Leaderboard

Whoa! Remind me to visit your house some day, sounds like the place to be... I must admit I am baffled by this - you are a philosopher yourself, so surely you must see the issue with this? When you probe a sample of matter on atomic scales, what are you really going to find? Will you find ‘atoms’? Of course not. What you will find are ensembles of electrons, protons and neutrons, in various configurations, plus an abundance of vacuum. That is all. What we call ‘atom’ is a convenient convention to give a short name to such quantum mechanical ensembles, largely for historical - not scientific - reasons. They are real, but only in a conventional sense; ontologically there is no such thing. No experiment will ever detect the ‘atom-ness’ of an atom, because the only thing there is on that scale are electrons and nuclei. But it gets worse. If we decide to crank up the energy and probe said protons and neutrons, we find that they themselves are also ensembles of more fundamental particles, being quarks and gluons. So on subatomic scales, there’s no such thing as protons and neutrons either, they are convenient conventions too, but don’t exist as independent entities in and of themselves. So what about quarks and electrons? Surely they are ‘real’? When you try and take a closer look at them, they turn out to be pretty slippery bastards - try to confine them into smaller and smaller areas, and they move about more and more wildly. Try to measure their momenta, and suddenly you can’t pin them down any more. Send them through a double slit, and they behave like waves; try to measure their spin vector, and each time you laboriously determine one component, the other two get erased! It’s like trying to nail jelly to the wall. So to our dismay, even the very notion of ‘particle’ turns out to be just a convenient tool. Even such a seemingly innocuous concept as ‘number of particles in a given volume’ turns out to depend on who’s counting them! There’s not really such a thing in reality - there might be something there, but it’s nothing like our intuitive notion of a particle, unless you zoom out far enough so that quantum effects become negligible. So what are we left with? The most basic elements of reality we currently know of - and this is almost certainly not the deepest level - are quantum fields. So we don’t have a universe with 10^120 particles with independent existence - all we have is one spacetime with 37 (depending on how exactly you count) quantum fields. That is all. You don’t have any more independent existence than does that flock of birds, since both are just complicated ensembles of the same 37 quantum fields (according to current knowledge). On those scales you are not different from those birds, and on other scales you are not the same. There’s no contradiction - both are correct. You take what is found on human scales to be absolutely real only because that happens to be the scale your sensory apparatus is able to probe. And that’s my central point - if you probe reality on human scales, then you and me and the birds are ‘real’. If you probe it on molecular scales, then atoms are ‘real’. If you probe it on atomic scales, then ‘subatomic particles’ are real...and at the bottom, what is real are quantum fields, according to current knowledge. Hence, there is no one reality - what is real depends on the scale of the instrument that probes reality. It is scale-dependent. This is called contextuality. You will never find a ‘bird’ if you use the LHC to look - even if you look in the same region of spacetime. And when you look at subatomic constituents, then sometimes you’ll find waves, sometimes various quantum objects, depending on how you set up the probe. Mostly, you’ll find nothing at all. I will for now forgo any mention of counterfactual definiteness and the empirical violation of Bell’s Theorem, which puts further nails into the coffin of ‘reality’. Or what might happen if you look still deeper, beyond quantum fields. Or you could go the other way - what happens if a hypothetical very large organism (~10 billions of light years in size) tries to build a machine to observe my cat? Because the speed of light is so slow on such scales, metric expansion would rip this life form apart long before he could become conscious of the outcome of that measurement. My cat could never become part of his reality. So what is real depends on how you probe! That is why both ‘bird’ and ‘37 quantum fields’ are equally valid realities, but in different contexts and on different scales. Neither one is more ‘wrong’ or ‘right’ than the other, but both are contextual and scale-dependent conventions. They are both real enough and useful, but only in their own contexts. I will leave it at this for now. Personally I think the rabbit hole is much deeper than this still - I happen to think that reality doesn’t just depend on how you look, but also on who’s looking. But I won’t get into this here.

I know I'm not first, but you continue to be obtuse. Bullshit. By providing one example after another of what you believe to be real you are defining for us what you think reality is. For example, In your second post in this thread: "I think the cannonball is real -- really real -- real even if no one is looking, its motion is real, and that physics describes this reality for us". Your position seems to be that the physics describing the cannon ball "describes this reality". So now you are obfuscating by claiming "well, I never actually said the words "The definition of reality is..."" Your little tap dance is fooling no one.

