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Foxfire_ posted:
Thanks ! I read the entire article and the only bit I really understood was the single sentence about Godzilla. e: Sodding bloody snipe. Here's the first image in my funny pictures folder  e2: Apologies; I thought this was the funny pictures thread. Lady Disdain has a new favorite as of 09:10 on Jun 27, 2021 |
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Jun 27, 2021 06:43
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Particles get ahead of their own EM fields and it all stacks up and manifests as a blue flash, and this happens constantly when you have a big pile of crap shooting high energy particles out, as in a nuclear reactor, creating a constant blue glow. Same thing is also what is looked for in neutrino telescopes, which also look quite cool. 
OwlFancier has a new favorite as of 06:53 on Jun 27, 2021 |
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Jun 27, 2021 06:49
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ultrafilter posted:Physics is badass. I'll see your  and raise you https://www.youtube.com/watch?v=mgNwtepP-6M Reactor brought up to 680 Megawatts in 50 milliseconds.
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Jun 27, 2021 08:45
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deoju posted:It's why Dr. Manhattan is blue in the Watchmen. Does he spend a lot of time in water then?
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Jun 27, 2021 08:58
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The Bloop posted:I still appreciate the effort but for most people, and speaking for myself specifically, a paragraph of algebra is the opposite of "grokking" something Wait for it. Think about it enough now and then and here and there and suddenly your brain might fall into the groove and play delicious music. Wait for it.
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Jun 27, 2021 13:21
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Zopotantor posted:I'll see your I love the ripple in the water after the flash.
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Jun 27, 2021 16:01
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Otteration posted:Wait for it. Think about it enough now and then and here and there and suddenly your brain might fall into the groove and play delicious music. Wait for it. I read a pile of fairly populist cosmology and quantum physics books back a few years ago, and I vividly remember how my brain felt all weird and stretched out after I had somewhat grasped some of the odder elements of quantum theory. It was strange and wonderful, and didn't last very long, but even passingly and vaguely understanding the extreme weirdness of the quantum world for a little while was a marvellous experience.
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Jun 27, 2021 18:03
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you should recreate that in new ways, follow the path of our good friend Kirk
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Jun 27, 2021 19:03
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Pookah posted:I read a pile of fairly populist cosmology and quantum physics books back a few years ago, and I vividly remember how my brain felt all weird and stretched out after I had somewhat grasped some of the odder elements of quantum theory. Odd what 300 billion neurons can do.
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Jun 27, 2021 22:42
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hazardousmouse posted:you should recreate that in new ways, follow the path of our good friend Kirk We’re gonna need another Razer CES event to really set the next person on the path to enlightenment.
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Jun 27, 2021 23:31
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One thing I think I’ve lost the understanding of to time is how objects increase in mass as they approach C. The theory was that if you were in a spaceship approaching C the mass would increase exponentially and it would take more and more power to keep accelerating, effectively capping your speed below C. Why doesn’t this apply to electrons, which are massless depending on how you look at it but also can apply light pressure to things implying that they have mass, or at least momentum to impart. If the latter is true why doesn’t their mass inflate like you’d expect and if the former is true, how are they able to exert light pressure with no mass and no momentum?
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Jun 28, 2021 13:58
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Electrons aren't massless. You're probably thinking of photons. Some actual physicist will have to explain that.
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Jun 28, 2021 14:41
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Jim Silly-Balls posted:One thing I think I’ve lost the understanding of to time is how objects increase in mass as they approach C. The theory was that if you were in a spaceship approaching C the mass would increase exponentially and it would take more and more power to keep accelerating, effectively capping your speed below C. Electrons have mass. Photons have no mass, but do have momentum. Mass isn't required for a thing to have momentum; momentum=mass*velocity is another one of those approximations that works until velocity starts increasing towards c. E^2 = (pc)^2 + (m0c^2)^2 Where p is momentum and m0 is rest mass. So for a photon, rest mass is equal to zero and that second term goes away, and you're left with E=pc, or p = Ec, which also equals Planck's constant divided by the wavelength.
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Jun 28, 2021 15:15
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Yeah I meant photons instead of electrons What I don’t get is if their mass is 0, momentum should be 0 no matter the velocity?
