Thought Experiments

I'm surprised that a thread like this didn't already exist in the Science & Technology section. This thread is dedicated to thought experiments, it will be nice to get some feed back and for others to share their own...


Into the Anti-world:

What would happen if we were to take a person and replace all of their particles with anti-particles and turn them into an anti-human? Would they be able to venture into the anti-world? I wonder what would be there to discover? Then we can take all of the anti-particles of the person and reconvert them back into particles and talk with them about their experience.


The non interference observation:

In the double slit experiment, "observation" means using a photon to measure an electron. What would happen if there was another way to measure electron? Would it still have the same "observer effect"?

How about bringing the room to a very cold temperature to slow down the vibration of the electrons, if the experiment is redone in this condition with and without the observer effect, will the conclusions be any different?

Also, I would just like to ask, how is it exactly that an observer interferes with the electron wave pattern? I think this experiment definitely needs more testing



Deterministic Quantum Physics:

What if the uncertainty principle just something that we can't understand? Back then, we understood sound and how to manipulate it but we didn't know about sound-waves until later, and the ones who proposed the idea were criticized because it sounded too mystic and unscientific. What if the uncertainty principle is just an estimation and the real quantum physics is not probabilistic but is deterministic?
If you throw the dice in the air, it seems like probability, but if you measure the wind-speed, the position it was in before it was thrown, the thrust of the throwing, and the amount of time it takes to reach the surface, you can determine what number it will fall on, but without that information it just seems probabilistic. The same thing may be happening with Quantum Physics. So I propose some thought provoking questions:

1) What is the cause of probability in quantum physics?

2) Are there any environment which affect the probabilities? And if so, at which occasions is one probability more likely than the other?


Well, that's all I got for now...

I watched between the wormhole (I think, you know the series with Morgan Freeman). The had a guy doing an experiment where he was able to suspend a drop of silicon over some type of oscillating liquid maybe water I only caught the end of it.

They said they could keep this going for days if they wanted. Also supposedly were able to demonstrate another form of the slit experiment. Like I said I only caught the end of it so I don't fully understand it but thought I would throw it out there for anyone interested.

The other night I conducted my own thought experiment. I was laying in bed with my wife , we were in the back to stomach spoon position. I had my head aginst the back of hers. So then I was wondering if I could have a thought transference to her. I concentrated on the phrase," Do you love me? So I just repeated it about 4 times in my head (I closed my mouth tight to make sure I wasnt inadvertantly mouthing it). Then after that 4th time she nodded her head and whispered "yes". I was blown away!!!! I gently shook her shoulder and asked why she nodded her head and said ,yes. She told me she didnt know why. I then told her what I was doing. Needless to say, my thought experiment was a sucess. I will continue to try more and report back with the results.

Oh and Gerald the show is through the wormhole

reply to post by Talltexxxan


What an interesting experiment. Please do tell us more when you try it again.

What an interesting experiment. Please do tell us more when you try it again.

I will try similar yes/no questions to her.
My wife, my own little lab rat.
Im interrested to hear if any other members have tried similar experiments.

Originally posted by arpgme
I'm surprised that a thread like this didn't already exist in the Science & Technology section. This thread is dedicated to thought experiments, it will be nice to get some feed back and for others to share their own...


Into the Anti-world:

What would happen if we were to take a person and replace all of their particles with anti-particles and turn them into an anti-human? Would they be able to venture into the anti-world? I wonder what would be there to discover? Then we can take all of the anti-particles of the person and reconvert them back into particles and talk with them about their experience.

Are you sure you have correctly understood the principles which explain the presence of particles and anti particles? You should know that the existance of anti particles , does not prove or even suggest the existance of an anti world, or shared universe so to speak. Anti particles are a part of our universe, just like oxygen and electrons are. Fundamentaly speaking, theres every chance that our own universe has functions and dynamics which would not come to pass at all, if it were not for these anti particles.

If you turned a person into anti matter, then all that would happen is that any part of thier being that was made of , for instance hydrogen, which came into contact with its correspondant particle, would simply self destruct on contact. It would be damned messy in other words.

The non interference observation:

In the double slit experiment, "observation" means using a photon to measure an electron. What would happen if there was another way to measure electron? Would it still have the same "observer effect"?

How about bringing the room to a very cold temperature to slow down the vibration of the electrons, if the experiment is redone in this condition with and without the observer effect, will the conclusions be any different?

Also, I would just like to ask, how is it exactly that an observer interferes with the electron wave pattern? I think this experiment definitely needs more testing

logicaly speaking, if you slow down the electrons vibration rate in order to perform an experiment of any nature on the electron, you are already observing it, and changing its natural behavior in order to observe it. Wether you actualy watch it hawk eyed the whole time is neither here nor there, because you have already skewed your result.

Deterministic Quantum Physics:

What if the uncertainty principle just something that we can't understand? Back then, we understood sound and how to manipulate it but we didn't know about sound-waves until later, and the ones who proposed the idea were criticized because it sounded too mystic and unscientific. What if the uncertainty principle is just an estimation and the real quantum physics is not probabilistic but is deterministic?
If you throw the dice in the air, it seems like probability, but if you measure the wind-speed, the position it was in before it was thrown, the thrust of the throwing, and the amount of time it takes to reach the surface, you can determine what number it will fall on, but without that information it just seems probabilistic. The same thing may be happening with Quantum Physics. So I propose some thought provoking questions:

1) What is the cause of probability in quantum physics?

2) Are there any environment which affect the probabilities? And if so, at which occasions is one probability more likely than the other?


