What are your favorite thought experiments?
What are your favorite thought experiments and why?
My example is the experience machine by Robert Nozick. It serves to show whether the person being asked values hedonism over anything else, whether they value whats real over whats not real and to what degree are they satisfied with their current life. I personally would choose to enter the machine though my answer would change depending on what my life is currently like.
My example is the experience machine by Robert Nozick. It serves to show whether the person being asked values hedonism over anything else, whether they value whats real over whats not real and to what degree are they satisfied with their current life. I personally would choose to enter the machine though my answer would change depending on what my life is currently like.
Comments (33)
"Would you rather [undesirable choice A. vs. undesirable choice B.]..." seems to be the casual go-to.
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But as far as contemporary philosophy goes, the trolley problem comes to mind. It's fairly basic yet touches on the main issues of life and society. Life, death, responsibility, action and inaction, blame, guilt, cause and effect, etc..
Its just so juicy
I think there's a pretty good chance that's just reality. Without the creepy demon.
I think The Ones Who Walk Away from Omelas can be applied to many moral questions. "The city's constant state of serenity and splendor requires that a single unfortunate child be kept in perpetual filth, darkness, and misery. Once citizens are old enough to know the truth, most, though initially shocked and disgusted, ultimately acquiesce to this one injustice that secures the happiness of the rest of the city. However, some citizens, young and old, walk away from the city after seeing the child".
Is the life of suffering experienced by factory farmed animals permissible for the pleasure it brings us?
The emperor's new clothes. Innocence and frankness is a lost quality in the way we think.
Quoting Captain Homicide
Do you still contribute to the animal farming industry though, or have you walked away from Omelas?
Quoting Down The Rabbit Hole
How much of 'us' is 'naturally recycled' after we die?
How much are we physically, part of all that has lived and died before us?
Do you think that if a human travelled at light speed ( I know that human 'mass' currently makes that impossible) then the human would not age?
I think we would age at exactly the same rate that we do now, but within a different temporal reference frame.
Now, that's a nice thought experiment. There would be no concept of time, and aging requires the existence of time it seems to me. This takes one back to a previous thread on change and time: does a physical change require a passage of time? For our little scamp, the photon, one has to ask if it changes other than position?
Attention physicists. Chime in if you are in the house. :cool:
I still eat meat though this is out of practicality regarding my individual circumstance rather than me approving of animal exploitation. If I had the means to live a vegan lifestyle I would.
I think that is the basis of the thought that is supposed to have started Einstein on his quest for answers, when he tried to imagine himself. 'hitching a ride on a photon.'
But if QFT is correct then there is no such an object as a free particle, there are only field excitations/disturbances. Which for me, suggests that we must be constructions of field excitations, yes? We sure need those physicists. Where are you @Jaded Scholar?
Quoting universeness
From memory, I think you're exactly right about that.
Quoting universeness
This is true, but I think in this context, the existence of "you" requires the sustained existence of those excitations, which are generally constricted to follow the rules of special relativity (sorry, but I have avoided talking about the ReehSchlieder theorem because I do not entirely understand how well it acts as an analogue for quantum entanglement), unlike the field itself which has much more wiggle room in terms of relativistic causality.
So I'm not 100% certain, but even within QFT, I think the question does reduce to the implication raised above: that if you could be accelerated to the speed of light, time would cease to pass for you at all.
Quoting universeness
According to Special Relativity, this is exactly what would happen, and you are right in noting that massive objects cannot reach the speed of light, but I think it's worth mentioning that it's only "impossible" because it would require an infinite amount of energy to do so - so it's more that the theory implies that it can't happen, but if it somehow could, SR is pretty clear that your local time would pass more and more slowly as you accelerated and would stop entirely at v=c. At that velocity, everything within your timeframe would effectively stop - the entire lifespan of the universe (even if it's infinite) would zoom past you. You're not wrong in saying that you would continue aging, just in a different temporal reference frame, but "continue" is maybe an ambiguous term in a reference frame where time has reached the limit of not passing at all.
However, makes a very interesting observation, noting that not everything that affects you is from within your own timeframe:
Quoting jgill
Of course, we do interrupt photons all of the time to take them out of their timeframe and merge them with matter. And I need to get into the weeds to mention that a human travelling at the speed of light would still be human-sized in the direction of travel (if infinitessimally thin when viewed from the side), so if you started your lightspeed journey in a non-empty universe, it's a safe bet that you would lose a few pieces of yourself before the end of time (probably all of them). Which I agree could conceivably qualify as an alternate definition of aging.
