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User: ThreeKelvin

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  1. Re:limitations of material on UCSD Students Test Fire 3D-Printed Metal Rocket Engine · · Score: 2

    Castings, sure. But rocket engines are usually welded. It's not really a usefull comparison.

  2. Re:10 years later and applications are still 32bit on The Chip That Changed the World: AMD's 64-bit FX-51, Ten Years Later · · Score: 2

    Most don't really need two cores, but that's not a reason not to want two cores.

    I fell in love with multiple core processors when I first got one, not because my computer in general became faster (I'll bet that all but one of my cores are idling most of the time) but because my computer wouldn't get unresponsive when I was doing computationally heavy tasks (or programs crashed).

  3. Re:Ok, so they know when you want another drink... on Robotic Bartender Programmed To Recognize When You Are Ready For a Drink · · Score: 1

    Interesting. Who's going to ask me to "go large for just $0.99 more", so I get the genuine experience that's so integral to McDonald and their competition?

  4. Re:So try to tell your boss he should adopt this on Linux 3.12 Codenamed "Suicidal Squirrel" · · Score: 1
  5. Re:It takes more than an antenna... on MIT's Inflatable Antennae Could Boost Small Satellite Communications · · Score: 1

    Actually, cubesats need at least a simple attitude control system, i.e., detumbling. Without one they spin up. See e.g. AAUSat II:

    We are still working on finding the reason for the fast rotation rate, especially why it accelerated over the course of 40 days. We have a number of ideas, der include the torque caused by the magnetic dipole generated by the solar cells.

    That said, being able to actually point in a specific direction with the sat is quite hard, and a lot of work.

  6. Re:OUCH on Man Killed By His Own Radio-Controlled Helicopter In Brooklyn · · Score: 4, Informative

    Kinetic energy is 1/2 * m * v^2, so using your numbers gives ~5195 joules. It's actually a lot of energy, about the same as a car going at walking speed, delivered as you say, at a knifes edge.

    They'll easily chop a man in half if the rotors don't break first.

  7. Re:Why a suit at all? on DIY Space Suit Testing · · Score: 1

    If your response to Anon was purely to the utility of ship-suits for this particular application, then I was doubly wrong (or triply, I'm not sure what I'm up to.)

    No worrys. I got a good smile out of it. ;)

    An external "ship-suit" could perhaps be usefull in some cases, e.g. on the ISS for EVAing, but I'm not really convinced. The only reason I can think of to send an astronaut out to do something is because her hand/eye coordination and manual dexterity is required on a particular spot. (otherwise they'd just send a robot) So, the "ship-suit" would have to have sleeves and gloves with which she could manipulate objects as easily as from a normal space suit.

    Tethering the astronaut would on the other hand be much simpler. Just clamp the Canada-arm onto the suit. No need for foot-fasteners and all that other fancy stuff.

    It's an interresting concept, but there's a lot of engineering tradeoffs to consider before judging one of the solutions superior to the other.

  8. Re:Why a suit at all? on DIY Space Suit Testing · · Score: 1

    I'm fairly certain ThreeKelvin's original comment was in reference to the article. ;)

    - And your analogy is definitly better.

  9. Re: Apples to Apples. on Workers at Chile's ALMA Telescope Strike Over Working Conditions · · Score: 5, Interesting

    No - striking shows the employer that the employees will not work under the terms set forth, but wouldn't mind doing the work if they could come to terms. It's a lighter version of finding a new job - and a rather more appropriate response in many cases.

    Now, the employer can respond in a number of ways. Just to name a few; She can fire the employees if she thinks that the pay is adequete to attract new employees, she can wait the employees out, or she can enter negotiations. You know - just like any other free market where people are negotiating prices and conditions.

    (On that note: I really don't get why some Americans are so much in favor of a free market when it concerns goods, but very much against it when it's labor.)

  10. Re:Why a suit at all? on DIY Space Suit Testing · · Score: 1

    The suit Cameron and Co. are building isn't for extra vehicular activity. It's a second, redundant layer of protection for the astronaut while he's in the capsule and beeing boosted towards space - sort of like the drivers suits used on race tracks.

    So, in short: Different problem, different viable solutions.

  11. Re:Why a suit at all? on DIY Space Suit Testing · · Score: 2

    Mass to orbit is horribly expensive, every kg counts.

    A "mini space ship" might not be much heavier than a space suit, but it'd have to fit inside the main space ship, which would then be heavier.

  12. Re:Great! on Easily-Captured Asteroids Identified · · Score: 3, Funny

    You know, that sounds like something that would significantly alter the tides.

  13. Re:Notify Xerox First on Xerox Confirms To David Kriesel Number Mangling Occuring On Factory Settings · · Score: 1

    You've got to elaborate a bit more than the short, uninformative sentences that you put up. What are you talking about? What is this "horribly thought out position" that you accuse me of having?

    Let me break it down for you. You accuse me of being either:
    a) a shill, or
    b) an idiot,
    even though I've pointed out some of the safety issues that stem from not being able to correctly copy when it would be assumed that you could, and by extension critizised Xerox (the company) for not comming forward with this, when they, as you put it "sat on the information".

