Thursday, November 26, 2009

If there were a Gedankenexperiment about Man's constitution - What would it be?



Courtesy of Wikipedia-Gedanken

A thought experiment, sometimes called a gedankenexperiment in German, is a proposal for an experiment that would test or illuminate a hypothesis or theory.[1]
Given the structure of the proposed experiment, it may or may not be possible to actually perform the experiment and, in the case that it is possible for the experiment to be performed, there may be no intention of any kind to actually perform the experiment in question. The common goal of a thought experiment is to explore the potential consequences of the principle in question.

Famous examples of thought experiments include Schrödinger's cat (pictured above) , illustrating quantum indeterminacy through the manipulation of a perfectly sealed environment and a tiny bit of radioactive substance, and Maxwell's demon, in which a supernatural being is instructed to attempt to violate the second law of thermodynamics.
Schrödinger wrote:
One can even set up quite ridiculous cases. A cat is penned up in a steel chamber, along with the following device (which must be secured against direct interference by the cat): in aGeiger counter, there is a tiny bit of radioactive substance, so small that perhaps in the course of the hour, one of the atoms decays, but also, with equal probability, perhaps none; if it happens, the counter tube discharges, and through a relay releases a hammer that shatters a small flask of hydrocyanic acid. If one has left this entire system to itself for an hour, one would say that the cat still lives if meanwhile no atom has decayed. The psi-function of the entire system would express this by having in it the living and dead cat (pardon the expression) mixed or smeared out in equal parts.
It is typical of these cases that an indeterminacy originally restricted to the atomic domain becomes transformed into macroscopic indeterminacy, which can then be resolved by direct observation. That prevents us from so naively accepting as valid a "blurred model" for representing reality. In itself, it would not embody anything unclear or contradictory. There is a difference between a shaky or out-of-focus photograph and a snapshot of clouds and fog banks.[3]
The above text is a translation of two paragraphs from a much larger original article that appeared in the German magazine Naturwissenschaften ("Natural Sciences") in 1935.[4]
Schrödinger's famous thought experiment poses the question, when does a quantum system stop existing as a mixture of states and become one or the other?
Each alternative seemed absurd to Albert Einstein, who was impressed by the ability of the thought experiment to highlight these issues. In a letter to Schrödinger dated 1950, he wrote:
You are the only contemporary physicist, besides Laue, who sees that one cannot get around the assumption of reality, if only one is honest. Most of them simply do not see what sort of risky game they are playing with reality—reality as something independent of what is experimentally established. Their interpretation is, however, refuted most elegantly by your system of radioactive atom + amplifier + charge of gunpowder + cat in a box, in which the psi-function of the system contains both the cat alive and blown to bits. Nobody really doubts that the presence or absence of the cat is something independent of the act of observation.[5]
Thought experimentation in general

In its broadest usage, thought experimentation is the process of employing imaginary situations to help us understand the way things really are (or, in the case of Herman Kahn’s "scenarios", understand something about something in the future). The understanding comes through reflection upon this imaginary situation. Thought experimentation is a priori, rather than an empirical process, in that the experiments are conducted within the imagination (i.e., Brown’s (1993) "laboratory of the mind"), and never in fact.

Thought experiments, which are well-structured, well-defined hypothetical questions that employ subjunctive reasoning (irrealis moods) -- "What might happen (or, what might have happened) if . . . " -- have been used to pose questions in philosophy at least since Greek antiquity, some pre-dating Socrates (see Rescher). In physics and other sciences many famous thought experiments date from the 19th and especially the 20th Century, but examples can be found at least as early as Galileo.

12 comments:

moonlight1021 said...

Curiosity killed the cat, but satisfaction brought it back.

moonlight1021 said...

Did you actually change the name of the post and a bit the body of the post?

The possibility of spaces with dimensions higher than three was first studied by mathematicians in the 19th century. In 1827 Möbius realized that a fourth dimension would allow a three-dimensional form to be rotated onto its mirror-image.


maybe in a world of higher than 3 dimensions you could have both instances co-existing. If things were to happen in a continuum in the absence of time, maybe then you could have both a living cat in the box and the dead cat outside of the box co-existing as a sort of continuum with no beginning and no end and no contradiction either, whereas you would not be able to make the difference between "dead" and "live" and this though paradoxical for our world, would just end up being properties of the cat that are being accommodated and accounted for in a higher dimensions world.

the Schrodinger's cat is such an interesting model, but i think when it comes to the interpretation below, it sounds a bit unreasonable--there should be an extension to this model for philosophical purposes of course so as to incorporate a solution to take the cat out without applying the labels dead/live. It requires defying the properties outside of the box, but why shouldn't there be a transition for this as well? (in theory at least)

"According to Schrödinger, the Copenhagen interpretation implies that the cat remains both alive and dead (to the universe outside the box) until the box is opened."

moonlight1021 said...

note: maybe this model could be reinterpreted using the notion of the existence of generations and generations of "cats", in terms of the idea of the cat species.

Rabbi Jonathan Sacks said...

Moonlight

I see you are speaking about the cat. Interesting that "cats" are an example of the safe external objects that education guides us to have Gedankenexperiments about.

Perhaps the Torah could give us some guidance regarding the best way to have Gedanken about ourselves?

moonlight1021 said...

Are there any special properties of the cat that make it so suitable (aka: "safe external objects") for this thought experiment or it's all a random choice as they could've chosen as well the dog, the rabbit, the mouse, the parrot, etc?

What would be the Torah perspective in dealing with this model?

Rabbi Jonathan Sacks said...

Moonlight

Why don't you re- read the first few Chapters of Braysheet, and see for yourself?

moonlight1021 said...
This comment has been removed by the author.
moonlight1021 said...
This comment has been removed by the author.
moonlight1021 said...

Sorry, make that "I don't see anything". What should I see?

Rabbi Jonathan Sacks said...

Moonlight

Lets wait and see if someone else might be able to see something.

moonlight1021 said...

So in a way it is possible that this answer "Let's wait..." would've been the similar answer those scientists would've given to the Schrodinger cat experiment too.

Once you have that experiment, you have to leave it like that or put the cat with that box within another box which would be be enclosed in another box, which would be enclosed in another box within another box and so on etc. and that's how it creates the notion of the generations of cats. This reminds me of "The Infinite Turtle theory":

A well-known scientist (some say it was Bertrand Russell) once gave a public lecture on astronomy. He described how the earth orbits around the sun and how the sun, in turn, orbits around the center of a vast collection of stars called our galaxy. At the end of the lecture, a little old lady at the back of the room got up and said: "What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise." The scientist gave a superior smile before replying, "What is the tortoise standing on?" "You're very clever, young man, very clever", said the old lady. "But it's turtles all the way down!"[1]

Dan said...

Rabbi,

I'm sorry.....I don't understand what you were trying to say with this post. Please explain???