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Sensei

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Everything posted by Sensei

  1. Acetylene is unstable gas. 1 kg is taking 1 m^3 of space at normal temperature and pressure (water has 1000 times more density). Gasoline is liquid. Therefor it's easy to transport and easy to make tank etc. etc. Maybe you thought about acetone?
  2. Displays used by modern devices such as ebook are using energy only to switching states. If pixel has the same color/brightness as in previous, it uses no energy.
  3. 1 Liter of Helium has mass 0.1786 g. 1 Helium-4 particle has mass = 4.0026/6.022141e+23 = ~6.646e-24 g 0.1786 g/L / 6.6465e-24 g = 2.687e+22 atoms in liter. 2.687e+22 / 10e+9 = 2.687e+12 seconds each one producing 10 billion atoms / 86400 = 3.11e+7 days / 365.25 = 85150 years..
  4. 1 m^3 of Helium costs 60 usd here. Even Deuterium is more expensive.
  5. Deuterium colliding with Deuterium will create Helium-4. Helium-3 can be created from spontaneous decay of Tritium. T+ -> He-3 + e- + Ve Two different ways for creating different Helium isotopes. Bombarding Deuterium fluid by highly accelerated Deuterium nucleus. or Bombarding Deuterium fluid by neutrons, producing Tritium, and then waiting for spontaneous decay of it to He-3. ps. Like mathematic said- it has no sense. Maybe just to prove theory. It would be the most expensive Helium in the world.
  6. They do. But you need to have gamma photons with f.e. 510,999 eV energy each. http://en.wikipedia.org/wiki/Two-photon_physics Result is matter production http://en.wikipedia.org/wiki/Pair_production http://en.wikipedia.org/wiki/Matter_creation y + y -> e+ + e-
  7. f.e. when two gamma photons with E=510,999 eV will collide they will produce positron and electron in pair production process. When we will learn that spin of electron is up, we know in advance that positron will have spin down. Or reverse. These particles are entangled.
  8. Photon has energy E=h*f Frequency to wavelength equation is f=c/wavelength so E=h*c/wavelength also E=p*c In laser which has well known wavelength (like green laser 525nm), the all photons have pretty much the same wavelength/frequency +- small tolerance (like +-10 nm). And they are emitted in the same direction, photons are going parallel (in reality it's not perfect parallel but for small distances it can be ignored). In contrary light bulbs are emitting photons with large range of frequencies, wavelengths from 350 nm to 700 nm and more in IR, in the all directions. If one range of photons is dominating over other then light bulb is emitting reddish, greenish, bluish etc. light. If quantity is pretty much the same regardless of frequency/wavelength, then light is white or gray (if quantity is low). Camera flash is emitting large quantity of photons at all visible frequencies in short period of time. Maybe poor photos is result of desynchronization between flash and photo camera? From mine experience I can tell flash should be turned on regardless of natural light, even in day light, if camera is detecting it has enough light to make good picture it's adjusting flash intensity, or automatically not using it (even if user requested it). That's at least in mine camera.
  9. I experimented with empty 0.5 L aluminum beer can (15 grams weight), connected to normal white thread 1 m long. It was spinning counter clockwise faster and faster for about 2-3 minutes, then slowed down at 5 minute to no spinning, and started spinning clockwise for another 4 minutes (with all the time stopper turned on). Then again changed direction to counter clockwise for yet another 3-4 minutes. It appears to be slowing down with time. I have been observing it for 18 minutes. After filling it with water it's spinning a lot faster. Reached 1 spin per second in maybe 13 seconds after starting up. It started spinning at reverse direction after 5m 38s (40s longer than empty).
