The reason why purple and violet look similar to us is because they stimulate our cones in a similar way, but most other animals don’t share the same types of cones and “post-processing”. This means that to other animals, purple and violet may look completely different!

Now imagine a violet flower petal with a purple pattern on it. Depending on the particular shades, this pattern might be completely invisible to us, while many other animals could see it as clearly as we can see an orange pattern on green background.

This is a selective list of some short stories and novels that use more or less accurate science and can be used for teaching or reinforcing astronomy or physics concepts. I include both traditional “science-fiction” and (occasionally) more serious fiction that derives meaning or plot from astronomy or physics ideas.

In fact, standard gravity theory predicts that gravity becomes so strong on this scale that matter will collapse into black holes. And because gravity reflects the shape of spacetime, its limitless intensification suggests that the spacetime continuum gets ripped to shreds, so that the featureless expanse of space we experience in everyday life cannot be a fundamental feature of reality. Either some other structure must replace it, or something must save gravity from blowing up at small scales, preserving the fundamental status of spacetime—or both. Either way, the standard theory must be incomplete.

What they found was that, when there were two grates in place, the atom passed through it on many paths in a wave form, but, when the second grate was removed, it behaved like a particle and took only one path through.

So, what form it would take after passing through the first grate depended on whether the second grate was put in place afterward. Therefore, whether it continued as a particle or changed into a wave wasn't decided until a future event had already taken place.

It turns out that if all the stars and all the planets in all the galaxies were before you in a terrifying, brilliant, impossible box, the color would you see (while no doubt experiencing a transcendent feeling of oneness) is the most boring color in the world.

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.

A fun online physics puzzle game!

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.