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Comment Re:How does space elevator save energy? (Score 2) 171

You only have to work against gravitational potential. The tether/earth provides the lateral kinetic energy.

Any cargo climbing to the upper floor would need to gain a proper orbital velocity. It might get it from the ground or from the upper floor or from its own engine. It means that you would need to provide some fraction of the lateral kinetic energy by accelerating laterally either the cargo or the upper floor.

Comment Re:Affect the moon? (Score 1) 61

The Moon causes tidal forces. These forces cause massive movement of ocean water. The movement in turn changes kinetic energy into thermal energy, effectively taking energy out of the Earth-Moon system. As within a system of two orbiting bodies the sum of kinetic and potential energy decreases with the distance between these bodies, the Moon recedes.

Submission + - The most energetic particles in the Universe dwarf the LHC

StartsWithABang writes: When it comes to the Universe, you might think that energy really is only limited by rarity: get enough particles accelerated by enough supermassive, super-energetic sources, and it’s only a matter of time (and flux) before you get one that reaches any arbitrary energy threshold. After all, we’ve got no shortage of, say, supermassive black holes at the hearts of active galaxies. And yes, we do find cosmic rays hundreds, thousands or even millions of times the energy that the LHC can achieve. But when we think about the Universe in detail, these cosmic rays aren’t unlimited in their energy, but are rather stopped in their tracks by the most unlikely of sources: the ultra-low-energy cosmic microwave background, left over some 13.8 billion years after the Big Bang.

Comment Re:In this house we obey the laws of thermodynamic (Score 1) 145

Look at this in another way: there is some planet with different objects placed on its surface, and these are well--isolated from each other. It would not be surprising, that each of these objects has a different temperature, would it? Because of e.g. its colour or its radiation surface. Now, let one of these objects be the air, and the other be some well--isolated, well--radiating building. Would not it be cool to put a thermodynamic engine in that building, in order to produce energy by reversing the greenhouse effect?

Comment Re:Pet Peeve (Score 5, Informative) 147

Charles Darwin, The Origin of Species:

When ducks suddenly emerge from a pond covered with duck-weed, I have twice seen these little plants adhering to their backs; and it has happened to me, in removing a little duck-weed from one aquarium to another, that I have unintentionally stocked the one with fresh-water shells from the other. But another agency is perhaps more effectual: I suspended the feet of a duck in an aquarium, where many ova of fresh-water shells were hatching; and I found that numbers of the extremely minute and just-hatched shells crawled on the feet, and clung to them so firmly that when taken out of the water they could not be jarred off, though at a somewhat more advanced age they would voluntarily drop off. These just-hatched molluscs, though aquatic in their nature, survived on the duck's feet, in damp air, from twelve to twenty hours; and in this length of time a duck or heron might fly at least six or seven hundred miles, and if blown across the sea to an oceanic island, or to any other distant point, would be sure to alight on a pool or rivulet.

Comment It is art (Score 5, Informative) 276

It is art, no prediction. It is obvious from the first glance. And the article confirms it:

If you're tempted to assume that the image was actually a serious depiction of what a future wrist computer might look like-well, no. Inside the magazine, which only had a brief editiorial about future computers, the editors pointed out that it wasn't a coincidence that it happened to be the April issue of Byte.

Submission + - Alternatives to Slashdot post beta? 8

An anonymous reader writes: Like many Slashdotters, I intend to stop visiting Slashdot after the beta changeover. After years of steady decline in the quality of discussions here, the beta will be the last straw. What sites alternative to Slashdot have others found? The best I have found has been arstechnica.com, but it has been a while since I've looked for tech discussion sites.

Submission + - Video of Britain's Taranis supersonic drone (abc.net.au)

chrism238 writes: ABC News (Australia) is presenting vision of the of a state-of-the-art drone touted as the future of British warfare, showing it soaring over what is thought to be Woomera in remote South Australia — "'Australia's Area 51". The Taranis drone is a joint project between UK defence and BAE Systems. The test drone cost 185 million pounds ($AUD336.5 million). It is designed to carry a payload of guided bombs and missiles, travel at supersonic speeds, and fly undetected by radar. The UK military says the Taranis will be operable via satellite from anywhere in the world.

The first test flight is being hailed as a "major landmark for UK aviation". The vision shows the sleek Taranis, named after the Celtic god of thunder, making a seamless take-off and conducting a number of manoeuvres over red desert during its first test flight. The British Military of Defence (MoD) will not confirm where the footage was shot, but in a submission last year to a UK parliamentary hearing, revealed that the Taranis Unmanned Combat Air Vehicle (UCAV) demonstrator had indeed conducted initial test flights at the Woomera test range.

Submission + - Gates returns to Windows 7 after being unable to install the Windows 8.1 upgrade 3

Artem Tashkinov writes: According to rumors Bill Gate's first day at his office in Redmond turned out to be a complete disaster mixed with ostensibly curse words no one had expected from him. He tried to install the Windows 8.1 upgrade but the updater failed continuously asking to reboot the PC. Microsoft's new C.E.O. Satya Nadella who came to help resolve the situation couldn't sort it out. In the end Gates said he would be returning to Windows 7 for the foreseeable future.

Submission + - Induction stove not compatible with Iphone

dovgr writes: There is a story in the Swedish news paper Dagens Nyheter, Google translation at http://translate.google.com/tr... , telling the story of a woman who bought an induction stove, that caused a noise in her phone whenever using the phone. When complaining to stove service company, she was told that the stove is only compatible with Samsung, and recommended her to switch phones.

Submission + - Slashdot forces a beta site by default

kelk1 writes: As a poor submitter found out (https://developers.slashdot.org/story/14/02/05/2328224/html5-app-for-panasonic-tvs-rejected---jquery-is-a-hack), Slashdot (https://slashdot.org) suddenly forced a preview of its beta site without any warning on all its viewers.

Judging by the comments, the feedback was immediate and clearly negative.

I cannot speak for the forum moderation side, but my reaction to the front page was an knee jerk: "Oh no!, not another portal full of noise I cannot speed-read through." Text and hyperlinks are what we need, please, and as little graphics as possible. Think lynx, thank you.

Submission + - CERN antimatter experiment produces first beam of antihydrogen (web.cern.ch)

An anonymous reader writes: "Matter and antimatter annihilate immediately when they meet, so aside from creating antihydrogen, one of the key challenges for physicists is to keep antiatoms away from ordinary matter. To do so, experiments take advantage of antihydrogen’s magnetic properties (which are similar to hydrogen’s) and use very strong non-uniform magnetic fields to trap antiatoms long enough to study them. However, the strong magnetic field gradients degrade the spectroscopic properties of the (anti)atoms. To allow for clean high-resolution spectroscopy, the ASACUSA collaboration developed an innovative set-up to transfer antihydrogen atoms to a region where they can be studied in flight, far from the strong magnetic field."

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