Category Archives: Physics
Did Someone Drop a Minus Sign?
A 275-foot smokestack falls the wrong way after the demolition charges go off. I hope they blamed the kids who got to set off the detonator for screwing it up.
Playing Catch-Up
How Can a Slower Runner Catch a Faster One?
Kinematics, the study of motion and how things move, encompasses the concepts of position, velocity and acceleration, but as anyone who has caught up to someone in a game of tag or on the running track knows, it’s acceleration that’s the most fun element of this concept.
The Show Which Must Not Be Named
ESPN Sport Science on Collisions: Video Break Down
Batman has The Joker, Harry Potter has Voldemort, and I have Sport Science.
Call on Me, Mr. Kotter!
Brainteaser posters aim to get people thinking about physics
One for example asks: “Two filled cola cans, one frozen, one liquid, roll down a short smooth slope – which one gets to the bottom first?”
Ooh, ooh, ooh! I know this one!
The questions are engaging but you have to think before answering. “Most of the questions do surprise,” she said, for example: “A clock on the equator runs slower, faster or identical to one on the North Pole?”
All the Q&A are here; there is a link to a document file for the answers down at the bottom.
Benjamin Banneker
Today in History: November 9. Benjamin Banneker
Banneker spent most of his life on his family’s 100-acre farm outside Baltimore. There, he taught himself astronomy by watching the stars and learned advanced mathematics from borrowed textbooks. In 1752, Banneker garnered public acclaim by building a clock entirely out of wood. The clock, believed to be the first built in America, kept precise time for decades. Twenty years later, Banneker began making astronomical calculations that enabled him to successfully forecast a 1789 solar eclipse. His estimate, made well in advance of the celestial event, contradicted predictions of better-known mathematicians and astronomers.
I’ve gone geocaching in Benjamin Banneker Park, which is how I first learned of him — like many parks named after people, there was a short history on a sign.
Now My Rabbit Ears Are All Wet
Pump-Powered Antennas Could Replace Metal Communications Arrays with Fountains of Saltwater
What they came up with is little more than an electromagnetic ring and a water pump. The ring, called a current probe, creates a magnetic field through which the pump shoots a steam of seawater (the salt is a key ingredient, as the tech relies on the magnetic induction properties of sodium chloride)
I think they meant “stream.”
Physics Wins Again
It’s all about the energy balance
Twinkie diet helps nutrition professor lose 27 pounds
His premise: That in weight loss, pure calorie counting is what matters most — not the nutritional value of the food.
The premise held up: On his “convenience store diet,” he shed 27 pounds in two months.
For a class project, Haub limited himself to less than 1,800 calories a day. A man of Haub’s pre-dieting size usually consumes about 2,600 calories daily. So he followed a basic principle of weight loss: He consumed significantly fewer calories than he burned.
His body mass index went from 28.8, considered overweight, to 24.9, which is normal. He now weighs 174 pounds.
2/3 of his calories from junk food. He improved his cholesterol, too.
Unjiffy Pop
Going Through a Phase
When a laser beam is intense enough, it can interact with the air around it in ways that lead to surprising effects. According to computer simulations to be published in the 12 November Physical Review Letters, the beam can act like a gas of quantum particles (fermions) or like a liquid droplet–and switch between the two as intensity is increased. Observing this transition in the lab would help researchers confirm that they understand the behavior of high intensity lasers in air, which they hope to use for improved transmission of signals across long distances.