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3 Questions -- Entanglement, 'The Observer Effect' and 'The Uncertainty Principle'

  1. Feb 3, 2015 #1
    Hi, I have 16 years old, I am planning to be a physicist in the near future, and I have 3 doubts, could you guys answer to me?

    1. Does quantum entanglement proves that everything is connected?

    2. 'The Observer Effect' and 'The Uncertainty Principle' somehow apply in the macro world?

    3. I saw one day a philosopher who said that because of 'quantum entanglement' he could sustain his theory about the "space can be an illusion of our minds" because the "Spooky Action at distance". And I ended up getting in doubt, tell me this is pseudoscience?
    Last edited: Feb 3, 2015
  2. jcsd
  3. Feb 3, 2015 #2
    I once read in a book that Quantum entanglement is usually thought of as some sort of faster-than-light connection, that however, is based on the fact that they are seperate "things",which does not seem to be the case.
  4. Feb 3, 2015 #3


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    1. Only if everything interacted with each other at some point. The universe is very big, and there are parts of the universe which are too far to detect yet. I don't think there's any way to be connected to them. For objects closer together, in practice, the effects of entanglement become invisible at macroscopic scales because it becomes impossible to track all of the interactions with the environment, and it looks totally random.

    2. Anytime we use a device or experiment to measure quantum effects, we are coupling the micro world to the macro world. So, quantum effects certainly effect the macro world.

    3. Without knowing the exact context, I cannot know if you are properly relaying the philosopher's statements, but it sounds like pseudoscience.
  5. Feb 3, 2015 #4


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    1. Quantum entanglement proves nothing. There are certain interpretations of quantum mechanics that would say that entanglement suggests the possibility that the Universe can be described by a single wavefunction, of which all particles are sub-systems. This is of course, very speculative, but interesting to think about.

    2a. The observer effect and the uncertainty principle do apply to the macro world. Even classically, a measurement slightly changes that which is measured, simply because of conservation of momentum and energy. You could say measure how fast a car is going by bouncing radio waves off of it. This changes the momentum of the car (a ridiculously small amount), but if you were measuring the speed of something much lighter, the impact would be a lot more significant.

    2b. The uncertainty principle also applies to the macro world as well. Anything with wave-like behavior has an uncertainty principle associated to it. One neat example is in sound waves. It's impossible to play a single note for an arbitrarily short duration. Instead of being a smooth note for a shorter and shorter period of time, the frequency spectrum of the sound will have a wider and wider range until what sounded like a single note, sounds like a random noise.

    3. Spooky action at a distance only implies (very generously) that there are certain aspects of quantum measurement events that cannot be explained locally (i.e., by influences traveling at or below the speed of light). If you want to separate the science from the pseudoscience, a good manner of intuition about quantum mechanics can be gathered by learning about actual physical experiments. Optics works particularly nicely for this.
  6. Feb 4, 2015 #5
    Thank you guys for the answers ♥
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