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Comments

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Watch Comet Siding Spring's Mars Fly-By, Live

photonic Re:So why not watch it *FROM* mars? (33 comments)

NASA obviously thought about this possibility, so yes, the event will be observed by at least 3 satellites orbiting currently around Mars, 2 rovers on Mars, the Hubble telescope and probably plenty of earth-based telescopes.

4 days ago
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Flight Attendants Want Stricter Gadget Rules Reinstated

photonic Re:That's not the reason you're being ignored. (405 comments)

I am afraid I am feeding a troll, but that is complete BS. It is a shitty job, since you have to get up at 5:30 in the morning and get paid very little for beginning crew, but it is not useless. Flight crew is needed to evacuate 200 people within 90 seconds in case of fire. They are needed to extinquish fires on board, if you don't everyone is dead (lithium laptop batteries are extremely nasty). They are neede to calm down drunk and annoying people, the legal limit is 1 crew per 50 passengers, so this requires a lot of social skills. They know how to handle a potential hijack situation. They are needed to serve you drinks, clean up people and toilets when someone throws up. They are fully trained to perform first aid to keep you alive until the plane can land. Source: a good friend flew for 8 years herself and now trains 18-20 year olds in 6 weeks to become a fully qualified cabin crew member.

about two weeks ago
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SpaceX Launches Supplies to ISS, Including Its First 3D Printer

photonic Re: Any news on the first stage landing tests? (129 comments)

Apparently, fiction does count as prior art in some cases. I guess the requirement that a patent must be 'non-obvious according to the state of the art" is greatly undermined if some artists already had the same idea before. This might depend on if the patent just describes the crazy idea (in which case the artist could have filed the same patent), or if the patent describes a new technical solution to an otherwise old idea. The famous example is that a crazy idea to raise a sunken boat with pingpong balls was rejected because the exact same idea was featured in a Donald Duck story 15 years earlier.

about a month ago
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SpaceX Launches Supplies to ISS, Including Its First 3D Printer

photonic Re: Any news on the first stage landing tests? (129 comments)

I am not so worried about the patents. Vertically landing a rocket has been described in the TinTin comic ''Objectif Lune in 1953, has been demonstrated on the moon in 1969, with the Delta Clipper in 1993 and more recently with the X-prize in 2009. The patent by Blue Origin (sponsored by your purchases on Amazon) is from 2009, and is being challenged. I didn't read the patent and I am not a patent attorny, but the 'on a boat' part seems very much like the 'on a mobile device' part that gets slapped onto old ideas.

about a month ago
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SpaceX Launches Supplies to ISS, Including Its First 3D Printer

photonic Any news on the first stage landing tests? (129 comments)

This time, they launched without the landing legs, but since they are still testing above water that does not matter a lot. Deploying the legs and soft landing on water have been tried successfully already, so I imagine they could test other things like partially flying back to the launching site, fuel permitting. The twitters are silent, so far, however.

about a month ago
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If Java Wasn't Cool 10 Years Ago, What About Now?

photonic Re:What's the point? (511 comments)

There is currently an enormous discussion going on at python-ideas (see various large threads towards the bottom). Guido himself seems to be in favor of including something like MyPy into Python's standard library, which is allows for optional specification of arguments and return types using function annotation. The main use would be for static/offline code analysis/linting.

about 2 months ago
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Magnitude 6.0 Quake Hits Northern California, Causing Injuries and Outages

photonic Predicted casualties / damage (135 comments)

Since it might take a few hours before the complete outcome is clear, USGS does make automated prediction of casualties and damages, based on earthquake magnitude, location and population in the area. The result in this case is most likely no casualties, with a small chance for up to 10 people killed, and a most likely damage of somewhere between 100M$ and 1B$.

about 2 months ago
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San Onofre Nuclear Power Plant Dismantling Will Cost $4.4 Billion, Take 20 Years

photonic Back of envelope calculation (343 comments)

