Wolfram|Alpha search

Wolfram|Alpha search is a new specialized search engine that focuses on focuses on algorithmic answers for scientific knowledge.  It easily beats Google or any of the other general search tools in its specialized area.

Even so, it's harder than it looks.  Here's one example:

what is the age of the universe

Result: 13.7 billion years

how old is the universe

Wolfram|Alpha isn't sure what to do with your input

Looks like it still has a slight bias towards more precise terms like age vs old. It does seem to handle both "how big is …" and "what is the size of …".

On the other hand, this is quite impressive:

planck time * age of the universe

Result: 3.2 x 1060 planck times

But the following doesn't "work" quite as nicely:

planck length * size of the universe

Input interpretation: (planck length) X (diameter of observable universe)
Result: 1.6 x 10-40 planck times

Instead I have to search "planck length universe size" and then scroll down to "Ratios" section to see the answer I was looking for: 5.4 x 1061 planck lengths.  Still, not bad.

YouTube used for research on animal behavior

In the story "Parrots Join Humans On The Dance Floor", NPR reports on researchers that have confirmed parrots most likely have musical rhythm, which would be the first animals to demonstrate an "appreciation" for music.

Here's what I found more interesting… Researchers wanted to find out if other animal species might have musical rhythm, but couldn't afford to buy a lot of animals to conduct experiments.  So they turned to YouTube, and searched using terms like "animal" and "dancing".  From 5,000 videos of all types of animals, they conclude that 33 parrot species and one elephant species demonstrated clear musical rhythm.

I wonder what other kind of research problems will be solved with YouTube?

So what gives parrots and elephants rhythm, while dogs & cats couldn't care less? The researchers notcied that both parrots and elephants are vocal mimics.  Perhaps musical ability is a side-effect of vocal mimicry.  Perhaps humanity's musical ability arose from vocal mimicry in human primate ancestors.

Russian and US satellites collide


Russian and US satellites collide (bbc.co.uk)

US and Russian communications satellites have collided in space in the first such reported mishap.

A satellite owned by the US company Iridium hit a defunct Russian satellite at high speed nearly 780km 485 miles over Siberia on Tuesday, Nasa said.

The risk to the International Space Station and a shuttle launch planned for later this month is said to be low.

The impact produced a massive cloud of debris, and the magnitude of the crash is not expected to be clear for weeks.

The reportedly non-operational Russian satellite, weighing 950kg 2,094lb, had been launched in 1993, while the Iridium satellite weighed 560 kg and was launched in 1997.

When two such objects collide with such force, the ensuing debris can destroy other satellites, says the BBC's Andy Gallacher in Florida.

But Nasa said the risk to the ISS and its three astronauts was low as the station orbits the earth some 435km below the course of the collision.

It is hoped that most of the wreckage from the collision will burn up in the earth's atmosphere, our correspondent says.

Hundreds of pieces of wreckage are now being tracked, reports say, adding to the tens of thousands of objects that are routinely tracked through space.

Some 6,000 satellites have been sent into orbit since 1957.

[Edited to add:] There is an animation of the satellite crash available for Google Earth.

"In the Shadow of the Moon"

Just watched a fantastic documentary In the Shadow of the Moon from 2006. It's a 1 hr 40 min documentary interview with ten of the Apollo astronauts. There's no narrator, just the astronauts and historical footage. The focus is their view of the overall experience, not so much the details. (watch the miniseries From the Earth to the Moon for lots of the details)

Be sure to watch through the closing credits, where the astronauts give their views on the persistent hoax theories that we did not land actually land on the Moon. I liked Charlie Duke's comment, "We've been to the Moon nine times. I mean, why did we fake it nine times if we faked it?"

All these men were interesting, but the real treat was Michael Collins' comments. He was the astronaut who stayed in orbit around the Moon while Neil and Buzz became the first men to walk on the Moon. Collins was simply spoken, animated, and funny in an understated way. Below are of some of the things Collins said in the movie:

On the day of the launch, as they got out of the van at the pad to walk to the elevator:

When you get out to the base of this gigantic gantry, it's … it's empty, there's nobody there, it's deserted. And you're accustomed to scores of workers, swarming like ants all up and down and around it, and you're in a crowd of people. And then suddenly, there's nobody there and you think, "God, you know, maybe they know something I don't know!"

Read More …

Crayola 3D sidewalk chalk using ChromaDepth

Just saw a TV commercial for Crayola 3D sidewalk chalk. Kids were drawing on the sidewalk with this chalk, and when they put on special glasses they saw it in 3D. Needless to say the televised 3D effects were simulated, so I dug around to see if there really is a 3D effect.

It's the real deal. The glasses are the important piece, not the chalk. The glasses in the Crayola kit utilize ChromaDepth, a patented diffraction effect that makes red look closer, blue furthest, and colors in between (on the spectrum) fall in the middle. Reading reviews, the chalk in the Crayola kit is probably more colorful than typical sidewalk chalk, but it's the glasses that are the important bit.

Chromatek's most recent patent (from 1991) has some good drawings that show how ChromaDepth works.

Chromatek sells glasses directly, a set of three for $7 + s/h. I'm almost tempted to buy a set just to see it in action.

Lunar eclipse

Although there are usually one or two full lunar eclipses a year, it's been a while since I've seen one. Things like clouds, or maybe it occurs really late/early are the usual reasons I've missed them.

But on Wednesday Feb 20, there was a full lunar eclipse and this time I got to see it. I also pulled out my camera and tripod and got this picture.

Feb 2008 Lunar Eclipse

Even with a decent digital SLR (Pentax *ist DS) it was tough to get a good picture. I had to shoot in RAW mode, then work on the exposure in Photoshop for the above result to match what I was seeing with the naked eye.