There’s something unnerving about unifying physics. The two theories that need to be unified, quantum field theory and Einstein’s general theory of relativity, are both highly successful. Both make predictions good to as many decimal places as experimentalists can manage. Both are grounded in compelling principles. Both do have flaws — including an unfortunate tendency to produce the number ∞ — but those flaws remain safely behind the scenes, never undermining the theories’ empirical successes.

And yet, if the theories are incompatible, something has to give. That is what makes unification so hard. In conferences, I see physicists go down the list of assumptions that underpin their theories. Each, it seems, is rock solid. But they can’t all be right. Maybe one will, on closer inspection, prove to be not like the others. Or maybe physicists have left the culprit off their list because it is so deeply embedded in their way of thinking that they don’t even recognize as an assumption. As economist John Maynard Keynes wrote, “The difficulty lies, not in the new ideas, but in escaping from the old ones, which ramify… into every corner of our minds.”

Hence the experiment achieves the genuinely spooky: a read-write operation across two laboratories connected by around 60 meters of fibre, in which the receiving atom becomes entangled with the transmitter, even though there’s been no direct interaction between them.

Interesting question, Well, assuming a maximum muzzle velocity of 1800 meters per second, you would at least be able to get the round up to lunar orbital velocity, so you could put the round into orbit around the moon if you aimed above the lunar horizon at just the right angle.

When you crumple up your gift-wrapping paper this year, you'll create a shape so complex that it has defeated the most sophisticated computers

Chi_b (3P)

the LHC was built to figure out what the Higgs field is (or Higgs fields are), how it works (or they work), and whether it is (or they are) elementary or composite.

Navier-Stokes

Standard Atmospheric Pressure (atm) is used as a reference for gas densities and volumes. The Standard Atmospheric Pressure is defined at sea-level at 273oK (0oC) and is 1.01325 bar or 101325 Pa (absolute). The temperature of 293oK (20oC) is also used.

In imperial units the Standard Atmospheric Pressure is 14.696 psi.
1 atm = 1.01325 bar = 101.3 kPa = 14.696 psi (lbf/in2)= 760 mmHg =10.33 mH2O = 760 torr = 29.92 inHg = 1013 mbar = 1.0332 kgf/cm2 = 33.90 ftH2O

ANTIPROTONS appear to ring the Earth, confined by the planet's magnetic field lines. The antimatter, which may persist for minutes or hours before annihilating with normal matter, could in theory be used to fuel ultra-efficient rockets of the future.

Plate tectonics is the great unifying theory of geology, which makes it all the more amazing that it has only been accepted for about 50 years. If you think we’ve got it all figured out by now, a paper published this week in Science may surprise you. And you'd be wrong if you were expecting to read about some dusty rock cores. The new information comes from a much shinier source: diamonds.

Contrary to popular culture, diamonds are not formed from the metamorphosis of coal under tremendous heat and pressure. It makes for nice poetry, but it’s not true. The real story is actually a bit more interesting than that.

Why is it that when you look in the mirror left and right are flipped, but not the up and down?

What the mirror really does is flip the order of things in the direction perpendicular to its surface
Because they don't flip left with right (or up with down), they flip the 3D space you're standing in "inside out"
This common confusion stems from our familiarity with photographs. We forget that we rotate them to face ourselves.

A review that I wrote of David Kaiser’s How the Hippies Saved Physics is now available at American Scientist. A quick summary is that I think it’s a marvelous book, telling in well-researched and entertaining fashion a story I’ve always wanted to know more about. I’m not convinced though by the main argument of the title, that this group of people “saved physics”, rescuing it from an oppressive “shut up and calculate” ideology by showing the way towards the importance of Bell’s theorem and helping start the field of quantum information theory. Perhaps the author though is just emulating his subjects, known for their playful outlandishness.

There’s yet another mathturbation post at WUWT. This one, by Andy Edmonds, argues that because weather is chaotic (in the mathematical sense), it’s impossible to model climate. In fact that’s the whole argument — a lot of words, but it boils down to nothing more.

But even though a chaotic system can’t be predicted, its statistical properties often can be. The statistical properties of weather — it’s long-term average and variation — are referred to as climate. Those who believe that chaos in weather makes climate modeling, or climate prediction, impossible, have failed to comprehend the difference between weather and climate.

All he’s doing is taking a pseudo-random time series and accumulating it, to create a pseudo-”random walk.” His “drift” has nothing to do with chaos, I could get the same behavior by accumulating truly random numbers in a random walk. It’s just more mathturbation.

New results from NASA's Fermi Gamma-Ray Space Telescope appear to confirm a larger-than-expected rate of high-energy positrons reaching the Earth from outer space. This anomaly in the cosmic-ray flux was first observed by the Italian-led PAMELA spacecraft in 2008 and suggests the existence of annihilating dark-matter particles.

Basically, though, the camera uses a special 'microlens' that captures depth information. The way I understand it, the microlens basically acts like a bunch of different cameras arranged in a grid, each capturing the scene from slightly different angles. The raw data from the camera looks quite distorted, but software can reconstruct the scene and calculate depth information by creating a 3D reconstruction based on the slight differences in angles between the different microlens elements.

This is a collection of video lectures on Quantum Mechanics taught by James Binney who is a Professor of Physics at the University of Oxford. In this series of physics lectures, Professor James Binney explains how probabilities are obtained from quantum amplitudes, why they give rise to quantum interference, the concept of a complete set of amplitudes and how this defines a "quantum state".

String theory

How do we control authenticity on the Web?
Who gets to decide what information is good and bad?
How can we prevent abuse of the Web, either by governments using it to exercise power over their citizens or by individuals with malicious intentions?

As I write this, it's still not clear how bad, or how big, the problems at the Fukushima Daiichi power plant will be. I don't know enough to speculate on that. I'm not sure anyone does. But I can give you a clearer picture of what's inside the black box. That way, whatever happens at Fukushima, you'll understand why it's happening, and what it means.

In this chapter I will explain a few things about how air behaves as it flows past a wing.

HOW DO AIRPLANE WINGS *REALLY* WORK?
Amazingly enough, this question is still argued in many places, from K-6 grade classrooms all the way up to major pilot schools, and even in the engineering departments of major aircraft companies.