  10. 1 W = 1 J/1 s 1 W = 1 A * 1 V so 1 J/1s = 1 A * 1 V 1 J = 1 A * 1s * 1V 1 C = 1A*1s so 1 J = 1 C * 1 V but Coulombs are quantized: e=1.6*10^-19 C (1 C is quantity of electrons/charged particles) so 1.6*10^-19 J = e* 1 V (that's exactly 1 eV unit, and kinetic energy of electron in 1 V) frequency of photon with 1.6*10^-19 J / ~6.62607*10^-34 J*s = ~2.4147*10^14 Hz (Infrared spectrum range) 1/~2.4147*10^14 Hz = ~4.135667*10^-15 eV*s (Planck const in eV unit) When electron is accelerated by large Voltage and then decelerated by collision with f.e. air molecule or other material (preferably in vacuum), it's emitting photon which is part or all of its kinetic energy. Look like Crookes tube is designed http://en.wikipedia.org/wiki/Crookes_tube Anode (on bottom) is with purpose bended to force electrons to decelerate. Electron must emit photon to be decelerated (or other way to lose energy - by collision with other particles). Crookes tube was used by Roentgen to emit x-rays the first time in history, using 100000 voltage. he was able to receive x-rays with maximum 100 keV. 500 kV will in theory allow making x-rays with maximum 500 keV.
  11. How can you know size of structure that has been passed to function? You don't have source code.. (do you plan making application which will be analyzing c/c++ source codes to check out whether they have potentially infinite loops ?) Size of structure might be dynamic. Might be operating system dependent. In early Windows we were using structures called tags, they have structure size as first member of structure. Before using some field we were checking whether data.size >= sizeof( data ) to check out whether structure has enough size (so it's running on XP for instance). What if structure is constant, but have pointer(s) to other structure that is changed? What if structure has pointers to pointers to pointers etc. they are all const, but final data (you have no idea how deep) is changing? What if changing counter is read from disk (or registry, or other hardware), and saved, and never stored in memory.. ? Infinite RECURSION, calling the same function over and over again, is NOT EXISTING problem. As I have already told you. Cpu stack is filled, and program is crashing and stopping working. Automatically. You don't need any program that will analyze it to tell whether it halted or not. Infinite loop, is completely different subject. The main Windows OS loop while( (bRet = GetMessage( &msg, hWnd, 0, 0 )) != 0){ if (bRet == -1) { // handle the error and possibly exit } else { TranslateMessage(&msg); DispatchMessage(&msg); }} is infinite from point of view of analyzing it automatic program.. It ends only when user clicked close button window or so. But it's inside of operating system! And initiated by user action (which detecting program has no idea about).
  12. Argument for electron being fundamental is such that it's not decaying to other particles with less energy-mass, as far as we know (unlike f.e. muon- which is decaying to electron and neutrino) Argument for electron not being fundamental is such that it can collide with positron and annihilate producing gamma photons (which also can be absorbed and reemitted at even smaller frequencies, producing even more photons). http://en.wikipedia.org/wiki/Elementary_particle "In particle physics, an elementary particle or fundamental particle is a particle whose substructure is unknown, thus it is not known to be composed of other particles."
  13. Why don't you use rectifier such as KBPC610 (6 A, 1000 V) which cost $0.5 and optionally fuze (6 A for KBPC610) and capacitor 450 V >100 nF, and regular AC 230 V? You won't be wasting batteries, and will have result very quickly.
  14. Experimental data will be even worser than calculated. You have no idea (and can't have) what is f.e. wind speed and its direction (it's variable, and not even constant while single bullet flight).. The longer distance (so time of flight is higher) the more influence of wind speed. Especially at the end of flight, when bullet has been already decelerated. Experiments are repeated dozen/hundred/thousand times, and at least Median of results is used (so the highest and the lowest results are ignored).
  15. Direct Current from batteries, and coil? This way you will make electromagnet.. You need AC to increase voltage. Or something else. If capacitors are connected parallel to battery, they are filled by electrons. Once you connect them serial, their voltage will add together. Changing from parallel circuit to serial circuit can be done manually (if you have not seen it, set up such configuration on breadboard; 4x 220nF electrolytic capacitors and 5 V batteries will give you 20 V on output) or better using transistors in switching mode. It'll be working in stages- fill capacitors, disconnect battery, change circuit from parallel to serial, utilize higher voltage, change circuit from serial to parallel, connect battery. Repeat process.
