What keeps a train on the tracks? How sure are you?

What keeps a train on the tracks? Yeah, right, that flange on the inside of the wheels. Obvious right?

Wrong.

What I like about this information is not just how the truth of the matter, despite it having seemed obvious to me since I was a kid, is incorrect, but how the truth of the matter is so subtle and elegant and beautiful.

And isn't this always the pattern of discovery?  And how many other much more complicated truths do I hold that might be debunked by subtle, elegant, and beautiful re-understanding?  Lots, I hope.

First seen at www.boingboing.net

First MSL Images From Mars

Here are the first couple of images from Mars, a shadow of the machine looking forward and a view of the rear left wheel. Amazing!!!

CBC: How to watch the Mars rover landing

Get info here from CBC about how to watch the landing of the Mars Science Laboratory's robot, Curiosity.  There are a bunch of options, and that CBC article contains a ton of links.  NASA coverage starts Sunday at 8:30pm PST, and the landing is two hours later.

Don't expect much awesome Mars imagery during this event.  Mostly it's going to be a bunch of tense mission specialists in front of screens at various NASA locations around the US alternately biting their nails, crossing their fingers, and knocking on wood.  Fully half of all missions to the surface of Mars have crashed.

In addition, round-trip light-time to and from Mars right now is about 28 minutes, so it's impossible for NASA to receive data from the spacecraft and respond with timely commands.  Re-entry is totally autonomous, and landing at Mars will take about seven minutes.  We'll hear about it at the speed of light--14 minutes later.

And then there will be great joy, or great sadness. 

And if there's great joy, it will be another number of hours before the rover powers up, checks its health, and starts returning pictures.

And then:  All eyes on Mars!

Don Pettit: Water Blob in Microgravity

Simplified: Higgs Boson

Tesla Motors Regenerative Braking

I just read an interesting overview of regenerative braking in electric cars.  When you step on the throttle, torque is applied to driving the motor and this consumes battery power, but when the car is rolling and you step off the throttle, reverse torque is applied to the engine and it immediately becomes a generator, not a consumer, of electrical power. 

I was always curious how this worked, and if you are too, and want more details, read the article.

Minute Physics' Letter to the Universe

Awesome, as seen at www.geekisawesome.com

Awesome Venus Transit Video

Wow.

13 Dominos

As seen here at isviral.com