J.C.MacSwell

I think Homo Sapiens might have a few weapons at their disposal that could take care of them.

I need one of those for when I go jogging. The stop watch I use is simply not accurate enough to measure my...cough...progress

492 light years? Should we start the plan and race to Nuke it now, before it gets us? Or is it too late and their's is already on the way?

Do I believe it at the same level as Newtonian Mechanics. No. But it certainly is a compelling model, though built on more uncertainty the further one goes back, I think. I have had ideas I liked better, but they never fit the evidence as well, at least to the limits of what I could comprehend. Still the best we have, and it seems to have evolved. Would it still be coined "the Big Bang", if named today?

As well as mass? The path would be effected by the mass of the bullet, given that other things being equal at any given point, the forces on the bullet would be identical (at that point). So a heavier bullet would respond differently than a lighter one, which would effect the forces going forward etc. Generally speaking there would be increased drag as it met the surface, which would rotate it but not initially pull it under (and some lift which might counter that rotation), depending on the shape and centre of gravity. With enough downward momentum it will break the surface, and the rotation would give it an angle of attack that would cause the refraction downward (or not if rotated upward). Without enough downward momentum to break the surface it would generally bounce/skip due to the lift. So I don't believe a generalized equation will work, unless it is a very complicated one.

Just a joke, but didn't know there was anything behind it. More massive things fall faster etc. Intuitive but untested in Aristotelian Physics etc.

Yeah, I guess that Greek urned it...

Surely they've shaken that stereotype by now...

OK, so you are assuming no losses due to friction and disregarding the rotational energy...an idealized case. So you know they are both at the same speed at the bottom, and that Y has a slightly longer path, though it is not defined exactly it is a smooth curve. Which one accelerates faster at the start? What is the speed of X, halfway along its path? How much faster is Y moving, halfway along it's path?

Same frame?

I assume this is homework. Can you tell us your answers for c) and d). I think that may help with answering b).

How does your conjecture explain gravitational anomalies, deviations from the idealized case, caused by such things as changes in terrain and density near the planets surface? Current theory explains it quite well and is used in mining to find ore deposits etc.

Thank God Planck did not take any of that into consideration.

The galaxy problem lies in the fact that the assumptions used to produce that formula, taking into account all the apparent mass in the galaxies, don't seem to hold true. (so Newton's law of gravitation wasn't matching the evidence) The speeds of rotation were calculated from the difference in the redshift (generally) relative to that of the galaxy as a whole. So one "snapshot" could provide a lot of information given the right set of assumptions and measurements. I don't believe they were noting any displacements over time to get the data.

That, and the events have to be adequately separated spatially. No one will interpret an effect to have preceded a cause.

Thanks, but I'm not Mach, and as far as I know it is unproven conjecture....metaphysics that may have helped toward the General Theory of Relativity. Your statements seemed to be directed along similar lines of thinking.

Sounds a little like Mach's principle (or conjecture) http://en.wikipedia.org/wiki/Mach's_principle

Hey...they laughed at Edison... So far we have: 2 votes: Einstein Feynman Maxwell 1 vote: ajb (voted for himself) Galileo Newton Dirac Walter Lewin Leonard Susskind Hawking Archimedes Watt Manfred Curry Sagan "Honourable" mention (by himself) to Swansont Disclosure: Although in a Science Forum, poll is not a scientific one, some have voted more than once, so far a pretty small sample size...but looks like we have a couple of our own among the favourite scientistists of all time...

Have you driven a car and turned on your headlights? What did you see? Relative to some inertial frames you were almost at lightspeed, but at light speed in none.

Must include the guy in my avatar, a young James Clerk Maxwell Feynman, for the wit as well as the science Always liked Archimedes, James Watt For a lesser known pick, Manfred Curry, scientist, inventor and yachtsman

You need to balance the pressures on the returns from the filter. If you get it close it should then self regulate...if more goes to one the level gets slightly higher and the head pressure will restrict extra flow to that jar/tank. If one jar is farther away you may need a larger tube to that jar/tank, or restrict flow to the other. You can use adjustable valves for fine tuning or simply pinch the tubing with an adjustable clip.

So..tea it is then...

This is the both the key...and in 514's example potentially misleading if not understood in the right context. In every day language it makes no sense.

Gravitational acceleration should not be a problem unless tidal forces become significant, unless of course something lies in your path...like, say, the Earth...

You can calculate as precisely as you wish, it won't make any difference. The results will not be accurate if based on the premise that you can transfer energy and momentum to one frame from another, using the same numbers, and not allowing for the difference. It might work in some universe, where you might want to patent your invention, but it won't work in this one. edit: When I do a thought experiment, or a mathematical model, that show results that violate physical law (it is not that uncommon), I know I have made a mistake...time to check the math or assumptions