studiot

Yes the correct way is in writing. I'm Old Fashioned in that I believe that important matters (like this) should be on paper not by Email. It's easy to claim an Email was never received, but you can't claim you didn't reveive a letter when the other party has proof of posting/delivery. But remember what ajb said "A nice letter". I would add nice = polite and businesslike. Short, not rambling. Get someone to check the English and spelling.

So do I take it that you propose your aether to be in some sense outside Spacetime?

Well, luke you have said what your aether is not. Please explain exactly what you propose it to be. That is what properties does have, defining equations, laws, rules of the road and whatnot.

Do I see Rylands embracing Fletcher or Carlill endorsing the Carbolic Smoke Ball or Kramer kissing Kramer As this is the season of goodwill?

I'm bored out of my tiny mind with the double slit. Can't we do something else for Christmas?

Are you sure someone didn't say the factor was 80, not 8? I make it 81 using a simple straightforward ratio. Please note that T means either temperature or temperature difference, but not both. Edit I see you read the question properly whilst I was working it out and posted more in your post#3.

It's called Stephan's Law. http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law or since Wiki makes a meal of it http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan.html

Good morning tar. Your question is a bit woolly, but a good one. No there is no general size limit. But thast does not mean we do not have to take it into account. As Ophiolite says it depends in part on the equation But also in part on the size and nature of the system. We often have to consider the spread of the activity through the system. Many good practical examples come from earth sciences since the Earth is very large relative to individual particles. Earthquakes start locally and eventually affect all parts. Oceanographers have a term called ocean mixing or flushing times. It is possible for one one of a bar of rock to be molten,but the other end to be liquid, at the same time because of heat transference rates. Children know this phenomenon in relation to ice lollys. I was once involved in modelling what happens to pressure in gas pipeline networks thousands of miles remote from a breach. In all cases the equations themselves do not depend upon scale, but some parts of the network remain unaffected for considerable periods. There is even a branch of mathematics dealing with size independence, to whit fractals.

Did you not find the hyperphysics explanation I linked to in post#8 helpful in illuminating this?

Thank you for trying to intercede, helpfully. But, as has already been pointed out, the specified existence of boundary conditions requires boundaries.

The airfoil, as with any material object, starts to fall the instant the force keeping it up there is removed. There is no honeymoon period before Newton and gravity kick in. Rockets work on an entirely different principle, which is how and why they will work in space, where airfoils will not. Probably, but not necessarily. I can think of several situations where this does not happen. For some objects yes certainly, but not for all such objects. In particular balloons do not meet this requirement. It also depends what you mean by 'weight'. Yes but again it also depends what you mean by 'weight'. That is a meaningless question since you haven't stated what 'pressures' you are talking about. Since you invoke Bernoulli and pressure, we could argue all night where you say the 'pressure' decreases and I say it increases simply because we are talking about different Bernoulli pressures. If you truly understand bernoulli, you will understand what I am referring to. The problem has never lacked clarity for me, but I think you are beginning to confuse yourself again, through lack of detailed knowledge I exhort you to aquire. I have already indicated that I am not prepared to suspend the laws of Physics for anyones' convenience. I is a shame if you choose not to aquire the knowledge necessary to provide satisfactory answers to your questions, but you must follow the laws of Physics, like everyone else.

Voodoo This is a thought experiment, remember. Or formally she sees all distances measured in the direction of relative motion as contracted by the Lorenz contraction. http://en.wikipedia.org/wiki/Length_contraction

If speeds are sufficinet then you need to make allowance for length contraction. The space ship is travelling at approx 0.9c directly towards the distant star. So the relative velocity is 0.9c So distance in that direction is subject to the Lorenz contraction, as measured by the traveller. An observer sitting warming his bum on the star can be considered 'at rest' as he watches the traveller approach so he will measure time dilation. The is then the same situation as the extended life of the muon as it approaches Earth. http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/muon.html

Ego has nothing to do with it. Gauss' Law does no such thing, for every conceivable volume. Nor is this about feeling. It is strictly about science. I have never seen a geometric sphere with corners. Can you show me one? Anyone looking at my drawing will see a dashed square, clearly labelled 'section'. This section can only be part of a 3 dimensional volume. Equally the only place where a field is shown in my sketch is within that volume. You claimed, and I asked you to demonstrate, that you can deduce the charges that produce that specified field, from the field alone. If you were unclear about anything in the sketch the proper course of action was to ask for an explanation - I would have been happy to oblige.

I'm sorry Robin, there can be no other explanation. You must work for British Rail! Points failure due to icing : 'The 'Wrong kind of snow' Trains running slow : 'Wrong kind of leaves' Water in signal box : 'Wrong kind of rain' and now, ................wait for it..............., the 'Wrong kind of change' Wow.

Exactly. There is another kind of change that does not involve time. Ergo you can have change without time. There is nothing more to be said.

I'm sorry. how did this add value to the discussion? Here is a field plot. Prove the charge distribution to be unique. I apologise in advance if you have more sophisticated drawing facilities than I do.

David, I like it. +1 Short and logically coherent. A clear simple example of change without time, I didn't think of. I have been wondering about the word 'abstraction' since it was introduced here. Thanks. One question: Nnouns can be 'concrete' or 'abstract'. Abstract (the adjective) in this sense has a more restricted meaning than in abstraction (the noun), which can be 'abstract' as we are using it or concrete as in the syrup which is an abstraction from sugar cane. What do you think?

The links are unavailable. Can you post the equations?

Robin, I said that change and time are different and that you can have one without the other (both ways). I also posted some examples somehwere in the depths of this or another long thread, I will try to look them out for you, but it will take me some time. Note that there is a difference between saying that some changes could still occur without time, and that time is not involved since time does exist so actual changes may occur over time. I would certainly grant that the majority of change needs different times for the two states involved in a change to occur.

Click on your user name in the top right of the screen. Choose 'Settings' from the drop down box' Choose 'Notifications' from the list on the left hand side (second from bottom in list). It is a good idea to monitor all the threads you start since folks will start to ignore you if you don't acknowledge their input as in this thread http://www.scienceforums.net/topic/86967-is-the-charge-distribution-for-an-electric-field-unique/ You have asked quite a few interesting and disparate questions over a wide range of topics in a short space of time. Might I ask where they are all coming from? And where the answers are all going to?

Better thought of as Force = mass x acceleration but acceleration = rate of change of velocity so Force = mass x rate of change of velocity = rate of change of {mass x velocity} (since mass does not change) and mass x velocity = momentum So Force = rate of change of momentum. It is the changing momentum that generates the force. They are simultaneous and the force is applied for as long (or as short) as the momentum is changing. Can you complete your question, now?

If you substitute the equation of the linear regression line into the defining formula for the coefficient of determination and play with the algebra for about a page you arrive at the definition formula for the coefficient of correlation.

I think I posited that you can have change without time so perhaps I ought to provide some examples. Any system that has multivalued outputs (so hated by mathematicians) such as step functions, parallel computing, quantum distributions which can be in more than one state at the same time. The change is clearly embodied in the selection process to obtain a particular output.

The answer is still No, even if the OP thinks he wishes to consider only the charges within the region since it is entirely possible to have zero charges within the region and the entire field and boundary conditions produced by an external charge distribution, even if there is an 'internal' charge distribution that could produce the specified conditions.