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User: bwoneill

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  1. Actually, 0.043 c on Leaked NASA Paper Suggests The 'Impossible' EM Drive Really Does Work (sciencealert.com) · · Score: 5, Informative

    I believe your math is wrong. U235 releases 202.5 MeV per atom undergoing fission, so that means 1 kg can generate 83.14 TJ from fission. Assuming 100% efficiency, a massless drive, and no mass loss from propellants, that means there is enough energy from fission to reach a velocity of 0.043 c relative to the rest frame.

    dE = (m - m') c^2 = m' c^2 (gamma - 1) => m' c^2 = m c^2 (1 - dE/(m c^2)) = m c^2 (1 - rho)

    rho = dE/(m c^2) = 83.14 TJ / 89.88 PJ = 9.25e-4

    rho = (1 - rho) (gamma - 1) => gamma = 1/(1 - rho) = 1/sqrt(1 - beta^2)

    (1 - rho)^2 = 1 - beta^2 => beta^2 = rho (2 - rho) = 1.85e-3

    beta = sqrt(rho (2 - rho)) = 0.0430

  2. Re:You're testing wrong on Ask Slashdot: Low-Latency PS2/USB Gaming Keyboards? · · Score: 2

    Actually, PS/2 keyboards can't have a latency less than about 50 ms. The PS/2 specification requires a clock speed between 10 and 16.7 kHz which means that the signal must be in the up or down state for 30-50 ms. http://www.computer-engineering.org/ps2protocol/

  3. Re:Chrome Remote Desktop on Ask Slashdot: How Best To Set Up a Parent's PC? · · Score: 1

    After my parents' Program Files were deleted when they installed a Flash update (curse you Adobe for bundling McAfee), I rebuilt their machine such that I would be the only user with admin privileges. For software updates, I use Chrome Remote Desktop because it's easy, secure, and most importantly, free. If they need to run a program that needs admin privileges (like TurboTax) I setup a special shortcut for them using RunasRob that will run the program as an admin without needing my password.

  4. Obligatory xkcd on New Theory About the Source of Pioneer Space Probe Deceleration · · Score: 1
  5. Re:Detection is cheaper on Ad Blocking – a Coming Legal Battleground? · · Score: 3, Informative

    Most of these methods involve using third party JavaScript which can be circumvented by NoScript.

  6. The full paper ... on Asimov's Psychohistory Becoming a Reality? · · Score: 5, Informative

    for those who are interested. I'm looking forward to reading it this weekend.

    http://www.pnas.org/content/early/2012/07/11/1203177109

  7. Re:This guy is an idiot on Eben Moglen: Time To Apply Asimov's First Law of Robotics To Smartphones · · Score: 1

    Asimov was a writer, who wrote fiction books. He didn't understand technology at all

    Asimov wrote more than just fiction, he wrote dozens of science books on topics including: astronomy, biology, chemistry, classical physics, and subatomic physics.

    http://en.wikipedia.org/wiki/Isaac_Asimov#Nonfiction

  8. Re:Well, isn't that... on US Metaphor-Recognizing Software System Starts Humming · · Score: 3, Funny

    Darmok and Jalad at Tanagra?

    But, but, but .... with the project called ADAMA it should be from Battlestar Galactica.

    Shaka! When the walls fell.

  9. Apes on Orangutans To Skype Between Zoos With iPads · · Score: 1

    Don't call them monkeys or they'll go Librarian-poo.

  10. Re:Pretty simple explanation... on Why Do So Many College Science Majors Drop Out? · · Score: 1

    The claim is that writing can't be taught on an industrial scale but science can be.

    No, these classes are taught this way out of necessity. If a grad student wants a physics degree, (s)he must do research. To this end, a typical physics grad student will TA for just a few semesters until (s)he gets a research project. This is a full time job. There just aren't enough incoming grad students to fill more teaching positions. I suspect it's similar for all the sciences.

    I don't know what it's like for English grad students, but I suspect that it's the exact opposite. As far as I'm aware, English majors don't need to do the same kind of time intensive research. I suspect that English grad students will teach classes throughout their higher education.

    Thus, even if there are the same number of incoming physics and English grad students, I suspect that there will be 4-6 times as many English majors available for teaching.