SCI-ART LAB

Science, Art, Litt, Science based Art & Science Communication

Sometime back I wrote an article titled "Is art antonym for science?'' Then one artist said , 'Krishna you are talking as if there is only one reality and that is the classical one. '

He also argued that what experiments I conduct in my lab can deceive people as in my presence the results can change *** when I do my observations! I felt like screaming when I heard his logic! Yes, he was talking about the famous double-slit experiment*, the 'observer effect' **** and quantum mechanics!

What is the most disturbing thing is he even argued that I should apologize for misleading people with my experiment results and my observations about my experiences in this world.

Should all scientists say sorry for the results they obtain in their labs? Because of their presence in their labs when experiments are conducted? Should intellectuals express regret for their rational thinking about the world they observe around them? How absurd that will look? How silly people can think, get and argue?!

This is the problem when people with mixed up views talk. You read something and don't realize it belongs to another world and set of conditions and try to bring it to another world and set of conditions and argue that the other person is wrong in his or her views.

But you have to deal with such people too in this world and if I do that in a soft and convincing way that would be better.

Therefore, this is my reply to him....

You are talking and arguing about quantum mechanics Chris. Yes, there are other realities but the reality of quantum world cannot govern the classical world and I am talking about classical world we deal with daily and not quantum world. How can you bring the arguments of quantum world to the classical world? That sounds silly to me.

The points I have made deals strictly with macroscopic (large, everyday, massive) objects that do not display quantum behavior. You might not personally know which way up the coin landed until you go look when you throw it into a well. But the coin would obey classical mechanics. In principle, if you took all the details, although the coin toss seems to be unpredictable, its unpredictability comes from the "hidden variables". If we know the velocity, momentum, rotation speed, mass, radius, ... of the coin and the depth of the well, stiffness of the walls, the precise way you dropped the coin etc. , you could calculate the coin's exact trajectory and deduce which side landed facing up.

In the case of Schroedinger's cat**, the true quantum behavior is exhibited by the single radioactive atom that is in a superposition of "decayed" and "un-decayed" states. A single atom is truly a quantum system, so that is fine. One must stretch the imagination to believe that the decay of one atom could immediately kill the cat ... But that is a bit of poetic license within the thought experiment, in order to get one thinking about how the quantum world defies everyday expectations.

Flawlessly accounting for the behavior of matter on scales from the subatomic to the astronomical, quantum mechanics is the most successful theory in all the physical sciences. It is also the weirdest. Einstein once asked, does the moon not exist until I look up at it? My answer to the Q is - whether we look at it or not, the moon exists but its existence becomes irrelevant until we look at it!

Quantum mechanics, as a theory, only differs from classical mechanics for microscopic objects like atoms and particles. In the quantum realm, particles seem to be in two places at once, information appears to travel faster than the speed of light, and cats can be dead and alive at the same time. Physicists have grappled with the quantum world's apparent paradoxes for nine decades, with little to show for their struggles. Some understood the logic in the way it should be done too. Unlike evolution, whose truths have been incorporated into the general intellectual landscape, quantum theory is still considered (even by many physicists) to be a bizarre anomaly, a powerful recipe book for building gadgets but good for little else in the real or classical world. The deep confusion about the meaning of quantum theory will continue to add fuel to the perception that the deep things it is so urgently trying to tell us about our world are irrelevant to everyday life and too weird to matter.

That "people change things by taking measurements in a lab", or "when we observe things we change the nature of the reality we observe" is not correct even in the quantum world. It is actually the particle exchange that changes reality. Not our observations. Whether or not humans ever look at the particle exchange is immaterial. In the classical world changing the results by our observations is completely out of question! Get this right first.

The idea that consciousness affects the outcome of the double slit experiment is a misconception. Photons don't alter there behaviour because someone is looking. Some idiot misunderstands the meaning of the term observer, in physics. In physics, an observer is not a person, per say. An observer is anything which detects. A motion detector, is an observer. A smoke detector is an observer. Even a camera, is an observer. In the double slit experiment, a light detector is an observer.

