A week and a half ago, when the advent calendar reached Newton’s Law of Universal Gravitation, I said that it was the first equation we had seen that wasn’t completely correct. Having done our quick swing through quantum physics, the time has come to correct that equation: If you say “Einstein equation” to a random… Continue reading The Advent Calendar of Physics: Einstein’s Gravity
Category: Physics
The Advent Calendar of Physics: Schrödinger
Newton’s birthday (in the Julian calendar) is Sunday, so we’re in the final days of the advent calendar. Which means it’s time for the equations that are least like anything Newton did, such as today’s: This is the Schrödinger equation from non-relativistic quantum mechanics. If you want to determine the quantum state of an object… Continue reading The Advent Calendar of Physics: Schrödinger
The Advent Calendar of Physics: Hydrogen
Today’s equation in our march to Newton’s birthday is actually a tiny bit out of order, historically speaking: This is the Rydberg formula for the wavelengths of the spectral lines in hydrogen (and hydrogen-like ions), with R a constant having the appropriate units, and the two n‘s being two dimensionless integers. This equation was developed… Continue reading The Advent Calendar of Physics: Hydrogen
Experiment vs. Theory: Where Did It All Go Wrong?
Over at Backreaction, Bee is running an advent calendar of her own, with amusing anecdotes about famous physicists. Apparently, it’s a good year for advent calendars. A couple of days ago, her story was a famous one about Heisenberg nearly failing to get his Ph.D. because he disdained experiment: Wien wanted to fail Heisenberg, but… Continue reading Experiment vs. Theory: Where Did It All Go Wrong?
The Advent Calendar of Physics: Einstein’s Nobel
Yesterday’s equation was the first real result of quantum theory, Max Planck’s formula for the black-body spectrum. Planck never really liked the quantum basis of it, though, and preferred to think of it as just a calculational trick. It wasn’t until 1905 that anybody took the idea really seriously, leading to today’s equation: From the… Continue reading The Advent Calendar of Physics: Einstein’s Nobel
The Advent Calendar of Physics: Science Works
Moving along in our countdown to Newton’s birthday, we come to 1900, and one of the most revolutionary moment in the history of physics, represented in today’s equation: This is Max Planck’s formula for the spectrum of the “black-body” radiation emitted by a hot object at temperature T. It’s also the equation highlighted on what… Continue reading The Advent Calendar of Physics: Science Works
The Advent Calendar of Physics: Entropy
As I said yesterday, I’m going to blow through another entire subfield of physics in a single equation, as our march toward Newton’s Birthday continues. Today, it’s statistical mechanics, a very rich field of study that we’re boiling down to a single equation: This is Boltzmann’s formula for the entropy of a macroscopic system of… Continue reading The Advent Calendar of Physics: Entropy
The Advent Calendar of Physics: Ideal Gas
Once again, the advent calendar is delayed until late at night by a busy day with SteelyKid– soccer in the morning, playing with a trebuchet after lunch, then Arthur Christmas at the Colonie mall. We’re running low on days to honor great milestones in physics, though, so I don’t want to skip a day entirely.… Continue reading The Advent Calendar of Physics: Ideal Gas
The Top Physics Breakthroughs of 2011
Physics World has released its list of the top ten breakthroughs in physics for the year, and it doesn’t include either fast neutrinos or the Higgs boson: The two physics stories that dominated the news in 2011 were questions rather than solid scientific results, namely “Do neutrinos travel faster than light?” and “Has the Higgs… Continue reading The Top Physics Breakthroughs of 2011
The Advent Calendar of Physics: Faraday
Moving along through our countdown to Newton’s birthday, we have an equation that combines two other titans of British science: This is the third of Maxwell’s equations (named after the great Scottish physicist James Clerk Maxwell), but it originates with Michael Faraday, one of the greatest experimentalists of the day. Faraday was a fascinating guy,… Continue reading The Advent Calendar of Physics: Faraday