Well, that's all I got for now...

edit on 19-7-2011 by arpgme because: (no reason given)

edit on 19-7-2011 by arpgme because: To add more thoughts

Probability is only used to describe an event when things like an objects starting position, spin rate, the wind speed, and other important factors are unknown, as they are in any half decent game of chance.

I guess thats probably the problem with quantum.

reply to post by arpgme

What would happen if we were to take a person and replace all of their particles with anti-particles and turn them into an anti-human? Would they be able to venture into the anti-world?

The person would instantly self-destruct in a massive explosion that converts all the antimatter in him, and an equal amount of ordinary matter from his immediate environment, into energy. The force of this explosion would be more than enough to atomize planet Earth.

In the double slit experiment, "observation" means using a photon to measure an electron. What would happen if there was another way to measure electron? Would it still have the same "observer effect"?

To measure something (in this case the position and momentum of an electron), you have to see it first. That means you have to shine a light on it. In other words, bombard it with photons. So no, there is no way to measure an electron, or indeed anything else, that doesn’t involve electromagnetic radiation (ie light) in some way.

How about bringing the room to a very cold temperature to slow down the vibration of the electrons, if the experiment is redone in this condition with and without the observer effect, will the conclusions be any different?

No. This isn’t about electron oscillation, this is about the movement of electrons through space.

Also, I would just like to ask, how is it exactly that an observer interferes with the electron wave pattern? I think this experiment definitely needs more testing.

By creating an event that collapses the probability field. No, it doesn’t need more testing. Most first-year physics students perform an experiment that demonstrates it clearly.

What if the uncertainty principle just something that we can't understand?

It isn’t. We understand it quite well, and it has been both experimentally and mathematically verified. There is a fundamental uncertainty to quantum effects and that, I regret to inform you, is that.

Back then, we understood sound and how to manipulate it but we didn't know about sound-waves until later, and the ones who proposed the idea were criticized because it sounded too mystic and unscientific.

Back when? The sixth century BC?

What if the uncertainty principle is just an estimation and the real quantum physics is not probabilistic but is deterministic?

This is the most obvious possible argument against the Uncertainty Principle, and was the first thing to be addressed and eliminated. Some of the best minds in the world tried to argue against the Principle and ended up having to accept it.

If you throw the dice in the air, it seems like probability, but if you measure the wind-speed, the position it was in before it was thrown, the thrust of the throwing, and the amount of time it takes to reach the surface, you can determine what number it will fall on, but without that information it just seems probabilistic. The same thing may be happening with Quantum Physics.

First, the macroscopic and the quantum worlds follow different principles with relation to causality, so one tells us nothing about the other. Again, both theory and experiment confirm this.

Second, even in the macroscopic world, the factors affecting the fall of dice are so many (many more than you have listed, e.g. the topography and coefficients of restitution and friction of the surface to which the dice fall, the angle of incidence, most fundamentally of all the momentum, etc, etc, etc.) are also random in the sense of not being predetermined by the experimenter, and neither you nor the most advanced computer in the world can ever have a hope of predicting the outcome. It is effectively random.

So I propose some thought provoking questions:

1) What is the cause of probability in quantum physics?

2) Are there any environment which affect the probabilities? And if so, at which occasions is one probability more likely than the other?

(1) is not thought-provoking, it is meaningless. Probability does not have causes; probability is a function of effects. Perhaps you mean, what is the cause of the fundamental randomness of quantum effects? The answer is that it is just the way the world happens to be made. Asking why is ultimately a question in metaphysics, not physics. Meaning that no verifiable answer can be given.

(2) All environments affect the probability of a particular outcome for a particular event. The likelihood of a given outcome is calculated using Schrödinger’s Wave Equation.

So Einstein was wrong and the world isn't deterministic? If Quantum Physics is truly probabilistic then it can't be deterministic. It seems as though determinism is evident in the macro field and probability is evident in quantum physics, but they are both physics? How can this be so? Is reality split in half following two different set of laws? If so then what is reality anyway? Does anyone think that the two can ever be joined?

reply to post by arpgme

So Einstein was wrong and the world isn't deterministic?

Einstein was right. The world, on the level of macroscopic, nonquantum events, is deterministic.

If Quantum Physics is truly probabilistic then it can't be deterministic.

Quantum mechanics is the realm of the very small. It applies to the world of particles smaller than atoms (though recent experiments have shown that in certain extreme cases macroscopic objects can also be forced to behave in a quantum way). However, when all these particle interactions are summed up, their effects on a macroscopic level are predictable and deterministic. We have no idea how this happens; there are many competing hypotheses, such as the Many Worlds interpretation, the Many Minds interpretation, decoherence, backward causality and so on.

It seems as though determinism is evident in the macro field and probability is evident in quantum physics, but they are both physics?

Yes. Both quantum mechanics and classical mechanics make testable predictions, and when tested, these predictions are fulfilled. They are both right and they are both most certainly physics.

How can this be so?

Is reality split in half following two different set of laws?

No, reality is not split. Our understanding of it is imperfect. Either ultimate reality transcends our undesrtanding of it through physics, or reality changes its appearance depending on how you look at it. We are using the wrong equipment to understand reality. This may include our brains.

If so then what is reality anyway?

At our present state of knowledge, this, too, is a question in metaphysics, not physics

Does anyone think that the two can ever be joined?

Yes, most physicists believe that we will eventually come to understand and resolve this paradox. Many philosophers, however, do not, and some even question whether interrogating reality in a scientific way is meaningful.