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The Physics of Space Battles

shoor Conservation of Momentum (373 comments)

If you're going to have reaction drive style thrusters for maneuvering, you're going to run out of fuel very quickly, dissipating mass, unless your thrusters are thrusting out little bits of mass at VERY high speed, in which case they could be used as weapons themselves. (Sci Fi writer Larry Niven came up with the idea of a reaction drive as a weapon, google the 'Kzinti Lesson' for more info.)

I think it would be interesting to have space battles where several fighters were somehow connected to each other via some sort of tractor beam, so they maneuvered by transferring momentum between each other instead of dissipating mass into the vastness of space; they might look a bit like bolas circling each other but with quick changes snapping in and out as they went in to battle, or maybe they would be tethered to a mother ship, somewhat like World War II aircraft carrier that sends out figher planes to do the fighting. The mother ship would have enough mass to let the fighters seem to be free to zap around easily.

---
("Cough Cough") I wrote an unpublished Sci Fi Novel (I did send it to a bunch of publishers at the time, over 10 years ago), where interstellar travel used 'draggers'. There was no faster than light travel so it took years and years to go between even nearby stars, (The travelers themselves would be in an accelerated frame of reference so it wouldn't be so long for them.) In the novel it took a long time to set up a system between two solar systems, similar to the way it takes a long time to set up a railway between two cities, but then you could use it very efficiently. A vessel would attach itself to a dragger, and be quickly accelerated (that's the hard part, dealing with the sudden accleration that would flatten everything against the back wall like you were in a super cream separator), the dragger, much more massive than the vessel, would be slowed down some, but then, at the other end, as the dragger wheeled around a star, the vessel would transfer it's momentum back to the dragger and slow down to become part of the other solar system.

The thing about conservation of momentum is that it means the center of mass of a closed system doesn't change. If two solar systems and the draggers going between them were a closed system, then the center of mass would shift as the vessel moved between one and the other, but, if the vessel returned to the original system again, then the original center of mass would be restored, and the energy used to move between them could be recycled, plus there wouldn't be reaction mass being spewed out all over the place.

yesterday
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Nvidia Sinks Moon Landing Hoax Using Virtual Light

shoor Is it healthy or unhealthy for society to have ... (275 comments)

I'm just wondering if when a society has conspiracy theorists speaking out freely, the 'tin hat' crowd, is that the sign of a healthy society or not.

It's bad I suppose when conspiracy theorists are flat out wrong, but would a repressive government try to silence them or do repressive governments only bother suppressing people who are telling the Truth?

Does it do harm in that when somebody really finds something bad going on people will tend to disbelieve them because of all the flakos (sort of like crying wolf too many times)?

Is there some sort of bell shaped curve of attitude towards what the establishment tells us in that a few people on one end of the curve will believe everything and bury their heads in the sand over any problem (like maybe global warming), and a few on the other end of the curve will leap at anything as a plot, while most people are somewhere in the middle? If there is such a curve, maybe it's characteristics (skew, standard deviation, etc) are what determine the 'health' of the society.

about a week ago
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Study: Chimpanzees Have Evolved To Kill Each Other

shoor Not just Chimps and Humans (222 comments)

Lions and wolves will fight and kill each other. One argument I've seen is that they are at the top of the food chain so there is no other animal out there to keep their numbers in check.

about two weeks ago
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Massive Study Searching For Genes Behind Intelligence Finds Little

shoor Re:This may sound silly...Epigenetics (269 comments)

I was wondering about epigentics myself. If I had points I'd mod the anonymous coward up.

about three weeks ago
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Microsoft Paid NFL $400 Million To Use Surface, But Announcers Call Them iPads

shoor Re:football can cause brain damage (405 comments)

I agree calling the thing 'Surface' could lead to confusion. If an announcer said something like "the coach is checking his Surface now", what percentage of viewers might have thought he was referring to something other than the gadget in the coach's hand?

about three weeks ago
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GSOC Project Works To Emulate Systemd For OpenBSD

shoor Re:Er? (automatic locale?) (314 comments)

Hmmm, it sounds like what's needed is a daemon that queries location from a GPS system as well as time, and automatically adjusts timezone and whatever (would you want it to change language? Seems like that's more of a user thing, and something you only change when you change users). Of course, it would require the system be hooked up to a GPS system, otherwise do things the old-fashioned manual way. There could be an app that puts up a map where you click on the location I suppose, instead of fiddling with configuration files.

