Flash Definition and 150 Threads

  1. dbecker

    Static electricity (like tree lightning) on my ceiling?

    I had a rough night of sleep tonight and woke about 3:30. At one point I was awake on my side and noticed a small burst of light in the room, which I found a bit odd, being familiar with all the things that blink, etc., and not expecting any. But I figured it was just one of those. Then, about...
  2. M

    Unexplained bright flash of light inside house

    Last night I was awoken by what seemed like an extremely bright flash of light. I sat up and saw another bright flash of light just outside my bedroom that seemed to originate just down the hall. I was worried there was an electrical short so I ran out and nothing. I thought maybe I imagined it...
  3. Dario56

    Extraction Flash Calculation - 4 Component and 2 Phase System

    I am performing extraction flash calculations for 4 component and 2 phase system. For anyone somewhat shaky with what extraction flash calculation is; extraction is performed, feed composition is known and we are calculating compositions of both phases at equilibrium, mole fraction of every...
  4. S

    How does metering device in an A/C cause flash gas?

    When refrigerant enters the metering device of an air-conditioner, the refrigerant enters the metering device as 100% liquid. When the refrigerant in a straight air-conditioner goes through the metering device, the metering device lowers the pressure of the refrigerant a great deal. The...
  5. Ivan Seeking

    Why do Lifesavers no longer produce a blue flash, but Altoids still do?

    Most nerds know that if you crunch a wintergreen lifesaver in your mouth or with a pair of pliers, it flashes blue light due to triboluminescence, . Breaking the bonds in the sugar molecules releases UV, which is then re-emitted as blue light by the wintogreen flavoring [ Methyl salicylate ] due...
  6. P

    (Relativity) A flash of light is emitted at x1 and absorbed at x1 + l

    My answers are quite different and here are my attempts a) What is the spatial separation ##\ell'## between the point of emission and absorption? (In the frame going ##v = \beta c##) From what I know is that moving causes lengths to be contracted according to the formula ##\ell_{travel} =...
  7. FireAP

    Time Travel -- The Flash or Avengers:Endgame?

    Summary:: Which form of time travel would be considered more close to reality: The Flash or Avengers:Endgame? Which form of time travel would be considered more close to reality: The Flash or Avengers:Endgame?
  8. S

    Flash in rocket will arrive first at front or back?

    Homework Statement A person in a rocket traveling at 1/2 c. There is a flash originated from the middle of the rocket. From his point of view, will the flash arrive at the front or the back of the rocket first or arrive at same time? Homework Equations Not sure The Attempt at a Solution Since...
  9. chemisthypnos

    Why are triple base propellants not used in firearms?

    I would think that the use of triple base propellants in hand-held weapons, such as assault rifles or pistols, would be greatly beneficial as its use would remove the muzzle flash. Also, it would decrease wear-and-tear on the weapon itself, I would think. I have found some people saying that...
  10. FactChecker

    B Lightning Flash Intensity & Color Shift for Moving Train Observers

    Consider the traditional thought experiment of moving train observers, the "stationary" observers, and the flash of a lightning strike at the midpoint of the train. It seems that the stationary observers would expect the train observers to see different flash intensities (due to different...
  11. J

    Can large static discharge cause vision to see white flash?

    I just googled to see if this was a known thing and saw there was a closed topic on the subject. Usually I like to think of myself as a creature of logic and love to point out when other people distort reality to support their emotions but now I am all alone and trippin' about what follows. For...
  12. M

    Automotive Flash Point of Petrol & Diesel: Pressure & Self Ignition

    Flash point temperature of petrol is lesser than that of diesel at the same pressure. Does this mean, if I take petrol and diesel as liquids in separate containers and heat them, rapid vapourisation (rapid enough to sustain a combustion) of petrol occurs at a lower temperature(fire point) than...
  13. cpscdave

    QNX & SQLite (On NAND flash drive)

    Wondering if anyone knows anything about this. It was mentioned to me in passing. That on QNX, with an ETFS file system when you append to a file, that it completely rewrites that entire file to another location on the Drive. This presenting an issue with extra NAND flash writes ultimately...
  14. M

    Difference between flash point, fire point and self ignition temperatures

    Is there any difference between setting petrol on fire directly(by contacting it with burning stick) and heating petrol in a vessel, increasing its temperature above itself ignition temperature and making it burn spontaneously? What is the difference between flash point,fire point and self...
  15. S

    How do flash traders handle payments?

    How do firms that do flash trading (i.e. computer trading) handle the payments for the stock that is traded? If I buy or sell stock, my broker (somehow) gets funds from somewhere and transfers money into my account. If I sell stock he takes money from my account or directly from me by check or...
  16. A

    I Flash open manhole cover paradox

    The superhero "Flash" races over a 3' diameter open manhole at 0.999 the speed of light. I realize that this exceeds escape velocity on earth, so assume the running is being done on Terry Pratchett's "Discworld" https://en.wikipedia.org/wiki/Discworld From Flash's point of view, the manhole...
  17. W

    Saving to Flash Drive: Copy Files & Drives?

