Recent content by bobob

Just get a small cylinder of helium from a welding supply. You can ususlly rent the cylinder and helium is dirt cheap. Use that to fill whatever industrial quality container you can use (using a regulator, of course). Alternatively. make your baloon out of a polyurethane coated fabric...

Hence the roomate could easily use a space heater in the other room. Nickle and diming over the small difference in electricity is silly unless you think having a second electrical drop is a good idea so each has a separate meter. Would you expect to have someone pay extra for using an electric...

You both share a living space. Oprn your windows and if that is too cold for your roommate, tell your roommate to buy a space heater. Since you will both be splitting the electric bill. it os not like the burden is all on your roommate. This is a simple low tech solution.

I am not sure how you want to implement this but there are many articles describing what you are asking about cooling to reduce emmitance. Do a google search for adiabatic cooling of charged particle beams. Here is one reference from CERN. https://accelconf.web.cern.ch/p91/PDF/PAC1991_1761.PDF

See this article: http://kirkmcd.princeton.edu/examples/guitar.pdf

If you are going to use o-rings, just get a copy of the parker o-ring handbook. The handbook will give you all the design dimensions for o-ring grooves, tolerances, etc for whatever size o-ring you want to use. Yes, it's easy to seal against a flat surface as long as the surface is free of...

Here is a great article that derives explains how a guitar pickup works in great detail. http://kirkmcd.princeton.edu/examples/guitar.pdf

If the two photons have a spacelike seperation when measured, the two photons were always spacelike seperated. The two photons produced by parametric down conversion have never interacted with each other. I think the use of the term "non-local" is not helpful here. It is used inconsistently to...

Asfar as the original big bang goes, what exactly happened is an open question. Physics can only provide models going back to, maybe ##10^{-12}## seconds afterward. As far as "zero-point" energy goes, there is nothing that can be used to create something from nothing. What you see regarding...

Oops... My mistake for not looking at the figure more closely...

This is a poor way of assigning grades. A much better way is for the instructor to write an exam with some idea of what he/she should represent what the average student in the class should know and set that as an average score. After grading the papers, make a histogram of the numerical grades...

Sort of. You have a triangle wave, so theoretically, your sampling frequency needs to be infinite since there are frequency components going out to infinity. The way to approach it is to do a Fourier decomposition of the triangle wave and decide how well you need the reconstruction to resemble...

The non-inverting terminal is at zero volts. The inverting terminal is therefore at zero volts, unless you are given an offset voltage or you assume the opamp will run against the rails and you are given that voltage or some additional information you have not posted. The KVL equations do not...

No, what might be "harful" is not really understanding what you are objecting to. If you assume some ether theory, you have implicitly chosen a spacetime geometry that gives you Newtonian physics, i.e., a central extention to the Galilean group, which actually is more complex than choosing the...

This is a complete misrepresentation of quantum mechanics which has been made popular in magazines like New Scientist, etc. When you prepare a state, you have choices of the states you can prepare with some properties being mutually exclusive. That exclusivity applies to nature as well and it...