DrRocket

You have stated no "on the other hand". The second (compound)statement is a restatement of first statement followed by a statement of the contrapositive.

All the above represent excellent counsel. Journals are in business to provide high-quality professional communications for professional researchers on the cutting edge in their field. In order to be of value to the discipline and of interest to the intended audience articles must represent valid, significant, original contributions to the knowledge base of the discipline. That is a high standard. It is intended to be a high standard. Valid: Your article must present results that are verifiable by others and have been verified by you according to the highest standards of your discipline. If the work is experimental you must present information that will convince the reader that the data is accurate and represents what you claim to represent to represent. If the work is theoretical it must contain full mathematical detail and reasoning. Original: Your paper must present something previously unknown to the community. In other words it must be a discovery. Significant: The results must be of real interest to the research community. That entails addressing issues that are recognized as being of importance by that community and that will be of use by others in producing new research in the future. Many papers are rejected for publication simply because they are not sufficiently significant to warrant publication -- journals have lots of submittals and limited pages. The standards are a mirror of what is required for a PhD dissertation. So ask yourself if what you have to say would warrant the award of a PhD degree.

Thanks for the heads up telling me that he had replied. I have provided what I hope will be the last reply to him. This is getting silly. Any respect that I might have harbored for Brian Cox in some deep recess has evaporated. He inserted his foot in his mouth, proceeded to nibble on his knee cap and is rapidly approaching his hip. For future reference: That particular blog entry is rapidly falling to the bottom of the pile and becoming a bit difficult to find. For purposes of easier access here is the llink http://blogs.science...1#comment-82145

The gaussian is integrable in closed form from -infinity to + infinity (using polar coordinates and a "trick") but there is in general no closed form expression for the integral of a gaussian over a finite interval. You are stuck with numerical approximations or,what is equivalent, with tables.

I'm guessing that I know EXACTLY how I and a lot others would respond in such a situation. I doubt that we would be immediately looking for someone else to come in an clean up the mess. I'm also guessing that my country's government also knows how they would be greeted in that situation, and that is one reason that the situation is unlikely to ever exist. A citizen army and a determined population can and does keep governments in check. The last government to get confused about who is really in control in my country was thrown out. They learned a lesson, and Britain is now also a democracy.

I strongly doubt that even you know what you meant.

Except, perhaps, if you call yourself Brian Cox. In general if you have a question and need a definitive answer: If it is about science, ask a scientist. If it is about engineering, ask an engineer. If it is about accounting, ask an accountant. If it is about cooking, ask a cook. If it is about philosopy, ............................... you are screwed

Wald -- Quantum Field Theory on Surved Spacetime and Black Hole Thermodynamics Best of luck to the OP.

A B A-->B T T T T F F F F T F T T

This will get out of hand and people will be talking past one another unless there is agreement on what one means by a "Faraday cage". There is the ideal Faraday cage of adademic classes on electromagnetism. There is also the much less ideal Faraday cage as used in engineering applications -- complete with non-ideal conductors, penetrations and imperfect seals.

In a nutshell that says that when one considers as the total quantum system two atoms that the Pauli exclusion principlle applies to the system as a whole and not just to each atom individually, but that when the interaction is weak, the splitting is small. This is based on elementary, non-relativistic quantum mechanics and the Schrodinger equation. Yep. That is pretty obvious. But that has absolutely nothing whatever to do with an assertion that heating up the atoms in some material instantaneously affects every atom in the universe. Brian Cox's subsequent, lame, attempt (in comments at the blog) to justify nonsense by invoking EPR phenomena and quantum entanglement, merely demonstrates that he is desperately trying to shohw that through some twist of logic that he is "right". In short the rock star is more concerned about his image than truth. He has inserted his foot in his mouth and cannot get it out. At the moment he appears to be chewing on his knee cap. An position of integrity would be for him to simply admit that he made some unfounded statements and retract them. But his ego will not let him do that. Hoist by his own petard.

A topological space is Hausdorff if given any two distinct point x andy there exist neighborhoods of x and y that are disjoint. My guess is thatt he book is probably an introductory point set topology book. A book like that is not an "advanced calculus" text, and does not require calculus as a pre-requisite, but it does require a level of mathematical maturity and familiarity with constructing proofs that is beyond what one normally expects of a student in an advanced calculus class.

