geordief

I will as soon a I can find it. The poster may remember it better than myself (maybe not as it was an "aside" I think) but it may save me time trying to track it down myself if he is able to jog my memory. That said I will have a go now and give myself a space to try and find it (it is sometimes easier once you actually make an effort) It was not this forum by the way.

I remember who it was but it is a little difficult to track down the post as it was in the nature of an "aside" and search terms are not immediately apparent to me. Actually I have pm'd the poster now and perhaps he will be able to tell me if I have interpreted his post correctly or even remember it (it goes back a good few months if not more like a year) Perhaps I should wait for an answer from him so as not to "put any words in his mouth".

Can I go a little off topic? I have heard (if I recall correctly) that the effects of "gravity" can be derived simply using Special Relativity. If that is so , can Minkowski Space-time diagrams be roped in to illustrate how objects move in the vicinity of mass and energy?

Do you mean me personally or "you" in the sense of "one" ? I am not qualified to define it myself as I am struggling to understand the concept at the outset (I am reading about intrinsic curvature at the moment to perhaps give you an idea of where I am in this regard) If you mean in the sense of "one" ,does that imply the phrase can be used to mean different things ,perhaps depending on the context?

I feel that this is a fairly common expression but what does it actually mean? If I write the phrase "The surface of spacetime" what does it describe? As far as I have been able to understand ,spacetime is a mathematical construct and consequently am I right to think that "the surface of spacetime" is also a mathematical construct and not a physical object as such? Is it a region where things happen? Is the event horizon of a BH such a region? Are there other examples? I think I have been told that you can make a surface mathematically in spacetime by holding one of the variables constant. Would this be right?

Thanks , that seems important to me .

Sorry if I sound hypothetical (and thick) but are you saying that the effects of relativity are not consequent on the speed of light being constant regardless of the inertial frame of reference? Suppose the MM experiment had given the expected results would we have had (a different version of) SR and GR anyway?

Thanks , that is great fun but I am not trying to understand time dilation per se. It is the particular assertion in the video shown on the OP that interests me as I have mulled over this possibility many times in the past and this is the first time I have come across this assertion. It boils down (I think) to that (in the body at any rate according to him) there are processes ongoing that run at the speed of light. Now I know atoms do not move at the speed of light but if there is any physical process in the body (or any other physical environment) that depends on the speed of light for it to function I would "bank" that information and ,as they say it would be "food for (my) thought" So ,is it yes or no? Is the speed of light absolutely inbuilt into all physical processes ? If we could create an em radiation free region of the universe would that region just "cease to exist" ? Is such a "region" totally impossible

Is the explanation in the video correct when it says that the bodily processes proceed at the speed of light ? This is a quote from the video. (around 5 min 36 seconds) "....so for any bodily activity to occur on earth the photons in your body have to travel a certain very tiny distance....." Is that rigorously true? If so I think I would find it very helpful. I think it would actually be even more helpful if that "finding" can be generalised to all matter (not just living matter).

Religious beliefs and practices may not be easily defined. It is not my thread. I doubt the OP will scold you for being OT even if he thought you were.

I don't see the link between the practice of individual making (rewarded) successful guesses and the formation of doctrines (presumably shared by the group). Isn't that where group behaviour becomes important? Any group behaviour at all is better (in evolutionary terms) than behaviour based on the individual (if that is even possible at that stage of human existence)

If (as seems indisputable) social cohesion gave an evolutionary advantage then ,if religious beliefs and practices can be linked to improved social cohesion (and there were not alternative ,competing methods of fueling social cohesion then the case for religious practices providing an evolutionary advantage would be very strong. Can that link be made? Is Phi's speculation about imagination a separate issue ?(kind of like the distinction between superstition and organized religion)

It is a good question. Why did social groups with "religious" beliefs prevail over groups where these beliefs were less formed? I feel it may be connected to warfare and conflict.. It is always the case in conflict that a leader is required to focus energy in times of emergencies. Religion allows potential leaders to showcase their qualities . If they pass the test of devotion to these imaginary folk then their other qualities may also become apparent. It is also a respectable reason to dispense with their services and pass the baton to a new leader (ritual murders of chieftains have been discovered in Europe). Religion and warfare seem intertwined. In our (mine at any rate) distaste for religious beliefs we should not overlook the system of resolving issues by armed conflict we are still wedded to and which is surely a far more pressing "problem".

To say that logic is an extract of the physical world may be true but it is also true to say that it is part of the physical world. Is the relationship a hierarchical one? Logic ,as a phenomenon only arises when the world is structured in such a way as to allow it to (attempt to) "look back at itself" but is it wrong (almost hybris) to posit that logic is foundation of the universe per se? (allowing us to imagine an entirely anarchic universe in theory) In passing, those happen to be the opening words of the Bible ("In the beginning was the word (=Logos in Greek) )... I didn't follow your heavy objects/light objects example , but doesn't logic always (by "definition" ) get the right answer eventually? Doesn't it just mirror the "outside" world albeit in a convoluted ,roundabout manner?

A pity I have to excuse myself from my own thread as I am not familiar with stress tensors (I have heard of them). There are likely to be other examples that might also go over my head.