    Hi all, Hope this is not too simple/dumb: When we save , say a Hard drive to a flash drive, are the saved files saved in the drive with a schema similar to the one that existed on the hard drive? Sorry I am being kind of lazy in not doing an experiment; thought someone may save me time...
  18. Vanadium 50

    How do encrypted USB flash drives work and how can we make them more secure?

    Before I start, a quote: "There are two kinds of cryptography in this world: cryptography that will stop your kid sister from reading your files, and cryptography that will stop major world governments from reading your files." Today you can buy, for $50-100, a USB stick with hardware...
  19. S

    Find out real locations of flash videos

    Hello,I want to find out real locations of videos which are played by Adobe Flash Player. Through reading many articles I realize the only feasible way is to sniff the HTTP traffic and even this method can fail. Is this thought correct?Senmeis
  20. AndyKeeble

    I Test the Speed of Light: Traveling Toward a Strobe Light

    Hello If I travel toward a strobe light, will the flash rate appear to increase? If it does, would that then mean that the light entering your eyes was entering faster than the speed of light? If the strobe flash rate does not increase then this universe is stranger than I thought. I have been...
  21. kyphysics

    Is Adobe Flash Safe to Use for Online Registration?

    Not a computer person, but a website I am interested in registering with requires Adobe Flash (along with Microsoft Edge browser and Java). I've seen warnings here and there about Flash being dangerous, but never looked into them from a technical perspective, nor followed up with those news...
  22. N

    I Mysterious Flashes of Light in Dark Room

    I saw strange flashes of light last night in a dark room and am wondering what caused them. They seemed the only happen when I moved the comforter, but it was not always in the same area. I thought at first it was a brief reflection of light, but I couldn't find a source for the reflection that...
  23. M

    Physics Problems on Flash Tv Series

    Hello, i am not sure where to discuss it but here maybe proper for this thread. I just want to discuss about DC's Tv show Flash and physics on it like singularity or parallel universes?
  24. P

    Fast Q-switching of flash pumped Nd:YLF laser

    Hi friends! I solved the problem 8.3 of ``Problems in Lasers Physics'' book (by Cerullo, Longhi, Nisoli, Stagira and Svelto) but I think there's a mistake on the solution presented in this book in page 196. This is a problem book with problems and solutions that follows closely the laser...
  25. duhuhu

    How can I protect my flash drive from reformat?

    Hey team! I have a flash drive that I have already put a few files on that cannot be deleted by any user other than me on my own computer, but I recently found out that anyone can reformat the flash drive and get past that. Is there any way that I can be able to read and write to and from the...
  26. B

    Anyone see the brief flash in Orion last night?

    Naked eye viewing clear sky a little before 3AM Central time I saw a "star" appear a little below and in line with the sword, only lasted about three seconds, no lateral movement, about the same brightness as the belt stars... then was gone. Roughly about 3:55-3:56AM Central. Line of sight...
  27. S

    Flash Boys" (Book): Computer Trading & Stock Market Insight

    For those interested in computer technology and the stock market, I recommend the interesting book "Flash Boys" by Michael Lewis. It describes some significant anti-free market aspects of "computer trading".
  28. R

    Why Do Modern Digital Cameras Flash Twice?

    I've noticed that when somebody takes a photo of me with a modern digital camera, I experience not one flash but two. Are there really two flashes for some reason or is it a perception thing?
  29. Dembadon

    Antiquated Switchgear: Arc Flash Hazards

    I am reviewing the LV and MV switchgear and their protection path within our plant. A significant number of critical breakers and enclosures are 20-30 years old and are in need of replacement. In addition to considering the operational advantages of upgrading the gear, I am trying to find...
  30. M

    Are There Any Customizable Particle Simulators Like This?

    Any good particle simulators with adjustable mass, gravity, repulsion. (3D would be nice, but I don't need it to be 3D)
  31. L

    Optimizing Camera Flash Performance: The Role of RC Circuits

    Homework Statement Consider the following circuit in a camera flash where a light bulb is in series with a charged capacitor: a) Derive, but do not solve, the governing differential equation for the circuit. (Hint: treat the resistor and the light bulb as a single resistance.) b) Assume...
  32. B

    What Gauge Wire for Remote Camera Flash?

    Hi all. Please pardon the amateurish question! My hobby is constructing camera traps which I use to photograph wildlife, using small "point-and-shoot" compact cameras. Currently I am working on a project that involves removing the flash unit from the camera proper and installing it...
  33. R

    Why didn't flash freezing make the polycaprolactone plastic brittle?

