swansont

You can only "observe" a photon by interacting with it.

The question still stands. If your course load is on pace to have you graduate in four years, it's a normal load (assuming you're full-time). If it's less, it's light. Modify that by the relative difficulty of the classes; you generally throw in a humanities or social science class every term because most schools have a requirement for those, too. They're usually intro courses and not too tough.

Do you get a second-hand high from someone doing drugs, in the privacy of their own home? And there's no hypocrisy in banning some drugs but allowing the consumption of alcohol?

Do you accept that wearing seat belts and lower driving speeds save lives? Much of that, if not all, is statistical as well. A LOT of science, especially medical, is statistical in nature. And that makes it easy to attack, because statistics can be manipulated and misrepresented, and people can be manipulated if they don't understand the statistics. Just like some people driving at high speeds or not wearing a safety belt will survive acccidents unscathed, whether or not you contract cancer under a given set of conditions is probabilistic.

Without defining what you think constitutes "conclusive proof," the statement is meaningless. The problem is in whether there has been a redefinition of what meets the standard of "conclusive proof" as science is not deductive. There is always uncertainty in scientific data, and one political ploy is to exploit that uncertainty. It is very easy to say, "I'm not convinced yet" but that really isn't enough, because the reason for this could be a misunderstanding of the science or what the data is representing, or unreasonable expectations of what data should be available. We've seen examples in this thread. One could be so contrary (or intellectually dishonest) as to say that gravity hasn't been proven conclusively. I don't think anyone would back that up by jumping off a cliff, but since science isn't proven as in a deductive mathematical proof, it depends on how much data you want collected before you agree that the conclusion is warranted. And it's far too easy to say, "No, that's not enough."

It's two classes, one with a lab. It does seem light; I recall taking four classes per term as an undergrad (not at ND, though) was the track to graduate in four years. How many credits is this and what's the normal course load?

I'm sure that the polling, telling the members of congress how to feel about all this, doesn't account for how badly the polls were written. I'd wager "Do you oppose flag burning" is going to get a higher positive response than "Are you willing to lose a certain amount of your first-amendment rights because it bothers some people" The same people who are against the right to burn the flag are probably going to get just as offended when protesters burn copies of the constitution instead, once they know it was the constitution that was burned.

This is flat-out wrong, too. Plenty of computation went into the design of the first atomic devices, before they were tested. They built a theoretical model based on smaller-scale experiments they could conduct, predicted behavior of the larger system, and then built the devices. That's science at work. Similar stuff happens all the time.

That's because there is no such rule. I can, for example, take a shut-down nuclear reactor and increase the neutron concentration by many orders of magnitude and see essentially no change in power. Yet if I change it by a small fraction when the reactor is critical and operating at power, I get a huge change in power. The function relating the two isn't linear. Climate is a nonlinear system, and there are many parameters. Conclusions drawn from a flawed premise are invalid.

OK, I have to concede that I would endorse an anti-flag smoking amendment.

I quite agree. It's be nice if, in addition, they can't find a reason that would prompt them to do so. But these probably have to be addressed separately.

I haven't seen the movie, and I am in no way anything like an expert on global warming or climatology. But there are some obvious logical fallacies and errors of science interpretation floating around this thread, besides the ones bascule has called out (or if he did address them, I missed it).

No, I disagree. Look at the limiting behavior will help. The lower block has to be able to exert a sufficient frictional force on the upper, and feel the resulting reaction force, in order to accelerate at 3.5 m/s^2. If mu is zero, the upper block "wants" to accerate at 7 m/s^2, and a blind person pushing would only feel like it was a 1 kg block. As mu increases, the system "feels" more massive, until you reach a mu where they always stick, and beyond that it's effectively a 2 kg mass. Until that point, the lower block has a smaller acceleration. Left as an exercise: at what value of mu will the blocks actually both accelerate at 3.5 m/s^2? (assume kinetic and sliding are equal for simplicity). I think an analysis of that problem will highlight what I said here and in the previous post.

But you posted this in the Chemistry/Inorganic Chemistry section... Possibly. You'd get neutrons from an (alpha, Be-9) reaction, but getting a sustained reaction is a much more complex problem. (It also depends on what you mean by "start a fission reaction." Chain reaction, or cause just one fission?)

A more generalized expression of what we call perpendicular, in two dimensions. x, y and z, for example, are mutually perpendicular in Cartesian coordinates. A dot product will result in zero; there is no way I can express one coordinate by multiplying a different coordinate by a scalar. (I can't change y simply by changing my x coordinate) However, if your scale is mm vs km, I can get there simply by multiplying by 106, which is just a number, i.e. a scalar.

A tube of material with high permeability would do this, to some extent. The field would preferentially pass through the material instead of the region inside it. But as Martin has already expained, this wouldn't do anything to shield UV, unless, possibly, you already had a plasma floating around in the atmosphere that was absorbing in the UV, and re-radiating at lower frequencies. Excluding the field might also exclude the plasma, as the charges would tend to spiral along the field lines.

This might help.

Scale isn't orthogonal to the first four dimensions. So, no.

A force perpendicular to the displacement does no work, so there is no change in kinetic energy and thus no change in speed. Velocity is a vector, so it has changed if the direction changes, even if the magnitude is constant. A changing velocity is, by definition, an acceleration.

The are also made in beta decays, such as K-40 and C-14, which means you are a very, very, very, very weak neutrino source.

Yeah, I remember giving that as a quiz once (What is Coles Law?) (Most memorable was the "Spell Bremsstrahlung" quiz. All spelled out. Two guys missed it.)