Slashdot Mirror


User: Fatllama

Fatllama's activity in the archive.

Stories
0
Comments
42
First seen
Last seen
Profile
(view on slashdot.org)

Comments · 42

  1. Re:Color me LED on Screw-in LED Floodlights · · Score: 1

    I feel ya; being able to take your living room to Yellow Alert is not just a good idea, it should be an inalienable right. Well, discretes with individual red, green, and blue channels exist already. Now I guess they just need to get crazy bright and then someone around here can make the front page by building the USB based DAC. If you can't wait you could just move into this place and fiddle with the dials yourself.

  2. Re:Color me LED on Screw-in LED Floodlights · · Score: 1
  3. Re:Amish Lights & Improvements on Screw-in LED Floodlights · · Score: 1

    Something else to keep in mind is that high brightness LEDs do not tolerate much heat and since the light-emitting area of an LED is very small compared to, say, a filament, heat must be pumped away either passively with a heat-sink (much like your CPU) or actively with a thermo-electric cooler (much like some people's CPUs). Here comes the expensive engineering problem.

  4. Scientific application; advice anyone? on Screw-in LED Floodlights · · Score: 1
    Does anyone out there have enough experience to compare these products to those offered by Lumileds? I actually use their Luxeon Star (and Star III) LEDs with narrow-band interference filters in a physics lab to drive optical atomic transitions in single trapped ions. I combine the light from a blue and orange LED with a dichroic mirror and then image the beams (roughly 1:1) using f/2 camera optics. Typically I can drive one (electric dipole) transition in 100ms and I won't spill the details about spot sizes, etc. unless anyone is interested.
    What is important to me is
    • Fast turn on/turn off times. No more than 10ms.
    • High total brightness, but particularly around the wavelengths 455nm and 615nm.
    • Small source size, narrow emission cone since the light must be captured and imaged.
    Anyone out there know if I can do better with these or any other solutions?
  5. Re:We demand you delete this article on How Not To Sell Linux Products · · Score: 2, Funny

    For someone in the thought police, we all think your boss is going to be very nonplussed to see you talking that way.

    ... which is only slightly better than making your boss doubleplusunnonplussed?

  6. OT: Re:Oh great... on MPAA, RIAA Seek Permanent Antitrust Exemption · · Score: 2, Funny

    If I put you in water, would you get wet? Or would the water get you instead?

  7. Also a Sci-Fi author on Big Bang Really a Big Hum · · Score: 1

    For those interested in cool quirky profs, the guy is also a decent sci-fi author. For my part, though, reading a sex scene written by a prof I see around the department for is a bit odd.

  8. Re:The real solution on MPAA Ruins Own Films As Anti-Piracy Measure · · Score: 1
    ...as opposed to now, where even us Mac users can use freely available utilities to 'back up' DVDs to our hard drives, be they rental or not (and in doing so, also remove CSS, region coding, and macrovision). Of course, these utilities are and should remain legal because they enable my fair-use rights: e.g. say I want to watch DVDs on an airplane; the hard-drive uses less battery power than the optical drive.

    By giving them the option of 'not taking that chance,' as you say, you rob yourself of liberty.

  9. Re:The real solution on MPAA Ruins Own Films As Anti-Piracy Measure · · Score: 1
    How would an RF modulator solve the problem? The connection problem is summarized here and several DIY kits about the net. The garbage signal added by Macrovision is outside the specifications of a normal video signal and needs to be corrected by (essentially) continually resampling "black" signal levels and rescaling the video signal appropriately; sounds like a job involving at least discrete logic, not just a simple mixer.

    Even if you've had good experience with a modulator (let's here it), the issue is still naked: why must I, Joe Honest Consumer, purchase previously uncessary equipment in order to view (buy a new TV) or to exercise my free use rights (buy a modulator and sidestep Macrovision)?

  10. Re:The real solution on MPAA Ruins Own Films As Anti-Piracy Measure · · Score: 1
    Wrong. My television set has a built in VCR and an RCA input jack. It turns out that when I hook up a DVD player to the jack, the picture on the screen is fskced because the signal is most likely routed through the built-in VCR.

    Does it give me the option of turning off Automatic Gain Control? No. Does this mean I have an outdated TV and should just replace it? Maybe. But I'll be damned if I thank the MPAA and DVD manufactures for treating me like a criminal when I just want to watch a movie I paid for.

    Seamless indeed.

  11. I love... on Music Industry Compared to Movie Industry · · Score: 2, Funny
    ... how near the end of the article, this jackass writes
    Even the blank CD formats are mired in confusing infighting over CD-R and CD-RW.
    Yeah, cause clearly DVDs currently have no problem of the sort cough and the difference between read-only and read/write takes a mind of staggering genius to understand. Fluff.
  12. That's it... on How Much Does A Cloud Weigh? · · Score: 4, Funny

    ... the cloud is a witch! No wait, ducks not elephants. n/m

  13. Re:Are you sure it's tea? on How About A Cup Of The Answer To Everything? · · Score: 1

    You, sir, are correct.

