Built on Facts

Katanas, Beatles, and Fingers.

I wasn’t sure I was doing anything for Halloween this year, so I didn’t have any costume plans. But then today it turned that in fact I was going to a party, and so I needed a costume with only a few hours notice. The costume stores were completely picked-over. What to do? I put on a suit, strapped a katana to the belt, and bought a pirate eyepatch. Bam, corporate raider. And pretty awesome looking too. Cost about a dollar for the eyepatch; I already had the sword.

Some physics? Sure, why not.

Here’s Wired on doing some acoustical science to figure out an impossible Beatles chord on “Hard Day’s Night”.

Here’s Swans on Tea on the free energy claim that’s been circulating of late. I’m going to write about this eventually if I get around to it, or maybe I’ll just wait to write the post until they have a working model. In that case you may be waiting for quite some time…

Here’s a cute physics puzzle from Dirac Sea: given a candle put in a centrifuge, which way will the flame lean? Easy if you’re familiar with a few concepts, but I’d best most people wouldn’t know.

Finally, I think this is kind of old but it’s neat nonetheless. A table saw that uses some snazzy electronics to instantly detect and stop itself from chopping off fingers:


  1. #1 Max Fagin
    November 1, 2008

    Yeah, I found out about that table saw quick stop technology 2 months after one of them sliced halfway through my finger. Oh well, live and learn.

  2. #2 Uncle Al
    November 1, 2008


    Infinite electricity, infinite hydrogen, and willing suspension of disbelief. Who else but Dr. Schund would supply energy plus levity? (Except maybe for Archer-Daniels-Midland)

  3. #3 Peter
    November 2, 2008

    Over at Dirac Sea no one has considered that flames are moving streams of gas. Moving streams of paricles with mass in a rotating (non-inertial) frame of reference will be deflected in that frame due to the Coriolis effect.
    So setting aside possible turbulence in the container due to air flow over the top, the candle flame will tilt inward due to the addition of the radial acceleration term to gravity and the bouyancy thing, but then an inward moving flame will also appear to curve (towards the direction of travel) as a result of the Coriolis effect.

    The walls of the container are going to deflect this air flow, and the gasses will also become more dense as they cool. These cooling gasses will then begin to “sink”, flowing back outwards and downwards, again curving (in this case away from the direction of travel) due to Coriolis effect…. The combined effects will set up a complex non-sysmeteric convection cell which may well be unstable*.

    Candles in a centrifuge are not unlike the weather systems in our atmospere!

    *Even simple flames in “still” air can result in unstable turbulent flow under a variety of conditions linked to complex feed back mechanisms between the air flow and oxygen and fuel supply to various parts of the flame (guttering)