Thread: Examples of a "quantum event"?

With reference to the Quantum Suicide thought experiment, I am conscious that it is valid only where death is caused by a quantum event.

The common example given is that of a trigger whose activation or otherwise depends on the truly random outcome of radioactive decay. (Or something.)

My question is: what other examples are there of quantum events, radioactive decay being apparently one of them? Or is there potentially an infinite list - so long as a result depends (as the trigger in the above example does) on measuring a quantum system?

Returning to my first point, that death must be caused by a quantum (not classical) event, given that classical objects are comprised of quantum systems (that is to say, everything is made of particles), couldn't it be argued that getting hit by a bus is a quantum event, or have I missed the point of the distinction?

Thanks in advance

It has to be a random event, with some probability of surviving.

Right - I guess what I'm asking is: what are other examples of a trigger, other than radioactive decay?

Originally Posted by mitya

Right - I guess what I'm asking is: what are other examples of a trigger, other than radioactive decay?

Actually, one can express it general terms as: if one prepares a particular quantum state and measures this state using an observable whose eigenvectors do not include the prepared quantum state, then the outcome of that measurement will be random with respect to all possible outcomes of that measurement. For example, if has prepared a photon to be plane-polarised in the vertical direction, then measuring the plane-polarisation at 45° to the vertical will produce a 50:50 probabilistic outcome of the photon being plane-polarised in this direction or not being plane-polarised in this direction. In other words, detection of the photon passing through the polariser could be used as a trigger. There are many triggers that could be used... too many to provide any sort of comprehensive list.