studiot

You might find this book from Cambridge University very interesting https://www.amazon.co.uk/Space-Time-Canto-Classics/dp/1107641683#reader_1107641683 This question (and others) is discussed in some detail by world famous experts. So which of Markus' pearls have we missed?

No I don't this and you previous still post show a preponderance of observer. An observer might go somewhere. The button won't. But I have already given a Mathematical (set theoretic explanation of how it is possible to observe without movement in this case) That is one of the points I wanted to bring out in further discussion. Granularity v continutity.

Wow is it really ? I thought it was just today's maximum forecast temperature for Somerset.

Thank you for your presentation. I note the previous thread referred to was 2010. So +1 for your dedication to the subject. I would like to offer some words of encouragement, but also echo Markus' comment. I have called your OP a presentation since I too am not sure what you want to discuss. Having said that I can't see any connection or need for one to Statistical Mechanics. Stirling Engines belong firmly in the realm of classical thermomechanics IMHO. Theoretically Stirling cycles offer advantages over internal combustion engine cycles in that they form a good meaty area block on indicator diagrams (PV or TS) as opposed to the very thin shapes of say Otto and Diesel cycles. This area, of course, corresponds directly to available work and indirectly to efficiency. Practically they suffer from the fact that simple analyses do not take the variation of specific heat with temperature into account or the conductivity of the working fluid. This makes them less attractive that at first (theoretical) sight. Now for some encouragement. History has shown many gifted practical people who may have been amateurs or professionals who introduced dramatic engineering developments. Examples include, The violin makers of old. The hovercraft (I see the rescue hovercraft was out again on the Severn Mudflats pulling someone out of the quicksand) was invented in a garage using a domestic vacuum cleaner. Last year another mechanical genius invented a super enhancement to refrigerated lorries for save energy. Harrison was a carpenter and thus considered beneath scientific contempt! So press on with your experiments, but please do clarify the point of this thread.

A very good point. How difficult it is to be objective about 'time' as it is so deeply embedded in our every day experiences. +1 Markus has indicated he has some additional thoughts, not yet offered - and so have I. I think some may be similar. I would add to this the notion of coordinate systems which have crept so deeply into our thinking about the world. Most of the argument has been about the nature and application of coordinate systems. This is a point I would like to address further, just as Markus +1 Thank you for making your position so clear so amusingly. +1 I like the play on words. Sadly this also means we must disagree. I don't think this will be a disadvantage to you, since you don't do Mathematics. But I know you think very carefully about things.

I said nothing whatsover to refer to time. I most certainly said nothing about movement. Nor does 'top to bottom' refer in any way to time. It is purely a spatial expression. Why this obsession with an observer? The colour changes in space only and whether it is observed or not. This 'whether it is observed or not' has been recognised by many famous philosophers in the past as important. Their scenario included time and if you transposed your argument to the famous Does a tree fall in the forest, or make a sound if there is noone there to see the fall or hear the sound? You would be forced to accept that the tree did not fall and no sound ensued.

Post your useless but amusing/interesting facts here. For instance Palindromic temperatures : 28o C = 82o F

I wonder, Does Good Philosophy v Bad Philosophy equate to Autobots v Decepticons?

This is a Physics forum. What 'matter' are you referring to that has no relationship to reality ?

Of course there is a suitable experiment that some 'Flatlander' could perform, without time. Any Flatlander angel on a pinhead that inhabited the dividing line would be aware of the difference between both sides of the line. That is fundamental set theory about the difference (that word again) between interior points and boundary points of a set. But yet again. The existence of something (including change from one thing/property value to another) depends upon the property or the things. It is entirely independent of the presence or absence of an observer or even whther or not an observation is made. So that button embodies a change that is independent of time. So let us return to the OP and discuss the OP question What is time ? Not what is not time ? When I entered this thread I thought that a good way to explore the Physics of such a difficult question would be to consider properties of time and whether time itself is a property or a 'thing'.

It is quite unclear from that mixed up paragraph what you mean by change. You say there is a change and then you imply there is only a change if and only if there is an observer. Then in the following short paragraph you deny the need for an observer. Personally I do not need time for a spatial only change. There is no change to the button with time, only with space. The button was multicoloured when it was formed and will remain so until it is destroyed. Face it. The property of colour is quite independent of time and may vary with other qualities.

