Parallel universes - Many worlds (Schrödinger's cat experiment)

Parallel universes - Many worlds (Schrödinger's cat experiment)

One of the greatest secrets of physics we still do not completely understand, is what happens when the smallest things interact with the big things, that is when quantum mechanics meets our everyday world? You have probably heard of a legendary Schrödinger's cat.

It is a thought experiment, sometimes called a paradox, that was excogitated by Austrian physicist Erwin Schrödinger in 1935. It illustrates what he saw as the problem of the Copenhagen interpretation of quantum mechanics applied to everyday objects, resulting in a contradiction with common sense.

Here is what Schrödinger devised: a cat, a flask of poison, and a radioactive source are placed in a sealed box. If an internal monitor detects radioactivity (i.e. a single atom decaying), the flask is shattered, releasing the poison that kills the cat. The Copenhagen interpretation of quantum mechanics implies that after a while, the cat is simultaneously alive and dead. Yet, when one looks in the box, one sees the cat either alive or dead, not both alive and dead. This poses the question of when exactly quantum superposition ends and reality collapses into one possibility or the other.

The problem is physics cant explain how the cat or the particle goes from being in a combination of two states at once, to being just one or just the other.Nor do we know how the decision is being made. This poses a problem for every single quantum mechanics experiment.In every case we can predict how likely it is for a particle to be in one state or another, but we still have no clue how it actually ends up that way. That is where “Many worlds theory” of the quantum mechanics comes in.

Diagram of Schrödinger's cat theory (Credit: Dhatfield/Wikipedia)


Many worlds proposes an idea that quantum system doesn’t actually decide, rather that at every junction where large everyday stuff interacts with the quantum system the timeline of history splits, and both possibilities happen on different alternate branches.

The quantum-mechanical "Schrödinger's cat" paradox according to the many-worlds interpretation. In this interpretation, every event is a branch point. The cat is both alive and dead—regardless of whether the box is opened—but the "alive" and "dead" cats are in different branches of the universe that are equally real but cannot interact with each other.


Source: MinutePhysics, Wikipedia

Featured image:  Schrödinger's Cat, many worlds interpretation, with universe branching. Visualization of the separation of the universe due to two superposed and entangled quantum mechanical states. (Credit: Christian Schirm)


Comments 5 years ago

Why do scientists still continue to use animals to test theories, when proof of afterlife/other universes are already known to exist? There is so much evidence now, eg dead people coming back to life and recalling what happened on the operating table. It is absolutely pathetic to use poison and radiation - this reminds me of Nazi experiments. If we still think we are the only ones in this Universe we deserve to become extinct..

aaaah ( 5 years ago

Okay, so I'm hoping that this comment is a joke or something, but I'm going to reply to it anyways. A thought experiment is not actually conducted. The whole point is that physically doing it would be useless, because we can't test to see if the cat was really in an indeterminate state. So I doubt that anybody has ever bothered to actually kill cats in this way, seeing as how it wouldn't prove anything. Schrodinger was just pointing out that quantum mechanics does not describe macroscopic objects (although I'm pretty sure there have been other non-animal involving experiments recently that have proven otherwise).

Sarita 5 years ago

Aha! the conundrum of the human mind-what lies beyond? One needs to understand the work of mystics/occultists who have cracked the mystery from a purely spritual point of view which the modern mind finds hard to accept. Rudolph Steiner was the only individual I know who I can call 'a spiritual scientist' and perhaps his theories would satisfy the most discerning scientist? SEEK AND YE SHALL FIND

Angel 5 years ago

What does a fish know about the water in which he swims all his life?

Angel 5 years ago

"Death" the great mystery...

Art McConnell 5 years ago

Since the cat meets all the criteria of a conscious observer, the experiment is never in a two-state state.

Art McConnell 5 years ago

It would seem more likely that the many possible/probable universes condense into one reality, which we call macro experience. All you have to do to imagine this is to open up to the possibility that our perception of the so-called "arrow" of time does not "flow" unidirectionally as we have always thought it does.

Lawrence L. Pierson 5 years ago

Follow up subscription, teach me!

Lawrence L. Pierson 5 years ago

The two worlds exist in the same place, time only exists in our perception in order to orient our physical bodies in the physical world, time has no meaning in the spiritual world. The cat still exists in the physical world after death, it simply returns to the dust of the earth from which it came. The spirit that gave life to the cat also continues to exist in the earth. Similar is true of the radionuclide, the atom decayed and physically changed form while the energy it held, like the spirit of the cat, is released. Both the life giving spirit of the cat, and the energy that held the atom together continue to exist, as do the physical materials to put them back together again.

Guest 5 years ago

Sheldon explained this better. No offense.

Totem (@Guest) 5 years ago


Tom 5 years ago

Schroedinger had too much time on his hands and overthought the whole thing way too much. Things either are, or they are not. there doesn't have to be an inbetween state. the reason some theories can't be proven is because they are just that! these types of "explanations" of our existence are just another way to avoid the truth that we are a created being, made in the image of God Almighty.

Lawrence L. Pierson (@Tom) 5 years ago


Post a comment

Your name: *

Your email address: *

Comment text: *

The image that appears on your comment is your Gravatar