Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 


Forgot your password?
Close
typodupeerror
×
Space

Dwarf Planets Accumulate In Outer Solar System 93

Posted by kdawson from the potato-radius dept.
An anonymous reader tips a piece in Australian Geographic indicating that Pluto may be in for another demotion, as researchers work to define dwarf planets more exactly. "[Australian researchers] now argue that the radius which defines a dwarf planet should instead be from 200–300 km, depending on whether the object is made of ice or rock. They base their smaller radius on the limit at which objects naturally form a spherical rather than potato-like shape because of 'self-gravity.' Icy objects less than 200 km (or rocky objects less than 300 km) across are likely to be potato shapes, while objects larger than this are spherical. ... They call this limit the 'potato radius' ... [One researcher is quoted] 'I have no problem with there being hundreds of dwarf planets eventually.'"
Hardware Hacking

Home-Built Turing Machine 123

Posted by Soulskill from the i'll-order-a-dozen dept.
stronghawk writes "The creator of the Nickel-O-Matic is back at it and has now built a Turing Machine from a Parallax Propeller chip-based controller, motors, a dry-erase marker and a non-infinite supply of shiny 35mm leader film. From his FAQ: 'While thinking about Turing machines I found that no one had ever actually built one, at least not one that looked like Turing's original concept (if someone does know of one, please let me know). There have been a few other physical Turing machines like the Logo of Doom, but none were immediately recognizable as Turing machines. As I am always looking for a new challenge, I set out to build what you see here.'"
Censorship

Submission + - Fixing Internet censorship in schools (computerworld.com) 1

Submitted by jcatcw
jcatcw writes: Schools and libraries are hurting students by setting up heavy-handed Web filtering. The problem goes back for years. A filter blocked the Web site of former House Majoirty Leader Richard Armey because it detected the word "dick," according to a 2001 study from the Brennan Center of Justice. The purpose of schools should be to teach students to live in a democratic society, and that means teaching critical thinking and showing students controversial Web sites, says Craig Cunningham, a professor at National-Louis University. He quoted from a National Research Council study, "Swimming pools can be dangerous for children. To protect them, one can install locks ... [or] teach them to swim." Web filtering also leads to inequities in education based on household income. Students from more affluent areas have access to Internet at home and, often, more enlightened parents who can let them access information blocked in schools and libraries. Poorer students without home access don't have those opportunities

Comment Planets (Score 1) 377

by shadowkiller137 (#31090608) Attached to: What Objects To Focus On For School Astronomy?
Planets are always fun to look at, for instance if you have decent optics you should be able to make out some of the colouration on Jupiter as well as some of the moons. The moon is also a good place to look, you should be able to see interesting shadows on the craters or if you have a half moon look that the line between light and dark you can get some interesting contrast there.

Comment Re:race? (Score 1) 397

by shadowkiller137 (#26887173) Attached to: Race For the "God Particle" Heats Up
From a Physicist's point of view, who ever publishes their paper about finding the Higgs first is going to be the one who is remembered an the one who would be a good candidate for a noble prize. Also the Fermilab physicists think that if they can find the Higgs they could get more funding for continued operation of the Tevatron.

Slashdot Top Deals

"Most of us, when all is said and done, like what we like and make up reasons for it afterwards." -- Soren F. Petersen

Close