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Sensei

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Everything posted by Sensei

  1. In that SpreadSheet you shouldn't play with first column where is time. At least not until you will understand whole equation. You change initial quantity (C2) and half-life (B2) fields. Columns D,E will be filled automatically, and graph updated. For f.e. half-life 10 seconds, and initial quantity 1000, you will see 1000,933,870,812,etc. going down quickly.
  2. Chlorine-37 based neutrino detector is triggered by neutrinos that have >0.814 MeV energy. Which means neutrinos produced by decay of Beryllium-7 (these have up to 0.862 MeV), or decay of Boron-8 (these have up to 17 MeV). If neutrino have less energy, detector is not triggered. It doesn't mean that neutrino was not emitted. It could be emitted but remained unnoticed. Purdue University even patented their method in the US: http://www.google.com/patents/US8642960
  3. We need to multiply measured mass of galaxy by ~500% (and call it dark matter) to match Newtons & General Relativity predictions. http://en.wikipedia.org/wiki/Dark_matter "Although the existence of dark matter is generally accepted by the mainstream scientific community, some alternative theories of gravity have been proposed, such as MOND and TeVeS, which try to account for the anomalous observations without requiring additional matter." You should also read this article http://en.wikipedia.org/wiki/Galaxy_rotation_curve
  4. I have explained half-life calculation in this thread http://www.scienceforums.net/topic/83245-a-question-on-radioactive-decay/?p=806204 You can simply use that Spread Sheet with your data. current=start*2^(-time) will give the same result as: current=start*e*(-time*ln(2))
  5. The question is whether we would recognize it as a (yet to be decoded) language. For some signal types it's very easy. For instance, put tiger to monkey's cage, and record sound they will be screaming. (Or record it in real wild world) That's sound of "danger", "tiger", "run away", "enemy". Recorded sound can be later used on different group of monkeys (same kind), or same group at different time (couple days, months, years later), to see whether they treat it the same way. That reminds me Myth Busters that tried to see whether duck quack has echo. They took single duck, but he/she didn't wanted to quack It took them some time to figure out they need two or more ducks. Apparently single duck didn't want to talk to himself/herself.. What a surprise.. See this video:
  6. That's problem with depressed persons - bother about things that are meaningless for healthy persons.
  7. What on Earth has quantity of possible ways of mixing words, with somebody happiness? Your problem is depression, not quantity of possible ways of mixing elementary particles, words, or letters. Do you tried taking medicine with Hypericum perforatum? http://en.wikipedia.org/wiki/Hypericum_perforatum That's correct. Book with finite number of pages, with finite size of font, will have finite quantity of ways words can be arranged. Infinite quantity of stars, infinite quantity of galaxies would lead to no Universe that we know. Read about Olbers' paradox http://en.wikipedia.org/wiki/Olbers%27_paradox Although it's not reason to feel depression.
  8. Do you know how neutrino detector is working? Perfectly stable Chlorine-37 is hit by neutrino that must have >0.814 MeV and it's changing to Argon-37, which is unstable element and decays back to... Chlorine-37 by electron capture. Argon-37 has half-life ~35 days. Cl-37 + Ve + 0.814 MeV -> Ar-37 + e- Ar-37 + e- -> Cl-37 + Ve + 0.814 MeV Detector can observe flashes leaved by decaying Argon, or count argon gas molecules. Chlorine based detector is working exclusively with neutrinos that exceed 0.814 MeV (which is quite a lot for Sun fusion f.e. p+ + p+ fusion is producing just 0.42 MeV). If Argon-37 wouldn't be decaying, or have half-life significantly longer, this reaction could remain completely unnoticed. I am working on application that will automatically analyze the all 3143 isotopes and show me all possible materials that could be used as neutrino detectors.
  9. That's exactly what I was talking about. You couldn't not have it at primary school physics.. http://en.wikipedia.org/wiki/Inverse-square_law http://en.wikipedia.org/wiki/Intensity_%28physics%29
  10. They don't have to match.. Horizontal axis is time. Vertical axis is distance from us in c unit (1=~300,000 km) I think so. It's purely theoretical. Imagine that mirror is approaching at v=2c. We have laser and sending beam of photons at that mirror. Mirror is reflecting laser to us and we measure delay between sending, and receiving. After 33-34 second that red line should be going back to bottom. I was just interested in intersection time.
  11. Isn't sound obeying inverse square law?
  12. The all good programmers that I met, know how to program computers a long time before going to university (if they ever went to... studying is learning how to learn.. if you learned already why to waste time for paper.. ? IT companies here are more likely hiring programmer that learned programming by himself, than those after university.. Most of job offers are with comment "no study required, you will write application in test day") Buy some books about C/C++, .NET Framework, install free Visual Studio Express from MSDN, and write programs. Instead of searching for some ready application on net, make it by yourself. You will see whether it's for you or not.
  13. Yeah. If somebody tried to calibrate satellite dish & receiver from Astra or Hot Bird, he should know how hard it is.. I really hate doing it. 1mm in wrong direction and there is no transmission. It's plain stupid to send signal for longer distances in the all directions (following inverse square law). It would waste a lot of energy to send data where is nobody who can listen for signal. When we're sending data (and receiving data back) to/from Voyager it's directional signal, like laser, very precisely adjusted to target. And we don't send signal to place where Voyager is now visible, but where it'll be after time needed for signal to reach that location. Where is nothing now from our point of view. Airplane pilots do the same- shooting at location ahead of enemy airplane. http://en.wikipedia.org/wiki/Deflection_%28ballistics%29
  14. Sensei

