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Everything posted by Flashman

  1. The probability of one solid object passing through another is not zero. It's some stupidly low number like 1x10^-23 but nevertheless remains "possible". Meaning that if you drop a penny on your desk a septillion times or so, one of these millenia, it will fall through... Though that might not be entirely accurate, it might be more like the possibility of the first plane of atoms passing the first plane in the other object being 10^-23, so it might just "stick funny". But remembering our Rutherford scattering experiment, that of an 8000/1 shot that you hit a gold nucleus, would mean that for one 8000 atom plane, into another, you'd most likely hang up on one atom. Which means that in bulk, with millions of atoms in a plane and millions of atoms deep, it's like setting up a "chicken run" packed with auto firing shotguns and saying, "on average there's enough pellet free space for a human to fit, so theoretically, you could make it through"
  2. Soot happens due to insufficient oxygen. Nitrous Oxides happen due to high combustion temperatures. Water injection metered properly should not cause soot, in fact it's a well known "fix" for cleaning out a carboned up engine. It can however reduce NOx. It's possible that a well tuned engine with water injection could meet tailpipe emissions standards without a catalytic convertor, and due to the change in thermodynamic properties occasioned by putting something other than gasoline and air into a motor, can enhance efficiency. However, catalytic convertors are mandatory, so no auto manufacturer is going to do it. There are rumbles that due to enhanced technological opportunities, and the quest for efficiency, that the auto manufacturers are fighting against mandatory equipment such as catalytic convertors, because there are ways to get the same result more efficiently without them. Consider that a motor has to allow enough unburned HC through to keep the cat hot and provide regeneration for the NOx catalytic component, and also has to put out enough NOx to regenerate the HC catalyst. Pyrolysis oil should be usable cleanly in motors that allow enough time for it's full combustion. Faster higher revving diesel motors would probably not be a good candidate, but slower, longer stroke, constant load motors would. In industrial turbine plants, steam injection along with the pyrolysis oil would probably enhance combustion efficiency, due to steam cracking the heavier chains during the combustion process. Anyway, back to the topic, I know there is some significant work being done right now on a similar system with a hydraulic accumulator and hydraulic motors. The hydraulic motors provide all the drive, the internal combustion motor is only run at peak efficiency. The hydraulic system is supposedly far less lossy than any electrical hybrid system. Equivalent I'm told to the normal losses in an automatic transmission and not requiring a conventional transmission, because the motors provide adequate torque across a very large speed range. Even before regeneration this means that this system should be nearly twice as fuel efficient as a conventional motor of the same displacement in a vehicle. That is qualified as such because vehicles do not use IC motors efficiently, the maximum efficiency of an IC motor comes only at full load at the top of the torque peak. Since most cars are specced with a motor that has 4 to 8 times the power needed to maintain highway speed, they barely ever see peak efficiency, because they are running very lightly loaded with the throttle nearly closed. This means that overall efficiency in use is only 15 to 20 percent. Since the vehicle is driven from pressure stored in the accumulator, the power of the IC motor is irrelevant to acceleration performance, so a much smaller motor than generally specified for a certain size of car can be used. There's probably a sweet spot, between running the motor all the time and it just keeping up, and oversizing it such that it cools off too much between cycles. Add into that the regeneration potential, where 80% of the energy stored in momentum is recaptured in the accumulator, and you get a vehicle that is approaching 4x the efficiency in use of similar sized vehicle. 100mpg is in sight for a family sized car with a system like that. The engineer that's working on this also has a somewhat novel form of IC engine that can be used with this system, that has greater efficiency than a conventional 4 stroke carnot cycle motor. If he gets it all together in an "all out" efficiency vehicle similar in concept to a Honda Insight, then 200mpg may be on the cards. By the way, going back to the idea that motors are 4 to 8 times too big, you will perhaps realise that a way of trimming them down to size is to reduce the volume of the combustion chamber, or the volume of chamber available for combustion. This is one of the benefits of water or steam injection. The volume taken by the steam reduces the pumping loss, effectively meaning that the motor is higher on the load curve, which is a more efficient range. There are of course limits on how much you can put in and still get the fuel/air mixture to go bang of course.