If I may, and with authentic respect… It’s likely bc you’re living now in a world where patience with bullshit and dissemblance leads to needless death and avoidable suffering… and you’re one of the good ones who desires neither

I agree, the tepui does not seem to be attached. And there seems to be no room for a large enough lake. Edit: here is a link to discussion about the water: Note that the picture is posted in the art section.

Most analogies have limitations, we all know that. They are used to offer an explanation as to what is basically happening. Invariably when getting down to the nitty gritty, faults, limitations will always be found. Still when I first became familiar with the rubber sheet/bowling ball analogy in the early to mid fifties as a hairy arse kid, It was a revelation to me. It was like someone turning on a light in a darkened room. It did its job for me. Since then of course, as I have learnt more, read more reputable books, the limitations are far more obvious. Anyway I did find a paper on the same subject with an evaluation of this commonly used analogy. https://upcommons.upc.edu/bitstream/handle/2117/176999/Fisidabo_Paper_vfinale.pdf;jsessionid=4185CF6A53188D7F069FE5F69750A73D?sequence=1 Evaluating the rubber sheet spacetime analogy by studying ball movement in a bent trampoline: Abstract. A usual qualitative analogy used to explain gravitation in general relativity is comparing spacetime warping by massive objects with deformation in a rubber sheet. Motivated by this analogy, which identifies planet orbits with trajectories of rolling objects on the rubber sheet, the movement of a small ball in a trampoline bent because of the presence of a heavy mass in its center is studied. It is concluded that the similarities between how masses move under warped spacetime and under a warped trampoline are only qualitative, and later some analogy flaws are outlined, which can be useful for general relativity teaching. Since the “relativistic model” does not match the ball movement in the experimental conditions, two models based on classical mechanics are presented to describe it. The models are implemented computationally and parameters of such models are optimized to match experimental trajectories. In the case of the most complex of these two models, the high accuracy between optimized and observed trajectories implies that the model is able to explain the experiment behaviour. Conclusions The two main questions this article addressed were evaluating the rubber-sheet analogy and predicting the orbit of balls rolling on a warped trampoline, by using in both cases data collected from the experiment performed in Tibidabo park. Firstly, no way of extending the analogy accurately beyond the rubber sheet being a visualization of the spacetime warping caused by masses has been found. It can not be considered as a complete spacetime where bodies follow geodesics, neither the orbits a ball follows on a warped trampoline are compatible with Newtonian and GR planetary orbits. The alternative model proposed by K.Thorne in [9], in which the rubber sheet only represents a slice of space instead of the full spacetime would help overcome some of the analogy deficits but would still not suffice to describe the apsidal precession observed in ball trajectories. Regarding the second question, two different physical models were proposed and compared to describe the phenomenon. Computational simulations of both the trampoline and the ball movement concluded that the proposed rolling sphere model can predict accurately the experimental results, outperforming the other model proposed, the point particle model. :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::...................................... We know analogies have limitations, so when explaining it to someone, that point needs to be emphasised. The same applies with pop science docos. They generally give a basic rundown on a situation or scenario, and obviously with limitations also. The relevant point is that those that are interested and/or attracted to that scenario, will probably go out of their way to do further research and learn more,including getting down to the real nitty gritty. What I'm trying to say, is that analogies do play a necessary part in educating, as do pop sci docos.

Thanks, didn't see that one. And reading the rest of that post, I'm seeing personal mental health needs that cannot really be met on the web. The family member getting typhoid suggests a challenging spot in a developing country. I hope there are people there working towards a more nurturing community -- sometimes it seems to me that America could, instead of trying to export our highly boasted values (often down the barrel of a gun), just send money and expertise for clean water, sustainable agriculture, green energy, and local entrepreneurship. When desperation drops, warlords and tyrants and religious zealots have less of a foothold.

