threshold protoplanet mass for forming gas giants of about ten Earth masses. Around more massive stars, a higher fraction of the disks can form protoplanets greater than ten Earth masses, so these stars are more likely to form gas giants.

Recent observations by John Johnson indicate a trend of increasing planet frequency with stellar mass, as our paper predicts. Future observations will improve statistics to solidify this result. In the more distant future, planet discoveries will find how processes like migration and scattering have influenced the distribution of planets we can see now.

The paper can be found through the NASA Astrophysics Data System. For more information on my PhD have a look at the main PhD page.