studiot

From a thermodynamic point of view per Caratheodory's version of the Second Law is appropriate. "Not all states are accessible, from a given state." (the shortened version) From a QM point of view there are electron orbital (bound) state transitions that are inaccessible. These are known as 'forbidden transitions'

The terms real and reality ; exist and existence can be thought of as ill defined. Instead of asking if something is 'real' can you offer me something that is not 'real'. How would I test this ? Can something which is not 'real' affect some things that are 'real' in any way ? Is Harry Potter Real ? Harry Potter has certainly affected millions of 'real' people. This, I would suggest, is the real reason behind why Science shies away from such terms (pun intended)

Let us do this a little bit at a time. Then it might 'click' for you. Did you understand lines 1, 2, and 3 above ? In particular did you understand how you get from line 2 to line 3 ?

If the entire cell was at absolute zero then every electron would be in its lowest or ground state, by the definition of absolute zero. So any change to even the state of a single electron would involve raising the temperature above absolute zero, something you have forbidden.

That's a cheap trick. I didn't say 'all' and I didn't imply they would say exactly the same thing, I stated that the circumstances would have to be exactly the same The aims of scientists at all times and in all places is to too wide ranging and multipartite to be a useful measure of anything. All to often I find Philosophical discussion lacking because it tries to tar too many monkeys with one brush and ends up with a paradox.

Yes different scientists often express apparently different views, but ask them both (all) to comment on exactly the same circumstances and they will most likely say the same thing. That 'thing' may be later found to be incorrect and Science as a whole will incorporate the new knowledge and no one would then support a contradictory view. For example there was general concensus that life could not exist and develop around the deep ocean geothermal vents, yet no one would deny that possibility today.

Wouldn't that be off topic anyway ? These are a particularly poignant example because they are endowed with mass. This 'type' of mass is called effective mass in this case and is a sort of inertial mass. And of course you can't really discuss gravitation without gravitational mass. It is one of those mysteries that Science has not managed to answer How does gravitational mass come to accord exactly with inertial mass.

Not sure this is relevant, but what about wave/particle duality. Your appeal to logic should be replaced by an appeal to rational thinking, which has much wider applicability. For example my red post box. The box is red because the enamel coat reflects incident red light and absorbs the rest. So when illuminated by a light source that includes red light the box appears red otherwise it does not reflect any light and so appears black. Normally light sources such as the Sun or car headlights include red light so showing the box as red. Sodium street lights do not contain red, they contain only a particular shade of yellow. So illumination by a sodium street light will show the box as black. Yes I agree that the two theories have underlying compatibilities, but so what if what you actually want to do is navigate to Australia? Navigators choose the geocentric theory as the most convenient for calculation, although they know it to contain a false premise. But there are other possibilities for two theories. The more complicated theory may actually reduce to the simpler one in certain circumstances, which is the case with GR and Newton. In the case of statics (my dam for instance) GR and Newton are identical.

A large number yes, but enough to cover the entire spectrum as claimed ? I agree there are many real world constraints on the process of conversion of the energy of photons to electron current and have nothing realy to add to your great job describing these.

What on Earth do you mean by that ? Surely you are not proposing a periodic table with infinitely many different elements ?

No I have not come across this one. Is it online and do you have a reference ? I do agree that studying the History and of Science and the Philosophy of Science can help understand the subject of Science itself, particularly looking at 'what was known at a particular time/stage and what thinking did it lead to' . Some Scientists (eg Millikan) , some Science Historians (eg Sarah Dry) and Some Philosophers (eg Berkson) and some Mathematicians (eg John Derbyshire) have been able to write briiliant expositions looking at these particular parameters. Were you going to respond to my previous post ? Edit, I just noticed that you provided a link to a rather expensive commercial site that seems more interested in making money than disseminating Science.

Can I just tell you something before I reply ? The use of the @ symbol on this site, in front of the member name, works to provide a notification to that member of a reply. But you have to do it correctly. Type the @symbol. Then start typing the member name. (case is important here) The site will offer a drop down box with suggested members that is adjusted as you type more letters. Select the appropriate member. The result will look like this @Davy_Jones But if you use the quote function from their post the member will also be notified. Hope this helps Now to your question. Thank you for the reply. That's cool and I have a better idea of where you are coming from. You also seem to be more au fairt with Philosophy authors or scientists discussing the philosophy of science. As such have you heard of Berkson ? He has written a philosophical book on this subject Berkson : Fields of Force : Routledge. My own answer is that that 'It depends upon the circumstances'. Consider a standard red post box such as you will find all over the UK. This one is situated under a street lamp with a sodium bulb. What colour is it ? Answer, it depends upon circumstances. In the day it is red, in the night it is black. For your question about gravity, there are many more circumstance. It depends upon scale and distance amongst other things. For instance if you wished to consider the structural mechanics of a dam, Newtonian force analysis is 100% accurate, whilst GR will not help you one bit. So in those circumstances gravity is a distributed force. In the circumstances controlling the motion of the planet Mercury, Newtonian force analysis is less than 100% accurate, whilst the GR view is nearly so, to the limits of our measurement capability. Does this move the discussion forward ?