  14. Re:The plan all along... on Matrix Reloaded on DVD Before Revolutions · · Score: 1

    Consider: the machines claim that this version of the matrix is number six. The rise and fall of Zion has happened 5 times before without a hitch, but this time things will be different, I think.

    When Neo merged with Smith in the first movie, Smith gained extra abilities. He now can multiply and can occupy the mind of a human in the real world. I think the reverse is also true: Neo gained some abilities through his collision with Smith as well, namely the ability to "interface" with the machines in the real world. The plan to destroy Zion will not go smoothly for the machines this time. You heard it here first, the "Matrix within a Matrix" idea is a cop-out and not worthy of the Brothers W.

  15. Re:Just as I suspected on 3 Major HD Makers Recalling Drives? [UPDATED] · · Score: 1

    Likely story.

  16. Re:Just as I suspected on 3 Major HD Makers Recalling Drives? [UPDATED] · · Score: 1

    But it's Thursday.

  17. Re:When are they going to learn... on A New Spin On Physical Phenomena · · Score: 1

    No, no, and No.

    1. The time taken to charge up the spheres is nearly instantaneous; it only depends on the capacitance of the system, which in this case is undoubtably small. Also, in the article they state that they wait dozens of hours for the system to equilibriate before making measurements.

    2. The charge is *not* uniformly induced on the two spheres not hooked up to the voltage source, which is exactly why they rotate. The *voltage* on the surface of each of the spheres is uniform (because otherwise, charge would flow to make it so; it's a conductor)

    3. Only one sphere is being charged. It induces *dipole* distributed charges on the other two spheres (like the moon induces a tide on the earth, not uniform, but dipolar) which then torque to line up with each other's dipole.

  18. Just read the paper, cute trick but no new physics on A New Spin On Physical Phenomena · · Score: 3, Interesting

    The Applied Physics Letters paper is just two pages long. There is no new physics here. Here's the skinny.

    Sphere A is charged up; the two others, B and C, are at different distances from A. Each sphere is polarized in a non-uniform way (because each sphere has two hemispheres, one closer to the charged sphere and the other farther... just as tides form on Earth due to the moon).

    The potential at the surfaces of B and C might be uniform but the charge distributions are not: they are dipole. Due to this dipole interaction (the more negativey charge hemisphere of one sphere wants to be closer to the more positively charged surface of the other sphere), Spheres B and C then tourqe to a different angle and will either a) stay there in the presence of some friction or b) oscillate back and forth in the absence of friction. Of course, there is always some element of friction due to the air and wire, but one can compensate by also oscillating the potential of A to make positive feedback, I imagine.

    The press release was, in this physics grad student's opinion, horrible. Implications that this research has some impact on our understanding of electrostatics or (gasp) quantum mechanics is irresponsible. It's a cute trick, though, and I'll bet it will find applications in mico-,nano-tech and perhaps other research areas (e.g. experiments requiring precision angular measurements ).

  19. Yes, on Internships in the Post-DotCom Era? · · Score: 1

    graduate school.

  20. David Foster Wallace on Top 10 New Sci-Fi/SF Authors? · · Score: 1

    ...a modern master of the short story and essay (i.e. collections like Girl with Curious Hair , A Supposedly Fun Thing I'll Never Do Again , and Brief Interviews with Hideous Men , all good, esp. Girl IMO) and the (very) long novel Infinite Jest . He's a delight to read and, I think, a breath of fresh air to a SF fan. His voice strikes me as very personal though he'll often acknowledge in his writing when he's hiding behing slick po-mo tricks and literary hijinks to avoid the reader's gaze. Very inspiring and memorable stuff.

  21. Re:don't forget on Top 10 New Sci-Fi/SF Authors? · · Score: 1

    The Big U ended, that's for sure. But in more likeness to a trainwreck than a knot of loose ends. A great book though.

  22. Re:This article is so bad it's not funny. on Speed Of Light Broken With Off Shelf Components · · Score: 1

    You're correct. The electrons aren't moving at 2/3 c at all. Drift velocities in metals are actually very slow (cm/s). However, voltage signals move at about 60% the speed of light (in a vaccum) through coax because of the dielectric material between the conductors.

  23. Re:One correction to your statement on Speed Of Light Broken With Off Shelf Components · · Score: 1

    No.

  24. Phase velocity != Group velocity on Speed Of Light Broken With Off Shelf Components · · Score: 1

    Nothing to see here. Move along.

  25. Horrible on Einstein's Theory To Go Beta Testing · · Score: 2, Insightful

    The CNN article is one of the worst examples of science writing I've *ever* seen. I even thought of submitting it for that purpose alone. Now, what does it mean that Slashdot took it seriously? Good lord.