I'm an old time unix user (going back to 4.2 BSD days). I like the idea of text configuration files for everything. But I wouldn't mind a front end app that was easier to use than constantly having to look at man pages on the formats of everything. A sort of IDE for all the text based config files the way an IDE is a helper for the text code files of a programming language. (But NOT a binary that bypasses the text configs! Which is what systemd seems to be doing, if I've been reading this right.)

about three weeks ago
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Scala Designer Martin Odersky On Next Steps

shoor Re:Why attack Java like this? (94 comments)

Isn't Python supposed to have suffered from a big revision change? My first thought, when I read about Dr Odersky making revisions is that he would be running into the same problem that Python did. Maybe Scala isn't as widely adopted yet as Pascal was, and he thinks he should fix it now before there would be too big of a flap over it. (Actually, if they're changing Java as I gather they are from the interview, wouldn't that also be a blowback for Java?)

I'm an old timer who has never used any of these new-fangled languages professionally (where new-fangled is anything newer then C), so I'm not trying to editorialize here, just wondering.

about three weeks ago
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Research Shows RISC vs. CISC Doesn't Matter

shoor Re:It's a question that WAS relevant (161 comments)

Back in the 1970s I worked at a computer manufacturer, writing code for their product's instruction set in assembler. The computers were designed and built around AMD2901 bit slices. The hardware guys implemented the instruction sets using microcode and, as the computers got bigger and more complicated some of the instructions got so elaborate that programmers found ways to do an operation faster using a few simpler instructions instead of one complicated one.

Nowadays, with the kind of speedups from using cache memory, branch prediction, and so on, I reckon it could be a whole different ballgame. I suspect though, that proving correctness might become the most important criteria, and simpler would make proving correctness easier.

about a month ago
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Can Our Computers Continue To Get Smaller and More Powerful?

shoor Re:yes. Especially per passenger. (151 comments)

The Concorde also had a sonic boom which limited the airports it could fly to. (Competitors may have exaggerated the problem, but I do believe it was a problem.)

about a month and a half ago
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Interviews: Ask Bjarne Stroustrup About Programming and C++

shoor Re:Is the complexity of C++ job security? (427 comments)

I'm not a C++ programmer. But I have come across situations where people seemed to deliberately use weird, obfuscating stuff just so nobody else could take their place, (I particularly remember a company where somebody had convinced management to use UUCP instead of FTP for internal data xfers because it was more secure. When I was being interviewed on the phone they asked me what I thought of UUCP, and I think I was one of the few people they interviewed who had even heard of it.)

So, if C++ is as complicated and full of stuff as I keep reading about, I can see how somebody might deliberately cultivate for themselves a set of esoteric off the wall constructions that they'd throw in their code just so nobody else could work with it, all the time selling management on how 'good' it was.

about a month and a half ago
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Interviews: Ask Bjarne Stroustrup About Programming and C++

shoor Re:Is the complexity of C++ a practical joke? (427 comments)

"Life is a learning experience, so break out the reference manuals"
That's fine if you're a student. I've been in situations where I was working for a small company and I had to fix problems for the company quickly so they could bill their client and make payroll. If C++ is supposed to be a bunch of languages rolled in to one, then, the code should be flagged, "This is C++ as a functional language, only people who know all the functional stuff should use it, or be hired to maintain it in the future, and don't stick in anything of exotic flavors X, Y, or Z from C++ in it". Or, if the company was serious about doing the product in a functional way, one could use Haskell or Scheme or whatever in the first place."

about a month and a half ago
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Wiring Programmers To Prevent Buggy Code

shoor Re:Premise flawed? (116 comments)

NOW, after my moderator points have expired, somebody posts something I would want to mod up!

