swansont

What's it like at night, far from civilization, with no moon?

It's true that the sum of the frequencies would be only a very small change, but you need more than just having two waves of similar frequencies. You have to combine the photons in some nonlinear material. You can then generate photons with the sum and difference frequencies. One common use of this is frequency doubling - take two photons at frequency w and combine them to generate a photon at 2w.

No, one can explain a lot of physics without writing down an equation. It's just that math is a fast way to do it, and to do it quantitatively. Math is the language. But the math doesn't compel the physics; E=mc and E=mc3 are both valid equations and would satisfy any mathematician, and yet they do not represent reality. To draw an anlogy, the English alphabet and language didn't compel the works of Shakespeare.

There is also energy from radioactive decay, which is significant. Life as we know it? Probably not. Life in some form? - not enough info to be sure.

Assuming this happened randomly, would it affect the outcome of the flip?

Ah, yes - Gravity Probe B. But it's not like the probe is news, just the launch. They've been working toward this for almost 45 years.

dic·tion·ar·y n. pl. dic·tion·ar·ies A reference book containing an alphabetical list of words, with information given for each word, usually including meaning, pronunciation, and etymology.

Here is a little more on gaseous diffusion separation.

I refer you to the words of Ernest Rutherford, winner of the 1908 Nobel Prize in chemistry: "All science is either physics or stamp collecting." Subset of chemistry. Bah!

Prompting people when they're offline doesn't do any good. The object would accelerate vertically if the vertical component of the force is greater than the weight. But that information isn't in the diagram.

There are two distinctions to be made. Color as a frequency of light, or color as perceived by our eyes. Neither white nor black is a frequency to be found in the spectrum. But neither is brown, or a number of other colors found in a crayon box or at the local home improvement/paint store. Those colors are how combinations of frequencies are perceived by our eyes.

I don't think "all virtual particles" is right - lots of virtual particles are not ones with zero rest mass. Particles with zero rest mass travel at c because that's the solution to the equations. Particles with rest mass travelling at either v<c or v>c are also solutions to the equations, but they are different solutions from each other. So tachyons, if they exist, can never travel slower than c. What do you mean by 'time travelling at the speed of light'?

A force that is at some angle is the same as the sum of two forces, one horizontal and the other vertical, and whose magnitude is given by the Pythagorean theorem if you were to draw the right triangle with the three vectors. The horizontal and vertical parts are the components. How big any given component is depends on the angle - you can use trig to figure that out. In your example there are other forces present that are not named. Gravity, for instance, exerts a force downward. The upward component of the force the rope exerts acts against gravity, and makes no contribution to the forward motion. That component would be given by the sine of the angle (400N * sin30). The component of the forward force is given by the cosine (400N * cos30) (using the angle in your drawing) (400*sin30)2+(400*cos30)2=4002 so you can see the component forces add (as vectors) to be the total force of 400N

The cosine tells you the component of the force doing the work. The perpendicular component doesn't contribute.

The dot product, that gives you the cosine, tells you what the projection of the vectors are onto each other. i.e. how much of the force is in the same direction as the displacement. A force that is perpendicular to the displacement can't add or remove energy, thus it does no work. A force that is in the exact same direction as the displacement does the maximum work possible. The cosine, in essence, tells you how efficiently you are doing the work with that force.

Also keep in mind that the division between chemistry and physics was originally defined a long time ago. With more recent discoveries, there is overlap where there didn't used to be. Chemistry used to be about what happened when you mixed a bunch of chemicals together. Now e.g. with QM, the theory describes molecular bonds, so both physicists and chemists are going to study it. Just like you have biochemistry and biophysics, there's physical chemistry and nuclear chemistry and chemical physics.

You need to break the forces down into their x and y components. Only the net force in the x direction (horizontal) does any work for displacement in that direction. Any components in the y direction make no contribution.