Monthly Archives: September 2010

Make It Un-So

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Tractor beams come to life

The device works by shining a hollow laser beam around tiny glass particles. The air surrounding the particle heats up, while the dark center of the beam stays cool. When the particle starts to drift out of the middle and into the bright laser beam, the force of heated air molecules bouncing around and hitting the particle’s surface is enough to nudge it back to the center.

So it’s a neat effect. But …

Because this technique needs heated gas to push the particles around, it can’t work in the vacuum of outer space like the tractor beams in Star Trek.

Which won’t stop you from labeling this technique with a Star Trek term that described something that’s only vaguely similar …

Kids, Don't Try This … Anywhere

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Kids Playing With Laser Pointers May Be Aiming for Eye Trouble

Sadly, this is too common, and this is just the latest incident.

He told doctors that he purchased the laser pointer so that he could pop balloons from a distance, burn holes in paper cards and burn holes in his sister’s sneakers.

…

Schmid said the boy wasn’t sure if the laser was dangerous, and he definitely didn’t know it could cause immediate eye injury.

I have a hard time connecting these two statements. Knows it would burn holes in things, but didn’t know it was dangerous.

I'm Not Willing to Believe You

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Question: How long would your Ph.D. have taken if everything worked?

We can use mine as an example. I did my grad studies in Microbiology and Immunology, but basically I was doing biochemistry type work (cancer research with a lot of molecular stuff). It took me just over five years to finish this sucker which is pretty typical in North America. Of course, when I take a critical look at my thesis and calculate: “What if this thesis literally shows all of my work, because everything I did, worked? What if I had magic fingers throughout my research and never had a failed experiment!?”

Using this rubric, I calculate that my Ph.D. in biochemistry/molecular biology type work could’ve taken about, DUM-DUM-DUM…

 

6 months

 

Note that this figure also includes the 3 months needed to write the damn thesis itself! This means that technically my thesis is reflective of only 3 months of successful experiments: or as I like to think of it — four and a half years of failed experiments!

Bull.

OK, it’s possible that the pathway to a degree in Microbiology and Immunology is very different from that of physics, but other than the subject matter, I don’t think so. I’m perfectly willing to believe that the data one uses for one’s thesis is gathered in three months, and my experience is similar, but that’s not the whole story. A Ph.D. is not just the dissertation — you can’t just write off the experience leading up to it. To claim that you could just walk into the lab and take data means that you had the requisite knowledge and lab experience, which you must have acquired as an undergraduate. And I don’t believe it.

To get my physics degree, I had a summer research grant, followed by two years of classes, along with part-time research, before more than three years of full-time research, then writing. I didn’t come into an established lab; I arrived at grad schools the same year my eventual thesis advisor did, so building up the lab took some time. I could have saved some time if things hadn’t broken — a hole in a new vacuum chamber, requiring it to be dismantled and sent back for repair, a broken feedthrough and ion gauge, problems with the atomic beam oven, lasers dying left and right. All of that added to the time it took, but I didn’t know anything about trapping atoms when I started in the lab, and you can’t fake that experience. Even if you start in an established lab, with more senior students to teach you the ropes, it’s going to take time to learn how all the equipment works and how to run everything. Best case for me, I think, would have been four years — two in the classroom and two in the lab. In reality, it was just a titch over six years from start to turning in the finished copy of my thesis.

Anyone out there with realistic estimates of how long your grad school career would have been, had everything gone right? Compare with the actual.

Uncertainty Squared

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Uncertain Principles: What Uncertainty Means to Me– And You, and the Universe

One of the most (if not the most) commonly maltreated physics concepts in journalism is the Heisenberg Uncertainty Principle.

[T]he origin of uncertainty really does spring from the idea of particle-wave duality rather than any ideas related to the act of measurement. It comes from the fact that, fundamentally, the position of a quantum object, like an electron or a photon, is a particle-like characteristic, while its momentum is associated with the wave nature of the object. Mathematically, the momentum of a quantum object is given by Planck’s constant divided by its wavelength (or, equivalently, the wavelength associated with a quantum object is determined by Planck’s constant divided by its momentum).

Perhaps we can start up the group Physicists For The Proper Treatment of the Heisenberg Uncertainty Principle, or PFTPTHUP (which would sound like blowing a raspberry, or Bill the Cat hacking up a furball, either of which could be one’s reaction to seeing the HUP abused in the media)

Can You Level-Up to an "A"?

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Learning Science in a video game

River City is a multi-user virtual environment, based in ActiveWorlds … Students make avatars, talk to citizens in the world (some are dumb AIs, but they can be puppetted by the teacher), and have a workspace in which they can perform water quality tests and other diagnostics, record the results, and create and test hypotheses. The software design includes the ability to record what steps students take, in what order, how often they repeat content lessons or experimental steps, and other aspects of their approach to solving the problem.

It’s not the first time a game has taught science skills, but this time it’s deliberate. I really like how you have the opportunity of creating a mysterious illness for the students to investigate, and this leaves open the possibility of it not being a real one. So instead of the the situation where someone could simply apply memorization to the problem and say, “Oh, the symptoms are X, Y and Z, but not A or B? It’s the plague. Fleas carried by the rats,” you have a number of perturbations which might not correspond to any real-life disease, and which means some actual problem-solving skills are in play. Which is tough(er) to do in physics.

Beavers … iiiin … Spaaaaace

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You need to a flashplayer enabled browser to view this YouTube video

Time lapse footage taken by Oregon State University alum Don Pettit during his time on the International Space Station. This one shows Earth from day to night.

Cool. Especially the aurorae.