    Hello, I am working on a science fair project with my son. His project is about the mobility of polymer chains depending on temperature and pressure. As part of his project we want to flash freeze a piece of plastic to show how brittle it becomes. We bought instamorph, which is polycaprolactone...
  34. 1rel

    Learning Photo Flasher Circuit Basics

    Hello everyone I'm new here, and currently trying to learn more about electronics. - Since my knowledge is very limited, I've decided to take apart some old devices from the garbage, and recently tried to understand a photo flash circuit from an old camera, and to trigger it with my own bench...
  35. Crush1986

    Solve Side Flash Problem: Current Through Person is 5000A

    Homework Statement Side Flash. Part of a bolt of lightning jumps through distance d in air and then travels through the person ( who has negligible resistance relative to that of air because of the highly conducting salty fluids within the body). The rest of the current travels through air...
  36. C

    Camera Flash Pop Sound: What Causes It?

    Hi everyone, I was wondering if anyone knew what causes the popping sound when an external camera flash is fired? Kind regards Cody
  37. Y

    Adobe flash player crash on both my computers repeatily.

    Hi The Adobe flash player kept crashing and really slow down both my laptops. One is Win 7 Pro and the other is Win 8. I can hear the fan running hard, the mouse is very slow responding. Then finally a pop up saying the Flash player crashed and ask whether I want to stop the plug in. It happens...
  38. M

    Calculating the Flash Frequency in a Neon Lamp Circuit

    Homework Statement A simple type of blinking light circuit can be constructed using a neon lamp. The circuit shown here has a 4.0 μF capacitor in parallel with a neon lamp. When the voltage is low in the RC portion of the circuit, the lamp does not conduct electricity. Therefore, it is...
  39. C

    Why does the thunder from lighting last much longer than the flash?

    I was walking home today when I noticed that the flash from a lighting takes a fraction of a second while the sound lasts a good 5-6 seconds. I couldn't think of an explanation for this, except a wild guess that maybe the source of sound is a line source and sound from different points on the...
  40. K

    Mechanically remapping buttons on a flash recorder

    I want to buy or build a button that transfers downward force to a sideways force. I’m adapting a voice recorder so my grandmother (who has a hard time pressing small buttons) can use it. Most reasonably priced flash recorders have buttons on the side and I want her to be able to access them...
  41. C

    Is it Possible to Flash Freeze the Human Brain and Send it into Space?

    I've seen online that you can get a handful of your ashes sent into space for a hefty fee1 and it got me thinking... Would it be possible when dead to flash freeze the brain and send it up into space in a radiation proof container and just allow it to travel through space like the voyagers do...
  42. S

    Difference between flash evaporation and cavitation

    Hi, what is the differencce between flash evaporation and cavitation ? Can i apply cavitation model for flash evaporation in cfd ? Thanks
  43. P

    How does the Xenon Flash in Lumia; or, if fact any compact device work

    I don't need basics, I know the causes how xenon flash "works" ; I need to know how do they minimise this kind of circuit in microprocessor? My question: The Flash tubes require kVs of potential difference to work. I am aware that big capacitors are required to make them work. This is okay...
  44. H

    Flash vaporization balance - ODEs, deviation variables, linearization

    Homework Statement Given the attached figure, a) Develop an ordinary differential equation that describes the dynamic height h(t) in the flash tank in terms of \dot{m}_{i}, \dot{m}_{l},\dot{m}_{v}, \rho_{i}, \rho_{l}, \rho_{v}, and A. b) Given the fact that the process is isenthalpic...
  45. K

    [executable file from flash] convert

    Hi all! I - Kumar! I am currently working on my project. And I have a question how can be done executable file from the flash?
  46. Y

    How to recover lost folder in the flash drive ( USB stick)?

    My wife lost a file that she worked directly from a flash drive. Somehow, the whole folder disappeared. Is there any way to recover that folder? Problem is she did not work off the C drive where even you accidentally deleted it, you can find it in the trash bin. She worked directly off the...
  47. Saxby

    Does Time Appear Differently for Observers in Relative Motion?

    If i was standing on the Earth at rest and a spaceship traveling at 0.99c passed by and flashed a light for a very small amount of time would this time appear longer for me or the pilot of the spaceship?
  48. Y

    Troubleshooting Adobe Flash Player Issues on Windows 7 with IE10

    Whenever I go to try and watch a video or look at an article that has a video with it, it always says you do not have the latest version of adobe flashplayer installed. So then I follow the instructions and download the new version, and it works for about 10 minutes and then quits working. I've...
  49. J

    Flash point ,autoignition temp

    Please see their definitions: Flash point The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air. (i.e. the lowest temp to start a fire) At the flash point, the vapor may cease to burn when the source of ignition is...
  50. D

    Are Camera Flashes Deadly? Shocking Truth Behind Fatal Camera Incidents

    killed by camera flash??! i've read a story from somewhere. a guy was trying to take photos using his camera. unfortunately he was standing near a high-voltage substation. once the camera flashed, he was killed immediately. they said that the electric current flows trough the camera flash to...
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