You know, I have one simple request. And that is to have sharks with frikkin laser beams attached to their heads! ~Dr. Evil Always look on the bright side …unless you’re holding a laser pointing device. ~Unknown The laser is, without a doubt, one of the most ubiquitous, archetypal technologies of modern times. And it is one of the most direct applications of quantum mechanics. But how do lasers work? It All Starts In The Atom The story starts deep within the atom. I’ve previously discuss the fact that particles are waves and that this forces electrons to have
jonah
Jonah is the author of The Physics Mill.
Astrophysics / Physics / Science And Math
Why Black Holes Glow: Accretion Disks
The patient accretion of knowledge, the focusing of all one’s energies on some problem in history or science, the dogged pursuit of excellence of whatever kind these are right and proper ideals for life. ~Michael Dirda Nothing can escape from a black hole, not even light. This is why we call them “black.” One would imagine, then, that black holes are black invisible menaces, lurking out in the depths of space. Surprisingly, though, black holes glow. The cover image shows a radio photograph of the center of the Milky Way. The center glow, Sagittarius A, is partly due to
Physics / Quantum Mechanics / Science And Math
Between the Two Shores: Covalent Bonding
But let there be spaces in your togetherness and let the winds of the heavens dance between you. Love one another but make not a bond of love: let it rather be a moving sea between the shores of your souls. ~Kahlil Gibran Two weeks ago now, I flew to Conway, Arkansas to attend the wedding of my very good friends Vincent and Mary. This and an academic conference got in the way of blogging for a little while but I’m back. As such I decided to a post in their honor about bonding. Not human bonding, mind you,
cosmology / Discrete Math / Geometry / etc.
Quantum Geometry: Causal Dynamical Triangulations
A “quantum gravity expert” is presumably someone well acquainted with the details of our immense ignorance of the subject. I suppose I count. ~John Baez I long ago promised that I would discuss some of my own research. Here’s the first post that makes good on that promise. Today I’ll discuss a theory of quantum gravity. Why Quantum Gravity? Without a doubt, the two greatest advances in physics in the last 120 years were the advent of general relativity and quantum mechanics. These two amazing theories have totally changed the way we see the world. Quantum mechanics describes the
Analysis / Mathematics / Physics / etc.
Between Being and Non-Being: Imaginary Numbers
Imaginary numbers are a fine and wonderful refuge of the divine spirit almost an amphibian between being and non-being ~Gottfried Wilhelm Liebnitz One of the first things we learn how to do is multiply numbers. . That sort of thing. But what if we multiply a number by itself? This is the familiar operation, which we call squaring a number. and . That sort of thing. You can take a number to a power by multiplying it by itself some number of times equal to the power. So if you square a number, you’ve taken it to the second power.
Physics / Quantum Mechanics / Science And Math
Reality Is—The Feynman Path Integral
Will you understand what I’m going to tell you? …No, you’re not going to be able to understand it. … I don’t understand it. Nobody does. ~Richard Feynman on the Path Integral The “paradox” is only a conflict between reality and your feeling of what reality “ought to be.” ~Richard Feynman, in his lectures on physics Quantum mechanics is a very strange beast. Things tunnel and ooze. You can’t know both position and momentum at the same time. These strange properties come from the amazing realization that particles are waves. Not only that, but the amplitude of the wave
Computer Related
R.I.P. Douglas Engelbart
Did you use a mouse recently? Did you type on a keyboard? Did you click on a link? Connect to a computer network? Odds are, if you’re reading this, you have. You can thank Douglas Engelbart (1925–2013) for all of these inventions and more. In December 1950, Engelbart had it all. He was engaged to be married, had a good job as a radar technician, and was generally doing well for himself. At this point, he decided that this wasn’t good enough. He decided he wanted to improve the world and that, although they were in their infancy, computers
cosmology / Physics / Relativity / etc.
Fixing the Early Universe: Cosmic Inflation
Expansion means complexity and complexity decay. ~Cyril Northcote Parkinson This is part three of a series on the early universe. In the first article, I described the history of the Big Bang theory and why we believe the universe started in a colossal explosion. In the second article, I described some inconsistencies in the Big Bang theory that need correcting. Now I’ll explain how the theory of cosmic inflation addresses these inconsistencies and why we might believe it in inflation. This explanation will use ideas from quantum mechanics and general relativity; you can find my articles on these subjects
Education / Physics / Science And Math
How I Got Interested in Physics and in STEM
The Google+ community, +STEM on Google+ Community, is asking people to share how they got interested in STEM. The format is a video. I decided that for this week, I’d record such a video and share it with you all. This is the first time I’ve ever done any kind of video recording, so this was a new experience for me. Hope you like it!
cosmology / Geometry / Mathematics / etc.
A Mess of Cosmic Coincidences: Problems With the Big Bang Theory
The furthest bodies To which man sends his Speculation, Beyond which God is; The cosmic motes Of yawning lenses. ~Robert Frost, I Will Sing You One-0 I apologize for the long time of silence! I graduated from the University of Colorado about a month ago and was immediately assaulted by a huge amount of family affairs… and then caught up in moving. Sorry about this, everyone! My regular Sunday update schedule should resume next week. Last time, I described the theory of the Big Bang. I gave some history of the theory, and some reasons for why we believe