  3. Excess stocks of turn of the 19th Century bolt action rifles were converted to emergency issue light machine guns in WWII with a few simple machine shop parts... It's very easy for a determined psychopath to do this. Rigging forward pistol grips or fold down stocks is trivial. There's nothing too complicated about making extended capacity magazines either. Jewish resistance fighters in the Warsaw ghetto made submachine guns out of plumbing parts. It's very rare indeed that a major shooting incident is the result of someone "Just snapping" they've been planning it for months, even years. Guns were invented, there's no putting the genie back in the bottle. All you can do is frustrate the hell out of enthusiasts while barely hindering the criminals and psychopaths. Doesn't matter if you make some collection of trivial gun features super double secret illegal or not, the "wrong hands" will find a way to get it.
  4. http://en.wikipedia.org/wiki/Chitin And hammers are usually pretty effective.
  5. Well I'd call it a glaring error that your construction appears to be missing a Planck.
  6. There might be 5mm allowance for using it on an older/newer body with an adaptor ring.
  7. Anyone who "really" knows probably isn't allowed to discuss it. However, last I heard, resolution from orbit was on the order of baseball sized objects, say 4 inches. There would be relatively huge problems getting much beyond this due to atmospheric instability and haze. Now spyplanes have much less atmosphere to see through, and may be able to duck below high level cloud and haze and can read a license plate from 10s of thousands of feet and a few miles away. Let's say they've got about half an inch resolution. But, if you want to get to a point of about quarter inch resolution that I figure would be minimum necessary for positive ID of someone, you'd need your basic UAV or a close-in photo-recon. That is why the troops are playing with radio controlled planes in the Afghan mountains and they haven't just lasered Bin Laden from orbit. Probably goes like this, satellite IDs area of suspicious activity, "spyplane" or recon confirms type of activity (can tell guns from sticks) and UAV will tell you who exactly is doing it...
  8. Presuming that the posters have to represent something in some degree of detail to convey a basic understanding of a topic or demonstrate the scope of it, I'd go for a kind of "fractal" approach. What I mean by that is, have something that's eyecatching and legible from across the room, large heading, maybe large central diagram. Then have elements that are eyecatching and legible from say 10ft away, interesting sub headings to pull the reader in, then have "half page" or single paragraph details under each subheading that are readable from 2-3 feet away. I guess I might aim for the style/layout of "Dummies" books for those. You can use your central large diagram as a kind of model that the subheadings label. Or you create the diagram to model what the subheadings refer to. Anyway, all I'm trying to say is to make it appealing at a range of viewing distances and try to suck people in towards it. Don't have large blocks of copy, and try to have a non-sequential format, such that people can stand at the right of it, and gain something from the text on that side, without having to "start at the beginning" and go through everything in sequence. You kind of want freestanding "nuggets" of information that people can read/absorb in 30 seconds. That's just my opinion really, good luck, Flashman
  9. He only has a 100mm refractor apparently, stand by, finding the story that mentions his equipment... Ah this is it... http://www.thestar.com/sciencetech/article/543342 Doesn't say what sort of video camera he used though, "professional" style cooled CCD, converted webcam, hacked handycam or what.
  10. Flashman


    When they find extraterrestrial bacteria, it's going to be a mindjob either way... in that either they have common DNA base pairs with earth life, or they don't.
  11. There are many parameters involved, it will vary by material and either thickness of material or depth of cut. Torque may or may not be so important since some edge moulding bits have a bearing on the bottom. Also important may be the cutting angle of the bit, this is often selected by material. Then of course in practical usage, cut quality comes into it, you can get a powerful high speed router and ram it through a material as hard as you can, and get a ragged cut with charred edges. These pages may help you in defining your problem fully and getting towards an answer... http://www.westone.wa.gov.au/toolbox8/furniture/toolbox/shared/resources_mw/tools_mach/tools/cut_speed.htm http://en.wikipedia.org/wiki/Speeds_and_feeds
  12. Oh right, somehow I got the idea that you were just complaining it didn't look right. Right, so are you wanting to know how many pixels are contained within the circle, or how many pixels are required to form the perimeter? The number inside the circle will be close to the area of the circle, the number on the perimeter close to the standard calculation for perimeter. These get more accurate as the size of the circle increases, but for the perimeter specifically, you'll tend to get overlapped pixels, maybe missed pixels, depending on how it decides whether to draw them or not. But, I get the feeling you don't really care about that and are just looking for a way to draw a circle, so you need the equation for a circle... http://en.wikipedia.org/wiki/Circle However many high level programming languages have an easy way to do this, whether included in the syntax of the language itself or as part of the standard libraries.