Interesting,does your answer hinge on the close (identical?) connection between our thought processes and "logic" ? My lazy assumption that logic might be "free standing" may have led me to overlook an obvious connection between time and logic ?

Perhaps a poor question but I would be interested in any answer. There is some debate as to whether there really is any direction to Time (whether the universe could run backwards just as well in theory) Without being competent too address that point, can I bring up what I think may be a similar situation - the way a logical sequence is ordered in the mind (and on paper). We have mathematical proofs as one type of example among many: we start with an axiom ( a starting point) and build incrementally until we have constructed (in this case) a hopefully self consistent edifice. This can (I think) only be done in one direction : we cannot start with the conclusion and work back to the axiom. So my question is really (as I say ,perhaps an unsubstantial one) :is there any lesson that can be drawn from these two sets of circumstances where things only work in one direction and never in reverse? Is there a connection between them? Maybe none? Perhaps to simplify the question ,is (the direction of)Time and (the direction of) Logic connected? ps : I put this in "Other Sciences" . Hope that works.

Claims sturgeon?

This would/could have occurred by accident at first? At what stage could this have become "conscious" behaviour? Can we /do we need to talk about wolves' behavior being "conscious" as opposed to "unconscious" (Can we replace "directly" with "consciously" in your quote? ) I am fairly sure that dolphins co-operate with fishermen in this corralling way in S. America to this day.

If wolves came to human habitation areas they would "scrap" with each other over available leftovers. The humans would try to repel them. Some of them may have been individually (or as a group) recognized by the humans and relatively** tolerated (rewarded?) if they kept other (more "vicious") ones at bay . Eventually they were given a job? **less actively confronted by the humans as the lesser of two evils. PS did humans ever hunt wolves?

Thanks,all. I have bitten off more than I can chew and so need to bow out/extricate myself but perhaps I have learned that it is not necessary to pin down this subject in a scientific way to understand a valuable amount. (I think my own aim in trying to find the "evolutionary " origin of this aspect of our lives may have been ,perhaps disingenuously as much to understand the process as its emergence) @Gee: maybe emotions are also connected to memory? Isn't that indicated in the opening line of Proust's famous work ?-the smell of the biscuit that brought him back in time. And also book reading is supposedly more efficient than digital reading on account of its tactile nature.

It is a hopeless task (in my eyes) to attempt any rigorous definition of what "art" is. Perhaps ,to digress it could almost be defined in that way -as something "undefinable" But is it a hopeless task to speculate as to what may have given rise originally to what we might now recognize as an artistic action? This is ,perhaps necessarily a thought experiment but if we go back ,in our mind's eye to the dawn of life to the period where organisms and later our closer evolutionary relatives were starting to communicate with each other can we imagine what these primal communications might have been like? I suggest as far fetched as this might seem ,it could be worthwhile owing to the extremely important place "art" holds in our present society. So this is my attempt to flesh out this speculation a bit. Let us imagine the leader in a human tribe has validated his "might is right" prerogative and had his way with one of the desirable females and further suppose that this female had previously been having relations with another less important male member of the tribe . This male member has been "robbed" of a "possession" (and perhaps a comfort) and there is a new situation in which his self image has perhaps been degraded. Now this male member must share this new situation with his associates in the tribe(all relationships in the tribe are connected) and I am postulating that he may use "art" as a way to express this. He can ,for example make gestures (ie communicate to associates) that extol the leader or he can make gestures that refer to his now cast down state. These gestures are separate from the simple acceptance of reality which he must follow one way or another. Suppose he extols the leader. He can , I imagine kiss his feet (or maybe elsewhere) symbolically and the way he does this can be done in a very free way. If he does this summarily,perfunctorily this is (perhaps ) less effective than doing it with a flourish. Can I speculate that this hypothetical "flourish" would count as genuinely "artistic" and so have I "unearthed" a realistic (if fictional" example of early art? If ,we go the other way and our male member wishes to gain allies in his perceived struggle against his unjust leader he can communicate with his associates in a way so as to express his discomfort with the situation (moaning , keening sounds that might be the beginnings of the blues ) Is there anything at all in this idea of mine? Perhaps it has been already thought of ,I don't know.

A bit unclear myself too. Suppose we have two distinct areas in the universe that cause gravitation disturbances ,such as two separate binary pulsars in separate parts of our galaxy perhaps. As I understand it both of these systems would produce disturbances in space-time that propagate at the speed of light .(as a wave , would that be right?) So the waves from each of these separate systems will come into contact with one another at some point and interfere with each other . Would that be a reasonable assumption ? Could that interference be detected ? (not the laser interference hopefully produced in a measuring apparatus)

This is way above my level of understanding but is it possible ,in theory that gravitation waves (caused I understand by changes in the gravitational field ) might actually have their own interference pattern if two gravitation "wavefronts" from 2 distinct areas combined? I understand that laser interferometry is being deployed in the aim of detecting gravitational waves but that is not what I am thinking of (well I don't think it is). I hope I am not too far off topic.

So is a photon a term restricted to quantum mechanics and a field a term that only has applicability in classical physics? Is a photon what you get when you examine a wave of light at high resolution?