Archive for Physics
January 5, 2009 at 5:47 pm · Filed under Physics
It’s NFL playoff time, which means that sports fans will be treated to the sight of the most high-stakes farce in sports, namely the ritual of “bringing out the chains” to determine whether a team has gained enough yards for a first down. We’ve all seen this: the play is whistled dead, a referee un-stacks the pile of players, picks up the ball, and puts it down more or less where the player was stopped. Then he tosses the ball into the middle of the field, to a second referee, who tries to replicate the spot closer to the center of the field. Then a guy on the sideline carrying a big stick (connected by a ten-yard chain to another stick held by another guy) tries to put the end of the stick at the same position as the ball.
Three plays later, the spotting procedure is repeated, and then the […]
Original post by Chad Orzel none@example.com
December 10, 2008 at 5:00 pm · Filed under Physics
I’m a little cranky after a day of reviewing grant proposals, so it’s possible that I’m overreacting. But commenter Neil B has been banging on about quantum measurement for weeks, including not one, not two, but three lengthy comments in Tuesday’s dog post.
For that reason, I am declaring this post’s comments section to be the Official Neil B. Quantum Measurement Thread. Until such time as I declare the subject open again, this is the only thread in which I want to see comments about quantum measurement. Attempts to bring the subject up in comments to other posts– even other posts having to do with quantum mechanics– will be disemvowelled.
So this is not just a public slapping down, I’ll provide some thoughts on the subject below the fold.
Read the rest of this post… | Read the comments on this post…
Original post by Chad Orzel none@example.com
November 20, 2008 at 5:12 pm · Filed under Physics
I seem to have been sucked into a universe in which I’m talking about the Many-Worlds Interpretation all the time, and Neil B keeps dropping subtle hints, so let me return to the whole question of decoherence and Many-Worlds. The following explanation is a recap of the argument of Chapter 4 of the book-in-progress, which will cover the same ground, with cute dog dialogue added.
The central question here is what sorts of things count as producing a “new universe” in Many-Worlds. The scare quotes are because I’ve come around to the opinion that the whole “parallel universe” language does more harm than good for giving people an idea of what’s really going on. Hopefully, I’ll make it clear why as we go on.
Anyway, to be concrete about it, let’s consider a really simple quantum system that may or may not involve the creation of a “new universe”: we have a […]
Original post by Chad Orzel none@example.com
November 14, 2008 at 6:57 am · Filed under Physics, Space, Science, Paranormal, asu, future, time, talk, timetravel, michiokaku, timetravle
JohnKit posted a photo:
I happened to catch this talk tonight:
—–
Beyond Center for Fundemental Concepts in Science at ASU
2008 Sci–Fi or Sci–Fact: Michio Kaku
The Fall 2008 Sci–Fi or Sci–Fact lecture will be given by Dr. Michio
Kaku, theoretical physicist and author of Physics of the Impossible: A
Scientific Exploration into the World of Phasers, Force Fields,
Teleportation, and Time Travel.
Date: November 13, 7:30pm
Location: Arizona State University Sandra Day O’Connor College of Law
School auditorium
Michio Kaku - Wikipedia
Original post by JohnKit
October 29, 2008 at 5:25 pm · Filed under Physics
Last week, I wrote about ion traps as a possible quantum computing platform, which are probably the best established of the candidate technologies. This week, I’ll talk about something more speculative, but closer to my own areas of research: neutral atoms in optical lattices.
This is a newer area, which pretty much starts with a proposal in 1999. There are a bunch of different variants of the idea, and what follows will be pretty general.
What’s the system? Optical lattices use the interaction between atoms and a standing wave of light to produce a periodic array of wells in which individual atoms or groups of atoms can be trapped. A one-dimensional optical lattice looks like a stack of “pancakes” of atoms, a two-dimensional lattice looks like an assortment of tubes, and a three-dimensional lattice looks like a crystal, a regular array of atoms localized at specific points in space.
These lattices can serve […]
Original post by Chad Orzel none@example.com
October 16, 2008 at 6:26 pm · Filed under Physics
One of the annoying things about trying to explain quantum mechanics to a general audience is that the weirdness of the theory forces you to use incredibly convoluted examples. Pop-science books about quantum physics are full of schemes that the producers of the Saw movies would reject as implausibly complicated.
I wish I was posting to say that I had found a way around this, but I haven’t. So here’s another entry in the thriller-movie school of quantum analogies.
Imagine that you and a friend are out hiking, and find yourselves kidnapped by a sinister conspiracy of some sort. You’re taken to a remote island, and shown an apparatus consisting of a dial on the floor and a remote control with a single button. You press the button, and the needle on the dial turns in a clockwise direction. There’s a mark on the rim of the dial at one position, but […]
Original post by Chad Orzel none@example.com
October 9, 2008 at 7:47 pm · Filed under Physics
In the spirit of the previous post, I thought I would provide a short list of the reasons why I am happy to be a physicist in the area of Atomic, Molecular, and Optical (AMO) Physics. Like nearly anyone who hung on long enough to get a Ph.D. in some field, I think the area I work in is the coolest thing ever, and here are some of the reasons why:
AMO Physics is cool because it’s the best field for exploring quantum effects. Pick up a book that deals with fundamental quantum issues– The Quantum Challenge, say, and look at the experimental demonstrations. Almost all of them come from AMO physics. AMO offers the cleanest demonstrations of all the weird stuff that quantum theory predicts– BEC, non-locality, superposition states, quantum information– and that’s every bit as cool as the Higgs boson.
AMO Physics is cool because it’s concrete. At the end […]
Original post by Chad Orzel none@example.com
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