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

 



Forgot your password?
typodupeerror
×

Comment Re:2 Words (Score 1) 810

Not so.

For commuting in the mornings, apparently it's good to have it plugged in and to have set the battery to do a quick charge before you want to go, that warms the pack up, and at the same time you can also preheat the cabin; that also helps because the climate control doesn't have to use the battery to do that and it clears the windscreen, so you gain both range and convenience.

Comment Re:Radiated power? (Score 1) 104

Actually the directional antenna helps with both RX and TX directionality and power equally; and there's almost certainly an attenuator that offsets the aerial's gain.

It doesn't help with the power coming from the laptop/tablet, but that's pretty small; some laptops will have gain control on their transmitters as well.

Comment Re:Spaghetti (Score 3, Interesting) 263

My understanding/way I imagine it is that; as you move towards the blackhole, the particles that make up the astronaut cause the event horizon to come out to meet them, and this curves the event horizon and this causes a local burst of Hawking-type radiation that rips apart the astronaut, and this radiation spreads out from the impact point in a wave; that in turn creates more perturbations of the horizon and so on. You end up with a very thin ring of fire all around the black hole. And this never goes away; indeed it forms the moment the black hole does, and so there's actually nothing inside the blackhole, just flat spacetime. In a sense I suppose the collapse never completely happens you end up with just a shell of matter.

Comment Re:No matter = no radiation (Score 1) 263

I have only a qualitive understanding of this, but I think Hawking radiation is the radiation that escapes the blackhole; but there's probably some quantum-generated particles produced that don't have enough energy to escape and promptly fall back in again.

So as you fall into the blackhole, it will get warmer and warmer, until you get burnt to a crisp by the Hawking radiation that forms near to the event horizon which is unable to escape.

It's kind of like a sonic boom, or more like a light boom.

Comment Re:So much for your noise floor (Score 1) 242

No, it's not omnidirectional, he's doing beam forming.

So he creates a 4W beam and aims it at the receiver. That's why when he moved the device, it went out; the beam was missing for a while until the transmitter figured it out and steered the beam to where he was now standing.

This works fine, provided the power density isn't too high; otherwise if people get in the way of the beam then they get heated up. A few watts may be the limit. more if the receiver is bigger.

Comment Re:Out of jobs? (Score 1) 736

Technology nearly always ultimately creates jobs, at least for a while.

Economists think that new technologies create jobs, at least in some phases. Generally, there's a few phases. Initially nobody uses the technology, and it's expensive, and nobody makes much money. Then more people use it, and the price starts to drop. This is the point where lots of money is made and usually lots of jobs. Finally, ubiquity, everyone uses it, and it's dirt cheap, relatively few, relatively badly paid jobs, and the total amount of money is not great. At this point you need a new technology. ;-)

e.g. Wireless internet equipment used to be rather more expensive, and all the companies and engineers used to make good money developing it, but now it's dirt cheap, and nobody is making much money on it.

Comment Re:Spread Awareness (Score 0) 218

YOU'RE GOING OVER THE SPEED LIMIT OF -127 MPH! YOU HAVE 10 SECONDS TO DECELERATE!
*car slows down below limit*
YOU'RE STILL GOING OVER THE SPEED LIMIT OF -127 MPH! YOU HAVE 5 SECONDS TO DECELERATE!
*car stops*
YOU HAVE BEEN JUDGED AND FOUND GUILTY
*drone fires hellfire missile*
*BOOOM*

HAVE A NICE DAY!
*flies off*

Submission + - Underground 'Wind Mines' Could Keep Datacenters Powered (slashdot.org)

Nerval's Lobster writes: Major IT vendors have been including custom-built wind- and solar-power farms in their datacenter construction plans. But while wind and solar power may be clean, they’re often unreliable, especially by the standards of datacenters that need a way to keep operating through any unexpected surges or drops in power. How about saving the wind that generates the power? That might work, according to researchers at the federal Bonneville Power Administration (BPA), and U.S. Department of Energy’s Pacific Northwest National Laboratory. A study published in February (PDF) outlined the potential benefit of pumping pressurized air into caverns deep underground as a way to store wind energy, then letting it out whenever demand spikes, or the wind drops, and the above-ground facilities need help spinning enough turbines to keep power levels steady. The technique, called Compressed Air Energy Storage (CAES) isn’t new: existing CAES plants in Alabama and Huntorf, Germany (built in 1991 and 1978, respectively) store compressed air in underground salt caverns hollowed out by solution mining (pumping salt-saturated water out of concentrations of salt buried far underground and replacing it with fresh water). But implementing such a technique for datacenters might take a little work. The BPA and the Pacific Northwest National Laboratory have already identified, and are evaluating, sites in the Pacific Northwest that would be suitable for CAES underground reservoirs; the first, which could be located in Washington’s Columbia Hills could—via existing CAES technology—store enough compressed air to generate a steady 207MW for 40 days of continuous usage, ultimately delivering 400 additional hours without adding any compressed air.

Slashdot Top Deals

Understanding is always the understanding of a smaller problem in relation to a bigger problem. -- P.D. Ouspensky

Working...