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« happy darwin's birthday: it's a dog's life, part 1 | Main | it's a dog's life, part 2 »


Re: "If you can feel gravity’s influence, you can conclude that he is accelerating." This is a little confusing the way you've phrased it. If you can feel a force pushing you back, it might be due to the force of gravity, or it might be due to acceleration, or it might be a combination of both. Right now I feel myself being pushed into my seat, but my couch isn't accelerating anywhere. The equivalence you've mentioned is exactly why we need additional information to determine the source of the force.

...Stark creates is something far more unique:...

My (now retired) Aunt was a Grammar teacher, and I had many lessons drummed into me early; one of them is that "unique," is NOT a comparative. The news commits this grammar crime "early and often." I thought you'd laugh about it, not take offense.

Inception was great fun (analyzed in WIRED), starting with its spinning pseudosphere top.

Classical (one exception) and quantum gravitations postulate the Equivalence Principle (EP), that all bodies vacuum free fall identically. Einstein’s elevator is definitive. Physics has looked. Bench top Eötvös experiments, lunar laser ranging and the Nordtvedt effect; observation of millisecond pulsar binaries with solar stars (hydrogen plasma), white dwarfs (Fermi-degenerate matter), and pulsars are definitive. No measurable observable violates the EP to 5x10^(-14) difference/average.

Some observables are not measurable. Whose shoes are more divergent, yours or mine? Vacuum has no geometric anisotropy toward massless photons, arxiv:0912.5057, 0905.1929, 0706.2031. Massed bodies remain unexamined, for that is chemistry. Gravitation acts upon mass.

Do opposite shoes vacuum free fall non-identically?

Metaphoric shoes. Do chemically and macroscopically identical, local inverse geometric parity atomic mass distributions vacuum free fall along divergent minimum action trajectories? Covariance versus reflection in space is not required by Special Relativity’s Poincaré group or General Relativity’s Einstein group. Do single crystals in enantiomorphic space groups falsify the EP?
Two parity Eotvos experiments, opposed opposite hands of alpha-quartz or gama-glycine.

Somebody should look. The worst it can do is succeed (re teleparallel gravitation, Einstein et al., 1930). A problem cannot be solved with the thinking that created it (e.g., errorless rigorous Euclid dinged on the surface of the Earth).

Regarding Black Swan, I am sorry but hated this movie because the scenario was so predictable and mostly because I hate when it is not necessary for a plot to show disgusting and sex things just to make people freak out or excited (hetero and homo unnecesseray sex scenes).
I might be old fashioned but I found the movie just ... gross and my lady was closing her eyes every 10 minutes for not throwing up.

Regarding Black Swan in a Physics perspective, the "conservation of angular momentum" explanation about rotational speed increasing while making arms closer to the body is "classical" (with a pun on words) but also always seem an awkard and not sensible explanation to me.

It first make people ask "What the hell is an angular momentum in the first place ?".

So you have to say "Hum hum" and develop quite abstract concepts and the guy surely goes out eventually wondering what question he had asked in the first place...

Another way : tell me if I'm wrong but why not use the "Coriolis effect" instead.
Sure, you could answer that almost no-one knows about Coriolis neither but that's wrong : everyone had one day to walk strangely on a moving merry-go-round to go out of it without falling ... Very easy to explain a Coriolis effect therefore.

Then, what I say is that the dancer HAS to make an horizontal effort to keep the arms in line with the body when they come closer (otherwise, they would go faster around since they had a faster linear speed before the action of making them closer) and the REACTION of this effort to slow down the arms acts naturally on the body by turning it faster... Kinetic energy has to go somewhere anyway...

What people think of that ?

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    Physics Cocktails

    • Heavy G
      The perfect pick-me-up when gravity gets you down.
      2 oz Tequila
      2 oz Triple sec
      2 oz Rose's sweetened lime juice
      7-Up or Sprite
      Mix tequila, triple sec and lime juice in a shaker and pour into a margarita glass. (Salted rim and ice are optional.) Top off with 7-Up/Sprite and let the weight of the world lift off your shoulders.
    • Listening to the Drums of Feynman
      The perfect nightcap after a long day struggling with QED equations.
      1 oz dark rum
      1/2 oz light rum
      1 oz Tia Maria
      2 oz light cream
      Crushed ice
      1/8 tsp ground nutmeg
      In a shaker half-filled with ice, combine the dark and light rum, Tia Maria, and cream. Shake well. Strain into an old fashioned glass almost filled with crushed ice. Dust with the nutmeg, and serve. Bongos optional.
    • Combustible Edison
      Electrify your friends with amazing pyrotechnics!
      2 oz brandy
      1 oz Campari
      1 oz fresh lemon juice
      Combine Campari and lemon juice in shaker filled with cracked ice. Shake and strain into chilled cocktail glass. Heat brandy in chafing dish, then ignite and pour into glass. Cocktail Go BOOM! Plus, Fire = Pretty!
    • Hiroshima Bomber
      Dr. Strangelove's drink of choice.
      3/4 Triple sec
      1/4 oz Bailey's Irish Cream
      2-3 drops Grenadine
      Fill shot glass 3/4 with Triple Sec. Layer Bailey's on top. Drop Grenadine in center of shot; it should billow up like a mushroom cloud. Remember to "duck and cover."
    • Mad Scientist
      Any mad scientist will tell you that flames make drinking more fun. What good is science if no one gets hurt?
      1 oz Midori melon liqueur
      1-1/2 oz sour mix
      1 splash soda water
      151 proof rum
      Mix melon liqueur, sour mix and soda water with ice in shaker. Shake and strain into martini glass. Top with rum and ignite. Try to take over the world.
    • Laser Beam
      Warning: may result in amplified stimulated emission.
      1 oz Southern Comfort
      1/2 oz Amaretto
      1/2 oz sloe gin
      1/2 oz vodka
      1/2 oz Triple sec
      7 oz orange juice
      Combine all liquor in a full glass of ice. Shake well. Garnish with orange and cherry. Serve to attractive target of choice.
    • Quantum Theory
      Guaranteed to collapse your wave function:
      3/4 oz Rum
      1/2 oz Strega
      1/4 oz Grand Marnier
      2 oz Pineapple juice
      Fill with Sweet and sour
      Pour rum, strega and Grand Marnier into a collins glass. Add pineapple and fill with sweet and sour. Sip until all the day's super-positioned states disappear.
    • The Black Hole
      So called because after one of these, you have already passed the event horizon of inebriation.
      1 oz. Kahlua
      1 oz. vodka
      .5 oz. Cointreau or Triple Sec
      .5 oz. dark rum
      .5 oz. Amaretto
      Pour into an old-fashioned glass over (scant) ice. Stir gently. Watch time slow.