Now, the thing about photons is, we can't actually detect them directly. We detect the energy released when they strike something. You can't detect which slit a photon passes through, without destroying the photon. So,if you observer/detect a photon, you're stopping it from hitting the screen. Basically, you're blocking one slit.

A photon doesn't change it's behaviour because it's being observed. Observing changes it's behaviour. If it passes through two slits, it acts like a wave. If you block one slit, it acts like a particle. No more, no less. That's all the double slit implies.

One of the important feature of quantum mechanics is the uncertainty principle which states that the product of the uncertainty of a particle's position and momentum must be greater than a certain value, in other words, the position and momentum of a particle cannot both be precisely known. This has to do with the probabilistic nature of quantum mechanics. When you measure a particle's momentum or position, there are multiple values that you might measure with different probabilities. After many measurements, you will arrive at a distribution averaged around what you would expect to measure classically with some standard deviation. Per the uncertainty principle, the smaller the standard deviation in position is (i.e. the higher the chance that you will measure your particle near the classical value), the greater it will be in momentum and vice versa. At large scales, the magnitude of uncertainty is so small that it won't even come close to the precision of the instrument being used to take the measurements. Interesting to note is that the uncertainty principle is an inherent property of wave-like systems and is not unique to quantum mechanics.

Thank you for telling me that I have a strange mind:). Most of the people of science look strange to you because they have seen more than  you did! And their world and perceptions vary from that of yours! This is another example of how truth and perception differ!

Previously when I read the articles to which you gave links on the WIKI so much information and so many references weren't there ( to tell you the truth I did not read them again when you provided the links because I didn't want to waste my time on something that I had already read earlier and found not so reliable). But on wikipedia, people keep adding information and make corrections as time goes by and when you alerted me about these references now, I visited these pages again and yes, you are right new information and references have been added. But it doesn't give enough stuff to the article to defeat my words. These studies are based on one case studies for instance the one where when one part of the brain is damaged, the other part takes all the functions of the other part too. This could be due to adaptation technique used by living systems in order to survive and need not be the scenario where full brain functions in the normal way. Still my argument stands as it is widely accepted. These things on wiki are studies that are still going on and not concluded yet.

And thank you for spending so much time on this subject and it is really a pleasure interacting with people that seek truth. And I enjoy more while dealing with people who have views that are different from mine. It gives me an opportunity to view a different world altogether and broadens my world when I try to understand it. As they say an enemy who criticizes you is always better than a friend who praises you. Okay, okay, before you protest, I accept, you are not my enemy here :).

In the field of science there is a warning too! It says - if you keep your mind wide open people try to dump all sorts of rubbish into it- therefore you should be able to differentiate between what is important and what is not and what to allow and what not into your mind! You made me laugh when you said that I have closed my mind because you didn't know that I installed filters at the entrance of my mind! No matter what you say, a 70% truth (WIKI has given only this rating to science topics on its pages and several scientists agree with this - perhaps we have all closed our minds despite all those references people give and let me assure you it doesn't affect our work in any way!) cannot pass through a 90% truth (actual peer-reviewed science journal ratings in the world of science) filter. If my filters give you an illusion of a closed mind I cannot help! Moreover, when you have real diamonds before you, what is the need for going for the  imitation stuff?! So I need not worry about your comments.

I understood the experiment with light part of it first. That is what I always think and tell my friends in other fields. The results of scientific experiments always depend on the conditions in which they are conducted. There is a story that people tell me & ask Qs about. It seems one person published a paper saying that onions contain Phosphorus and another one published a paper saying that they don't contain phosphorus. Which one is correct and which one should we believe - people ask me. I tell them given the conditions in which these onions are grown and the genetic compositions they are made of both could be correct!

Now my reply to your other points.

