Strange

The gullible, you mean. I think you might be in the wrong place: the clue is in the title Science Forums.

For example, the Voyager probes are now outside the solar system. They are no longer firing any thrusters so there is no force causing heir continued motion. But they will keep going, possibly forever (space is big - they are quite unlikely to hit anything). They will not keep going in a straight line - because of gravity they will end up in some sort of orbit around the galaxy. But they won't come to a stop.

I guess that is another factor: they have shared their ideas with friends down the pub or on a gaming forum. The friends, who know equally little, are all like, "Wow man, that's amazing" and so they think they have come up with something clever. This might explain the curious phenomenon where many start or end their post with something like "I would love to know what you guys think" and then get all upset when some fundamental errors are pointed out, or a few simple questions asked.

Yes. If the Earth did not orbit the Sun it would fall straight towards it in the same way an apple falls to Earth from a tree. (Do you understand the significance of that comparison?) Friction requires a mechanical contact between two surfaces. So if you slide a pencil across a table, there is friction because gravity pulls the pencil down and it "sticks" to the table. There is nothing to cause (significant) friction in space. (There is a tiny amount of gas, and there are tiny tidal effects - but they can be ignored as they are so small.) A force, by itself, does not cause friction. I'm not sure why you think it does. Unless you are trying to extend our everyday experience on Earth where, for example, a ball or a bullet will be stopped by air-resistance (friction) and will fall to Earth. If you throw a ball in space it will keep going until it hits something.

Have you already filed a patent? If not, then it is too late. You cannot file an invention which has been published.

Only if it acts in (or against) the direction of motion. If it acts at right angles to the direction of motion (which is what gravity does to an orbiting body) then it will not change the speed. Remember, in F=ma both F and a are "vector" quantities.In other words, they have a direction as well as a size. The acceleration is in the same direction as the force: towards the Sun. (Not along the line the Earth is moving).

We had one science teacher at school who focussed on the design of experiments rather than just "memorising facts". I think it was really useful and engaged even those who weren't usually interested. This also relates to getting your science education from popular sources whcih say "we did this experiement and got this result". No information about the complexities of the design and the technology (well, maybe the technology) and what has to be done, over many experiments to eliminate confounding results. Or how, sometimes, those confounding results are actually new science (which dogmatic scientists are supposedly blind to). There was a great example I heard a while ago. A team was researching the damage to neurons caused by strokes. They had run various tests to eliminate various causes. One of them (the effect of interferon, I think) they said, "well, there is no way this could be a cause, but lets do the test anyway". And they found a whole new cause of brain damage and treatments to reduce it. I relate to this because I used to work as a test engineer. I would come up with a test plan and people would say, "why are you testing that, it could never happen." Of course, they wouldn't thank you when it found another bug... And ironically, it is they who repeatedly say, "But Einstein said..." and aren't deterred even when it is pointed out that no one cares (as far as the science is concerned) what Einstein said. Or that he was sometimes wrong. http://xkcd.com/1206/

But, otherwise, yes: iron is at the minimum energy level.

You expect people to spot errors in gibberish?

No there is only one deluded crank here. The rest of us can read what is written as the definition of the thought experiment. Close. But not quite there. After seeing the flashes, the woman calculates the time when the two strikes occurred. She knows that they happened an equal distance away, and both flashes travelled at the speed of light. Therefore one happened before the other. That's it. Simple, isn't it.

The rotation of the cloud of gas and dust that the solar system formed from. No. No. Just changes the direction.

You apply an initial force to start it moving but you don't have to supply a force to keep it moving. Newton's 1st law, remember. (Well, OK, there is air resistance so it will slow down and you would have to keep hitting it. But there is no air in space to slow the Earth down.)

There is no force in that direction (as you can tell, because it doesn't accelerate in that direction). The acceleration, and therefore the force, is towards the Sun.

How do you know that?

Indeed. It may be easier to think of the universe becoming less dense, rather than "larger" - which can lead to thinking of it as a large sphere, which may not be accurate.

Man, I just asked a question ....

I have read your posts. The only thing I am being "dogmatic" about is that you have not explained how you have eliminated mundane causes. You have just asserted they are not possible. Your reluctance to answer this very simple question suggests you have made no such effort. You have just decided, arbitrarily, that there can't be one. Sorry, not convincing. And it is this lack of rigour in your approach that will cause people to be sceptical, not any sort of dogma or taboo. Insulting your audience is not really going to help, either. Also, "watch the video" is not a good argument as there is nothing to judge size, distance, speed or to separate camera movement from movement of the object. Plus, human perception is a notoriously unreliable tool (as has been demonstrated by Actual Science).

I'm not sure what that means. Imagination is in your head. How does it "encircle" anything? Incomprehensible. Or, at least, I can't imagine what it means. (See what I did there.)

I am not "attacking the problem" whatever that means. I am commenting on your apparent lack of critical thinking. But feel free to prove me wrong: Please list all the alternative causes you have considered and the precise steps you have taken to rule them out. It is the obvious default assumption. The null hypothesis. It is up to you to provide evidence (beyond "hey look at this") that the reasonable assumption is invalid. Making the assertion "do not have a known mundane explanation" is unconvincing unless you provide details of which mundane explanations have been considered and what exact steps have been taken to eliminate them.

You are right. But I found this easier to follow: http://en.wikipedia.org/wiki/Proton%E2%80%93proton_chain_reaction

Not all the byproducts are contained, but the "fuel" (for want of a better word) must be contained. Actually, I'm not sure but I don't think fusion creates a lot of gamma radiation - that is another of its potential advantages.

I thought I would give it another go. See if it has learnt anything from the other conversations. (Assuming it is supposed to learn.) It seems to have turned into a bored teenager: Not even amusing.

And yet you are jumping straight from "unidentified but with possible mundane explanation" to "controlled!! intelligent!!! plasma!!1!" Please list all the alternative causes you have considered and the precise steps you have taken to rule them out.

That isn't osmosis, but diffusion. It happens because all the molecules (water and salt) are moving around at random. So after some time, it all averages out. Put a drop of ink in a glass of water and watch it slowly spread out until it disappears. Same thing. Yes, because it weighs less. (That is what "less dense" means, effectively). It is like oil on water: the oil is less dense and so it floats.

It isn't about the rate at which energy is released, after all you can have both an atom bomb (fission) and a hydrogen bomb (fusion). Fusion occurs in large atoms, which means they form solids. So materials like uranium and plutonium. This means they are relatively easy to work with and contain. Fusion works with light elements (typically hydrogen) which is a gas. This means that to have a fusion reaction you need some way of containing a gas a very high temperatures (like 100 million degrees). It also requires very high pressures. No material can withstand that, so it needs to be contained by magnetic fields. But trying to contain a hot, rapidly moving, high-pressure plasma in a magnetic field is not easy. Transmutation might be useful for converting nuclear waste to something less hazardous. I don't know how practical it is on a large scale.