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Everything posted by Flashman

  1. For superheating it appears to be homogenity rather than purity that counts. It does sound unusual that it still had lumps in when this happened, but then a molten lump of butter isn't really going to have sharp edges that might have worked as nucleation sites (and those edges will presumably be rather cold.) However, there appears to be another effect for some milk/water/starch combinations where it will boil over in a flash, if it was not pure butter but a blend. That article does not have much detail, but I presume it might be a result of emulsifiers working to keep small bubbles in suspension until a critical point is reached.
  2. Superheating... essentially a liquid may get hotter than it's boiling point. When something disturbs it, a slight knock or inserting a spoon, it boils over. Most often happens when you microwave a drink, superheat it, set it on the counter or drop sugar in it, and it boils over. Here's a better explanation.... http://en.wikipedia.org/wiki/Superheating
  3. Personally I'd try the super-saturated salt solution idea, you use the heat of solution to soak up more heat in a given size container. As recommended for thermal ballast in some passive solar systems.
  4. Hi folks, I have been getting the feeling that either I'm getting dumber, or that wikipedia articles in general are getting more dense and impenetrable to the average reader. This appears to be happening at an increasing rate over the last year. I've had the experience several times of having to cross refer to a dozen other pages to even determine if the page I'm looking at is actually relevant to what I wanted to know. I realize that technical subjects often require specialized terminologies. I've returned to entries that were perfectly clear 12 months ago, to find out that the essential facts are buried in the voluminous recantings of a derivation from first principles in order to be fully and technically correct. Even in my own area of specialization I am finding some entries to be so gnarly as to actually hinder the grasp of the essential information that they might otherwise impart. Some of this seems to be the result of rolling articles together, such that a simple concept that has more advanced analysis and theories pertaining to it, gets lost when those get merged with it. Some of it just comes I guess from a well meaning effort to communicate as much as possible in as little space as possible in case you happen to be using a 2400 baud modem still and have a 10 volume set of technical dictionaries at your disposal for "decompression". Perhaps I'm expecting too much, I guess I'm expecting something on the comprehension level of the Brittanica or other encyclopedias. Occasionally I've ducked out to the "simple english" version of an entry to try and get some insight, but often those are just non-existant or wayyy too dumbed down. So I'm wondering if other folks feel the same thing sometimes, that some articles just go into way too much depth to be useful any more. I mean if you need a major in it to understand the article, why are you looking it up in wikipedia? I guess it's handy for a relative few. Not being a "wikipedian" as it were I don't have the first clue what one would do about it, petition for a "normal english" version? Flashman
  5. Our mall has a redeeming feature at least, these folks... http://www.scienceline.net/
  6. Ah, I was reading you as just wanting to see the flame.. the problem I believe is that the stoves will tend to overheat when run open. Maybe you can enjoy a period of running it open, with careful adjustment of a damper and keeping an eye on a chimney thermometer, but I doubt there's any makers that would actually recommend this.
  7. I think I'm understanding you better but not quite. Was the spectrum on axis or off axis? Was the banding parallel or perpendicular to the axis? A further thought, eyelashes tend to give some refraction of light, not a lot, I think this is because they can be thought of as sort of like glass tubes with pigment stuffed up the middle, this is noticable due to the eye being so close to them, as they flicked up and down as you blinked your eyes open, they'd "sweep" through the spectrum as the angle to the light changed. The outer "tube" of the hair not being very transparent, more translucent, means this effect is somewhat weak.
  8. Something like these??? http://www.firesidereflections.com/osburn_w.html
  9. Back to the flyback transformer in a backpack... If you have a powder, loosely packed in a tube and apply a high voltage charge to it, what should happen is the grains all fly out of the tube, mutually repelling each other. They also tend to spark between each other somewhat. (At least this is what happens when you open a handfull of small cut paper confetti while insulated and having your other hand on a Van der Graaf generator) In low light conditions, this might produce a somewhat effective spark show. I'm wondering if this effect could be used with an electroluminescent powder to better effect under normal illumination. I'm also wondering if discharges between particles would be enough to kick off a narrowly pyrophoric (self igniting) substance, that is normally fairly safe. Trouble with all the powder in a tube pyrophoric or near pyrophoric when induced with something (O2, electrostatic discharge) is that you might fire them before they're really clear of the tube, getting enough energy to fire the rest of the tubefull before it's expelled and having like a magnesium flare burning off your fingertips.
  10. If all colors were being projected together, it could have been a result of how the eye and brain dark adapt and adjust to intensity. This may have been due to the lights being dimmed. The light from the projector scattering off random dust may not have been very intense, and in the darkened surroundings your eyes switched from cones to rods. The cones perceive color, the rods mostly intensity. So for an instant when you opened your eyes, the individual colors of the image were noticable in the projector beam, but your eyes/brain in adjusting to the overall illumination level switched to processing info mostly from the cones, whereupon it appeared white. I think I've got the basic outline right there but I'm fuzzy on the exact details. Cones can work in low light situations but take a long time to get dark adapted, for example, go outside, look at the night sky and you see a lot of white stars, keep looking for ten minutes and you see yellow, red and blue tints to them.
  11. Hi folks, With the ubiquity and cheapness of web and other video cameras these days, and their usefulness for recording rapidly evolving events in the lab, I was wondering if there's any utilities to help use them in a lab setting. I'm thinking of software that makes it easy to obtain measurements from the recorded video, or from stills of that video. Examples might be measurements of time elapsed, measurements of angles, easy calibration of an image to a scale. Other things that might be useful would be direct control of gain on a webcam during the capture phase such that one could make estimates of relative intensity for flames, glows, or incandescence. Even if it were possible, a color calibration such that one could get rough and ready spectrographic estimates. I'm just thinking that a simple webcam would be a highly useful investigative instrument if such software tools existed to make handling the analysis easier. It would also help us cheapasses with ancient $20 hamfest oscilloscopes, trying to do stuff that yer $3000 digital storage scope is optimised for. (Although yes, I know about scope software for soundcards) So, anyone know of anything at all that makes lab video or cam usage easier in any form, or is a "killer app" for this kind of stuff? Thanks, Flashman. (BTW, haven't got specific uses yet, just trying to stock the "arsenal" so I can better plan future campaigns as it were)
  12. Flashman

