Severian

I understand what it means. Why don't you?

I agree with this statement. I suspect the reasons for Israel not making this point are political: if they are in a conventional war with Lebanon they would not fall under the US's war on terror remit any more; they would also provoke Lebanon into throwing conventional troops at the war (which Lebanon has not done); finally they would remove any possibility of leaving Lebanon without a regime change, making them responsible for security in the area for years to come.

I hope that was a typo

That's not quite what I meant though. I mean that when two particles interact, in principal one could imagine them getting enough of a kick to go superluminal. This doesn't happen because the momentum conservation is always 4-momentum in the SR sense. (This is why I said that the real objection isn't really the <c bit but the way we add momenta.) This is a slightly different reason though. The endpoints fall at a specific (non-zero) mass value for zero neutrino masses, and the deviation from this provides the neutrino mass squared). However the position of the endpoint is of order a GeV2 (it is a baryonic mass scale since it is beta decay) while the neutrino mass is order (0.01eV)2, so you have to measure the endpoint very accurately. In principle, your error measurements will be gaussian and if the error is large enough you will sometimes get the neutrino deviation going the wrong way, giving a negative mass-squared. In other words it is due to the extreme difficulty in measureing such a small quantity. (Unless of course this is a different experiment which which I am not aware.) I presume you are refering to this (I am not sure you can access this outside a university?) I am not familiar with this paper at all, so wouldn't like to comment. I will print it off and take a look. Yes, that occured to me too. You really need a mechanism for doing the exact opposite of your animation, ie. you need the light from the far away ends getting to you first. That is not entirely fair. HEP has made quite a few predictions which didn't have to be true. For example if SR was wrong would we have been able to correctly measure the W and Z mass and have them agree with the theory? (The theory which assumes SR would have predicted the same ratio, but I don't think the assumption of SR in the data taking would necessarily have agreed.) In SR it is both, but the second property doesn't require it to be universal - only the ordering of different times has to remain the same. If I think about my derivation of time dilation in my lectures to first year undergrads I can see exactly why this is. In the thought experiment one measures distance by firing a laser from the observer to the object and recording how long it takes. Clearly this parallels sonar. This bit I am not so convinced about because the reason SR somes about is because of the assumption of universality of c in all frames. I suspect you will have to change your light/sound speed for the different frame and thus get a different answer. I haven't done the (non SR) calculation either though...

Why not try it and find out?

The inability of the Standard Model to predict the masses of the fundamental particles is a failure - or at least shows that it is incomplete. I know of no model which can predict them though, so I have nothing to replace it with. However, the Standard Model does tell us what mass is and why it exists, and even gives us a cause for mass - it is an interaction of the fundamental particles with the vacuum. Why should I do it in non-mathematical terms? That is like refusing to pay your tax bill unless the government can explain your tax bill without using numbers. The fact of the matter is that some particles have zero charge because they are trivial representations of the symmetry group U(1) - does that count as mathematical? It probably does, but your inability to understand what it means does not make it wrong. Why is it wrong? It fits the data.

Although I take you point, this is a wee bit bogus though because the bat can (I presume?) also hear sounds which something else emits. So a bat would still hear a supersonic jet passing overhead - it just cannot use its sonar to detect it. We don't emit the light we use to see so we are phenomenologically very different from a bat.

One of the favourite ones these days is allowing only gravity to exist in the extra dimensions (the 'bulk') while contraining the other three forces to work in the the normal dimensions (the 'brane'). Ajb presumably knows more about that than i do...

The paralels to the build up of WWII are ill advised in my opinion. After all, the people invading other countries this time are the US, UK and Israel.

If your theory could predict the masses and charges then it would be more predictive, so more desirable. Note that we do understand (on some level) why some particles have zero charge and how some zero charge particles convert to two opposite charge particles. This is part of the Standard Model.

Well. if you take the light in one side of the cloth and channel it out the other side, then it is still going to be reflected by the person's body and come right back at you. To do what you are suggesting one would need for the cloth to know exactly which bit of the cloak is on the other side of the person's body, channel the light to that part of the cloak and fire it out in exactly the same direction...

That wouldn't be very useful since only the cloak would be invisible - not what was inside. (It would be nice for fashion in cold climates though.)

I would have thought your favourite animal would be a snail? (I quite like snails myself, especially with a little garlic.)

Beef, Medium-rare.

But the objects would need to be completely identical. These are not.

I find that hard to believe. I am not a millionaire and I have been on plenty yachts.

Do you have any details about what his anti-semitic comments were? the only bit in the article is: It would be useful to know what he actually said which is causing all this fuss. I presume there was more than this.

This is a fairly well known phenomenon for the sound emitted by supersonic aircraft.

The real reason is rather simple. Quantum mechanics contains objects which don't commute. By that I mean [math]xy \neq yx[/math]. Clearly x and y cannot be ordinary numbers since ordinary numbers do commute. The simplist mathematical objects which don't commute are matrices, so we use them to describe these objects. I should point out that the matrices are just 'representations' of the quantum mechanical 'operators'. They are not really the operators themselves. If we could come up with some other mathematical object which had the same property we could use that too.

Dan Brown wouldn't know a good riddle if it jumped out from behind the bushes dressed as a ballerina and punched him on the nose.

His apology seems quite sincere: "After drinking alcohol on Thursday night, I did a number of things that were very wrong and for which I am ashamed. I drove a car when I should not have, and was stopped by the LA County Sheriffs. The arresting officer was just doing his job and I feel fortunate that I was apprehended before I caused injury to any other person. I acted like a person completely out of control when I was arrested, and said things that I do not believe to be true and which are despicable. I am deeply ashamed of everything I said. Also, I take this opportunity to apologize to the deputies involved for my belligerent behavior. They have always been there for me in my community and indeed probably saved me from myself. I disgraced myself and my family with my behavior and for that I am truly sorry. I have battled with the disease of alcoholism for all of my adult life and profoundly regret my horrific relapse. I apologize for any behavior unbecoming of me in my inebriated state and have already taken necessary steps to ensure my return to health." He should still get the book thrown at him for drink driving though.