No I have not read the article you advertised. Are you now telling me that it is different from your opening post ?

I can't imagine why not. You wrote it. Seems very clearly numbered 1 through 7 to me.

Of course. When one charge is positive and and negative the direction will be opposite to the situation when both charges are postive. We denote this by a plus or minus sign. OK gentlemen, so by you definition I would be incorrect to say that the colour changes from top to bottom on this circular button ?

No, no and no. Marcus has already made the point that the change is there whether it is observed or not. He has also introduced a universe with no observers and no time, but I did think it was now accepted that the teacup universe contains change. Activities can only exist in time in a universe that includes time. You have simply declared that my cup and saucer universe does not work. You have most definitely not demonstrated that this is the case. Observations are simply a scientific term for interactions between distince entities. As Markus points out, an interaction cannot occur in a univese with only one occupant. That is why is was necessary to introduce another. In the case of my static universe the interaction will never change, since there is no time. Yet change exists in that universe since each observer can determine the sign of the interaction. So a difference of charge sign will inevitably lead to a particular interaction sign and the existence of any difference is a change.

Are you suggesting that change is the only activity of an observer ? My previous post suggests otherwise. You have also coupled this to a second unproven statement "and observers exist in time."

Yes perhaps my momentum example was flawed, especially since momentum inherently contains time as a 'dimension' in the physics sense. But before the Science of Electrodynamics there was the Science of Electrostatics. So let us indtroduce the saucer to your teacup universe, or let us create new static universe exactly the same apart from now including a saucer. Further let the cup and saucer each have an electrostatic charge. The the cup will observe the saucer and the saucer will observe the cup via the electrostatic interaction. Note there is no need for a physics time dimension in this universe. Electric charge is a fundamental physics dimension in its own right, (although we now use electric current for administrative reasons).

The whole point of my examples is to show that this is not true. But in a light hearted way. Next time I am run over by a bus, I will try (as an intrinsic observer) to determine whether it is just the momentum of the radiator I feel or that of the whole bus.

They are your premises, not mine and you numbered them not I. I merely used your numbering. I don't know, your premise 5 was quite unclear as I have already said. However it is where you first introduce a fundamental field so it must be necessary. So what are the field variables ? It is up to you, as the author, to define them. Please don't tell me you know what General Relativity is, but don't know what a Field is? Both 6 and 7 have mixed unsupported statements with premises. Premise 6, for instance introduces an 'observer'. Any statements of the properties of this observer must fllow by rational deduction from 6 plus the previous 5 premises alone. No other material is allowable. But thank you for replying.

Let us go back to your desert and savannah example and accept that they can or do exist in and through some amount of time, say from 1900 to 2000 in round numbers. That is what I mean by persist do you have a different definition. Now let us take your proposed journey, walking through the desert. I hope you will agree that the desert persists in space as you move from one place to another ? (and yes I agree that in this case it also persists in time) Then you pass from desert to savannah. Do the places you have just walked through cease to persist? Was the savannah not persistent just because you were not walking through it? I look forward to your detailed analysis of the situation as you move through the landcape and from one landscape to another. I am particularly interested in your reason why you consider there is a difference between being in different parts of the desert and being at different times. If you say that you can walk through the desert because different places persist in time, Why can you not say that you can be in different places because the desert persists through space ?

Thanks. +1 I was worried you were proposing that there was no such thing as an entity (either physical or non physical). Hence my offering some example situations (eddies and convexity) where you can extract 'an entity' from the surroundings ie draw an imaginary line round it I am uncomfortable with the suggestion that non physical things are confined to processes, however. Convexity is a static property, not a process.

Well yes there is a non physical relationship between two physical entities, but how does that answer my question ?

More particularly you singled out the physical which is why I asked why you though it made a difference. Does it make any difference to free will, self or consciousness whether they are 'physical' or not?

I guarantee that if the box is not opened for 200 years after the cat is placed in it, said cat will be very dead. Interpretation. Time of cat being definitely dead and motionless + 200 years (very exact) Time of decease uncertainly with very inexact uncertainty of 200 years. Exactly as predicted by both QM and Classical M.

Why does it make a difference whther they are 'physicsl' or 'non-physical', whatever those two terms mean ? Surely non physical things can affect the physical world For instance convexity v concavity eddies.