Archive for February, 2013

Banana Power

Could You Build a Banana-Powered Generator?

Interesting thought experiment. However,

I am assuming the energy from the beta decay and electron capture don’t matter. Maybe they really do matter, but antimatter energy is cooler.

The reactions actually release more energy than the 1.02 MeV of annihilation, and since charged particles release their energy as they travel through a material, you’re going to capture much of this energy (not the neutrino energy, though) so it turns out this is a bad assumption, given that only 1 in 10^5 decays give you a positron.

Quantum Heads or Tails

The Quantum Coin: A Simple Look at the 2-State Quantum System

A simple way of picturing [a two=level] system is a coin. A coin is a single object with two sides to it. In the quantum world, the two sides of the coin would have two possible quantum states. A quantum state is a state of a quantized system that is described by a set of quantum numbers. A quantum number is a number that expresses the value of some property of a particle which occurs in the quanta

I'm Still Not Ashamed

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I’ve already explained that I’m not embarrassed about this — it’s tied in with something Sean mentions around the 10:30 mark: you really don’t have to worry about this in order to do quantum mechanics. Apart from the embarrassment bit, I don’t think I have much (if any) disagreement with any other point. This is good stuff.


On Meteors and Megatons

I have two major objections to this form of analysis, where nuclear weapons are used as some kind of barometer for general energy release. The first is about the character of energy release is important — because it affects how these things are felt at the human scale. The second is about whether these sorts of comparisons are actually clarifying to the general public.

I think the objection is ironic, because no protest against measuring nuclear explosions in kilo- or Megatons of TNT is made, although it’s a similar same issue — does detonating 50 kT of TNT give the same result as a nuclear blast with the same yield? Another thing making it a poor argument is that not all nuclear blasts are the same — ground vs airburst, for example. If we are to compare on effect, then you create the bizarre scenario in which a two detonations of the same energy release aren’t classified the same. This isn’t meant to be a precise equivalence.

We can compare earthquakes, at least in energy release, and do so because they are relatively common. Even still, we can’t equate the devastation because it depends on the quality of construction in the affected region. A 7.0 earthquake in Haiti caused of order a quarter-million deaths, while other quakes of similar strength cause few, or none. Meteor impacts, though? We don’t have a common ground for comparison.

As for the suggestion of describing the event in terms of actual damage, sure. I think journalists already tend to do this, though.

Scientific Illiteracy

Scientific Illiteracy

There is certainly a problem, but when it reaches the level of elected officials it has gone beyond a problem of literacy. I’d venture to say that Paul Broun being Chairman of the US House Committee on Science, Space and Technology is not so much illiteracy as bordering on the abdication of responsibility on the part of the GOP. That someone like this could be elected is surely a symptom of the illiteracy in the US, but brings with it a whole new level of problems.

When elected officials, the very people we ask to lead our country, are ignorant of how the world works, how can our country be expected to survive much longer?

Also, I can’t help but think that if meteor impacts had been brought up as a point of discussion a few weeks ago, there would have been a backlash of anti-science opposition, attacking the science and scientists involved and accusations of fear-mongoring. (Now, of course, there’s a possibility of an overreaction and advocation of programs that will be nothing but safety theater.) There seems to be a tendency to deny there is any problem until it has reached a crisis level.

Pole Dancing — With Quadrocopters

Video: Throwing and catching an inverted pendulum – with quadrocopters

As you can see in the video embedded above, at the end of Dario’s thesis two quadrocopters could successfully throw and catch a pendulum.

Many of the key challenge of this work were caused by the highly dynamic nature of the demonstration. For example, the total time between a throw and a catch is a mere 0.65 seconds, which is a very short time to move to, and come to full rest at, a catching position.

Another key challenge was the demonstration’s high cost of failure: a failed catch typically resulted in the pendulum hitting a rotor blade, with very little chance for the catching quadrocopter to recover. A crashed quadrocopter not only entailed repairs (e.g., changing a propeller), but also meant recalibration of the vehicle to re-determine its operating parameters (e.g., actual center of mass, actual thrust produced by propellors) and restarting the learning algorithms.

Bursting Your Bubble Redux

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Getting Your Noisy Ducks in a Row

The Worst Kind of Science Hype

For a scientific theory, that means:

The new theory must be consistent with everything that came before,
The new theory must explain this new observation, and
It must lead to a new prediction of an observable phenomena which can go out and be tested.
Don’t be fooled by these claims; they’re a dime-a-dozen. But one that holds up to scrutiny?

Now, that’s science. Not hype.

I Just Love Reading My Name in the Paper, Butch

Science Online 2013: Science Comics

My contribution in the session was apparently good enough to repeat, so of course I’m going to link to it. It’s actually a different take on the jargon discussion — cartoons have a limited word count and restricted ability to convey information, so sometimes you have to limit the audience to whom you are trying to appeal by requiring that they will be familiar with the unexplained context of the cartoon. Exactly the scenario of a cartoon which is based on the physicists’ spherical cow joke — if you aren’t already familiar with the joke, you won’t understand the cartoon. So there’s a delicate balancing between the scientific literacy (or scientific cultural literacy) of the audience and the humor you’re trying to convey.

Making Snowflakes

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