  16. Hawking radiation is theoretical physics. Not confirmed by experimental evidence.
  17. Materials are often opaque at one photon frequency range, and transparent at other frequency range. As a result we can take photos of our body internals using x-rays. X-rays are differently reflected or refracted by bones than other organs, making easy to distinguish them, or external unwanted objects that were f.e. shoot at body.
  18. Quote from http://en.wikipedia.org/wiki/Mass_in_special_relativity "The mass of composite systems" "The rest mass of a composite system is not the sum of the rest masses of the parts, unless all the parts are at rest. The total mass of a composite system includes the kinetic energy and field energy in the system." When we say f.e. proton has mass 938.272 MeV/c^2 we are talking about sum of relativistic masses of quarks, not rest masses of quarks.. It doesn't have to, if there is absolute frame of reference (which we cannot find). With extreme acceleration to relativistic velocities, new particles are created. p+ + p+ -> p+ + p+ + p+ + p- (proton colliding with proton is creating three protons and one antiproton) If relativistic mass is not real, then it has completely no sense. But it's real experimentally confirmed result.
  19. Literacy world map 2007: http://upload.wikimedia.org/wikipedia/commons/c/cf/Literacy_rate_world.svg Maybe he meant secondary illiteracy..
  20. If you can't read, you can't gain other people knowledge and learn from past discoveries (other way than mouth to mouth, it's easy to skew). If you can't write, you can't share your knowledge with other people and leaving sign "I was here". Maybe some peasants or cavemen thousands years ago had some knowledge, especially in agriculture and natural medicine (f.e. how to use vegetables and herbs), but this knowledge not written by anybody get lost in time.
  21. 150 years ago majority of people could not even read and write... One of the greatest improvements in Positivism in half of XIX century was building primary schools for everybody, even the poorest peasants in villages. Illiterate persons can't share their story with us, so we know how Egyptians, Romans, middle age people etc. lived only from stories written by rich nobility..
  22. You can't use vacuum. Imagine you have closed box half with air, half with water. If you will pump out whole air, it will cause water to have lower pressure and it will be still filling whole box, just with smaller density, lower pressure.. So why not fill it since beginning with pure water, without leaving any room for air? On youtube there is video in which scientists are pumping out whole air from closed room where is glass of water on table. After a couple seconds water in glass is starting boiling just because air is not pressing it anymore enough (it's changing state to gas). But if you are really bothering with arcs of electricity in air (why?), then use pure oxygen instead of air.. Electric arc will be making ozone in the worst scenario. Electric arcs are used by welders all the time.. Are you using silver for both electrodes? Lead probably would create some lead oxide http://en.wikipedia.org/wiki/Lead%28II%29_oxide Using AC instead of DC is making harder to find out what is going on, as 1/100 of second electrode is producing Hydrogen, 1/100 of second it's producing Oxygen. So they and result oxides are mixing together..
  23. You can see it on your own eyes by building diffusion cloud chamber and placing magnetic/electric field around it. If you're not familiar with them watch f.e. this video http://www.youtube.com/watch?v=Efgy1bV2aQo On youtube there is plenty tutorials how to build them though. I have build couple. It's $20 investment, if you have access to dry ice.
  24. You don't need any arguments to function to have not infinite recursion... int count = 100000; // global void f1( void ) { if( count > 0 ) { count--; f1(); } } When function is calling other function return address is stored on cpu stack. It has finite size. On Windows stack has default 1 MB size per thread. When stack is filled, application is crashing and is shut down automatically by operating system. So, there is really no problem in modern times. In the beginning of computers, it could be problem to detect whether program is halted or is simply crunching data, without task manager, GUI etc. which allows us now to check what is going on with our application.
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