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grifter

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Everything posted by grifter

  1. ha ha that would be awsome cap'n THANKS (written on a palm)
  2. You could use my server, but...its not always on.... it has about 25% up-time, with support for php mysql and Cpanel controll and natrually it would be free... but I'm not sure how much longr it'll be in-action for, I'm having bandwith issues :/
  3. I have a Mountain bike, but I'm saving up for a new one, (I'm saving up for allot of stuff at the moment....hmmm) The one I have is a Raleigh but i want a Santa Cruz Nomad: http://www.santacruzmtb.com/nomad/ what a killer of a bike (with a killer of a price tag)
  4. found a great page on the Scharnhorst effect, worth a read ! http://www.npl.washington.edu/AV/altvw43.html
  5. lol who said anything to do with being ahead...
  6. Apparently there are only 41 months that have two Full Moons in every century, next time someone says once in a blue moon, you know what the odds are [math]\frac{41}{12\times100} = \frac{7}{600} or ~0.01666...[/math] p.s. 41 months per century is on average data from: http://www.obliquity.com/astro/bluemoon.html
  7. some people, eh, try reading the thread before you post (i say this only out of respect)
  8. Ah come on, its better than any windows OS computer (maybe not Linux) And I'm not ashamed to admit my love for the palm, I'm sure there are loads of palm users on this forum, who would love a palm-friendly theme......Come on Admin, lets see what ya got
  9. I am a palm user (as are I suspect many members on this forum) I love using my palm, it beats most other devices.....Accept when browsing the INTERNET. Would the Great person who is in charge of new themes on SFN consider installing a palm-friendly theme i.e. http://www.vbulletin.org/forum/showthread.php?t=92071&highlight=palm there are loads out there, this is just one example... Thanks guys:D
  10. I don't know the level of understanding you already have, but for some basic (U.K. GCSE level) Physics information including a few useful constants and equations..http://www.physics.org/ And ofcourse HyperPhysics posted above for chemistry, a great place to learn allot very quickly, bullet-point style, head to http://www.4college.co.uk/ (I actually find this site useful) And as for Biology.....ask a biologist
  11. This Thread is becoming very messy...
  12. I agree with IA a dynamic equilibrium can be set up: let's take water as an example, at equilibrium the same amount of water evaporates, as condenses i.e. the same rate of phase change; between gas and liquid, if you are asking when this occurs Then I'll answer that here too: When the partial pressure, of gaseous water is the same as water's vapor pressure... and of course I cant really mention that (^) without mentioning triple point, a temperature (and pressure) at which all three states can exist simultaneously, for the example above (water) this point is 273.15 K and 6.0373057 X 10^(-3) atm, for this to occur you need perfectly flat surfaces, therefore avoiding problems occurring with surface tension. There are no real "intermediate" stages, as insane_alien said, it either is or it isn't, otherwise effects like triple point wouldn't occur. I think thats the question you asked......
  13. grifter

