The ISS's pressure-fed hypergolic systems involve three fluids at extremely high pressures, and two of them are highly reactive compounds that spontaneously combust on contact with each other. LOX and CH4 won't do anything without an external ignition source, and the main tanks are likely to be...
Note that Apollo was initially pressurized with an Earthlike mix and had to be built to withstand 1 atm. The mass savings was largely from not having to carry replacement N2. It's not something that anyone has bothered with for spacecraft since, though reduced pressure O2 is still used for EVA...
Xenon has a higher atomic mass and is still quite easy to ionize, so it costs less energy to ionize a given mass of propellant. It also has a higher mass to charge ratio when ionized, which decreases exhaust velocity. This decreases propellant efficiency, but greatly reduces the power needed to...
Hydrogen is notorious for leaking through tiny gaps or even solid materials, causing material compatibility problems, and for violently exploding in a very wide range of concentrations. If you have to ask these questions, you probably shouldn't be messing with it.
Almost no kitchen appliances require DC and very few have transformers, rectifiers, etc. Many are made up of nothing more than simple resistive heaters (which don't care about AC or DC) or AC motors (which require AC and won't function on DC) and switches.
Some appliances have electronic...
Viscosity in the absence of some disturbance would lead to a fluid sphere at equilibrium rotating as a whole exactly like a solid sphere. Cyclonic weather patterns and such occur because the atmosphere is being pushed around by things like solar heating, which still might confuse him. Or perhaps...
This is unlikely to show any effect due to the magnetic field, anything you see is likely just due to the cold, air-obstructing magnets. The flame isn't substantially magnetic like iron is, it needs to be moving through the magnetic field or carrying an electrical current, or the magnetic field...
It has very little to do with the LED characteristic, apart from the LED requiring a higher voltage than a near-dead battery can deliver...it could be used to drive other circuitry as well. The Joule thief is just an extremely simple switching converter that can produce a few volts from very low...
Buy a cheap MP3 player like a Sansa Clip that plays FLAC or WAV (or other lossless format), get some free audio synthesizer software or write a short program to generate audio files with whatever waveforms/mix of frequencies you want (within the audio range, anyway). If you want white noise...
As already mentioned in this thread, photons are their own antiparticles. Photon trajectories are deflected toward normal mass, and only toward it. We see no sign of oppositely lensed "antiphotons", and photons show no sign of inconsistency in their behavior in gravitational fields...star images...
You're forgetting the resistance of the power source and transmission lines. If the heating coil were made of a similar length of similar gauge copper, it would draw huge amounts of current, but most of the voltage would be dropped across wiring rather than the heating element.
If you just want to cancel out an electronic signal, you just need an inverting amplifier, and arrangements to match delays through the amplifier and outside it. Or if you know the wavelength, a partially silvered mirror in front of a fully-silvered mirror, with a half-wavelength separation...
A single zero cross detection circuit won't give you phase...as has already been stated, phase is relative. Two zero cross detectors and a reference signal will give you phase, though, as the difference in zero crossings. You will need to treat the rising and falling edges differently to handle...
They don't, actually...they deflect them, the electrons experiencing a force perpendicular to their motion and to the direction of the magnetic field they're moving through, which is only sometimes toward or away from the magnet. And if the electrons aren't moving and the field's not changing...