swansont

I'm assuming the middle. If you are standing on a sphere of radius R, all of the mass inside the sphere attracts you. (Uniformly distributed mass outside does not; everything cancels)

The shape distorts, depending on your frame of reference. You have a meter stick. An observer who is moving relative to you, measures it as being a "0.9-meter stick." There is no structural change to the stick. It is not an illusion (a trick of the eye), since you can use identical measuring techniques. Neither of you can prove who is right about the length of the stick, since both of your reference frames are equally valid. So, is the stick really a meter long?

Zombie Feynman likes it. The issue I have is when they fail to recreate an effect and declare the myth busted; all they have demonstrated is that the incident didn't happen, not that it couldn't. That's the rigor it lacks.

But there is no structural change. Length is different, time is different, depending on which frame you are in.

I'm sold, because nobody — nobody — could, y'know, photoshop a dog's head onto a walrus's body.

You'd fall in. And exhibit a damped oscillation and eventually come to rest in the center (assuming no rotation)

Who said I was worried? What I take seriously is the effect of the doom-mongering, and crappy information going unchallenged. Severian hit the nail on the head earlier. The same science and scientists predicted the black holes to begin with. You can't pick and choose — science isn't on the a la carte menu. No, I wouldn't. And here you reverse your argument. You're the one who suggested that saying zero was the better alternative, since "people like certainty." What if something unlikely happens in a science experiment, and it was shown that the scientists had misrepresented a small risk to be zero risk? That is the loss of credibility that will put an end to experiments.

Density is mass/volume You need both mass and volume in order to determine the density. Archimedes discovered a way of determining the volume. Weighing was the easy part.

That's not the direction to take this discussion.

Not if it wasn't moving, and it wouldn't be "otherwise identical" if you added mass. That's not the point under discussion. The issue is whether center-of-mass KE results in an increase in mass. But since I can get a change in KE from a change in frame of reference (it's not an invariant under a Lorentz transformation), the answer has to be "no."

Video of making them and another, made at Fermilab, and an explanation (OK, now I gotta blog about this. edit: done)

My favorite college professor explained it by whacking a desk with a meter stick, just moments after a student had moved their hand out of the way. The spatial coordinates of where both the hand and stick had been the same, but the student was spared injury because the time coordinates weren't also the same.

No, the burden of proof is still on those who contend Bigfoot is real to establish the credibility of the evidence. You have to exclude the other possible explanations for the "evidence," through a combination of quality and quantity of your data.

Because of the context in which it has been said. Several people stress that the probability is small, but when the response "but it's not zero," the tone is that of contradiction. "It's really small" means don't worry. A response of "But it's not zero" is taken as "On the contrary, we should worry." As is a mention of how many Google hits mention the LHC+catastrophe is taken in the same light. If you are in agreement that the risk is negligible, perhaps it's best not to post in a fashion that suggests otherwise, and fans the embers.

I wouldn't say that time has energetic or physical properties, just as I wouldn't say that length had those properties, either. An object has properties. Time and length are dimensions; real but not physical, at least in my sense of the word.

Wow, that ad campaign is about the same level of stupidity as Rolling Rock beer announcing they were going to project an advert on the moon with a laser.

It depends on how you define inertia. If it's momentum, then yes. If it's mass, then no. (one must draw the distinction between inertia, the principle, and inertia, the property)

And then you have the converse of the problem, with one symbol representing different things. [math]\lambda[/math] , for example, can be wavelength, mean free path, decay constant, linear charge density, or eigenvalue (and maybe more)

I assume part of it is the time one wishes to spend dealing with subscripts. Easy to write by hand, but more effort to format on a computer.

This is a science forum. Debate the evidence, lose the anger.

However, the use of "see" does not mean that this is an illusion. Using the same measurement techniques, observers in different frames will measure different values.

Have you stopped beating your wife? Please respond to this easy question. It's not an "easy question" because you have created a false dichotomy. Is energy a physical thing or a consideration? (you've been asked this a number of times. Continued avoidance of addressing this issue will be interpreted as trolling. If you can't answer it, how can one expect and answer to this concerning time?)

This is the misconception we're discussing. If you add energy to an object, you can increase its mass; a hot cup of coffee has slightly more mass than an otherwise identical cold cup. But not if that energy is kinetic energy — KE is frame-dependent. IOW, if I had a sensitive enough scale, I could detect the mass difference in the case of the cup of coffee. But the scale does not change its reading because of relative motion between me and the scale.

In atomic clocks, you place the atoms in a coherent superposition between two states — in standard clocks used today these are hyperfine states (cutting edge devices have started to use optical transitions). What that means is you put half of the atoms in one state, and half remain in the other. The quantum-mechanical state you create — the wave function — oscillates at the frequency characteristic of the energy difference between the states. You can't interpret this classically, and trace it back to physical motion. You just can't. See? Right there, you called time a physical thing. Nobody else is doing that You didn't answer my question before: is energy a physical thing? I think anyone who presents a video of the Bohr atom as support for their position simply can't lecture anyone about "standard scientific knowledge."

Also On the Abuse and Use of Relativistic Mass by Gary Oas http://arxiv.org/abs/physics/0504110 and another article by Lev Okun (specifically section 5: The Virus of Relativistic Mass) http://arxiv.org/abs/hep-ph/0602037