Schrödinger’s Cat is one of the more famous thought experiments in modern physics, created by Austrian physicist Erwin Schrödinger back in 1935. The Telegraph summarizes the gist of the experiment as follows:
In the hypothetical experiment … a cat is placed in a sealed box along with a radioactive sample, a Geiger counter and a bottle of poison.
If the Geiger counter detects that the radioactive material has decayed, it will trigger the smashing of the bottle of poison and the cat will be killed.
The experiment was designed to illustrate the flaws of the ‘Copenhagen interpretation’ of quantum mechanics, which states that a particle exists in all states at once until observed.
If the Copenhagen interpretation suggests the radioactive material can have simultaneously decayed and not decayed in the sealed environment, then it follows the cat too is both alive and dead until the box is opened.
The University of Nottingham’s Sixty Symbols YouTube channel provides a more complete explanation. But with or without any further introduction, you can watch the off-kilter animation, above, which imagines the origins of the original experiment. It was created by Chavdar Yordanov for an animation show in London.
Note: An earlier version of this post appeared on our site early last year.
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In quantum mechanics and in modern physics in general, the observer is often held as not really an entity which has nothing to do with the experiment, as it could happen in a classic environment more than a hundred years ago, but still as an entity which starts affecting the experiment only when, at the end of the experiment itself, he wears a white overall and starts carrying out measurements. On the contrary, the observer is part of the experiment since the beginning.
Schrödinger’s Cat-1935 (from Wikipedia):
“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 a Geiger 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 first atomic decay would have poisoned it. “
We are talking about Schrödinger’s supposition, according to which the cat is in an unknown state (alive or dead), as it is impossible, before opening the chamber, to know if the poison has been released or not. Let’s find some mistakes in the reasonings around that, hoping that they look like mistakes to the readers, too:
1) The steel chamber is not perfectly tight! Therefore, in the observer’s opinion, it is always open!!! Perfectly tight chambers do not exist (thermal or gravitational tightness).
The wave function would collapse on time anyway, as a perfect tightness of the chamber with cat, poison, counter and radioactive substance inside, is impossible. An external observer immediately interferes with the experiment, by the gravitational pull exerted by his own body on the cat, on the poison, on the counter and on the radioactive substance, or also by the heat of his own body, which is transmitted towards the chamber, which is not perfectly tight. Hence, the cat is surely dead or alive, but never a mixture of those two different states. The observer can’t even deny he knows the state of the cat before the opening of the chamber, as the death of the cat has an effect on the observer himself, as it transmits less heat towards the observer (cold body of a dead cat) and this would slightly change the physical state of the observer himself, who is a permanent and compelled observer. The same can be stated about an alive cat, which is warmer and which sends more heat to the observer, so sending a thermal information on its state and even though such information is not expressly requested by the observer.
2) Quantum physics would allow the observer to chose to observe or not. This is absurd!!! The observer is not free! He must always observe!
Einstein’s God, that who is not playing dice, is not giving us such a freedom. The observer is not free to refrain from observing. If I don’t look at the Moon, does the Moon exist? My answer is yes, also adding that I cannot stop looking at the Moon, as also if I turn back, I still interact with the Moon, gravitationally etc (also this is a looking at). Since the beginning of the above experiment, as an observer I affect the events inside the chamber of Schrödinger by the gravitational pull exerted by my body, or also by the heat transmitted by my body. And even if I want to keep my eyes closed, at the end of the experiment the higher quantity of heat transmitted by an alive cat (or lower, in case of a dead one) throug a non perfectly tight chamber, inexorably informs my body on the state of the cat!