I hope my math is correct: Taking numbers from wikipedia, considering only units 2 and 3: both were in operation for a bit more than 29 years and were producing about 1 GW at full power. Ignoring any production time lost for maintenance (my guess is they would run with a duty cycle of 80-90%), the total amount of produced kWh would be: 29 years * 365 days/year * 24 hours/day * 2 GW = 5e14 Wh = 5e11 kWh. The price for the decommissioning would thus come down to around 4.4e9 $ / 5e11 kWh = 0.0086 $/kWh, so let's round it up to 1 cent per kWh. Average price for electricity in the US seems to be around 0.10 $/kW, so the cost for the decommissioning seems acceptable, though not negligible.

about 3 months ago
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Mars (One) Needs Payloads

photonic Re:Payloads? Here's what I would like to see. (77 comments)

As you said, the low density of air at Mars might be a problem. The theoretical maximum power that can be harvested with a wind turbine is P = 1/2 * rho * A * V^3. Some numbers from Nasa show that the density rho is about 1% of the value on Earth, and an average speed of 10 m/s (around 5 Beaufort) is also not exceptional. Finally, you will need a relatively big mechanical device, which is hard to build light and reliable, since it has to survive a rocket launch.

about 3 months ago
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Update Your Shelf: BitLit Offers Access To Ebook Versions of Books You Own

photonic What could possibly go wrong (82 comments)

Great, one guy who actually owns the book takes a high resolution scan and puts it on the internet, everyone else prints it out and signs it ....

about 4 months ago
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Making an Autonomous Car On a Budget

photonic Re:Just 2 models of Audi? (61 comments)

Electrical power steering is much more common than you assume, especially in the last few years. I know that at least my 8 year old smallish European car has an electrical one.

about 4 months ago
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SpaceX Injunction Dissolved

photonic Mission accomplished (98 comments)

I don't think Elon expected to win that easy, but look how much publicity he got for filing a simple claim and getting a temporary injunction. He got to say a few times how they are 4x cheaper than the old guys, that might be remembered by some press and politicians the next time there is a big contract up for grabs.

about 5 months ago
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Feds Issue Emergency Order On Crude Oil Trains

photonic Similar incident in Italy (211 comments)

There was a similar incident in Viareggio 5 years ago: a train carrying LPG derailed and crashed into a platform in the center of town during the night. The resulting explosion killed 32 people and destroyed a whole block of houses. In this case it was LPG, not crude oil, so I guess a tiny leak would have been enough to cause problems. You would have to make the tanks extremely strong to prevent that. And there is even other dangerous goods, there were some nasty accidents with trains carrying chlorine, which doesn't need fire to kill people.

about 5 months ago
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Ask Slashdot: How To Back Up Physical Data?

photonic tin foil hat (245 comments)

Since having this nightmare, I've exported my phone's VCF file to an online repo, made online notes of all my bank account numbers and passport ID, I keep ICE numbers with me at all times (separate from phone/wallet), and I've hidden a spare mobile phone and house key in a box in a nearby field. But there must be more to do!

I think the only thing left to do is buying loads of a aluminium foil.

about 6 months ago
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SpaceX Files Suit Against US Air Force

photonic Bloody rocket dealerships (176 comments)

It is about time that the FTC steps in and allows SpaceX to sell their rockets directly to the Air Force. Blame the rich local rocket dealerships, we corrupted their local politicians to create laws that are only designed to maintain their business model of selling old fashioned rockets. What people in the street want is to buy a next generation rocket, directly from the Internet, without having to talk to one of those sleazy rocket salesman. I am getting confused, you were saying Elon?

about 6 months ago
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Most Expensive Aviation Search: $53 Million To Find Flight MH370

photonic Re:Tracking` (233 comments)

Data charges would be much less than that, $20 extra per ticket would be unacceptably high. Some spokesman for Inmarsat (who obviously has a big interest in making permanent data connections mandatory) said that data costs for such a flight would be on the order of 1$/hour for the whole aircraft. Data rates should also be pretty low, 1 GPS coordinate per minute would have helped enormously for both the AirFrance and MalaysiaAirlines crashes, the detailed high-bandwidth data you can always get from the black box if you can find it.

about 7 months ago
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Your Car Will Tell You How To Hit the Next Green Light

photonic Re:Part of this is a late April fools joke. (364 comments)