    Now, as dos1 pointed out above:

    Actually, this is the case when earlier disclosure helps security, because when more people are aware of this problem, more people will take action to prevent it from happening (like setting higher quality setting as default).

    So, again I must say: sorry, what?

  14. Re:Notify Xerox First on Xerox Confirms To David Kriesel Number Mangling Occuring On Factory Settings · · Score: 0

    Sorry, what?

  15. Re:Notify Xerox First on Xerox Confirms To David Kriesel Number Mangling Occuring On Factory Settings · · Score: 1

    Sorry, I just can't seem to parse your post and grasp the meaning. Could you perhaps elaborate a bit?

  16. Re:Notify Xerox First on Xerox Confirms To David Kriesel Number Mangling Occuring On Factory Settings · · Score: 3, Informative

    It isn't a security issue so the only purpose served by his going public without him contacting Xerox is to stroke his ego.

    It isn't a security problem? Seriously?

    What if a doctor copies a prescription or your medical journal? Government officials copies personal information for use with a visa? Police officers copies statements? Or any other place where you'd want to copy something, that must be copied correctly?

    Sure, it's not a computer security issue, but it's definitly, among other things, a security issue.

  17. Re:Need to Do More on NZ Professor Advocates Civil Disobedience Against Mass Surveillance · · Score: 1

    They don't have to. You just have to use the set of scales you've constructed and the paper to weigh everything, then, though the weight of the final product will be off, the relative weight between the ingredients won't.

  18. Re:First steps? on Crowd-Funding a Mission To Jupiter's Moons · · Score: 1

    They haven't had an unsuccessful one either. They're an amateure rocket group, that are working towards launching a person on a suborbital trajectory and that takes quite a bit of time, man power and money. They've come a remarkably long way since they started a couple of years ago, given their budget.

  19. Re:What's the Daenishmarkian word for 'scam'? on Crowd-Funding a Mission To Jupiter's Moons · · Score: 1

    Exactly.

    Kristan Von Bengtson is the co-founder of Copenhagen Suborbitals, an amateure rocket group, that as its first goal are going to send a man 100 km up. Though they admittedly are a delightfully whacky, there's no scam.

    See e.g. their launch of a guided rocket, test of their liquid engine (which went CATO during the test) or one of the many other videos available.

  20. Re:Carnivore meat is not inherently toxic. on What's Stopping Us From Eating Insects? · · Score: 1

    Yes, however none of them feed exclusively on mammals.

    Neither do cats. They'll eat anything they can catch including, but not limited to, fish, birds, rodents, and insects.

  21. Re:Good Question on What's Stopping Us From Eating Insects? · · Score: 1

    Cats look a lot like rabbits after they've been cleaned. ;) I believe the alternative comes one of the world wars where people couldn't be so picky about where their protein came from. (Pidgeons are by the way known as roof-rats.)

    Sure, there's biomagnification, but that applies as much to tuna, shark and other sea-living creatures that we eat without any ill effects. (If we don't overdo it of course.) I've been googling a bit myself, and though I did find a couple of recipes for dishes with cat, I found nothing to indicate that they are "highly toxic" as you previously stated. The closest I found was:
    "Scientists have said that those eating wild cats could be exposed to harmful bacteria and toxins.",
    which is true about all wild animals that we eat.

  22. Re:Good Question on What's Stopping Us From Eating Insects? · · Score: 1

    Roof-rabbits are poisonious? Where did you get that idea from? (a.k.a. "Citation please!")

  23. Re:nearly 3 tons - so? on Russian Vehicle Delivers Spacesuit Repair Kit To ISS · · Score: 4, Insightful

    If we're talking metric tons, then they're a measure of mass, not weight. Mass and inertia of an object doesn't go away just because it's in a weightless environment.

  24. Re:Ah yes, government control of health care on Obamacare Software Glitch Will Limit Penalties Charged To Smokers · · Score: 1

    You know, that doesn't sound like socialism at all. More like capitalism and egoism taken to the extreme.

  25. Re:300 Hz on Modeling How Programmers Read Code · · Score: 4, Informative

    Human eyes "flicker" when they look at something. They will remain stationary for a time, then move quickly to another position. (See Saccade.)

    The time for one of the fast movements between positions is in the order of 20 ms when reading, giving us a frequency of about 25 Hz. (It's only half a sine wave, so the period is 40 ms.)

    Using the Nyquist-Shannon sampling theorem, we get that we must sample the eye movement with a frequency of at least 50 Hz, otherwise we'll get aliasing. Now, bring in the engineering rules of thumb, which say that it's no good riding on the Nyquist limit, but you'll need to oversample the signal a bit in order to get a useable result (It of course all depends on what you'll be using the signal for. In feedback control you usually oversample by a factor of 8-20, and in signal processing in the neighbourhood of 2-8) and you end up with a samping frequency of 100 - 400 Hz.

    So, in summary, 300 Hz sounds like a perfectly good sampling frequency, perhaps even a bit in the low end, depending on what you'll use the sampled signal for.