Stop the Bleeding

Wednesday, January 2nd, 2013

For many centuries, bleeding patients was a standard treatment for many diseases. Cancer? Bleed the patient. Headache? Bleed the patient. Fever? Bleed the patient. Pneumonia? Bleed the patient. Bleeding was accepted medical wisdom.

Perhaps surprisingly to modern patients, bleeding worked, at least some of the time. I.e. the patient would get better. Of course, a lot of the time if the doctor does nothing, the patient still gets better. No one bothered to ask whether it was the bleeding that caused the patient to get better or not. Few people even knew how to phrase the question.

Daylight Standard Time

Saturday, October 4th, 2008

I just checked when Daylight Savings Time begins next year to see if it would be possible to schedule another Birding BoF at SD West 2009 or not. Sadly the answer is no. Daylight Savings Time starts the day before the conference on March 8! It doesn’t end until November!

Let’s face it: “Standard” time is now the odd one out. There’s almost twice as much daylight savings time as standard time in any given year. If all the late risers out there (and candy manufacturers and barbecue vendors) really can’t stand dawn and dusk arriving at a reasonable hour, maybe it’s time to bite the bullet and just eliminate standard time completely.

Adaptive Optics on the Cheap

Friday, September 28th, 2007

I can’t believe this actually works. Can the answer really be this simple and this cheap? Back when I was doing astronomy in grad school, some of my colleagues were spending huge amounts of time, money, and effort to create really fast adaptive optics systems that would bend mirrors just the right way to account for atmospheric noise. Instead can we really just take a bunch of pictures and paste them together in Photoshop?

Well maybe not quite that easy. The more technical release notes:

The camera works by recording the images produced by an adaptive optics front-end at high speed (20 frames per second or more). Software then checks each one to pick the sharpest ones. Many are still quite significantly smeared but a good percentage are unaffected. These are combined to produce the image that astronomers want. We call the technique “Lucky Imaging” because it depends on the chance fluctuations in the atmosphere sorting themselves out.

So they’re still using adaptive optics, but then applying this additional averaging filter to further improve the image. Apparently high speed cameras are also part of the equation so they can take more pictures closer together, which we couldn’t do 15 years ago. (Astronomical photography is harder than regular photography because you have so much less light to use.) Still if you could remove the need for adaptive optics completely, you’d really have something. Adaptive optics systems are still well beyond the reach of the amateur. Computers, CCDs, and Photoshop aren’t though.