Like I said my article was mainly based on the analysis of my own mind and psychological world that are embedded in the classical world. I felt it is important to analyse both scientific and artistic features of a the same mind for this study. As I couldn't find people who are willing to cooperate for this studies, I was the only person available for these studies! However, I took individual artist and scientist perceptions into account too. The very fact that some other artists too accepted them shows that they are not very far away from these artistic mind realities. Some members might not agree with what I say - it depends on their mental make up. That is okay with me - not all human beings will be alike.

These are not what I believe in or what I assume, they are the things that my artistic and scientific sides of mind are actually made of. Is it an illusion or "maya" in Buddhism and Hinduism (these two religions say the whole world is an illusion !)? Yes, everything is relative ( I have seen the video and said the same about it - an artist 's perception of the world is different from a scientists' perception of the world and a scientist can see much more than an artist) and just because an artist sees less than a scientist you cannot say it is not correct - given the limitations he has, an artist's partial view of the world is okay even if it is not the entire truth. You cannot blame the artist for his limited view of the world. Aren't artists happy with what they see?

A person who sees only a circle is happy too. A scientist who sees atoms in empty spaces too is happy . Is common man on the street bothered about these things? Only scientists can read more into perceptions and truths and sympathise with common man because others cannot see the world in the way they do. But that doesn't make so much difference to a common man! "What the heck, I am happy with what I see" is all he thinks about! Some people say if you bother more about the finer points of the picture, you cannot enjoy your life. But scientists have a different view on this. And people here say each and every person enjoys his or her own madness whatever it is! And who are we to say they cannot do that?

And am I experiencing all these just because I believe in all these? I gave it a thought too. I compared my experiences and views with the perceptions of other people (yesterday I asked my scientist friends to read my article and tell me whether what I said about the world of science is different from their perceptions). They said they are not drastically different from mine (now don't tell me I am imagining this too!) Maybe they are not universal truths. But Majority of the people I asked have the same perceptions as I do! Even if they are my beliefs - like you say, they tally with others' perceptions too. Even if this world is an illusion, when majority accepts it as true, it is taken as "truth" in this world- even though it is a relative one. That is where, you & I differ in our views. " Classical reality" may not be the "absolute reality or truth", but know what - go out and ask the common people in this world. You will be surprised to see that majority of the people accept them as real truths! I see here that you feel -some of the people - like the ones in science like me - should deal in the way of real truth and not classical realities. But I think when you deal with the classical world, you deal with classical realities and when you deal with quantum world, you deal with quantum realities. You don't mix them up if you are a real person of science. As a writer, I deal with classical realities more  than the quantum realities as not many people around are familiar with the second type and even if they do understand the quantum world, it is immaterial when you deal with the classical world in our day to day lives.

( Let me also clarify before somebody points this out  that Classical Reasoning can also fail sometimes for macroscopic objects and they exhibit quantum behaviour, if you, for instance, lower their temperature to near absolute zero so that all of the usually available degrees of freedom become correlated and go into the same quantum state.  What I say above holds only for ordinary temperatures in this world. Also, it is a standard interpretation within the physics community that quantum uncertainties and effects reduce and cancel out as a microscopic system of quantum world gains more and more particles).

If we go after illusions they stunt our growth as individuals. Yes, I believe in this too! I understood your view point and you are okay somewhat! But at the same time, I don't feel I said something wrong because these perceptions of mine have roots in real truth too. My "classical reality" might not be absolute truth but is very close to it. In the absence of absolute truth, I went for the one that was closer to it, i.e., the one based on science. Science too has limitations as it is still in its infant stage and has to grow a lot. So we cannot say what all science says now is the universal truth. Tomorrow somebody might disprove what is accepted as universal truth today. Didn't Einstein disagree with Newton and propose a new theory for gravity? And scientists are still struggling to understand and prove Einstein's perception of the world. Twenty years from now another genius might propose another theory. Is there a limit to these perceptions of the world? Anybody can see the world around in any way he or she likes and live in illusion and think that it is the true one. But science tells us to seek truth with a rational mind and not to live in illusions. HOWEVER, rational minds too differ in their rationality & until something is proved beyond doubt with several similar-condition-experiments and by reproducing the results over and over again and is acceptable to majority of the experts in the given fields these "playing games" continue! Science cannot progress if it doesn't follow the path of truth of the moment.