If by 'keep on going' you mean do things, like work, then it is energy that keeps it 'going'. Energy has some funny properties. If you have a box divided by a partition, where one side has a more energetic gas than the other side, the partition will be accelerated, and move. That is an example of doing work ( much like the pistons moving in your car's engine let you travel down the road ) When the gas on both sides of the partition has equal energy, obviously the partition will stop moving, and no more work can be done. Notice that the total gas still has energy, but it is the difference in energy that allows work, and processes to happen. So, we have useable energy, which can do work, and un-useable energy which cannot. We call this process, of converting useable energy into un-useable, entropy. Entropy can also be a measure of the 'order' of a system, which means that, although it can be reversed locally ( life is proof of that ), it must always increase globally. That is where the idea for the 'heat death' of the universe comes from. Once entropy of the universe is maximized, and there are no more energy differences, all work and processes will cease, and the universe will essentially be dead. This is a rather simple explanation, which is, hopefully, suitable for your level of understanding. If you should need elaboration, don't be afraid to ask.

Well spotted, @Ghideon!! My bad. I didn't give it a second thought. You really have an inquisitive spirit. Keep it up, is all I can think of saying now. 😮

This sounds reasonable to me - I’m ok with the above. Also, scientists very often use convenient conventions simply because they are what it says on the tin: they are very convenient and useful. ‘Atom’ is much more convenient than ‘quantum mechanical ensemble of bound particle states’, or the even more cryptic quantum field theory version of it. I don’t think you are ‘wrong’, I can see where you are coming from. But I do think you might be reading some of these quotations a little too literally. Scientists often forgo rigour and use sloppy terminology when speaking to lay audiences. What we say and what we mean are sometimes different things! But I think the main issue is what we mean by ‘reality’. And as I’ve tried to show in my previous post, this is not at all a straightforward concept, because it isn’t absolute - it’s relative and contextual, and depends on how you detect it. Quite a bit like space and time in fact!

Not being as uncouth as you, coupled with my superior upbringing and refinement, I resisted with all my might to say the same thing!!😉😜

I think it depends a bit. The Far right in Europe is a bit more obsessed with ethnocentrism rather than the economic identity that has ben assumed by conservatives in NA, but also Australia. Conversely, there have been left-leaning parties who have for a long time supported coal, as miner unions and similar groups were a strong voter base. Fundamentally there are few who want to do outright unpopular measures that could directly affect people's lives in the short term, which is why they try to kick it down the road for as long as possible. Someone will have to do the unpopular thing so (and likely promptly lose the next election). Though if there is enough public pressure some of that can change. In Germany, public opinion for nuclear power went down the drain after Chernobyl (though it was already fairly critical earlier, for a range of different reasons). And although it has taken many years, ultimately the Overton (ha, take this autocorrect) window has shifted enough that it wasn't possible for any party to expand nuclear programs. But you are correct that these changes often take long (say, a generational change) before things start rolling.

Sure. In my view, admittedly coloured by the fact that I am a mathematician, I hold that Theories operate on Principles, in a way similar to the way in which theorems operate on axioms (which Physics does not have) in Maths. The view I have been promoting here in several ways is that Philosophy deals with the Principles of any subject not the detail. It could even be said that the subject itself is the detail. I also hold that it is a 'good thing' that we have an independent process or discipline scrutinising the Principles.

The royal family was given the illusion of being rich - the people that are rich are the communist party and the roman catholics which own the largest number of assets in the world. The royal family is a product. Choose your poison - Communism or Friendly fascism...

Again the royal family was affected because of the environment...not because of genetics. To me when you believe something without evidence it basically becomes a religion.

Show me the proof that inbreeding is wrong? Or better yet, show me the proof that inbreeding leads to genetic defeats? To me it sounds like a few narcissists scientists got together and decided to play god because they saw a co-relation in the two without taking into account the environmental factors as well as what you eat that leads to genetic defects. If you were in Chernobyl, then it would lead to defects. To me it sounds like a few people that want to prevent us from having kids at all or having more of them so the rich stay rich and the poor stay poor. To me it sounds like someone is playing god so we don't engage in the act of reproduction but they use our kids as battery cells inorder to keep this system running along. There is a strong link between being poor and poor health...but to me it sounds like we are paying the price for the carelessness of the previous generation and they want us to suffer and our kids to suffer. In nature, inbreeding happens all the time - the only reason why diseases happen is because of the environment not because of genes. Genes are just switches that get activated when there is changes to the environment. These people just want to kill the love and are trying to play god and remove impurities and imperfections of the human race and to me it's these narcissists that took over and started to play god because they had the power to.