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Gilded

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Posts posted by Gilded

  1. I sometimes scoff at radioactive things portrayed as glowing green. :) It's a common misconception, and is perhaps most famously featured in opening sequence of The Simpsons (the nuclear fuel rod). The green glow of radium watches for example is from chemiluminescence of the sulfide paint materials, not the radium itself.

     

    If you throw something very radioactive in water it might seem to glow blue due to Cherenkov radiation. If something is really radioactive it might be hot enough to emit blackbody radiation in the visible spectrum (just like lava) but that wouldn't be green light either.

  2. What you're apparently missing here is that gamma ray photons aren't a byproduct of annihilation; they are pretty much the only product. All the mass of the reacting particles is converted into gamma rays, regardless the type of these particles.

     

    As for efficiency all annihilations are theoretically 100% efficient. You'll get the same amount of energy from a kilogram of positrons and electrons as you get from a kilogram of hydrogen and antihydrogen.

  3. Barack has played Pong

    but McCain used to throw stones

    at Salem witches

     

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    Carbon dating works

    below sixty-thousand years,

    not on John McCain.

     

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    That McCain guy, eh?

    Promises of grand change, has

    a grand prostate too.

  4. Here in Rio, we know kebab as greek barbecue (when rolled up), there is an urban legend which says these 'greek barbecues' are made of cat meat... i love urban legends :)

     

    Ah, that's more like gyros right? The difference isn't too big I suppose. I'd say the urban legends are mostly made up by people who hate foreign cuisine, immigrants or just great food in general. :) Some people I know who don't like kebab keep saying how it's made of rats etc.

  5. This is one of those rather "pop-scientific" articles of New Scientist but I thought I'd make a thread about it anyway (even though it's also a "controversial claim").

     

    How war debris could cause cancer

     

    But isn't this really old news though, or is the controversial part mentioned later in the article (assuming someone here has subscribed)? It has been known for ages that a single alpha particle can ionize many molecules, knocking off lots of electrons before it has slowed down enough to capture two for itself, so what's new? Or does that "mimicing beta radiation" part imply that the electrons are more energetic than previously thought?

  6. I think there was also some concern about sustained hydrogen fusion in sea water regarding the underwater H-bomb test(s?)... Anyway, people sure like to be afraid of the unknown. My little sister always worries about all sorts of diseases and catastrophies, a few days back I was joking about the LHC killing us all and she was sort of half-listening and said "the what?" at which point I said something like "err, nothing" and left the room. ;) Even back when I got my first radioactive mineral chunk I tried to explain to her how it posed no danger especially if it's in a protective box but she didn't really listen to the science behind it since she knew some radiation was dangerous.

     

    Regarding the magnetic monopole matter, I think there have been some claims that it could pull matter apart somehow due to "uneven" magnetic fields or something. But magnetic monopoles are really interesting particles of practically no danger at all and scientists are really trying to find them since they are predicted by so many theories.

  7. Heh, you're quite a bit like me Ladeira. :) I should drink a lot more water though, my room is usually hot as hell and I often drink as little as one litre a day. Btw you should really try kebab, it's great. Although the kebab I've eaten hasn't got that much to do with original kebab. :D Anyway there's a lot of variety too, like these sort of rolled up kebabs, bread kebabs, kebab with fries or rice... In Finland you can get an Iskender kebab in almost every kebab place, and they're made of win and awesome, so to speak. --This-- is a very typical portion... man I'm hungry. :D

     

    Dudde, ever been to Hardee's? :D

     

    041116_monsterTB.hmedium.jpg

     

    Btw there's no Burger King, Pizza Hut, Taco Bell or Hardee's in Finland. Can you imagine what sort of constant agony my life is? There's always McDonald's of course, but I'd gladly go for something heavier.

  8. A synthesizer or a piano is indeed great to start with, even my friend who's currently a drummer started out with piano. I don't have an actual piano myself, but I do have a Korg X-50 synthesizer which has great sounds for its price range. I especially like the organs. In these days I definitely recommend a synthesizer instead of a piano, with the $1000+ ones you're not really missing out on the sounds or the feel of the keys and you can practice different kinds of techniques (traditional piano, organ, pads, synth leads...). I agree with Dudde that other instruments get easier if you go with keyboards, I also tried acoustic guitar couple of years back but it felt sort of hard so I quit. :D But now I feel much more confident, as I've learned more about music in general and my finger dexterity is on a whole new level.

     

    Anyway, don't take this piano hype too seriously. ;) If you want to go with the guitar, go with the guitar.

  9. Sodium can have a thick oxide layer protecting it so the not igniting part isn't that weird, but I'm not really sure about the KNO3. It probably requires higher temperature to convert into nitrite than for just melting, but with a bunsen burner it should've been achievable. Weird.

  10. I don't know about a rhenium ring but a rhenium diboride "jewel" would be nifty. ;) Rhenium is one of those elements that hasn't had too much research done on the toxicity, but it seems it quite non-toxic and isn't too reactive.

     

    I'm not sure about dysprosium, it also has an unknown toxicity status and seems to be around as soft as gold. Oh, and as insane_alien pointed out it's a bit reactive just like other lanthanoids and doesn't make a good ring metal in its pure form.

     

    If you want more suggestions, these zirconium rings seem pretty cool. While your spouse would probably frown upon a ring with cubic zirconium (ZrO2, common fake diamond material), I don't think that's as much the case with the actual metal. ;)

     

    Or how about tungsten? It has the same density as gold, but it's much, much harder and has the highest melting point of all metals, I suppose that could symbolize something. :) Tungsten isn't that exotic though, and isn't much to look at.