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Jun 28, 2021 16:37
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See equations in the post above you. Like most things in relativity, Newton's equations like p=mv are accurate enough until you get a significant fraction of the speed of light. At that point, turns out momentum is caused both by mass but also there's a term which doesn't include mass which can grow with your energy (which grows with speed)Phanatic posted:Where p is momentum and m0 is rest mass. So for a photon, rest mass is equal to zero and that second term goes away, and you're left with E=pc, or p = Ec, which also equals Planck's constant divided by the wavelength. So p=Ec which means all you need for momentum is energy. For most things the majority of your energy is in mass, but for photons all the energy is from its frequency. This might make intuitive sense if you think of momentum as difficulty to stop - high energy gamma radiation won't be stopped by paper which can easily block visible light - the only difference between gamma photons and visible photons is the feequency. BrianBoitano has a new favorite as of 16:49 on Jun 28, 2021 |
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Jun 28, 2021 16:42
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We understand everything about physics except when things get real big or real small or real fast or real slow, is my understanding of it. So really we don't know jack but our guesses are maybe getting better. E: forgot about real hot or real cold. Weird poo poo in there, too.
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Jun 28, 2021 16:45
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Jim Silly-Balls posted:Yeah I meant photons instead of electrons There are two ways to resolve what seems to be a contradiction (photons are massless, photons have momentum). First is to say, well, momentum doesn't just depend on mass. And that's true enough. But there's a more intuitive way to think about it, in my opinion: photons aren't actually "massless," if by "mass" you mean the thing that we intuitively think of as "mass" - inertia. The thing is, physicists use the word "mass" to mean three different things, and it's confusing as heck. In a classical sense, in stuff like Newton's Second Law (force = mass*acceleration), "mass" means "inertia," aka resistance to changes in motion, and that's what I'm gonna call "m" in this post. Inertia is very intuitively tied to momentum - the more inertia something has, the more momentum-change it takes to change its motion. But in special relativity, how much inertia something has depends on your frame of reference - it's relative. So physicists instead usually use the word "mass" to refer to something invariant - the "rest mass," which I'm going to call "m0" but physicists usually also call "m", which is how much inertia something would have if it weren't moving, which all observers agree on. This is what the famous equation E = mc2 is about - that "m" in there is inertial mass, which is something relative - it depends on how much energy E an object has (including kinetic energy, so it depends on how fast the object is moving, and is relative). Physicists prefer the version posted above - E2 = (pc)2 + (m0c2)2, where p is the momentum and m0 is the "rest mass," also sometimes called the "invariant mass." So you can see momentum doesn't just depend on rest mass, but also on energy content. That's the approach that Phanatic and BrianBoitano took to explaining it. But I say, photons may have zero rest mass, but they do have inertial mass, because the E=mc2 equation tells us that anything that has energy has an equivalent amount of inertia. Therefore, they can have momentum, because momentum is essentially about inertia. (The third kind of mass is "gravitational charge," i.e. how much gravity something produces and how much it is affected by gravity. That's the mass in Newton's law of universal gravitation (force of gravity = gravitational constant*mass1*mass2/distance squared). Newton surmised that this was the equivalent to inertial mass, but it was only a weird assumption until Einstein came up with general relativity and explained it.)
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Jun 28, 2021 23:13
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Phanatic posted:E = mc² π ≈ 3.1415926... Phanatic posted:E² = (pc)² + (m0c²)² π = C/d Basically Bill Hicks' acid tripper was correct: https://www.youtube.com/watch?v=XoacbEcvmYo
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Jun 29, 2021 02:33
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Rrrreal fuckin high on drugs
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Jun 29, 2021 02:46
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Post your favorite science essay
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Jun 29, 2021 04:35
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Wasabi the J posted:π ≈ 3.1415926... That's an unfortunate Youtube thumbnail. EDIT: but fitting if the rumor of Bill Hicks metamorphosing into Alex Jones through a profane ritual involving overpriced nutriciticals and chili is true Screaming Idiot has a new favorite as of 05:10 on Jun 29, 2021 |
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Jun 29, 2021 05:07
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NEVER!
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Jun 29, 2021 11:05
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Foxfire_ posted:Cherenkov radiation. The speed of light in a not-vacuum is slower than in a vacuum. You can go faster than light in a medium. It's the light version of a sonic boom from electrons going faster than the local speed of light. I've worked on a nuclear power plant and seen that when they were switching around the fuel rods; the pictures and video do give an idea, but ultimately do no justice to the real thing. It is unearthly light, lingering into the void beyond the light visible to your eye. ...And perfectly safe to watch if you do it on top of the reactor with +30m of purified and treated water between you and the source. EDIT: Oh and the 3 youngsters who started the evacuation in the burning building I mentioned earlier? They got some small citations and monetary awards from the city and the union of the insurance companies of Finland already, and will most likely get the national emergency services, or the presidential citations, come the next Independence day. Order of the White Rose of Finland, most likely, if its by the President. Der Kyhe has a new favorite as of 19:14 on Jul 4, 2021 |
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Jul 4, 2021 18:54
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Der Kyhe posted:They got some small citations I read that and started thinking they got a parking ticket or a speeding ticket.
