The Thing

I have a thought about a Stirling cycle refrigerator. I know that a stirling engine when reversed will generate a heat difference. And yes they are being built. What I don't understand is where does the cooling occur? Does it occur in the normal heating portion of the engine or the cooling portion? I think it is the heating portion, but if that part gets cooled down, does the other part of the engine get heated up? If we can connect a second stirling driven by heat from focused sunlight to the cooling stirling we can create a stirling-stirling refrigerator, can't we? What temperature can focused sunlight get to? Also, is there a way to calculate the amount of heat the stirling cycle fridge would be able to remove? As in, how low the temperature of such a fridge can reach? Thanks.

Okay, thanks calbiterol and YT. Yeah, I think we should split the thread. The problem now is that I know how the stirling engine works and I have a design, but I DON'T know what temperature difference it will run on and whether it is powerful enough to generate enough electricity (Will I have to use weak magnets?). Also, I have no heads or tails on how to even BEGIN building this thing. Well, that's the problem.

Okay, I'll have a go at trying to explain the cylindrical stirling engine. A flashlight that you clutch normally is cylindrical, right? With a bulb at the front. I'm trying to think of a design that would be the same shape, with the heating portion being in contact with the hand, thus it has to be at the very outside of the flashlight. Anyhelp with this design? And I'll try to explain the beta stirling engine design that I had in mind. Take a normal beta stirling engine, the tube containing the air, the displacer and the piston would be cylindrical already. At the top of the engine, attached to the piston and the displacer, is a mechanical wheel that's used to crank the displacer as well as to generate electricity (is that plausible?). I got the idea from the picture attached of the beta stirling engine. The wavy red lines are of course heat, and the hand will grasp the entire cylinder there. I need to make sure that the radiator part, the cooling portion, does not get any heat from the hand. Well, should this work? Also, I could switch the cooling & heating portions around so that the cooling's at the bottom, but then I need longer sticks for the cranking wheel or I have to place the wheel at the bottom. Well, that's it for my thoughts today. Any help is greatly appreciated! Incidentally, how long do you think this thing will take me to build if I work for 6 hours a day but with only small hand tools such as drills?

For once I am speechless. ...... Incidentally, has anyone been to Las Vegas and seen the fountain in front of Bellagio? Amazing too. But the video, that's just one house as opposed to a billion-dollar hotel.

Thanks calbiterol. And YT, your idea might just work. Anyways, for the flashlight: I'm struggling to create a plan for a stirling engine that is cylindrical. The only types I've seen are the disc ones with a giant wheel on top or in other funky shapes, none cylindrical though. Any help please? One more thing: what decides the temperature difference required to make a Stirling engine move? I don't want to build an engine and find out that it requires 200 degrees temperature difference to move . EDIT: After some thinking, I think a beta stirling is the way to go . The tube containing the piston and displacer, the lower portion can be grasped by the hand. The upper portion, the cooling part, the user must NOT touch with the hand. Is that plausible? I'll have to think of a way to make sure that the heat from the hand doesn't travel to the cooling part of the flashlight. I HAVEN'T workout ANY details for it though . Oh yea, please answer my questions above too . Thanks.

Thanks calbiterol. So should I create one large stirling engine or an array of smaller ones? I've heard that building a low heat difference stirling from scratch instead of from a kit requires attention to details and you have to work very carefully. Is that true?

Hmm...I know a lot of the "batteryless" flashlights are either shake or squeeze-trigger types. I've never seen or heard of a body-heat flashlight before, which is why I asked. Now to think about it, I'll spend my Christmas building one of those gadgets . Alright! Thanks a great deal calbiterol! A core that's always hotter eh? A lump of plutonium-238!!! Yea! Now I need to think of a way to build several VERY small Stirling engines. Any help would be greatly appreciated.

Okay, everything makes sense, except... the recharging during room temperature part. How does THAT work?

Say if I were to create a hand-heat-powered flashlight about 20cm long and 5 to 6 cm in diameter, is that enough to power a small incandescent bulb? Or are LEDs the only way to go? How long would the batteries take to recharge?

I remember from a few years ago when I was learning VB that the Random function in VB gives you the same random numbers over and over again. So the first random number would always be, say, 0.145 <-just an example. And the second would always be something else. ALWAYS. You have to use a Randomize command to randomize the random function . Confusing...

There are two glasses of water, one is 10 degrees above room temperature, the other 10 degrees below. The water in each glass is identical, glasses are identical, conditions for both glasses of water are identical as well. They are left in a room. Which glass of water will reach room temperature first? Why?

Okay, it's those puzzles where you look at a picture of words arranged in funky ways and decipher the hidden message: I'm sure everyone's done these, but in case someone hasn't, here is an example: Symphon That would be Unfinished Symphony. So, attached are the clues. Have fun.