From my own experience, when I had really difficult, gnarly problems, the code came out really clean at the end. The bugs came when I was least expecting them with stuff that should have been a piece of cake.

I think it might be a bit like what somebody once told me about private airplane pilots. Statistically, accidents didn't happen the most when people were novices, but after a certain number of flight hours. I don't remember exactly what they were. Actually there were 2 peaks, for the sake of argument I'll say that one was at 2000 hours and one at 8000 hours flight time. An interesting phenomenon.

about a month and a half ago
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Comparison: Linux Text Editors

shoor Re:You're welcome to them. A few words re Emacs (402 comments)

Hear Hear,
I generally use vi myself, though I've actually forgotten some of the fancier stuff. I even have some muscle memory for emacs which I acquired because I had an Atari 500 ST back in the 1980s. Having cut my teeth on old glass teletypes (Uniscopes, Hazeltines, and even genuine VT-100s with the gold keys pad) I needed a basic term window and text editor for my Atari. The best text editor for the Atari that I could find on Usenet in the old binaries groups was 'Micro-Emacs', a very stripped down version of emacs, but in using it, my fingers learned CTR-E to go to the end of a line, CTRL X 2 to split a screen, etc. It's because of that that I still use emacs sometimes for very basic stuff. (I always install the -nox version). Heh, back in the 80s, I knew if I was on a fast computer at work if I could use emacs and it was responsive, which made Micro-Emacs, running on my Atari so well, all that much more impressive.

about 2 months ago
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The Simultaneous Rise and Decline of Battlefield

shoor Re:Holy shit, this IS news for nerds (208 comments)

IANAG (I am not a gamer). Also, I did not RTFA, but I did read the summary, where it explicitly didn't comment on the game itself, but on 'poor behavior'. I think there's a difference.

about 3 months ago
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Evidence of a Correction To the Speed of Light

shoor Re:Ummm (347 comments)

Ah, this is getting off topic, but your comment raised a question in my mind. Suppose the light is blue shifted for an observer approaching it so that it does have the energy to form an electron-positron pair, but for another observer not approaching it as fast, it doesn't have the energy. Might one observer see the pair formation while the other did not?

about 3 months ago
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After the Belfast Project Fiasco, Time For Another Look At Time Capsule Crypto?

shoor Re:Time release escrow (170 comments)

Could the encryption be in the form of a one time pad? Then it would be 'unbreakable'. Perhaps there could be several one time pads, and only when all of them were brought together would the data be decodable.

Ultimately, the only suggestion I saw, including suggestions on the site, that would be as inviolable as the laws of physics, is sending the message in to space as electromagnetic radiation to a place where it would be echoed back. But first you would have to have something in position to do the echoing, so that won't be practical for a long time.

All the other methods depend on the world not changing too much. Governments, laws, and institutions remaining stable, Encryption methods not being cracked. Using a satellite in a far elliptical orbit would work with present technology, but if the message is supposed to be kept for 50 or 100 years, technology might catch up and the satellite be retrieved sooner than the originators wanted.

about 4 months ago
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After the Sun (Microsystems) Sets, the Real Stories Come Out

shoor Re:Cool Technology (166 comments)

Despite being on the Internet for a pretty long time (I made my first post to Usenet in 1984) I only have a hazy notion of what Facebook is. I've heard about it, and in googling and stuff actually been on Facebook pages of some sort I think. I say this to establish my credentials as NOT being a Facebook fanboy.

Nevertheless, I've heard that in other countries when there were revolutions and stuff going on, people used Facebook to rally and organize. So give the devil his due. (Or am I getting Facebook mixed up with some other social media thingy?)

about 4 months ago
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Become a Linux Kernel Hacker and Write Your Own Module

shoor Re:First Tutorial I've seen with Goto... (143 comments)

I got my intro to programming in the mid 1960s with 'the college computer' a PDP-8 that we programmed in Fortran using punched cards. In those days, just getting access to a computer was a pretty big deal, but things were changing, so 'programming paradigms' started appearing, and the first one that I remember was 'structured programming'. This is where I first heard the mantra of 'goto-less' programming. (Before that, the mantra was not to write self-modifying code, which was something you almost had to be writing assembly language code to be able to do, though COBOL had an 'alters' statement as I recall.)

