The Theoretical Minimum is a series of Stanford Continuing Studies courses taught by world renowned physicist Leonard Susskind. These courses collectively teach everything required to gain a basic understanding of each area of modern physics including all of the fundamental mathematics. The sequence begins with the modern formulations of classical mechanics discovered by Lagrange and Hamilton in the late 18th and 19th centuries, and then moves on to the radical new theories of relativity and quantum mechanics discovered by Albert Einstein and others in the early 20th century. The sequence concludes with a study of modern cosmology including the physics of black holes.

Apparatus is a sandbox puzzle game for Android devices. Use your hammer to pin planks and wheels together to build anything you can imagine, connect your apparatus to motors and give them power using batteries.

Admittedly, I haven't tried it, but it looks like a lot of fun and I really like sandbox games. I almost wish I had an Android device now.

Information about the incident at the Fukushima Nuclear Plants in Japan hosted by http://web.mit.edu/nse/ :: Maintained by the students of the Department of Nuclear Science and Engineering at MIT.

I am writing this text (Mar 12) to give you some peace of mind regarding some of the troubles in Japan, that is the safety of Japan’s nuclear reactors. Up front, the situation is serious, but under control. And this text is long! But you will know more about nuclear power plants after reading it than all journalists on this planet put together.

There was and will *not* be any significant release of radioactivity.

By “significant” I mean a level of radiation of more than what you would receive on – say – a long distance flight, or drinking a glass of beer that comes from certain areas with high levels of natural background radiation.

European robins may maintain quantum entanglement in their eyes a full 20 microseconds longer than the best laboratory systems, say physicists investigating how birds may use quantum effects to “see” Earth’s magnetic field.

Quantum entanglement is a state where electrons are spatially separated, but able to affect one another. It’s been proposed that birds’ eyes contain entanglement-based compasses. Conclusive proof doesn’t yet exist, but multiple lines of evidence suggest it. Findings like this one underscore just how sophisticated those compasses may be.

“How can a living system have evolved to protect a quantum state as well — no, better — than we can do in the lab with these exotic molecules?” asked quantum physicist Simon Benjamin of Oxford University and the National University of Singapore, a co-author of the new study. “That really is an amazing thing.”

European robins may maintain quantum entanglement in their eyes a full 20 microseconds longer than the best laboratory systems, say physicists investigating how birds may use quantum effects to “see” Earth’s magnetic field.

...

Even in laboratory systems, atoms are cooled to near–absolute-zero temperatures to maintain entanglement for more than a few thousandths of a second. Biological systems would seem too warm and too wet to hold quantum states for long, yet that’s exactly what they appear to do.

Zoom from the edge of the universe to the quantum foam of spacetime and learn the scale of things along the way!

So Horava did the unthinkable and amended Einstein's equations in a way that removed Lorentz symmetry. To his delight, this led to a set of equations that describe gravity in the same quantum framework as the other fundamental forces of nature: gravity emerges as the attractive force due to quantum particles called gravitons, in much the same way that the electromagnetic force is carried by photons. He also made another serious change to general relativity. Einstein's theory does not have a preferred direction for time, from the past to the future. But the universe as we observe it seems to evolve that way. So Horava gave time a preferred direction [...].

With these modifications in place, he found that quantum field theories could now describe gravity at microscopic scales without producing the nonsensical results that plagued earlier attempts. "All of a sudden, you have new ingredients for modifying the behaviour of gravity at very short distances," Horava says.

“We view the speed of light as simply a conversion factor between time and space in spacetime,” Shu writes. “It is simply one of the properties of the spacetime geometry. Since the universe is expanding, we speculate that the conversion factor somehow varies in accordance with the evolution of the universe, hence the speed of light varies with cosmic time.”

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