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Comment: Re:why not use it in space? (Score 1) 196

by Tipa (#32616726) Attached to: Deformable Liquid Mirrors For Adaptive Optics

He winced because vacuum doesn't have a temperature. You have to have something to heat up before you can measure its heat.

A telescope in Earth's orbit would receive just as much solar radiation when not eclipsed by the Earth's shadow as some point directly beneath the Sun on the Earth's surface -- more, because Earth's atmosphere scatters and reflects a lot of the radiation.

Science

Invisibility Cloak Created In 3-D 113

Posted by kdawson
from the can-you-see-me-now dept.
An anonymous reader writes "Scientists have created the first device to render an object invisible in three dimensions. The 'cloak,' described in the journal Science (abstract; full text requires login), hid an object from detection using light of wavelengths close to those that are visible to humans. Previous devices have been able to hide objects from light travelling in only one direction; viewed from any other angle, the object would remain visible. This is a very early but significant step towards a true invisibility cloak." The "object" hidden in this work was a bump one micrometer high. The light used was just longer than the wavelengths our eyes detect. To get a visible-light cloak, the features of the cloaking metamaterial would need to be reduced in size from 300 nm to 10 nm.
The Courts

Cop's RADAR vs Driver's GPS - which is right?-> 5

Submitted by martyb
martyb writes "ars technica has a story up about a driver who claims his speeding ticket should be thrown out because his GPS proves the police officer's radar was wrong. (AP version of the story here.) The accused 17-year-old, Shaun Malone, has an ace up his sleeve: his step-dad is retired deputy Roger Rude. Rude encouraged Shaun to fight the ticket after the log he downloaded using software provided by the GPS unit's Colorado-based supplier showed Shaun was going the speed limit within 100 feet of where a Petaluma officer clocked him speeding.

"Radar is a pretty good tool, but it's not an infallible tool," said Rude, who spent 31 years in law enforcement. "With the GPS tracker, there is no doubt about it. There is no human interference."
Petaluma police Lt. John Edwards said he could not discuss Shaun's case but disputed Rude's contention that GPS is more accurate than a speed gun.

"GPS works on satellite signals, so you have a delay of some type," Edwards said. "Is it a couple-second delay? A 30-second delay? Because in that time people can speed up, slow down."
Which would YOU believe? Any suggestions on what Shaun could do to help defend himself?"

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