I haven't done the maths myself, but I actually read about some practical estimates on this exact thing in Bill Bryson's "A Short History of (Nearly) Everything" (my favourite book): I'm not sure what portion of a body generally gets dispersed to become part of another human or any other organism, but for anything short of a hermetically-sealed chamber, the amount is always nonzero. Whether you are buried, cremated, etc., it only takes a few centuries before a substantial portion of the atoms that comprised you have gotten into the atmosphere and circulated through various physical processes, ultimately distributing very far and wide, including into the atomic makeup of every other human that currently lives. At least a few dozen of the atoms in your body were once part of Isaac Newton, a few dozen were part of Socrates, Cleopatra, Ghenghis Khan, and even the long-forgotten hominid who first artifically kindled fire. But, to continue (roughly) plagiarising Bill Bryson, the process does require a few centuries - you are not yet one with, say, Elvis Presley.
Imagine a heavy ball falling at a rate V_h. Then imagine two smaller balls, which, because they are lighter, fall at a slower rate, V_l. If you connect them with a long rope, do they still fall at the rate V_l? When you shorten that rope, do they still fall at V_l? What if you make that rope shorter and shorter, up to the point where they are touching each other, but still separate objects - do they fall at V_h or V_l? What if they are pressed together, as two halves of the heavy ball? Do they fall slower just by the very act of imagining them to be separate? Clearly, this is ridiculous. The source of some objects falling slower than others cannot be a difference in how gravity affects heavy and light objects, but must be due to some other factor (air resistance). Without this external factor, even a hammer and a feather would fall at the same rate.
And it was beautiful to learn that the astronauts who went to the moon on the Apollo 15 mission actually brought a hammer and a feather with them, to televise them falling at the same rate, vindicating Galileo's hypothetical claim, 300 years later. :')
Wow! ('Very Valuable Scholar,' a.k.a, 'Jaded Scholar,') those were very interesting posts indeed.
Firstly, thank you for your various conformations regarding my own, small 'related to' physics, knowledge base.
Next:
Quoting Jaded Scholar
I have no knowledge of the Reeh-Schlieder theorem, but, after I have finished this post, I will start to learn about it, until my current physics grasp gets overwhelmed again, but I am sure my efforts will expand my understanding a little, so thanks for directing me to the theorem.
Quoting Jaded Scholar
But these points are all based on the relative reference frame of an observer, yes?
To an observer, I would not seem to age, if I was travelling at light speed, but in my own temporal reference frame, I would.
Is there any physics that indicates that I would not live my normal human lifespan, relative to any other object that exists with me, in that same 'light speed,' temporal reference frame?
Is this just an intuitive prediction based on:
The Earth rotates at approx 1,000 mph. Earth orbits the Sun at approx 67,000 mph. Our solar system orbits the centre of the Milky Way at approx 514,500 mph, the Milky Way is moving at approx 1.5 million mph and we also have the expansion rate:
"More recently, using Type Ia supernovae, the expansion rate was measured to be H0 = 73.24 ± 1.74 (km/s)/Mpc. This means that for every million parsecs of distance from the observer, objects at that distance are receding at about 73 kilometres per second (160,000 mph)."
Regardless of all these relative speeds, I still age as I do, in my current temporal reference frame, so I 'intuit' that regardless of my speed 'relative' to any other existent in the universe. I will always age at the rate I do, due to my own personal 'entropy,' is that not true?
So, photons do age, in their own temporal reference frame, from the stand point that they had an instant of becoming and they exist until such as, a moment of absorption?
Is this flawed thinking from a physics perspective, or more specifically a quantum physics perspective? Perhaps a better question to ask is are photons immune to entropy?
Quoting jgill
As jgill indicates above, if a photon changes position and can be absorbed and emitted, then it must experience duration, or is this again, just an incorrect 'intuitive' thought based on 'classical' notions of physical reality.
A further point, might be the suggestion that an observer would never see a spaceship fall into a black hole, it would seem to be frozen in time, at the event horizon, BUT, the spaceship would actually fall into the black hole (and get spaghettified,) yes?
Quoting Jaded Scholar
This is fascinating. I have heard this book in audio on youtube, but I have always fallen asleep to it in the past, perhaps I should buy a paper copy and read it properly :blush:
You would think such scientific findings, would help to alleviate the human fear of death, in that we are all, and in the main, always have been, partly, varieties of all who have lived before.
If human consciousness is ever proven, to be also quantisable, then perhaps each new human consciousness is also partly, built on spare parts of disassembled consciousnesses that have existed in the past. I find that 'religion,' more plausible than any other I know of, but it's not panpsychism or any kind of woo woo theosophism, imo. For me, the word religion is very soiled however. I am with Hitchens in his insistence that 'all religion is pernicious.'
Quoting Jaded Scholar
Yes, especially when it's so 'intuitive' (I realise this is a problem when it comes to my own thinking,) to assume that heavier (or more dense) objects would fall faster, especially when it is true that heavier/more dense object do create 'more' gravity.
