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Sensei

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Everything posted by Sensei

  1. You're talking about obvious, must have, things that should be done with the all data coming from $_GET/$_POST/$_COOKIE etc. (not just session id). Checking IP is not replacement for basic checks, but yet another level of security. All mine Internet bank accounts, and stock market brokers that I am using, are utilizing this technique. You cannot be logged to the same account from two different computers at the same time. Good secured services refuse it immediately. They ask you "you're logged from IP x.x.x.x, do you want to terminate session and open new one?".. Even better is making history of logging with IP recorded. And showing this info to user when he/she is starting session. User will be immediately warned about logging somebody with "wrong" IP, at wrong date and time.
  2. Do you meant 250 thousands or 250? I can't believe in second without serious issue in program.. I am often programming particles, and putting them to octree/kd-tree is obvious standard procedure of speeding them up.. If you "forgot" to turn Floating Point Model: Fast, instead of default Precise, this also can cause several hundred percent slowdown.
  3. Session id stored in cookie should be id to database entry in currently open session table. Database record should store IP address of owner of session, and code should check whether db IP matches with what is clients IP. This will make sure that even if somebody intercept cookie value, he/she won't be able to use it, because their IP will be different than original client that opened session. As long as they didn't intercept whole client network and are able to show up as the same IP..
  4. Cubic lightyears? Light year is not unit. Do you meant m^3 * s^-3? or m^3 (simply volume)? Do you really meant "x = ed = f" Before editing there was "x*e*d=f" Either way, units don't match between sides of equation.. How can you say that energy x in Joules is equal to force f in Newtons.. ?
  5. Energy has unit Joules [J], or electronVolts [eV]. How can you add it to variable that has unit Newtons [N]?
  6. But quantity of particles is unitless, isn't?
  7. All a,b,c,x,y,z are forces in Newtons [N]? So how can you write "b is the ammount of fusion a star has done (how much mass has converted to energy over that star/blackholes life span from start to present)" "Amount of fusion" is in what unit? Is it quantity of particles that fused in star?
  8. What are UNITS of your variables.. Is that too hard question?
  9. anonymousone, so you have basically no idea what we are talking about when we are saying about providing math formulas to confirm theory.. Equation must have correct units. You cannot mix length, with mass, and time, and energy, forces, charges etc. just like that. Show units of a,b,c,x,y,z etc.
  10. Take piece of iron. It doesn't attach to any other iron. It's no magnet, yet. Attach to one of its end small neodymium magnet. Now whole piece of iron is attaching to iron. Take off neodymium magnet, and it's no longer attaching to iron. Take piece of iron, roll up wire on it. Pass current through wire. Whole piece of iron is becoming magnet (electromagnet). Until current is flowing through wire, it's attracting or repelling to/from other magnets or iron.
  11. So the correct link is https://www.youtube.com/watch?v=WN1Wnkm2_Zc https://www.youtube.com/watch?v=WN1Wnkm2_Zc You can't change size of letters in links (it had all characters lower case). Do I need to mention it doesn't work? I have just tried it with 18 powerful neodymium magnets.
  12. None of your youtube video links work (posts #45 #55). "Movie doesn't exist" etc. comment I see.
  13. If you have voltage difference f.e. 2.5 V and you will attach to it f.e. green LED which is emitting green photon with 532 nm. Energy of single emitted photon is E=h*c/wavelength=4.135667*10^-15*299792458/532*10^-9=2.33 eV. Electron in such circuit has kinetic energy 2.5 eV at the beginning. LED is emitting photon with 2.33 eV. So electron after emitting such photon will have 2.5-2.33 = 0.17 eV kinetic energy. It's called voltage drop on element. http://en.wikipedia.org/wiki/Voltage_drop If you will start playing with voltage of circuit, you will see that if electrons have too small kinetic energy (less than 2.33 eV in our case), LED will simply stop emitting light, and no current will be flowing through whole circuit (electrons can't pass through LED, which is blocking them). So, electrons flowing in circuit from negative electrode through electronic elements they lose their kinetic energy (emitting photons etc.), giving part of energy to wires heating them up a bit, and at the end, they end up in positive electrode. Quantity of electrons that was at beginning (on negative electrode), matches quantity of electrons at the end (positive electrode).
  14. Quantity of electrons in closed circuit is always the same. They are not appearing from nowhere, nor they don't disappear. You should better read about Lepton Number Conservation. http://en.wikipedia.org/wiki/Lepton_number (it's violated only in high energy physics). Electrons that are in wire at the moment, are accelerated when magnet is moving above wire. No electron is created or destroyed in this process. Electron in 1 Volt difference has 1 eV (1 electron volt) kinetic energy that can be used to f.e. heating, or emitted as photon (by light bulb, or LED), or utilized other way in circuit.