I am going to take you up on this because, as ever, things are more complicated than this over exaggerated popsci ideal. Yes theories must match any observations in their domain of applicability but, There are situations (theories) where we have learned to make a transformation of a difficult problem to an easier one, solve the easier one and make a reverse transformation back to the original. These techniques (theories) can be be very successful and as accurate as required. It is often stated in popsci that relativity is the most tested theory or QM is the most tested theory. Again this is an exaggeration. The theories I am referring to have never been know to fail, yet they premise upon which they are founded is known to be imaginary. I refer to such techniques as Virtual Work, Maxwells Mesh Method, the theory of logarithms, and many more. Thank you for your response I did not ask you to answer this question You asked specifically and I responded specifically to this request with a request for clarification to avoid discussion at cross purposes, which most of this thread has been. Note I did not ask you to define a force or state what a force is. But I did offer reasons for my quandrary because you had already pointed out that different scientists, in different situations, use the term force in different ways. This is a fair and reasonable observation that deserves proper discussion. So I just wanted to get us on the same page as to the sort of force we were talking about. I was also trying to acceed to your request about using layman's terms, since laymen are even more hazy about forces than scientists.

Well if this really is the long goodbye, perhaps you will at least try to answer questions from your next victims.

That's an interesting point of view, How does it play out with p, d, f orbitals where the max probabilities are more remote from the centre ?

Yes you understand that physics correctly, but things are a bit weirder than you have presented since what you have said is incomplete. Let us call the Earth E, the Traveller T and the Star S. So there is a relative speed between T and S of 0.8c. Which means that they are not in the same frame. So we must convert the 3Ly separation to one frame or the other the T frame or the S frame, it does not matter which. This will give us the 'proper distance' between T and S. The proper distance Lo is always longer than the measured distance between moving objects and is the same in all frames. So we use the formula [math]L = {L_0}\sqrt {1 - \frac{{{v^2}}}{{{c^2}}}} [/math] Substituting the given data [math]3 = {L_0}\sqrt {1 - \frac{{{{\left( {0.8c} \right)}^2}}}{{{c^2}}}} = {L_0}\sqrt {1 - 0.64} = {L_0}\sqrt {0.36} = 0.6{L_0}[/math] [math]{L_0} = \frac{3}{{0.6}} = 5[/math] light-years This is what I mean by your original statement was incomplete. (no criticism intended I am being detailed in order to help) Because you originally stated that S is 5 Ly from Earth. Since this is the 'proper distance' it must already be corrected for any motion between E and S, which you have omitted to say. It is possible, though not generally the case, the S will not be also moving relative to E. Just to add that when you start to combine the effects of two relative velocities the calculation becomes more involved. You can't simply add them up. Note here that it does not matter whether T is travelling towards S or away from it, but T must just be passing E when the measurement is made.

One of the issues we faced is that new wiring, even if extending or replacing existing, has to be to the new colour code. This is all fine and dandy if all the wiring is new but it also means you can have dirty brown connecting onto red, blue connecting onto black and green/yellow connecting on to green. Not ideal.

Yes there were accidents due to red green colour blindness mixing up the earth and the line. +1 for the colour blindness issue. The opportunity was taken to harmonise with the european dirty blue and dirty red/brown when the first change was made. Pity because it had to be changed again when yellow stripes were added to earth. Of course the American colour convention is quite different, as is their wiring layout.

And you are clearly not a trained diver. The carbon dioxide reflex will happen despite a functioning brain, as every diver is taught to control.

It's what you do every night. 🙂 It is interesting to note that in a Newtonian analysis centrifugal force is not a force. But in a D'Alembertian analysis of the same situation, it is.

What do you mean by 'occurs' ? Are you asking if there are any primitive organisms/lifeforms that have a rudimentary nervous system but no brain ? I don't know the answer to this, perhaps a biology special;ist can answer it. But Galvani started investigating this hundreds of years ago. Or are you asking if a more complex organism can be kept alive after its brain has stopped functioning ? Well 'brain death' is one reason for doctors switching off life support systems on patients whose bodies still have living functionality, including neuro(sub)systems that still function.

I like the idea of fundamental interactions, as opposed to fundamental forces. +1 Davy specifically asked about forces so it would be a better idea to find out what we mean by a force before throwing it out, lest we throw the dog out in mistake for the cat.

I already did and you didn't answer. You also ran away from my comment about religion.

It is a question of speed. The electrons in an ordinary vacuum tube are not moving fast enough to warrant more advanced mechanics such as relativistic dynamics. Sub atomic particles in particle accelerators, and natural particles cosmic rays in nature achieve speeds such that relativistic calculations need to be employed. For most normal interactions the electrons 'orbiting' the nucleus in atoms are not moving fast enough for relativistic calculations to be needed. So the Schrodinger theory of wave mechanics uses classical (newtonian) evaluations of the dynamics. There is a more advanced theory making relativistic corrections due to Dirac.

Before offering any discussion I would be interested to learn what you understand by a 'Force' ? I ask this because your question is clear cut black and white yet most things in Nature become more complicated than that when we enquire more deeply into them, often much more complicated. Forces and how they operate, what other physical quantities they affect or need and so on fall into the category of being much more complicated. Even when considered in a newtonian manner, gravity operates differently from say electromagnetism, although there are similarieties as well.