Is gravity a push, a pull, or not a force at all, but a consequence of geometric spacetime warping.
I think this wee 15min vid is a good one, for making the main points involved (it also mentions your Galileo contribution).
:lol: I think I would need both @Jaded Scholar and @jgill to 'baby step me,' over all the hurdles presented to me by the Reeh-Schlieder theorem. Either that or become a mature student at uni again and gain a maths and then a physics PHD.
I just kept trying to drill deeper and deeper, using provided links, starting with a wiki entry.
From even this first sentence, I soon became overwhelmed:
[i]The ReehSchlieder theorem is a result in relativistic local quantum field theory published by Helmut Reeh and Siegfried Schlieder (1918-2003) in 1961.[/I]
I clicked on the 'local quantum field theory' link, which took me to:
[i]Algebraic quantum field theory (AQFT) is an application to local quantum physics of C*-algebra theory. Also referred to as the HaagKastler axiomatic framework for quantum field theory, because it was introduced by Rudolf Haag and Daniel Kastler (1964). The axioms are stated in terms of an algebra given for every open set in Minkowski space, and mappings between those.[/I]
So, I then had to click on the 'C*-algebra ' link and the 'Minkowski space' link, after I tried to follow the HaagKastler axioms, with limited success. :rofl:
I think I will stick to what I can garnish from youtube vids by the likes of Sabine Hossenfelder, Sean Carroll, Carlos Rovelli, Brian Cox, Jim Al Khalili, and other such 'science presenters/popularisers,' that put out their attempts to explain the basics for folks like me.
The thought experiment consists in looking at objects to attempt to get the idea of a continued existence of objects as well as trying to find the reasons for why we believe objects to exist in a manner distinct from our perceptions of them.
We can't. Yet we do assume both, quite strongly, yet we don't have good reasons for doing so. It's really hard. But fascinating notwithstanding the futility of such an exercise, it's an obsession.
Using this argument we can never have a reason to believe in the world becuase we cant ever escape our senses short of omnipotence and even then you wouldnt know if it wasnt just another simulation.
It's not doubting that there is an external world, Hume never doubts this, what he is pointing out as problematic is in having an idea of external existence which is different from our specific perceptions of them.
Where do you get off the train? (meaning, at what point do you hit the 'its now a futile endeavour' line in your enquiry?)
I don't think it's of much difference to other issues like freedom of the will, or matter thinking, personal identity and so on.
You get off whenever you get tired of it or bored with it or find a unique approach that may be somewhat satisfactory.
Imagine there is a world where doppelgangers can be created identical to other people in terms of biological structure, genes, memories, abilities, absolutely everything.
Some questions:
1. If a doppelganger was created of you, how do you know you are not the doppelganger? Could you convincingly win an argument with your doppelganger about who was the real doppelganger?
2. What if you were met with this same doppelganger scenario but from another family member or friends. You could only pick one to bring back to your life with you and you would never see the other again.
This depends on whether the 'identical' memories include the moment at which the DG was created. Typically, you'd have that memory (i.e, you could remember before and after the creation because you knew it happened) where the DG could not.
I think this is why the Teletransporter TE is so good - it stipulates that this isn't the case and that both versions had the 'exact' same memories. I suppose another version is to stipulate that you don't know the DG was created. Same issue
Yes, this is a very good point. I think it would have to be something like you go under a medical procedure and wake up afterwards having gained a doppelganger. Then I imagine your memories would be lined up.
As I see it, the argument is but one of infinitely many examples of a logically valid but false arguments, that presents negative evidence with regards to the epistemological utility of constructive logic, and thus in turn presenting negative evidence regarding the epistemological utility of a priori philosophical arguments, such as transcendental arguments. In other words, even ideal reasoners can be expected to draw rationally "correct" yet empirically false conclusions about the world. In which case, what is the point of AI and cognitive science?
Interesting example!
Quoting sime
There is more to an ideal of reasoning than the ability to apply logic in a valid way. There is also the pattern recognition applied to diverse empirical observations that allow for recognition of false premises. For example the "training set" which is hugely important to the results yielded by modern AI.
Yes, very much so. The successes of Machine Learning generalisation are entirely the consequence of ML models evolving over time so as to fit the facts being modeled, as opposed to the generalisation performance of ML being the consequence of a priori and constructive mathematical reasoning, as if purely mathematical reasoning could predict in advance the unknown facts being modeled.
And yet many popular textbooks on ML written around the turn of the millennium presented the subject as if successful generalisation performance could be mathematically justified in advance on the basis of a priori philosophical principles such as Occam's Razor, Non-informative prior selection, Maximum Entropy and so on. Notably those books only very briefly mentioned, if at all, Wolpert's No-Free lunch theorems that put paid to the idea of ML being a theory of induction.