February, 2008 | robhogg.com

robhogg.com » 2008 » February

I happened to come across a picture that a friend of mine took a couple years ago that I thought you photographers out there would appreciate.
Vincent was a ranch hand at the Muir Trail Ranch in the Sierra Nevada mountains for a few years. His cousin Hilary is quite a bareback rider and he asked her to ride one of the ranch horses through a stream towards him. Vince lay on his stomach in the ice-cold stream and allowed the horse to run right over and past him, knowing that the animal was trained to avoid stepping on people.
They did a few passes of this, each time the horse calmly trotting right over Vince, and here is the result:
(Copyright Vincent Solari)

980_robot_judges_compressed.JPGTeam 980, the Thunderbots have finished building their new 130 pound, two-speed, lean machine!

To catch you up on this one: an international high-school robotics competition is well underway for the 16th year, and the number of teams participating has roughly doubled every year. FIRST Robotics (For Inspiration and Recognition of Science and Technology) was started by Dean Kamen (inventor of the Segway) as a way of inspiring high-school kids (and adults!) with real application of science and technology to something that everyone wants to do – build a robot!

These beasts weigh 130 pounds and are about 3x3x5 feet. They move, and they move fast, and they do all kinds of other tricks depending on what the game is for the year. The build season starts in January every year and for exactly six weeks each team of students, mentors, teachers, parents, and team fans all get together and figure out how to play the game and how to make their robot the coolest bucket of bolts that ever rolled the earth.

I had the pleasure of founding Team 980 with my father and some other engineers and it is still going strong, with the team’s seventh robot recently completed and shipped to the first competition.

In the next few weeks the team will be participating in regional events at major arenas in three different cities. Think of a basketball game, cheering fans and loud music and all, except the students get to take turns competing down on the floor!

For more info on this all-around incredible experience and to follow Team 980 on their run for the title, check out:
Team 980 Homepage
2008 Game Animation
FIRST Homepage


A friend of mine has a Stellanova floating globe that I got to play with. After fooling around with it a bit it became clear that they are using a little feedback system to control the electromagnetic force – some variant of a PID controller. Maybe they use some hall effect sensor for input to control their electromagnet?

It was pretty cool, I could grab the globe and pull it down a little bit and feel the pull get stronger instantly, and then go the other way and feel it let off a bit. The control is very tightly done with a small but very strong magnet (probably rare-earth) that is embedded at the top of the globe.

So basically you could pull the magnet out of the globe (or find an equivalent magnet) and embed it at the top of any object that weighs about the same as the globe, and you’d have yourself a floating [insert object name]!

Ideas anyone?

puppis_a_small.gifI have always been amazed at the concept of a neutron star, simply from my repeated attempts to imagine something that can exist that is that dense.

Neutron stars are formed after the supernova of a star that is about 4 to 8 times bigger than our sun. After the explosion of the supernova is winding down, most of the leftover mass of the star pulls in on itself under gravity – and it crunches in so hard that the individual protons and electrons that make that mass get squashed together and turn into neutrons, thus neutron star.

Now here’s the incredible part. All the mass of that neutron star is so squashed, that it only takes up a volume that is about 10 miles wide! That means that all that mass (about 1.4 times more than our sun) is squashed into an area that is smaller than London, England. That means that one teaspoon full of that neutron star material would weigh about 100 million tons – which is as much as a mountain!

Stars which are bigger than 8 times the size of our sun tend to turn into another beast (supposedly), a black hole. This is because the mass involved is so large that it pulls in light around it as well – and so the object can’t be viewed!

For more on Neutron stars, see the “Ask an Astrophysicist” site provided by NASA Goddard.