There are two realities  at the moment - while one belongs to the classical world, the other one deals with the quantum world.  Science accepts that. But they are not absolute truths too! That is the irony of it all and that is why there is so much confusion in this world about science and what the scientists say.

But, can you prove beyond doubt your way- and perceptions of the people you quote- is absolute truth? Okay let me ask you this Q. If I ask you to write about the same subject how do you put these what you call " classical view of realities" in the way of 'universal absolute truths'? No, you can't! We can't even stop experimenting in our labs. We can't stop writing about classical world truths!  That will hinder our progress. That is the paradox!! Face it pal!!!

                                                                                           ----

* Double-slit experiment ( of quantum world)A particle, say, an electron is fired by an apparatus; goes through a screen with two slits; and hits a fluorescent screen. Even if we record the location of the electron's impact with exquisite precision, we cannot reconstruct the electron's path, because it didn't have one. Indeed, if we fire a large number of electrons, one at a time, the statistical distribution of impact locations will tell us that each and every electron went through both slits, and its probability of impacting the fluorescent screen at different locations varied accordingly. In short, between the two measurements (counting the firing of the electron by the apparatus as the first measurement) the electron had no classical trajectory.

** Schrödinger's cat argument ( of classical world): Put a cat in a box, along with the apparatus that triggers the poison if it detects the decay of that radioactive atom. Wait the requisite amount of time and open the box. If a live kitty jumps out of the box, you know that the cat was alive all along. Its classical state is well-defined and can be fully reconstructed from the observation. Similarly, if the kitty is dead, not only can you tell that the kitty has been dead for some time, a qualified vet may be able to tell you exactly how long that time was. So there, once again the cat's classical state is well-defined and can be fully reconstructed.

Do you see the difference? In the case of the double-slit experiment, the electron (because it belongs to a quantum state) had no classical state between measurements. In the case of the cat, it had a classical state all along, because it is a classical object.

***In the ambit of the so-called hidden-measurements interpretation of quantum mechanics, the observer-effect can be understood as an instrument effect which results from the combination of the following two aspects: (a) an invasiveness of the measurement process, intrinsically incorporated in its experimental protocol (which therefore cannot be eliminated); (b) the presence of a random mechanism (due to fluctuations in the experimental context) through which a specific measurement-interaction is each time actualized, in a non-predictable (non-controllable) way.

****The observer effect, which notes that measurements of certain systems cannot be made without affecting the systems. Heisenberg offered such an observer effect at the quantum level  as a physical "explanation" of quantum uncertainty. It has since become clear, however, that the uncertainty principle is inherent in the properties of all wave-like systems and that it arises in quantum mechanics simply due to the matter wave nature of all quantum objects. Thus, the uncertainty principle actually states a fundamental property of quantum systems, and is not a statement about the observational success of current technology. It must be emphasized that measurement does not mean only a process in which a physicist-observer takes part, but rather any interaction between classical and quantum objects regardless of any observer.

So when we talk about truths of the world, we really mean facts of the moment about the classical things unless we mention about other worlds. Period!

Views: 365

Replies to This Discussion

353

http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec13.html

--

One of the important feature of quantum mechanics is the uncertainty principle which states that the product of the uncertainty of a particle's position and momentum must be greater than a certain value, in other words, the position and momentum of a particle cannot both be precisely known. This has to do with the probabilistic nature of quantum mechanics. When you measure a particle's momentum or position, there are multiple values that you might measure with different probabilities. After many measurements, you will arrive at a distribution averaged around what you would expect to measure classically with some standard deviation. Per the uncertainty principle, the smaller the standard deviation in position is (i.e. the higher the chance that you will measure your particle near the classical value), the greater it will be in momentum and vice versa. At large scales, the magnitude of uncertainty is so small that it won't even come close to the precision of the instrument being used to take the measurements. Interesting to note is that the uncertainty principle is an inherent property of wave-like systems and is not unique to quantum mechanics.

