Category Archives: Physics

It's Always More Complicated Than You Think

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The Hidden Truths About Calories

Odds are you sometimes think about calories. They are among the most often counted things in the universe. When the calorie was originally conceived it was in the context of human work. More calories meant more capacity for work, more chemical fire with which to get the job done, coal in the human stove. Fat, it has been estimated, has nine calories per gram, carbohydrates and proteins just four; fiber is sometimes counted separately and gets awarded a piddling two. Every box of every food you have ever bought is labeled based on these estimates, too bad then that they are so often wrong.

Now Do the Integrals, Dammit!

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All Possible Photons (pdf alert!)

Subtitled “The conceptual and cognitive art of Feynman diagrams”

Made from stainless steel and air, the artworks grow out of Richard Feynman’s famous diagrams describing Nature’s subatomic behavior. Feynman diagrams depict the space-time patterns of particles and waves of quantum electrodynamics. These mathematically derived and empirically verified visualizations represent the space-time paths taken by all subatomic particles in the universe.
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Gathered together, as in the 120 diagrams showing all possible space-time paths of 6-photon scattering, the stainless steel lines (and their variable shadow, airspace, light, color, form) reveal the endless complexities that result from multiplying and varying fundamental elements.

The Sky's the Limit

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Is There a Limit to How Tall Buildings Can Get?

Ask a building professional or skyscraper expert and they’ll tell you there are many limitations that stop towers from rising ever-higher. Materials, physical human comfort, elevator technology and, most importantly, money all play a role in determining how tall a building can or can’t go.

But surely there must be some physical limitations that would prevent a building from going up too high. We couldn’t, for example, build a building that reached the moon because, in scientific terms, moon hit building and building go boom. But could there be a building with a penthouse in space, beyond earth’s atmosphere? Or a 100-mile tall building? Or even a 1-mile building?

Slicing it Right Into the Entanglement Hazard

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ZapperZ has a takedown of an article that purports to apply QM to golf; the critique is Quantum Physics And ….. Golf?!

He addresses each point but I think he misses one important aspect of the first issue, on entanglement. Creating and maintaining entanglement isn’t easy, but more importantly, there’s the ol’ bugaboo

Entanglement might one day allow us to communicate instantaneously across the light-years of distance between stars. But for golfers, entanglement offers a more practical benefit.

I have watched golfers tee off and then twist and bend their bodies as they follow the flight of their ball, trying to influence the ball’s course through the air. It doesn’t work, of course.

But if the golfer and the ball could somehow be entangled, then every movement the golfer makes would instantly have an effect on the golf ball. The golfer could literally steer the ball in midair.

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The body English would work!

No, no, no; a thousand times no. Entanglement does not allow for instantaneous communication and does not allow you to influence distant objects. Entanglement allows you to do one measurement and determine the states of two particles, with one particle possibly being far away — it does not enable you to change that state.

Nature, Dissin' the Maser

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Microwave laser fulfills 60 years of promise

Because of this [low power] impediment, most in the field gave up on masers and moved on to lasers, which use the same principles of physics, but work with optical light instead of microwaves. Lasers are now used in applications ranging from eye surgery to CD players.

The poor maser lived on in obscurity. It found only a few niche uses, such as boosting radio signals from distant spacecraft — including NASA’s Curiosity Mars rover. Those masers work only when cooled to less than ten degrees above absolute zero, and even then they are not nearly as powerful as lasers.

To paraphrase Ray “Bones” Barboni, this is the exact frikkin’ thing I needed. A little pique after a blogcation to get the blood going again. And to quote Jules Winnfield, “Well, allow me to retort.”

First of all, “microwave laser” is just … wrong. The maser came first, so popularity aside, you don’t just ignore the history. That’s like touting a cover song while ignoring the songwriter who first recorded it. Blasphemy.

Second, and more importantly, the “first practical maser”? The mind boggles. Well, my mind does, anyway. Hydrogen masers have been the best atomic clocks at time scales out to a day or so for quite a while, and even with the advent of laser-cooled atomic clocks in the past decade, they only surpass masers after about a day of integration. (This is why the even more advanced optical clocks you read about every few months cannot be called better, in some sense — they don’t yet run long enough to make a significant contribution to timekeeping). You can make the argument that the world’s timekeeping, backbone for GPS and other timing-dependent technologies is living in obscurity, but I can’t see how that isn’t practical.

Boson Betting

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After Particle Search, Some Wallets May Lose Mass

[The Higgs discovery] prompted a worldwide settling of scores as physicists — inveterate gamblers — examine the data to decide whether it is time to pay up on longstanding bets about the existence of the boson, which has been the object of a 40-year manhunt.

I’m not sure inveterate gambler is correct. This is more like betting on the Super Bowl or the NCAA basketball tournament, on which casual bets are made (or so I hear). I’ve heard stories of how Vegas is more hesitant than other cities to host physics conferences because physicists don’t gamble as much — we know a bit about probability and tend to understand the gambler’s fallacy, and spend time scribbling on napkins talking shop than going to the casino, more so than the typical conference attendee.

A Different Pitch Experiment

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Challenging Batters and Physics Experts Alike

The conflict was this: A split-finger is usually gripped to reduce backspin on the ball because backspin prevents the ball from dropping. The typical Magnus effect on the ball will tilt it slightly in toward a hitter.

“But the particular pitch that was unusual broke away from a right-handed hitter,” Nathan said.

Stumped, Nathan sent the video to the physicist Rod Cross at the University of Sydney in Australia. Cross performed several tests — often using polystyrene balls for better movement — and came up with what he views as a plausible theory. He published his findings in an article in the American Journal of Physics in January.