    UFO technology

    Possibly... the "anti-gravity" claims of such devices in modern folklore have been attributed more to an ion-thruster type effect... http://en.wikipedia.org/wiki/Biefeld%E2%80%93Brown_effect Note if you're doing this on a saucer shaped vehicle you effectively get an ion pumped Coanda effect.
  13. Flashman

    UFO technology

    Since the earth is considered to have a net negative charge, you'd be charging it for years to lift off. Also some experimenters say they have observed movement towards the positive pole of a highly charged capacitor.
  14. It should be within a percent or two if you just take the known delay of the injector and the known flow rate at known regulated pressure. For example, your injectors are specced at 14lb/hr@45psi, your fuel pressure regulator is 45psi, you see 25% duty cycle on them at 60mph, 4 cylinders, you're using 14lb an hour total, with a fuel that weights 7lb a gallon that's 30 miles to the gallon.
  15. You can cheat and just read pulses off the injector harness.
  16. Flashman

    time travel

    Yeah I moved forward 2 minutes while scanning this post and didn't kill my grandfather or anything.
  17. http://en.wikipedia.org/wiki/List_of_civilian_nuclear_ships IIRC there was a nuclear powered "Hindenburg" proposed in the 60s... yeah, that one didn't get too far.
  18. Hi folks, It is my contention and speculation that the aphorism: "You can catch more flies with honey than vinegar." Is completely false. I contend that vinegar is very effective at catching flies, whereas honey is useless. This is due to the observation that I found I had a leakage of a honey dispenser (One of those squirty ones that sits on it cap) that had been sitting on an open shelf unattended for some time, and it had ZERO, ZIP, NADA, insects caught in it. Whereas an aqueous preparation of malt vinegar, water and dish soap, theorised by myself to mimic the odor of rotting fruit and thus attract fruit flies, catches and kills dozens of fruit flies a day. Discuss, Flashman. (BTW, this seemed most appropriate section for this, please direct me otherwise if I was wrong)
  19. If you have a car that uses electronic fuel injection, it's easier to derive it from injector pulse data.
  20. Some of the ideas for "nuking near it" to nudge it off course seem horribly inefficient to me, seems like you'd get a tiny impulse from radiation pressure, because there's no atmosphere to couple a blast wave to it. So then you'd think about nuking practically right on top of it, to vaporise material off that side, but you'd be risking busting it up then and shotgunning us. Then if you start talking about something that approximates a space weapons platform, you get the "what if some mad dictator...." So what I'd figure on being the best plan is a bunch of "small" mirrors, you get NASA to throw up three, Russia to throw up three, China to throw up three, European Space Agency to throw up three, Brazil to lead a southern hemisphere consortium to throw up three, Japan to lead an indo-asian consortium to throw up three... These should be sized by agreement such that you need 80% of them to focussed on the same spot to "do" anything, then when an asteroid strolls along and is all "Hai, can haz impact plz? Lolz." then all of 'em can get the eggheads together, and figure the best spot to hit it to achieve deflection and do it in concert.
  21. The back of my envelope says... Get 3 2Ohm 5W or 10W ceramic or "sand" power resistors, connect them in parallel, space them round your tank, wrap them up, power with 2 D Cell batteries, and you get 13.5W of heating for about an hour and a half to 2 hours. But, this is kind of slow constant heating, improves recovery time a bit. Possibly a better way to do it is to figure how much gas the gun uses per shot, and thus the heat of vaporisation required, and rig a timer to dump that amount of energy into the tank more rapidly, then turn off. So, how many shots do you get per how many gram fill of CO2? What is the typical timing between shots?
  22. If it is for electronic devices that will be left in cars in the sun (Or built into the cars), like voice activated navigations systems, or cell phones, then maybe the higher curie point of the Alnico is important.
  23. Here's something of an idea that might fly. It's recently been realized that computer keyboards and mice can harbor a lot of pathogens, and medical professionals may inadvertently transfer pathogens between patients by sharing a computer... So, might be a project to investigate the effectiveness of various bactericides on cleaning and keeping keyboards clean, and whether something like an antimicrobial surface, like the copper/brass doorknob effect could be applied to medical use computer peripherals. You'd probably have to get co-operation from your IT folks so you could maybe have test keyboards in one of the main computer rooms, and/or take agar prints off the keyboards etc... This has the potential that if you hit on something real simple and/or clever, that there would be real world applications for it.
  24. They're doing it backwards in Russia, a few places in the north they have old atomic icebreakers or subs tied up providing power for industry or homes.
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