--

Quantum Field Theory, which describes a world made of fields.  In QFT the electron is not a particle, it is a spread-out field (a property of space).  The field concept is not easy to grasp, but once you are comfortable with it, it all makes sense.  The weirdness of QM and even the paradoxes of relativity vanish in QFT.  Please take a look at my website: Home Page - Quantum Field Theory

Another way of looking at it is this: In either the double-slit experiment or in the case of Schrödinger's cat, the outcome of the experiment cannot be predicted based on the initially available (classical) information. However, this is where the similarities end. Because once the result becomes known, the state of Schrödinger's cat (or your coin) can be fully reconstructed classically. In contrast, the electron had no classical trajectory, so reconstructing it is not possible even if the outcome of the experiment is known.

Now you may argue that even a macroscopic object like a coin or a kitty is not perfectly classical, because it contains a finite number of quantum particles. True. But for a complex object like these, any deviation from the classical state becomes so exceedingly tiny, it will never be measurable. Things would be different for intermediate-size objects, e.g., something made from only a thousand atoms or whatever. There, the classical reconstruction of the object's trajectory would not be perfect anymore. And as we further reduce the number of particles (that is, the number of independent degrees of freedom that describe the object) the classical description increasingly becomes an approximation until it loses its meaning completely, as in the case of a single electron in the double-slit experiment.

--

You see, the boundary between classical and quantum is still a topic of continuing discussion in the field of physics. While it is a standard interpretation within the physics community that quantum uncertainties and effects reduce and cancel out as the system gains more and more particles, the fact is, physicists have already been able to devise ways to allow macroscopic systems to exhibit quantum behavior. Surprising, right?

This type of macroscopic quantum weirdness, however, requires macroscopic objects to be in very low temperatures, extremely close to absolute zero, to be seen. The reason for this is that when the object is at the normal room temperature, each particle experiences a random sequences of bumps from other particles (environmental influences), and that incessant interaction destroys the superposition state.

--

I want to put a question mark against the classical notion of objective existence--if not a spike into the notion. I am not going to say that there is no objective existence. I will question how we sometimes think (thought) about it classically. This will not answer the quantum question but may shed light on it. Although there are special issues of quantum mechanics, what we will see is that the quantum and the classical are not as different as might be thought. Specifically the thoughts below will suggest that 'interaction' and 'observation' are or might not be essentially different (certainly, observation is interaction).

What I will say is not new. It occurs in some form in the writings of Plato and Alfred North Whitehead and surely others who have pondered such issues.

Imagine a 'universe' that has never had, is not having, and never will have interaction with ours. Except that we can imagine it, it might as well not exist for us. But even the imagination is ours, in our universe and has nothing to do with the other universe. You may think that that universe exists but 'it' might not; you may think 'it' does not exist but it might; you might think it does and it does... (A side issue: what are we talking about when talk about something that we we say 'does not exist'? This is the classic problem of negative existentials that I happen to think is not a deep problem in itself but is an occasion to clarify the nature of linguistic meaning).

If there is something in my universe that does not affect me in any way it might as well not exist for me. But it might affect someone else or one of Jupiter's moons and that might affect me; but in that case it does not satisfy the premise of the previous sentence.

Ultimately the existence of something that has no effect is a moot issue. To exist is to be causal (in some sense). The pertinence to the question is that observation is a special case of cause and effect.

These reflections walk a narrow path between the rocks of (old metaphor) solipsim (it exists because I think it) and absolute objectivity (it exists in splendid isolation from everything else including observation).

These thoughts could have occurred before quantum theory (and in some form or other did).

I wonder if thesethoughts above point to the importance of philosophy and physics for one another (which is not at all a new idea).

--

https://www.quora.com/Why-doesn-t-the-double-slit-experiment-prove-...

RSS

© 2024   Created by Dr. Krishna Kumari Challa.   Powered by

Badges  |  Report an Issue  |  Terms of Service