You tell me There goes my idea of the Ferrofluid train down the drain <--- W00t! I'm a rapper w/ m4d sk1llz0rz OMFG! Seriously, is there any application of the near frictionlessness property of ferrofluid beyond that of lubricating bearings? Is it more frictionless than, say, machine oil? Thanks.

I have a stupid question that I honestly don't know the answer to: Is it possible to build a flashlight that is powered by body heat? Say you just simply clutch it and the heat from your hand powers the flashlight? I wouldn't expect it to be uber efficient tho...

Okay... no response... MagnaView Fluid=Ferrofuid Helps anyone?

Okay, I posted this in the physics section but got no replies whatsoever. Perhaps it is better here: can a mod delete the post in the physics section? It has the same title. So, MagnaView Fluid, How frictionless is that thing? If I were to push a magnet covered in magnaview fluid in a plastic tube, would the friction between the fluid and the tube be greater or smaller than the friction between the magnet and the air if I were to push a levitated magnet? Is it possible to create a sort of "magnaview train" and push it and accelerate it using magnets? I'm planning on doing an experiment on this...

How frictionless is that thing? If I were to push a magnet covered in magnaview fluid in a plastic tube, would the friction between the fluid and the tube be greater or smaller than the friction between the magnet and the air if I were to push a levitated magnet? Is it possible to create a sort of "magnaview train" and push it using magnets like in a linear particle accelerator? Would it be efficient? I want to do a small experiment on this .

Wow, an ATP powered linear actuator? How much energy is produced from that stuff if I, say, put 100g of ATP decompsing into ADP in a jar of water to heat the water to use the steam to drive a turbine? How does one extract ATP from cells? Or can you synthetically, er, synthesize it and use that? I would suppose that extracting from cells wouldn't give you a pound all at once, so how do I get the ATP to power a motor?

Yes YT. Sorry for harrassing you with PMs. Anyways, I contacted a research facility in my city sponsored by 2 universities, and asked them to help me on this project (it has changed into a science fair project ) as well as using tritium and solar cells to generate electricity (my 2nd design). Here's what I got back from them: [Tritium is an _extremely_ hazardous material that requires a tremendous amount of care in handling. Here we have gone to long and _expensive_ lengths to ensure that 3H is properly handled.It's safe to say that there is _no_ chance that we'd be able to conduct any measurements with tritium. it makes sense that if there is enough radiation to heat up a flask of water and run a radio, then there is enough radiation to heat up your body, which is mostly water. You can imagine that if the radiation is heating up your body, it is also causing a lot of biological damage. Which means that IF you had a radioactive source (what we call) 'hot' enough to run your electricity-generating turbine, it is logical to assume that for safety sake, you would not be able to come within a country mile of it. Understand that you must _handle_ the material before putting it into your lead-shielded apparatus, and proper safety measures must be in place to handle a very hot source.Non-trivial, to say the least] And he said that there were "good ideas that we might be able to exploit" and he'll "get back to me". And I have 2 questions: 1) I thought tritium is only dangerous when inhaled or somehow got into your body? I thought tritium's radiation is so weak that it's stopped by your skin? 2) I'm not getting the 2nd paragraph completely. A MILE? Why? So, can anyone help?

How much energy does ATP give off when it changes to ADP? Can we somehow harness that energy to, say, power nanobots? Is this an exploitable area. I'm asking because I'm considering doing a project on this in a university lab hopefully. Any suggestions is welcome. How can I actually SHOW that the energy can be used? How can I convert the heat that ATP gives off to electricity efficiently? And how much ATP is needed to power say a very small lamp (battery powered ones)

What are some ways that researchers are currently harnessing nuclear power for batteries? I know the RTGs and those using decay heat to heat water to generate electricity. I've heard of the Beta Voltaic way, what's that? Are there any other ways to create efficient nuclear batteries? And how do they get rid of the materials after the battery's exhausted after decades? Like the water from a decay heat battery? Thanks.

Mosquitoes are attracted to the color blue twice as much as any other colour. Koalas are teh only animals besides humans and other primates that have fingerprints.

Thanks a lot woelen. I didn't word the question right, but you answered it anyways. Should have known it was obvious from the unit (watt), but my brain short-circuited. Anywayz, YT, in your original thread you said you were going to post the circuitry of the device with thermocouples and a valve, solenoid but you never did. Could you post them now?

Thanks swansont & YT. I have just one more question. The P in watts, is that the amount of power given off over a time period (how long?) or at any given time? Thanks a lot for your help.

Thanks swansont. However, could you illustrate the usage of that formula by calculating, say, the power that can be generated from 1 gram of Pu-238? (half life and Q-value in previous posts). I'm not really getting the N part. Is it simply just the number of atoms in the sample, or is it something else? So could you show me how to use the formula please? Thanks.