I remember being somewhat startled by the idea of excluding gotos. How could you write non trivial code without any goto statements? I actually thought of it almost as a challenge to figure out how to do so. The opposite of structured code was 'spaghetti code'. Anyway, it's become a conventional bit of wisdom that I suppose is just automatically passed down to each generation of students without anyone ever seriously questioning it, except those who find they really need it sometimes. At some point I started defiantly putting an occasional goto in my code again, but not often.

about 4 months ago
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The Sci-Fi Myth of Robotic Competence

shoor Using the word 'kill' in the article's title (255 comments)

A discussion of decision making algorithms for various situations is a reasonable topic, but using the word 'kill' with respect to what the robots should do was bound to provoke responses the kind of responses the author is bemoaning.

about 4 months ago

Submissions

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Why doesn't somebody invent a GOOD archival system

shoor shoor writes  |  more than 5 years ago

shoor (33382) writes "It seems like the topic of good archiving, via tape, hard drive, optical media or whatever, is always coming up with a lot of debate and no good conclusions. There certainly seems to be a need, and I wouldn't think the problem is all that hard. (Too hard for me, but not for a small research department with an engineer, materials scientist, and appropriate lab equipment.)

To me, an archival system is write once because, from personal experience, I've lost as much stuff I wanted to keep by overwriting it as by any other method. The main factor is pure longevity of course, but other factors are ruggedness (could it withstand moisture? a small fire? getting knocked off a shelf in an earthquake?), compactness (dvds and tape are sure a lot better than punched cards or floppy disks), and cheapness. I would say it doesn't have to be particularly fast, but it should have random access ability, which leaves out tape.

The way the media is written doesn't have to be the way it's read. Trying to think how I might do it if I had the scientific/engineering chops, I conceptually start with old fashioned photographic film. The negative is exposed to light when the picture is taken. The negative is still very fragile until it gets chemically fixed. After that it can safely be 'read' (exposed to light) while an indefinite number of positives are made. In a hypothetical computer data archiving system, the fixing operation could, for example, be a chemical reaction that is triggered somehow immediately after or while the data is set, and it could be triggered mechanically or in response to heat or UV radiation or a magnetic/electrical charge, or something exotic that I haven't thought of, while at the same time, some other effect (mechanical, electrical, photonic,...) is causing chemicals to react, as in photography, or perhaps tiny nanoparticles to either accumulate in a region or disperse or maybe molecules/particles just rotate slightly in one direction or another due to a magnetic field or polarisation of light. What matters is that the end state is stable and non-destructively detectable.

It doesn't really seem like it should be all that hard to do, so what's the problem? Not a big enough market? Not glamorous enough? Are the current solutions just considered good enough? Or is it actually a much tougher problem than I imagine?"
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Is there open source ganzfeld software?

shoor shoor writes  |  more than 7 years ago

shoor (33382) writes "I recently saw a BBC documentary, one of a series on supernatural science, about ESP. They mentioned "ganzfeld experiments" which seemed to be the most reproducible versions of ESP. I've always been very skeptical myself about ESP, but this particular episode of this series seemed less skeptical about the possibility than about other subjects it's tackled (zombies, levitation, etc). So it occurred to me that it shouldn't be that hard to write software to allow do it at home ganzfeld experiments. Basically, the computer chooses randomly from a set of pictures, the 'transmitter' person, stares at a picture, maybe tries to draw it, for a set amount of time, then the 'receiver' who has been isolated is shown a set of pictures, one of which was the image, and tries to pick the correct one. The computer could keep track of the statistics of success and so on. Here's a link to a website that offers a little more background (and skepticism) than the documentary: http://skepdic.com/ganzfeld.html If I wrote up a program, would there be a chance of copyright or patent flack over it?"

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