True story: The lecturer that taught us general relativity at university was a fantastic guy that was also pretty good at drawing cartoons. For one of the questions on the final exam, he drew a scene of a guy being stopped by a policeman: "I am stopping you for crossing the red light." "I saw it as green, I swear officer." "Fine, then I will write you a ticket for speeding." The question was to calculate the speed of the car, given the wavelengths of green and red light and the velocity of light.

about 7 months ago
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Adaptation From Flash Boys Offers Inside Look at High-Frequency Trading

photonic Re:Forbit all HFT (246 comments)

contribute to society except for profit for themselves

Your opinion, fortunately we aren't slaves to one person's opinion as to what is valuable "to society". I am sure all the employees, their families, children, dogs, etc. of the HFTs, producers of all the networking and computing gear they use, the buildings and home they inhabit, the doctors they visit, and so on, might disagree with you about the lack of contribution to society.

That is a bad argument: People making money with organized crime spend money on employees, family and goods too, but that does not make it a good thing. If the HFT people would not be skimming billions of dollars from the market, millions of people might have received 100$ more since their pension fund would have done slightly better, and they would have spent it the same. What did the HFT contribute to society to rip off all those people?

about 7 months ago
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Adaptation From Flash Boys Offers Inside Look at High-Frequency Trading

photonic Re:Forbit all HFT (246 comments)

The question is if it is not too late to introduce regulations. These leeches probably made enough money to corrupt Congress for the next 100 years.

about 7 months ago
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Adaptation From Flash Boys Offers Inside Look at High-Frequency Trading

photonic Forbit all HFT (246 comments)

HFT should be banned, there is nothing these robo-traders contribute to society except for profit for themselves. The argument that they provide for liquidity of the market, or whatever, would not change if everyone would be trading at second scale instead of microsecond scale. My proposal (as someone how knows nothing about stock markets): make it a level playing field and only allow trading at say exact 30 second intervals or so, which should be synced world-wide. In this way, the big firms would only have an advantage over the small guy when new information becomes available in the last half second before the deadline, instead of on every instance of new information. After everyone has placed their orders for the current round, the stock market then takes a few seconds to update all stock prizes, after which everyone has 'infinite time' to compute his action for the next round.

about 7 months ago

Submissions

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Possible collision between cube-satellite and old space junk

photonic photonic writes  |  about a year ago

photonic (584757) writes "The BBC is reporting about a possible collision between Ecuador's first satellite (a small cubesat) and debris from an upper stage of an old Russain rocket. If confirmed, this might be the 3rd case in recent years, after a high-speed collision of an Irridium satellite with a dead Russian satellite in 2009 and a collision earlier this year between a Russian laser reflector (which can be tracked very accurately) and a tiny piece of a debris of a Chinese weather satellite that was destroyed in a missile test."
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Man extradited to the US after uploading child-pornography to MS SkyDrive

photonic photonic writes  |  about 2 years ago

photonic (584757) writes "The national Dutch broadcaster reports (Google translate fails due to cookie warning) that a man living in Amsterdam was extradited to the US for the production of child-pornography. The man is a US citizen and the offenses were allegedly committed in the US and other countries, so the extradition seems uncontroversial. The interesting detail is that the man was apparently caught after he uploaded some of the offending files to Microsoft SkyDrive. Are the authorities actively scanning all your files or do they simply give Microsoft (and Dropbox, Google, ...) a list of hashes of known illegal material?"
Link to Original Source
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NIST releases report on WTC 7 collapse

photonic photonic writes  |  more than 5 years ago

photonic (584757) writes "After a 3 years of study, NIST finally released its report on the collapse of World Trade Center building 7. The main conclusion is that the building came down due to fire, not due to debris damage or some conspiracy demolition team. The fire started pretty small after the collapse of WTC 1, but was left to burn several floors out completely. The important finding is that the collapse was triggered by thermal expansion of beams, which could detach asymmetrically loaded girders from the main columns. Some limited pancaking of floors than caused lack of lateral support and buckling of a single column. This triggered the failure of the entire core of the building, which finally fell down as a single piece. Crackpot theories can be discussed in the Digg comments, so please limit the discussion to the science here. All documents can be found here, which read like a porn magazine for finite element junkies. Awesome movies are here. And yes, they used Beowulf clusters to do the simulations, some of which lasted for several months."
Link to Original Source

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