  15. There is no such thing as "volts of electrons". I, current, has unit Ampere. If 1 A current flows through wire for 1 second, it means there is ~6.24*10^18 electrons flowing through it per second. I=Q/t or Q=I*t Q is charge, and has unit Coulombs. 1 electron has charge -1.602*10^-19 C so 1 C / 1.602*10^-19 C = ~6.24*10^18 electrons.
  16. Nonsense. It's test of yours credibility. If you can't calculate simple stuff that everybody here know, that's well established fact, and you are starting with theory of everything, you have to know everything about basics to be even able to think about more complex things. I am not requiring you to know data of the all isotopes of the world. Find mass by yourself on the net. Simply show equation how to calculate emitted energy.. That's true. I am trying to show how little you know about basic things. You just claimed that fusion releases dark energy!! And now you can't even show how to calculate release of normal energy. That's really silly.
  17. When you will move magnet above wire or piece of metal, electrons in that wire/metal will start flowing in one or the other direction. When you will move wire above static magnet, you will have the same effect. The faster movement, the more energy is produced (the higher current, or the higher voltage, or both). It's energy coming from movement of wire or magnet. If magnet and wire are static (their velocity relative to each other is 0), current doesn't flow.
  18. Answering post #34 takes less than 5 minutes or so..
  19. After that comment, I have no doubt that you don't even know what is energy of proton, electron without looking to Internet, and how to calculate energy emitted by fusion or fission. Please show me that I am wrong. Show us for instance what will be energy released by for instance decay of Carbon-14, math step by step.. Stars indeed are emitting photons, neutrinos, accelerated to relativistic velocities protons, electrons and other particles. But mainstream physicists don't consider them to be dark energy.
  20. I agree that there should be performed set of experiments sending radiowaves and light photons parallel to each other to see whether there will be delay or not between them. Quite easy to perform experiment on small distances, but much harder to perform on larger cosmic scale. Nothing should be taken for granted, without extensive experimental proof. The majority of scientists believe in it. I have seen swansont mentioning it constantly in many threads for example. Don't forget about neutrinos coming from supernovas arrive a few hours before photons. And it's explained by medium between us and supernova that is absorbing and emitting photons, slowing them down. And neutrinos don't have such absorption cycles arrive before them, even though according to SR they should arrive later (because of mass). Of course these discoveries are much much newer than Einstein theory and he could not predict everything with limited data. Experimental data are quite bended to match well established theories. It's easier for scientists than completely abandoning theory and starting from scratch. You can see this clearly with mismatching GR with galaxy scale, velocities of stars around galaxy center, by introduction of DM.
  21. Every day is beauty. It's just relative to where you are.. The most happy day to somebody, might be the worstest day of life for somebody else. Thousands peoples, millions animals, and billions of vegetables are dying in a day, and thousands peoples, millions animals, and billions of vegetables are born in the same day..
  22. Ideal gas law is primary or secondary school knowledge.. http://en.wikipedia.org/wiki/Ideal_gas_law Pressure * Volume = Quantity of Particles/Molecules * kb * Temperature The higher temperature, the higher must be volume and/or pressure. For instance, Earth's air molecules have velocity ~340 meters per second. If you will cool them they will move slower, and volume or pressure will have to change accordingly. How to check this? Fill balloon with air or other gas. Place something cold inside (like f.e. dry ice, or piece of metal going to outside and constantly cooled down). Balloon will start shrinking when gas inside will start cooling down. Velocity of gas particles will be slower and slower. Kinetic energy of gas particles will be lower and lower. We could even change gas particles to liquid, and then solid in extreme situations.
  23. Not "some" but "all". In the mainstream physics all photons always have speed of light by definition. You mixed states of matter with massive/massless particles. Matter can be in states: solid state, liquid state, gas state and plasma state. You should say: "no particle with mass can move faster than speed of light". It is postulate of special relativity. Radio waves are not atoms. Calculate how many atoms have human. Calculate how many data you have to transfer. Calculate how many data you can transfer using given radiowave frequency. Calculate time you will spend sending data.
  24. Photons emitted by your LCD/LED monitors are the most likely polarized. You just need polarization filter to see effects. I have made photos and showed in this thread: http://www.scienceforums.net/topic/80366-particle-location/page-3#entry783255 Have you read this? http://en.wikipedia.org/wiki/Polarization_%28waves%29
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