  13. Your problem is that pixels often aren't truly square. The amount of deviance from square depends on your particular display device. CRT monitors may be able to be calibrated so that they display everything in the correct aspect ratio by altering the controls.
  14. The "resolving power" of a telescope is limited by it's aperture. This means it can support about 50x magnification per inch of lens or mirror diameter. So, if you want 400x magnification, you need to be looking at an 8 inch scope. Department stores sell cheap 60mm refractor (telescopes with an objective lens) telescopes that advertise something ridiculous like 675x magnification, but for all practical purposes they are only good to about 120x... if that, due to generally poor quality lenses. Telescopes with objective lenses get very expensive as they get larger, making reflector telescopes, "newtonian reflectors", with a parabolic mirror, the most economical in larger apertures. The most cost effective type of newtonian telescope is known as the "Dobsonian" a basic "no frills" newtonian design on a simple altazimuth mount. Here is a reasonably priced example of an 8 inch "dobsonian" style reflecting telescope... http://www.skywatcherusa.com/8-dobsonian-telescope-s11700.html This size should be able to be transported in any small car. For larger 10 or 12 inch dobsonian type telescopes, you may need a wagon/estate car or a small van to transport them.
  15. Interesting... Something that occurs to me though, is wondering if the anatomical changes in sapiens specimens represent a re-adaption to using the arm overhead. If the neanderthals retained a shoulder and arm structure closer to a brachiating ape, then habitual overarm movements might not displace their bones in the same manner. Although it's also curious that chimpanzees are known to throw rocks and sticks, both in hunting and to ward off attackers. The contention in this article... http://www.newscientist.com/article/dn3085-neanderthals-strongarm-tactics-revealed.html That bone changes may be caused by performing an action as little as once a week, makes one wonder why some rotation of the humerus has not been observed in other older hominidae if such overarm throwing was as "natural" in them as it is in modern chimps.
  16. Sort of a funny/curious story about that... "back in the day" circa '95 or '96 I was playing around with slackware and a 486DX33 machine with 8MB RAM... I put 2 floppy drives in the machine, then discovered that the drive and head IDs were switched from "normal" on one of the drives, however, this particular motherboard seemed to handle that rather strangely, and with a buddy, we were able to figure out how to make a device with 4 heads and double the number of tracks, that formatted to 2.88MB (with two floppies in of course) Now, the interesting thing was, it turned out also to be twice as fast... wee were seeing about 250-300KB/sec off it... not satisfied with this.. we then stuck a second floppy controller in the system and crosswired two more drives, and got another 2.88 "fast" floppy drive. Now, the HDDs we were using were clunky old non-DMA non-EIDE 400KB/sec beasties... so we got the crazy idea of combining the floppy volumes, and mounting it as a swap file... so we managed to do that and got a ~5MB device with 600KB/sec DMA transfers (FDD controllers have DMA) and it was faster than swapping to a HDD swap partition! However, 5MB was rather on the small side, and I'd borrowed one of the drives for the test, also made quite a lot of noise as you can imagine... Not toooo long after that, that machine got a decent DMA capable HDD with 1500KB/s + performance and so the config was not revisited.
  17. Interesting stuff, maybe NASA can use it in the joints of their solar panel arms Wonder how many million miles you could get out of a car engine coated with it....
  18. I watched more closely again. It seemed "real" at first because the poor quality video made it look like they ran together when tipped off his hand, also one time he dropped one it looked a little like it squished out from between his fingers. However, with replaying and getting a better feed (do video sites drop quality with demand sometimes?? seems like it) then they appear more solid, and more suspect, particularly when the surface of the liquid looks bumpy.