The Principia is a tour de force that is a monument to the genius of Newton. It is also nearly unreadable and is probably the very worst place one could go for an understanding of calculus. A great deal of understanding of the foundations of mathematics has emerged since calculus originated in the minds of Newton and Leibniz. Modern formulations and explanations are more elegant, more easily understood and far deeper than what was available in 1687.

It would be best to drop this.

This guy can slap you so quickly that you even know what happened. http://en.wikipedia....Takayuki_Mikami And this guy was even faster. http://en.wikipedia....etaka_Nishiyama And Mikami taught this guy, who damn near broke my arm after I punched through his block in an exercise. Any one of them could give you a slap that you would definitely notice.

On a good day, 15 years or so ago, it cost a minimum of $3000/ lb to put a payload into low earth orbit. Double that to get away from the immediate gravity well of the earth. It has not gotten one bit cheaper since then. Now, how many million tons of waste do you wish to send to the sun ?

I suspect that the origin of this question involves the notion of relativistic mass which in general is greater than the rest mass. That is a relativistic effect. The relativistic theory of gravity is general relativity. In general relativity, what we call gravity is the effect of curvature of spacetime, and that curvature is determined by the stress-energy tensor. The stress-energy tensor does indeed include mass/energy and hence relativistic mass. Therefore one might naively expect that relative motion might result in a stronger gravitational effect, but that naive expectation is incorrect. The stress-energy tensor and the Einstein curvature tensor are, obviously, tensors. In particular that means that, while the expression in specific coordinates is dependent on the observer, the actual tensor quantity itself is not. Tensors are invariants. Thus curvature and the attendant gravitation are not dependent on the observer or on any relative motion. The individual components depend on the observer, but, as with the matrix expression of a linear transformation in terms of different basis vectors, the underlying function is independent of that expression. You cannot, for instance, cause a body to form a black hole simply by choosing a reference frame in which it has sufficiently high velocity. Being a black hole is a physical event, and events are invariant.

Don't you know ?

One of the possible models for space (not spacetime) in cosmological theories based on general relativity is a 3-sphere. Absolutely no one knows if that is actually the case or not. If it is the case, the sphere is extremely large.

Shannon had no concept of "informational energy". He did develop the important concept of entropy in the context of information theory and that concept mirrors the definition of entropy from statistical mechanics. This is physics forum and only the definitions of energy that are pertinent to physics are germane to this discussion. Metaphysics is completely irrelevant, and largely useless. See elfmotat's link to a discussion of energy by Richard Feynman. It is quite clear. No anger. But I would have hoped for much greater understanding of science and sentence construction by the time that someone reaches your age and level of schooling.

Too bad about that gravity thing. The description of the flow of gas due to a pressure differential does not ordinarily take gravitation into consideration, because in most practical situations the effect is negligible. But in your decidedly impractical/impossible scenarios it is quite a significant factor. Ever wonder why our atmosphere (about 14.7 psi at sea level) does not simply vanish into space ? --- gravity.

Hoover

You take too much on faith. I have yet to see a science forum in which staff and "experts" are not a mix that runs the full gamut from knowledgeable to nearly clueless. Check everyone. Check even more diligently when the source or the subject is new to you. I have seen millions of dollars lost, and failed missions, because people believed "experts".

1.. As swansont said, many stainless steels are non-magnetic. Be sure that what you are trying to attract is ferromagnetic. Test it with a permanent magnet. 2. Your electromagnetic will work a bit better if it has a magnetic core than if you merely have a solenoidal coil. Try inserting a carbon steel bolt or rod in the center, or just wind your coil around it. 3. You may be having a problem with resistive heating of your coil, reducing current draw from your battery. The strength of the magnetic field is dependent on two things -- the amperage of the current and then number of turns in the coil. You might try wiinding many more turns, which would provide a stronger field for the same current draw or less current draw for the same field or a combination of the two effects. Alternately you might use a larger battery, but beware of overheating and melting your coil. 3.. Two inches is a significant distance for a small magnet, particularly if the target is at all massive. 4. You can also use AC to power your electromagnet. A small transformer of the sort used to control model trains would be ideal and let you control the current somewhat. If you have many turns on the coil (and you should) inductive impedance will help to limit current draw.