    Impure HCl

    Ironic? Not at all. It was not mine intention. I simply suspected he doesn't know how to calculate it after seeing question: "if i react 91% KOH with that impure acid would the KCl be pure enough to be used in further reactions to obtain another substances with it?"
  15. Sensei

    Impure HCl

    You should first learn how to calculate in moles, how to convert to grams, how to calculate concentration etc. etc. If you have 32% concentration of HCl in 1 L, how many grams do you have of HCl?
  16. They just bought satellite & drone building company, so expect real-time maps in a couple years. You will see on map your own car on road you're going.. http://www.businessweek.com/articles/2014-06-10/googles-bought-a-satellite-startup-to-make-maps-not-internet-connections
  17. I am getting 2 grams as well. You didn't calculated sodium nitrate concentration.
  18. I think so it's possible, but there must be meet couple requirements: - faster than light object must be approaching us (not perfectly directly), not receding. - faster than light object must be reflecting light. Suppose so faster than light object is flying with v = 2c to Earth, at t = 0 it's 100*c distance from us. We're sending photons in that direction (without knowing about object - similar like active radar is working), and photons are reflected from it somewhere around 33-34 seconds later, and then going back to us after 66-68 seconds after sending them. In the mean time object is long time gone. So we cannot perform yet another test. If we would be sending photons continuously in the all directions, we could see that object to be receding from us (photons send later by us, would return quicker, after reflection, than those send earlier!).
  19. Force has unit Newtons. Energy has unit Joule. You can't say "joules of force". In physics we don't use word "obliterate". Do you rather meant annihilation? Potential energy = m*g*h m - mass in kg g - Earth's acceleration 9.81 m/s^2 h - relative height To rise 1000 kg for 1 meter, you would need 1000 kg * 9.81 m/s^2 * 1 m = 9810 J.
  20. You are probably thinking about amount of energy that could be released by fuel when it would be burned (with gaseous oxygen). Not quite the same what I was thinking. http://en.wikipedia.org/wiki/Energy_density
  21. Ton of hydrogen and antihydrogen will release the same amount of energy as ton of f.e. carbon and anticarbon. So material doesn't really matter when we're are interested just about matter-energy conversion rate.
  22. Joule [J] is unit of energy, not force [N] J = kg*m^2/s^2 N = kg*m/s^2 1 ton is 1000 kg 1 ton could have energy E=m*c^2=1000 kg * (299,792,458 m/s)^2=1000 * 89875517873681764 = 8.988*10^19 J but you would need 1 ton of antimatter to release that all energy..
  23. I have few lasers, and none has linear polarization. If you have polarization filter, you can find out yours LED/LCD/mobile phones screens polarization. See this thread how I am doing so: http://www.scienceforums.net/topic/80366-particle-location/page-3#entry783255 Modern mobile phones that I checked have screens emitting not linearly polarized light.
  24. I have no idea what are you talking about. Experiments made by Jenkins & Fischbach were made in 2006.. So why are you introducing some "20 years ago" fairy tale, that has nothing to do with article.. ? Ephraim is professor on the Purdue University http://www.physics.purdue.edu/people/faculty/ephraim.shtml Science is constantly making experiments. Prepare Chlorine-36, prepare Manganese-54, and start recording decay rate whole year. If you will have steady decays per second while long term observation, you will have proof and counter-argument for Fischbach & Jenkins observations. You obviously didn't take into account that RTG uses Plutonium that's decaying by emitting alpha particle. That might have meaning. I would expect RTG to have voltage/current stabilizers. Also RTG are using Peltier effect that's very little efficiency. They're not designed to be detector of decays per second, but to be power source. What I noticed is that Manganese-54 decays by both beta decay- and beta decay+, and electron capture: Isotope Manganese-54 Protons 25 Neutrons 29 Mass 53.9404 [u] Nucleus Energy 50232.3 [MeV] Parent 50232.3 Daugther 50231.5 Alpha decay prohibited (-8.7587 MeV) Proton emission prohibited (-7.55958 MeV) Neutron emission prohibited (-8.93835 MeV) Manganese-54 -> Iron-54 + e- + Ve + 0.69713 MeV Manganese-54 -> Chromium-54 + e+ + Ve + 0.355216 MeV Manganese-54 + e- -> Chromium-54 + Ve + 1.37721 MeV Chlorine-36 also decays both by beta decay- and beta decay+, and also electron capture: Isotope Chlorine-36 Protons 17 Neutrons 19 Mass 35.9683 [u] Nucleus Energy 33495.6 [MeV] Parent 33495.6 Daugther 33494.9 Alpha decay prohibited (-7.64155 MeV) Proton emission prohibited (-7.96448 MeV) Neutron emission prohibited (-8.57926 MeV) Chlorine-36 -> Argon-36 + e- + Ve + 0.709681 MeV Chlorine-36 -> Sulfur-36 + e+ + Ve + 0.120219 MeV Chlorine-36 + e- -> Sulfur-36 + Ve + 1.14222 MeV That's why I suggested Ephraim to try also Copper-64 that's also both beta decay- and beta decay+. Wrong. You should perform such experiment regardless of his opinion. But use various radioactive materials. There are proton emitters, neutron emitters, positron emitters, electron emitters, alpha emitters, gamma emitters. Each one should be independently checked at various distances from the Sun. And of course they should not be used to power on whole satellite! Actually I know Ephraim Fischbach. We were talking about his experiments with neutrinos. He asked me what experiments I would like him to perform and I suggest few, that you would definitely call highly speculative..
  25. See article http://en.wikipedia.org/wiki/Energy_density Ethanol 30 MJ/kg Methanol 19.7 MJ/kg
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