  19. hmmm perhaps I'm thinking backwards again... however, the only way that is possible is to have high surface tension. Sodium ethanoate does nothing special? http://en.wikipedia.org/wiki/Sodium_acetate Seems to me it's some combination of supercooling and adding table salt to stop it crystalising. Seems there's a lot of voodoo chemistry in those clips though, that heat to 550 degrees thing is obviously wrong. I think basically you're just making sure there's no crystals of the acetate forming..
  20. Wow that looks fun The "explanation" sounds sort of rightish, since when you highly polarise a substance you reduce it's surface tension, so to completely depolarize it you'd give it high surface tension. At a guess I'd say the last thing you'd want to be in excess would be the vinegar, because that has a polarising effect, so if you don't put enough bicarb in it probably won't work.
  21. Reasonableness! Pah, that's a slippery slope, next you'll be insisting people have a sense of proportion and don't see everything in black and white terms.
  22. Flashman

    ghost theory

    Yer average "psychic" tends to be skilled at psychiatric tricks, much as a stage "mentalist" is. In other words, they could quite well pick up cues that homicide investigators give unwittingly about their hunches, and could quite well have the capacity to "profile" a killer much like a legitimate psychiatrist would. Hence, even a fraud may have some use in some investigations. I have heard that there's psychics out there trying to make a name for themselves that along with a few hundred other crackpots, phone in a prediction for every murder that appears in the media, they only have to get "close" every so often in well publicised cases to be able to say "Look how good I am". There are known to be phenomena, radio waves and magnetic fields that stimulate the visual cortex directly, causing perceived flashes of light etc. I have heard of them being measured at "high strangeness" sites. The brain could quite well play tricks on you here, it has a tendency to fill in the blanks. This can result in false perceptions. I have noticed this in dim light when very tired, an unexpected object whose form is difficult to make out initially, like say a purse sitting in the middle of the floor at night, might rapidly resolve in the brain as a cat, then a shoe, then a pile of VCR tapes, as the brain tries to make sense of it, before latching onto what it actually is. Since the brain tries to make a face or figure out of virtually anything, then any strange visuals, whether from radio waves directly stimulating the visual cortex, strange earthglows from piezoelectric stress, marsh gas, light falling on dusty air, are quite likely to be interpreted as a figure. Now if you go somewhere where local conditions predispose towards creating a strange visual in some manner, and there is a reputation for ghost activity there, then even more people than normal will tend to see ghosts, because the brain is even more predisposed to mistranslating inputs because of what it is expecting. So the brain can be a highly imperfect instrument due to high susceptibility to suggestion. So, if you're gonna "ghostbust" you need to ask yourself are you looking for the thing that stimulates visual misinterpretations or are you looking for the misinterpretation itself. The former, you might find, the latter is in someone's head and nowhere else. You can completely miss the former, if you're too busy looking for the latter. However, although 99% of paranormal phenomena may be explained by misdirection or mis-perception, there's that pesky 1%. It's pesky because of all the crap you have to sift through to end up with it. It's like trying to find a needle in a haystack, when someone has dumped a gross of pins in there, by the time you're picking out the 80th pin or so, you begin to doubt the existence of a needle. Science should be all about that last fraction of a percent. Why did Einstein bother if Newton's laws were good 99% of the time? Why did Rutherford care that 1 in 8000 alpha particles bounced back? Rolling a ball backwards and forwards a few hundred times and not having to invoke special relativity to explain it's motion is no evidence that Einstein was wrong. Neither is shooting 5000 alpha particles at a gold film and getting no ricochets a disproof of Rutherford's work. These however are reputable science because they make predictions testable in certain circumstances, or because they are repeatable under the same conditions. We also may be facing a complete failure of current technology in gaining evidence about these phenomena, let alone a lack of suitable testable hypotheses and controlled environments in which they might be tested. It's like early 19th century men of science hearing about the concept of television broadcasts and trying to detect them.
  23. Odd, that sounds more like nickel but that should have been magnetic as the powder.
  24. It would essentially be determined by the speed of sound in that material.
  25. My best guess right now is chromium powder, in which case when you crystalise the green stuff then dehydrate it, it should turn purple.
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