  11. I started playing keyboards relatively late, around the age of 17, compared to all those music schooled people who have played like five different instruments since they were 3. :D

     

    I've also decided to start playing the guitar (which should arrive this month) and perhaps bass guitar later on. I agree with Snail that regardless of age you should pretty much just go for whatever new (preferably legal ;) ) thing you want to do, whether that's glassblowing, golf, pyrotechnics or playing the guitar. :)

  12. Even though scandium develops a beautiful golden tint when the surface oxidizes I'd say it's too reactive to be used as jewelry material (aside for small amounts in alloys).

     

    Iridium has a beautiful silvery color and doesn't really tarnish at all because it's extremely unreactive, even more so than gold or platinum. I haven't heard of pure iridium wedding rings, but that doesn't mean it can't be done. I think a 10/90 alloy of iridium to platinum is often used in platinum wedding rings, but that's a bit low on the iridium (and platinum is expensive as hell compared to iridium).

     

    Btw while iridium is very hard it's somewhat brittle, so if it does fall a long distance it will break rather than get dented. But this would have to be quite a distance and I haven't heard of people throwing their wedding rings around too much. :D Actually, the brittleness matters more if and when you're going to have to get the ring resized as I don't think that can be done in a normal jewelry store. Then again, this is circumvented by wearing the ring on a necklace rather than your finger if that's acceptable.

  13. Uranium, eh?

    I would like ten kilograms.

    Weight-lifting you see.

     

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    Osmium is dense!

    But not quite as dense as that

    silly Phi for All.

     

    ---

     

    Thermite is great stuff

    for melting metal garbage

    like Mercedes-Benz.

     

    ---

     

    Physicists say that

    black holes sort of suck stuff in

    but Phi for All blows.

     

    ---

     

    "Red Bull gives you wings"

    I suppose it can indeed

    if taken with booze.

     

    ---

     

    Imperial Guard,

    Space Marines, Chaos, Necrons,

    Dark Eldar, Tau, Orks...

     

    You are wrong, doctor!

    Oh no! Not the asylum!

    I am not insane!

  14. You can buy liquid nitrogen without any sort of special license, but I'd imagine you have to buy quite a bit of it. It doesn't cost that much though. And yes, it can be used in a non-laboratory environment, preferably in some sort of metal container which can withstand the low temperatures well. While nitrogen gas is probably quite pressurized I don't think that's the case with liquid nitrogen, judging by every nitrogen freeze presentation I've seen having a vacuum flask of non-pressurized nitrogen.

  15. Color change can be achieved by having two solutions of compounds that dissolve well in water (and won't change the color) but which together react to form a compound, water soluble or not, that colors the water. Can't think of any examples at the moment, but there are many such reactions.

     

    Flames on water is a bit tricky, unless you want to use a thin film of some sort of flammable liquid on the water... or have some sort of volatile slowly evaporate from the water. Perhaps you could show them how you can extract hydrogen and oxygen from water through electrolysis and then burn it to form water again? I think that would be somewhat cool for grade schoolers, but I'm not sure if they have the attention spans for that. ;)

     

    If there's one thing I would've wanted to see in grade school it's all kinds of flashy stuff. Perhaps a green flame from a solution of ethanol and boric acid, or a flash and even a small mushroom cloud from a small amount of aluminum powder and an oxidizer like potassium perchlorate. Or perhaps a mixture like zinc powder + ammonium nitrate + ammonium chloride, which can be ignited with a single drop of water. I'm still somewhat impressed by all kinds of flashy stuff (in larger scales though ;) ) and I'm 20. :D

     

    There's some nifty stuff outside chemistry as well, like tesla coils and Jacob's ladders but I'm not sure how you could apply them for "magic".

  16. Items:

     

    -A vacuum collapser from the game Weird Worlds

    -The Heart of Gold spaceship from The Hitchhiker's Guide to the Galaxy

    -Some photon torpedos from Star Trek

    -That weird spontaneous combustion thing the alien bounty hunter used in X-Files

    -A lightsaber from Star Wars. And possibly a Death Star

    -Some of those glowing (and low resolution) glowing crystals from Space Quest III

    -A necron gauss gun from Warhammer 40k

    -A BFG 9000 from Doom. The chainsaw seemed somehow especially cool too

    -A rocket launcher from any of the Quake games. Rockets seemingly unaffected by gravity? Count me in!

    -The TAC gun from Crysis (nuclear grenade launcher)

    -Any robot from One Must Fall 2097. Nova or Pyros preferred

    -A few of those ridiculously large swords from Final Fantasy 7. I wouldn't say no to some Summon materia or mako cannons either

     

    So uh, I've had my share of scifi. I'll list more items and possibly some characters later.

  17. As I was thinking about going for a greasy kebab I started wondering how healthily do SFN users live? Since this is a very broad topic I was thinking of having the main focus on dietary habits with a touch of recreational... substances. :D

     

    Personally, I probably drink less alcohol than I literally burn (ethanol and boric acid makes for a neat green flame). I think I last had a drink like 3 months ago. I don't smoke, and have never done any recreational drugs. I do eat quite a bit of fast food (burgers, pizza or such usually around three times a week) and drink around a liter of soft drinks a day. And as mentioned in another thread I should really exercise more.

     

    So, does swansont eat Luther Burgers for breakfast? Does Phi for All eat huge buckets of chocolate ice cream when no-one's watching? Come on, let it all out. ;)

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