rootbear

53 ms·

571.
by rootbear 11y ago
The author, Chad Orzel, is the author of the book, "How to Teach Physics to Your Dog", which I thoroughly enjoyed. The chapter in which he explains the Bell Theorem I had to read twice, but I eventually got it. He also wrote a seq
572.
by rootbear 11y ago
I found various types of old graph paper in my father's desk when I cleaned it out. I've kept most of it. He's an EE and a ham radio operator, so he had lots of things to graph.
573.
by rootbear 11y ago
The Ascent of Man series was shown in the US on public television and I was a huge fan. I had forgotten that Szilard was featured in it. I'd really like to go back and re-watch that series.
574.
by rootbear 11y ago
I used to work in the SVS and Ernie, who made those images, got to be a real expert on the complexities of the moon's orbit. He did some really great work. Check out the SVS website for more.
575.
by rootbear 11y ago
Nice illustration in wikipedia. I first learned about this feature of the moon's orbit from one of Isaac Asimov's science essays. In many ways, the Earth and Moon are like a double planet, though not so much as Pluto and Charon.
576.
by rootbear 11y ago
The prefix code to control my car's shields is 16309. Maybe I should change it.
577.
by rootbear 11y ago
Ah, ha! Now I know why Don A. Stuart (John W. Campbell) in the short story "Night" (1935) mentioned a bismuth coil as being part of an anti-gravity device. The device opens a time portal and sends the narrator into the far futur
578.
by rootbear 11y ago
I have a fondness for the names of those first generation computers (my Mac Pro was named PROZAC in tribute) and I've always liked the name of the BRL Electronic Scientific Computer, BRLESC, which was surely pronounced "burlesque
579.
by rootbear 11y ago
Whoa, I didn't know that. I quoted the 230kbit number from memory, when I researched it several years ago, when my parents still had dial up. I'm not surprise that MRO is faster.
580.
by rootbear 11y ago
Similar story here. My dad responds well to his old jazz recordings.
581.
by rootbear 11y ago
The Doppler shift is tracked, as it tells them how fast (in radial terms) the spacecraft is going. Some years back, I watched the live coverage on NASA TV of the Cassini spacecraft going into orbit around Saturn. When they went into orbit,
582.
by rootbear 11y ago
The data rate to Mars isn't shabby, at about 230kbps, roughly four times the speed of a fast dial-up connection. I used to point that out when the only Internet at my folks' house was dial up. Eventually, my iPhone cell connecti
583.
by rootbear 11y ago
The downlink is actually 1kbps, with 2kbps optional, by using both amplifiers with opposite circular polarizations. But they can't use that trick all the time. A nice article with more technical details is at http://www.pla
584.
by rootbear 11y ago
Fifteen years ago, the modern parts of the Pixar animation system used Tcl/Tk for the GUI. The older code looked like Tektronix 4013 displays... I didn't work on GUI code much, but what I did do was fun. Since this was an inte
585.
by rootbear 11y ago
I know that the climate models that run on the supercomputer at NASA Goddard are in Fortran. Specifically, Fortran 90/95.
586.
by rootbear 11y ago
And in C11, I believe they are now optional. EDIT: Oh, and kudos on the day 1 vs day 0 comment; very funny!
587.
by rootbear 11y ago
Nice discussion, thanks for posting.
588.
by rootbear 11y ago
Yes. To get there in less than ten years, it had to be low mass, since a high mass spacecraft would require a launch vehicle we don't have. Since it is low mass, it can't take enough fuel to slow down. Thus, a flyby. Getting the
589.
by rootbear 11y ago
Interesting document! As a contractor working for Chrysler, my father worked on the Saturn 1B stage telemetry system. The flight data recorder, I think. This was in Huntsville, AL, where I grew up.
590.
by rootbear 11y ago
Yes! I was pleased to see that.
591.
by rootbear 11y ago
I completely agree. I keep saying that nothing interesting happens in less than 10,000 years. Or a million. Compared to the Universe, human lifetimes are instantaneous. Such a pity.
592.
by rootbear 11y ago
I don't know why that article quotes two weeks. I've read the 16 months figure in several places and it was mentioned in the press briefings yesterday. There might be a specific subset of data that will take two weeks to get. Per
593.
by rootbear 11y ago
Amazing. I wonder what platforms those are.
594.
by rootbear 11y ago
I assume portability is why the function declaration is old K&R style and not ANSI prototype style. I'm always surprised when I see K&R style in modern(ish) code. I do miss the ability to declare multiple parameters of the same
595.
by rootbear 11y ago
In the press conference, the PI was asked about a future mission. He said that he has thought about orbiters and landers and considers the Pluto system to be a valuable science target. But he said that we need to study the New Horizons data
596.
by rootbear 11y ago
Whoa! I hadn't thought about that. The speed of New Horizons hasn't been constant, of course, but the accumulated time difference is probably close to what you calculated. There would also be a correction due to it being farthe
597.
by rootbear 11y ago
Amen. I work at NASA and I'm gobsmacked at the beauty of the New Horizons imagery. I can't wait to see the good stuff. Isaac Asimov's science essay collections had a profound effect on me. I learned physics years ahead of whe
598.
by rootbear 11y ago
I agree that dark matter isn't the best name. We could call it ether...
599.
by rootbear 11y ago
I'm fascinated by projects like this. I'd never have the time or skills to pull it off myself, sadly. No one has yet mentioned the similar relay based computer by Harry Porter, which I'm sure has been mentioned on HN before,
600.
by rootbear 11y ago
At the recent Maker Faire in Washington, DC, I asked the Raspberry Pi guy about the DSI display and he said that it is coming soon, but he didn't have specifics. The delay appears to be the complexity of getting it cleared for EMI. The

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