SCHRÖDINGER’S CAT Daria Andreeva (LVI

MATRIARCH COMPETITION ORCAS

Agnes Rose, LVI

Pods of orca whales inhabit every major ocean, with each family able to survive from the help of an experienced hunter, the grandmother. Grandmother whales can live 80 years or longer, whilst most males generally only live until the age of 30. After various studies, we have learnt a great deal about a specific population of these whales, known as the Southern Residents.

Each carf is born into a matriline (the mother’s family), where they spend most of their life hunting, eating, playing and even communicating with each other through their own specific calls. A young whale also shares a dialect with neighbouring families meaning they can socialise regularly. Once a female reaches the age of 15 these interactions become opportunities to mate with the neighbours’ young males. She and her calves return to the matriline and continue their life together, whilst the male remains with his own mother. This mother then gives birth on average every six years until the age of 40 when she enters menopause. This is fascinating as it is only known for some species of whales as well as humans for females to continue to live for years after they stop reproducing. Grandmothers then lead the pod and begin to hunt for salmon; during this time she shows her young where to find the most fertile fishing ground as well as sharing 90% of the salmon she catches with the pod. The grandmother’s expertise can be the difference between life and death for these families. Because most of the pod are daughters or grandchildren of these elder female whales, they focus the later portion of their lives on benefiting the whole pod, allowing younger females to concentrate on reproducing.

These populations of Southern Resident Killer Whales are critically endangered due to the rapidly declining salmon populations. We desperately need to invest in restoring the salmon populations to prevent extinctions of these impressive creatures.

SCHRÖDINGER’S CAT

Daria Andreeva, LVI

In 1935, Erwin Schrödinger devised a thought experiment in discussion with Albert Einstein; a cat is placed in an enclosed steel chamber along with a vial of poison which may or may not be released according to the random decay of a radioactive isotope.

An observer outside the chamber does not know whether the cat is deceased or not until they open the box. Although there are many variations of this experiment, such as one with gunpowder or with a non-radioactive poison which the cat has the option to consume, the concept remains the same: according to the Copenhagen Interpretation of Quantum Mechanics, the cat is simultaneously alive and dead, in two separate timelines, until an observer opens the chamber. This illustrates what is meant by the cat existing in what is called a quantum superposition.

Although quantum mechanics has succeeded in being the most precise and accurate branch of any science, regarding experimental predictions and measurements, there is broad disagreement about how to interpret it all – how to understand and describe this theory.

This first analysis of the thought experiment is referred to as the Copenhagen Interpretation. In this interpretation, the observer is in absolute control over the situation and the act of opening the chamber is what ends this turbulent state by determining the outcome one way or the other. One of the most well-known scientists who is associated with this interpretation is Niels Bohr, who argued that the observer simply observes and does not determine the result. It is only in the eyes of the observer that the cat simultaneously exists in two states and that the outcome of the observation was determined well before the box was opened. The cat is not at the focus of this interpretation.

However, this is not the idea that Schrödinger wanted to promote, instead he wished to illustrate the absurd nature of this paradox and all the possible conclusions being able to exist at once. This Many-Worlds Interpretation was further formulated by Hugh Everett in 1957. In this interpretation, the observer has less importance and the cat’s undefined state carries on even after the opening of the chamber. Yet, all these states are decoherent, meaning that all the possible outcomes do not have interactions with each other and do not affect one another, so existing in separate timelines of outcome. Another interpretation of this thought experiment is the Relational Interpretation (first proposed by Carlo Rovelli in 1994). In this interpretation, everything in the system, including both the animate and the inanimate objects, are considered as observers of what is occurring. For example, the cat can be considered an observer of the apparatus whilst the person carrying out the experiment is considered as the observer of the entire system which includes the box or chamber in which the cat partakes. Prior to the opening of the container, the cat has all of the information about the nature of its state as well as the state of the apparatus placed with it due to it being alive or dead (i.e. if the atom has decayed or if the gun has fired, then the cat would be deceased and so aware of this fact). Despite this, the person carrying out the experiment has no knowledge of the events that may or may not have transpired within the enclosed steel chamber where the cat and the weapon are located.

This therefore means the two observers have different accounts of the situation. For the cat the current position that it is in is obvious as it is the one experiencing it. On the other hand, the experimenter bears witness to the superposition the cat seems to appear to be part of. This is only resolved by the experimenter’s observation, by opening the chamber and so, the two observers are exposed to the same amount of information as each other, allowing for a definite result.

Schrödinger was mainly concerned with the question: When does this superposition stop existing and when is the answer clear that the cat is either one state or the other? One’s initial response would be to assume that the observer cannot be in more than one state at once unlike the cat who is capable of being in this unknown state. Does this mean that the cat is a required observer for this experiment to be concluded or is an external observer required too, to provide a more well-defined state? All these alternatives seemed absurd to Einstein. He was impressed by this thought experiment and in a letter to Schrödinger (that was dated from 1950) he wrote, ‘Nobody really doubts that the presence or absence of the dead cat is something independent of the act of observation.’