    Stars

    If the cloud is localized and not, itself obscuring said, Stellar object, the other cause of obscured stars is rain/precipitation. Rain will refract the light being emitted by the star. Take one specific "point" in time, imagine a molecule of water is directly in the path between the star, and your eye, the light is being refracted, different "colors" by different amounts, this will result in an image, your brain will not recognize as a star, if this occurs enough within a period of time, your brain will build up a picture that is very "blurry," (it will be hard to make out the stars,) the same effect will occur if you are using a telescope, or camera etc etc and as for snow; Snow is NOT transparent, it also has regions of increased opacity (for light in the visible spectrum) due to increased/ decreased density.. this again will result in poor reception of light this is a highly simplified version of what is occurring, with only a few effects mentioned.... I have given this as the primary post (above) is worded in a way that prompts a simplified response, if anyone would like a more accurate or descriptive answer, post below...
  14. An article in the April 26, 1993 article of Physical Review Letters, titled: "First Measurement of the Left-Right Cross-Section Asymmetry in the Boson Production by e+ e- Collisions", had 417 authors, ouch
  15. Yea I apologize, considering myself an astrophysicist, I should NEVER rule ANYTHING out and yes, there are a few convincing "big crunch" arguments, most of which reside on arxiv... there arguments revolve around the average density of the universe being enough to halt the expansion and begin a contracting... but as Martin and myself said above, this argument has stopped "holding water" as a result of recent research....
  16. No, recent mapping of cosmic microwave background radiation and the observation of distant supernovae; as standard candles (objects of known luminosity), shows (quite conclusively) that the expansion of the universe is accelerating. The positive value for the cosmological constant, is attributed to quantum vacuum itself, which exerts a force repelling gravitationally on larger scales. This is all proof of the continual expansion of the universe theory...
  17. lol, I'll just run my churchill tank over it, that should do it!!!
  18. there are two main methods for producing BP the ball mill method and the precipitation method, bith have pros and cons, ball mill is much easier but it requires allot of ball mill usage (there again so does the other one...) the downside of the precipitation method is that it is very labourious Ill post the two methods below: The ball mill method 1. crush the charcoal with a hammer between two sheets of card. then Sieve the ground charcoal through a 30 mesh sieve. 2. Weigh out the charcoal, for every 100g of charcoal, add 67g of sulfur, 1/4 fill the ball mill with this mixture. Put the media in and run the mill for 3 hours. 3. on opening the mill, you should find an incredibly fine black/greyish powder. Sieve this to get the media of the mill out, and weigh it. In a separate container, place 75 grams of potassium nitrate for every 25 grams of charcoal/sulfur powder you have. Put the potassium nitrate in your ball mill, and mill it for 3 hours. You should have a very fine white/greyish powder. 4. Now mix the charcoal/sulfur mix with the potassium nitrate. Don't bother to mix it very thoroughly, since that will happen in the mill soon enough. To this mixture, add 6% of water. I spray it over the powder that I spread out on a sheet of paper to make sure all of it becomes wet. Put the wet powder in your mill and let it run for 5 hours. Every hour or so, check to see if the powder is still wet. If it dries out the risk of accidential ignition greatly increases. 5. Sieve the powder to get the media out, spread it out on a large sheet of paper and let it dry. If possible in the sun. Needless to say you shouldn't heat it in order to dry it more quickly, just be patient. 6. When dry, sieve the black powder through a few sieves to get several fractions for different purposes. The precipitation method 1. Take your raw charcoal and crush it with a hammer between two sheets of paper. Wear old clothing and do this outside, since it is very messy. Sieve the charcoal through a coarse sieve (about 30 mesh). 2. Weigh the charcoal. To every 100 grams of charcoal, add 67 grams of sulfur, and fill 1/4th of your ball mill with this mixture. Put the media in and let the mill run for 8 hours. 3. While the mill is running, place 600 ml isopropylalcohol in a large container for every 100 grams of charcoal/sulfur mix you have, and place it in the fridge. 4. When you open your mill, you should find an incredibly fine black/greyish powder. Sieve this to get the media of the mill out, and weigh it. In a separate container, place 75 grams of potassium nitrate for every 25 grams of charcoal/sulfur powder you have. Put the potassium nitrate in an old pan, and add 40 ml tap water for every 100 grams of potassium nitrate. 5. Place the pan on the stove and bring it to a boil while continuesly stirring. When the solution starts boiling, start adding small amounts of water while stirring all the time untill all the potassium nitrate has dissolved. 6. Add an extra 10 ml tap water and the charcoal/sulfur mixture to the boiling potassium nitrate solution. Stir the charcoal/sulfur mixture in the solution. Make sure there are no dry clumbs left. 7. By now, your isopropylalcohol should have cooled to at least 0 deg C or colder. Take the isopropylalcohol outside, and pour the potasium nitrate solution/charcoal/sulfur into the cold isopropylalcohol. Make sure there are no sources of ignition nearby! Stir for a few seconds. 8. Cool the mixture again to 0 deg C at the fastest rate you can. The faster the better. 9. Filter the mixture through an old cloth, and squeeze to get all the liquid out. Discard the black liquid. 10. Spread the black mush out on a sheet of paper, and dry it in the sun. Don't try to dry it inside since it will produce a lot of flammable vapour from the ispropylalcohol. When it is still slightly wet to the touch, press it through a sieve to corn it. Then dry it further. 11. When dry, sieve the black powder through a few sieves to get several fractions for different purposes.
  19. grifter

    Photon Stats

    To be honest it depends what you mean by "how big." An excitation of the electromagnetic field can extend arbitrarily, far across space. However, we only ever detect them at points. (not to say that they are or aren't point particles....as it is a point-like particle)
  20. simply think of it as conservation of energy, if the atom is to remain unchanged when it accepts a photon it must release one, however if an atom is to release two photons when one is input, the atom must already be in an excited state, (this happens to be the principal lasers work on) this can be seen as electrons "moving up" "energy levels" when they are excited, this excitement can occur when a photon of a specific frequency interacts with the atom; when the excited electron "drops down" to its ground state it must emit energy, this is in the form of a photon, Okay?
  21. grifter

    Beta decay

    sorry, it's a bit late, but with the current work-load I'm faced with I'm suprised I havent premenantly bonded with the chair: Anyway, without further ado I shal Impart some knowledge as to the nature of this resulting e+ e- plasma: (p.s. sorry if its a bit rushed and un-explaned but I've got some exam revision to do...) In order to estimate the properties of the e+e- plasma, the following experiment was conducted (If my memory serves) a thermal energy of ~10^50 ergs was "put" into a 1.5 solar mass neutron star the stellar-evolution was then tracked: The efficiency of (e+)(e-) pair production was ~3% and the entropy of the plasma to be ~10^10 per baryon. This is a large value !!! Therfore I expect the energy of the (e+)(e-) pair plasma to be in the region 10^51 to 10^52 ergs. which for those of you who like to work in Joules ~ 1×10^46 joules hope this helps
  22. grifter

    Nitro Kits

    intercoolers are specificaly designed for use with turbos and supers as oppose to just cooling down air in the cylinders, the turbo (or Super) is cooled to increase efficiency (as more o2 mollecules can be present @ any one time due to the gas mollecules having less less Ke) in response to the Why nitro question: The addition of nitromethane in fuel provides more power therfore a smoother idle, thus making the engine easier to tune. O2 isnt used as it will combust at lower temperatures. any pure N present will react with oxygen @ the spark plugs (during a spark) to form Nox (where x varies) just increasing the ammount of combustion taking place... just a quick one: perhaps another reason O2 isnt used as it will auto-combust as the piston returns to the top, therfore causing knocking, which would drastically reduce engine preformance...(not 100% sure at the pressure pure O2 combust at, might wanna chech that..)
  23. neither, there are 14 phases of ice they are: amorphous ice (three forms low, high and very high density) Ih Ic I 2-12
  24. The cause of the non-zero [math]\lambda[/math] is derived from non-zero vacuum energy density causing the longrange repulsion effect resulting in the accelerating expansion of the Universe.
  25. I believe that the definintion you are refering to is the law of conservation of energy, the translational symmetry of the quantity conjugate to energy, (time). N.B. The reason that energy is conserved roots from Physic's lack of distinguishment between different "points" of time (Nother)
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