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Jul 4, 2021 20:16
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SerthVarnee posted:I read that and started thinking they got a parking ticket or a speeding ticket. Something akin to "few thousand" stipends and a small placket from the city. Also something that is yet to declare by the Insurance Union, and most importantly, it remains to be seen if they are honored by the National Emergency Services (Life Safer-Medal) or by the actual Presidential honor of being awarded with the White Rose of Finland. The latter includes an invitation to the Independence day celebrations with the President of the Republic, aka. they are invited to the largest TV-show of the country; the independence day celebrations in the formal residence of the Finnish President.
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Jul 4, 2021 21:47
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SerthVarnee posted:I read that and started thinking they got a parking ticket or a speeding ticket. gotta love autoantonyms
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Jul 4, 2021 21:53
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Der Kyhe posted:It is unearthly light, lingering into the void beyond the light visible to your eye. I saw it at my University’s reactor years ago. I’ve tried to tell people, it was a color I’ve never seen before or seen since, which doesn’t make much sense I know. But it was amazing in person.
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Jul 4, 2021 22:22
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Seems like a good time to ask, is it true that nuclear power plants essentially use radioactive materials to boil water to create steam, to drive turbines to create electricity? That's how it was explained to me in school and it always seemed so ridiculously lo-tech. Like, we just replaced coal with uranium but fundamentally, the main process is the drat same?
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Jul 5, 2021 18:25
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Pookah posted:Seems like a good time to ask, is it true that nuclear power plants essentially use radioactive materials to boil water to create steam, to drive turbines to create electricity? Yup. That's literally it.
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Jul 5, 2021 18:33
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-Zydeco- posted:Yup. That's literally it. And on a nuclear-powered vessel, the steam exhaust is also your hot-water heater!
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Jul 5, 2021 18:36
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Pookah posted:Seems like a good time to ask, is it true that nuclear power plants essentially use radioactive materials to boil water to create steam, to drive turbines to create electricity? Yep. Incredibly simple and also insanely complex
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Jul 5, 2021 18:48
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They’re similar enough to the point that there have been proposals to install small modular reactors in decommissioned coal plants in the US.
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Jul 5, 2021 19:00
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How much could that save in man hours?
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Jul 5, 2021 19:38
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By popular demand posted:How much could that save in man hours? 4-7.
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Jul 6, 2021 01:05
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LostCosmonaut posted:They’re similar enough to the point that there have been proposals to install small modular reactors in decommissioned coal plants in the US. Would that be cheaper than a new plant? I read a report, possibly linked form the forums, that a lot of cost overruns on nuclear plants are from trying to reuse designs and the civil engineering being different due to geology, geography etc and needing twice as much rework as doing it from scratch. The weight and other considerations on a reactor vessel would be very different to a coal furnace.
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Jul 6, 2021 01:32
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Wait, really ? I'd always wondered how they worked, but assumed they were too complex for me to understand, so I never bothered to look. Lads, my mind has been blown 
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Jul 6, 2021 01:43
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Pookah posted:Seems like a good time to ask, is it true that nuclear power plants essentially use radioactive materials to boil water to create steam, to drive turbines to create electricity? Yeah. Boiling water reactors (BWRs) are basically as simple as “we put a bunch of spicy rocks together and they vibe with each other inside their foil packages underwater (but not too much  ) and the water boils and we pipe it through a bunch of turbines to extract energy from its expansion”.Most plants in most countries are pressurized water reactors (PWRs), but that’s just an extra step where the pressurized water heated by the core exchanges that heat with another loop of water that is allowed to turn to steam. Modern coal power stations are in some ways more complex than nuclear. They’re not like shovelling coal into a locomotive firebox. There’s a whole chemical plant inside. You may notice that they have a heat exchanging setup like a PWR, too. But they’re still terrible for the planet and everyone on it. Platystemon has a new favorite as of 04:32 on Jul 6, 2021 |
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Jul 6, 2021 02:10
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You can do stuff like using a magnetic field to siphon energy from ejected beta particles, but that's only really worth doing at the really really small end (<1W). Economies of scale mean steam is king. You can also build a solar plant that uses steam. Instead of expensive photoelectric panels use cheap mirrors to concentrate the sunlight, and use the heat from that to boil water.
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Jul 6, 2021 03:54
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The Lone Badger posted:You can also build a solar plant that uses steam. Instead of expensive photoelectric panels use cheap mirrors to concentrate the sunlight, and use the heat from that to boil water. Aren't those how those giant solar farms out in the SoCal/Nevada deserts work? 
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Jul 6, 2021 04:45
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Aren't those molten salt
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Jul 6, 2021 04:58
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