Category Archives: Physics
Amongst Our Weaponry …
Our main weapon is surprise. Blah, blah, blah …
Uncertain Principles: Four Things Everybody Should Know About Quantum Physics
4) Quantum physics is not magic. No matter how strange its predictions may seem, quantum physics does not suspend all the laws of common sense. Quantum physics is a rigorous, precise, mathematical science, not some mish-mash of mystical mumbo-jumbo.
Quantum physics does, however, redefine what common sense is. To some extent.
Remember these. Because nobody expects the quantum inquisition.
For more detail, read Seven Essential Elements of Quantum Physics
This Ain't Like Dusting Crops, Boy!
Dispersion of Sound Waves in Ice Sheets
The most striking thing about these recordings is the synthetic-sounding descending tones caused by the phenomenon of the dispersion of sound waves. The high frequencies of the popping and cracking noises are transmitted faster by the ice than the deeper frequencies, which reach the listener with a time lag as glissandi sinking to almost bottomless depths.
And there’s more: …Sounds like Star Wars Blasters (which they do)
[M]any people were thinking about the cause of such sounds and the resemblance to the famous laser gun sounds in Star Wars. First: the dispersion of sound waves, meaning higher frequencies reach the listeners ears earlier than deeper frequencies, is not only an effect experienced in ice sheets, metal is another solid that can perfectly manipulate the speed of frequencies travelling through the material. Because huge thin metal plates are very rare to find (infinte plate called in physics), long wires are the best to experience the dispersion effect. The longer the wire the stronger the down glissando effect. Slinkies are good toys to demonstrate that.
Float Like a Butterfly, Sting like Faraday
Verena Kräusel and her colleagues performed their trick by beefing up an existing electromagnetic-forming machine. Such machines use a bank of capacitors to discharge a current rapidly through a coil. The coil converts the current into a powerful magnetic field. When the component to be worked is placed next to such a machine, the coil induces in it a corresponding field. Like poles repel, and the repulsion between the two fields is strong enough to make the metal distort.
Alternate Histories
Lasers would never have shone if Mandelson had been in charge
Can’t really speak to this, as I have no familiarity with the British funding climate (other than knowing the have been cutting budgets). But this would be one strength of science funding, that many countries deem it worthwhile, and recognize that funding basic research is a necessity. Fundamental discoveries are the raw material of later applications, once the field matures.
The Replacements
If it sticks, force it. If it breaks, it needed replacing anyway.
Uncertain Principles: Eucatastrophe in Physics
Sometimes, an equipment failure can be the best thing that happens to an experiment. This is particularly true in labs that rely on short-term labor like post-docs (who are generally hired for about two years) and graduate students (who are in a given lab longer, but typically in charge of the experiment for only a few years), where kludgey short-term solutions implemented in order to get fast results can become locked in as new experiments build on the first one.
I’m proud to say that there is no duct tape in the devices we’ve built. It exists in one or two places in the lab (even involving ductwork). When you’re in it for the long haul, there’s more incentive to do things right. But I remember at TRIUMF, we needed a variable voltage reference, which ended up being a 2 9V batteries in series discharging slowly through a MegaOhm-ish potentiometer acting as a voltage divider. Dial up what you need, and it lasted long enough that it was easier to replace the batteries than do up a proper circuit.
Watt's Up With That?
YoGen Makes a Splash in Pull-String Charging
A 5 Watt charge can be generated with a very easy pull of the string. It doesn’t matter how fast or slow you pull, the same charge is generated.
…
I also got a demonstration of their prototype pedal-powered charger for laptops, which is reportedly capable of a 50 Watt charge, with just an easy push of a pedal.
The problem, of course, is that Watts is a unit of power, not energy, which is what they mean by “charge.”
Roll Up with the Magical Mystery Tour
Of Mice and … Oil
Oil Drop Navigates Complex Maze
Diffusion of the chemical gives you a concentration gradient, which gives you a chemical potential gradient. It’s all “downhill” from there.
All Done Here
The Onion: World’s Physicists Complete Study Of Physics
“Yeah, that about does it for physics,” said IUPAP member Sukekatsu Ushioda, powering down Japan’s Super Photon ring particle accelerator. “All done. Math can pretty much take it from here.”