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  1. K

    Trauma causing temporary unconsciousness: what happens physically?

    I am a fan of combat sports such as boxing and martial arts. In competition a person might get hit and temporary lose consciousness, often for a fraction of a second before they regain their senses. I would like to know what is happening on a physiological level when this occurs. What is...
  2. K

    A few questions about solid-state relays

    Okay, good. I am essentially hoping to use a variable PWM and a low-pass filter as a variable DC voltage. Although, the board is also capable of digital output at +5V, +0V. Would it be sufficient to drive the relay using just a 178-ohm current-limiting resistor? In the picture, I did not...
  3. K

    A few questions about solid-state relays

    Thanks for the help; however, I don't think I completely understand. Specifically: I'm not sure what you mean by 'supply voltage'. Do you mean the control voltage? The SSR only has four pins, two for the control and two for the load connection. If you do mean the control voltage, I do plan...
  4. K

    A few questions about solid-state relays

    Today I bought a solid state relay, the datasheet for which can be found here. My goal is to use it to switch 120VAC, controlled by an Arduino Uno board (with Atmega 328 microcontroller). I am very rusty since my days in EE classes, and have not worked with solid state relays at all. In the...
  5. K

    Education pays on BLS website.

    Whoops, sorry, I accidentally used the figure from the Master's degree row.
  6. K

    Education pays on BLS website.

    "Education pays" on BLS website. The Bureau of Labor Statistics has this page on their website: Source: Bureau of Labor Statistics, Current Population Survey, 2010. This just seems very odd to me. This says...
  7. K

    Speed of light barrier

    Thank you kindly Mr. tiny-tim!
  8. K

    Speed of light barrier

    I am not an expert on Physics and have for the past year been engulfed in work, so I am very rusty. I read a comment online recently that essentially said the laws of physics simply prevent any object from accelerating to the speed of light (infinite energy required?), but do not say that an...
  9. K

    News Alternatives to First-Past-The-Post Voting

    I think this would discourage less intelligent or less informed voters. Maybe that's a good thing.
  10. K

    F=ma, but Gravity is a Force with no mass?

    The force will vary according to mass. So a 10-pound bowling ball will have twice the gravitational force ("F" in your equation) as a 5-pound bowling ball. But they will both have the same acceleration ("a" in your equation). Gravity follows the same laws everywhere, but the actual...
  11. K

    News How true/accurate is Gasland

    What frustrates me is that it's so hard to form a real opinion without being an expert on the subject yourself. I can't trust the filmmakers or their targets, because they all have an agenda and $$ to make. For what it's worth, I drink Colorado groundwater pretty much daily.
  12. K

    To Blow, or Not To Blow?

    As people age, they are allowed to do more and more "inappropriate things". Once you hit about ~75 you can just fart/burp/blow your nose anywhere you want.
  13. K

    I Interesting Practical Mathematical Problem

    Think about it this way: whenever you move the drill in one direction, you are sacrificing room on that side. At 2/3 you are sacrificing the most room while the other side can compensate. If you go further than 2/3 you create a 'dead zone'.
  14. K

    Car stopping on a dime

    Would it not be appropriate to solve a system of equations, d=1/2 * a * t^2, d = 17.91 mm, and a * t = 55 mph? Doing this I get about 16.9 kilometers / s^2, or 1721g.
  15. K

    Hard work vs natural talent

    Welcome to the world. Even the smartest people eventually realize there are people who are better. You don't have to be the best physicist, just be the best at being you.
  16. K

    Would you eat in vitro meat even if were proven to be 100% safe?

    If you assume its 100% safe, then what's the problem?
  17. K

    News Romney pays 15% taxes

    Wow! What a pointless thing to say. What if I said "If you don't like the way the pyramids look, tear them down and rebuild them." When a person has to become a politician just to influence politics, that doesn't sound like much of a democracy.
  18. K

    Are you a vegetarian?

    If there are any vegetarians in this thread, could you explain the rationale behind eating some meats?
  19. K

    News Mitt Romney's candidacy

    I don't think business credentials and ability to revamp the economy are interchangeable. The government isn't a business. That is, their goal shouldn't be maximum profit. I think people's concern are not with a rich man's business credentials, but his motivations. If his goal truly was the...
  20. K

    So that's megaupload down

    Good riddance that they are gone, I do think they crossed some boundaries. I am a bit concerned that there was some foul play between UMG and the authorities, considering UMG's history with MegaUpload. IMO it's *way* too easy to pirate things. I think this comes from: a lack of sensible laws...
  21. K

    News Mitt Romney's candidacy

    Really, hmm. I definitely read an article that said Rick said it himself. Sad what journalism is coming to these days!
  22. K

    News The 2012 presidential election poll

    It's more than just women who are disgusted by him. I will never understand how it's acceptable for someone to go around preaching about religious moral values but be a total dirtbag in their own personal life. Drives me crazy and I'm sure it just gives the groups he claims to represent bad names.
  23. K

    News Mitt Romney's candidacy

    Whoops! I was actually thinking of Rick Santorum on that one. Sorry. I would edit my post if I could.
  24. K

    Women are crazy. Interpret this text exchange for me, please

    I'm normally the driver, trip planner, and chief engineer on the "women are crazy" train, but I think the way you rejected her offer was rude. Then when you said "you can still eat breakfast" it showed how little you understood about the situation. I think if you had said "Sorry babe, I...
  25. K

    What do 'nerdy' guys like in girls?

    I doubt it can be safely generalized. Personally I am kind of vain and want someone who is beautiful.
  26. K

    Accidentally Asked Someone Far Out of League

    I had a pretty attractive (read: stone-cold fox) professor for one of my sophomore year gen eds. I happened to run into her at a bar that semester while some hip-hop/R&B music was playing. I said "Hello Mrs. X, not preparing lesson plans tonight?" She responded "No, I don't even want to think...
  27. K

    News Mitt Romney's candidacy

    The good: Romney is frank about his views, which I respect. He plainly says that he is against gay marriage, against medical marijuana, and even believes women should never hold the presidential office. The bad: But, he comes off as a rich guy out of touch with the common person's financial...
  28. K

    News Wikipedia blackout

    If you are disappointed then I am not sure what you expected! Their goal is to capture the attention of millions of average people, inform them, and persuade them in the 5-10 seconds they are likely to spend on the page. A splash page like they have would definitely not be the right place...
  29. K

    News Wikipedia blackout

    Copyright infringement isn't theft. It's copyright infringement. Those things have formal, legal definitions and are not interchangeable. If you infringe on a copyright, you will be charged with copyright infringement, not larceny. The crimes are related in the sense that the perpetrator...
  30. K

    Credit Scores - why are mine going down?

    It's been from all three. Two have changed roughly -50 and one -75. I am so truly baffled by this whole thing.