The Wykehamist
is taught, being more intuitive, but Heisenberg’ s— and often a combination— lends itself more easily to calculation in quantum field theory, the successor to the quantum mechanics of the early twentieth century.)
Since the 1920s, quantum physics has come a long way, most significantly in its applications. In 1959, Richard Feynman gave a lecture titled There’ s Plenty of Room at the Bottom, where he suggested that control of matter at the atomic scale could enable radically new forms of computation. And thus, quantum computing was born.
There have indeed been significant developments in quantum computing since then. Quantum supremacy( when a quantum computer outperforms any classical machine on a well-defined task) was reported by Google in 2019 with their Sycamore processor. Quantum computers pose both advantages and threats; the increased processing power that quantum provides allows for more complex simulations than have ever been run before; solar power can be optimised, drugs can be tested without the need for lengthy and expensive human trials, and complex chemical reactions can be analysed. In the future, there is a very real possibility of curing cancer or running the world entirely off clean energy with the technology currently being developed.
Equally, quantum computers have their downsides; NIST has predicted that hackers will be able to use quantum technology to break current widely-used public key encryption schemes by 2030. Fortunately, NIST and other organisations are already preparing for such an event. Were we to remain unaware of this threat, the possibility of returning to a digital world without privacy would become a very real one— one with more serious implications than ever, given the increasing digitalisation of finance, communication, and personal data.
Another application of quantum physics with, perhaps, a more subtle impact is quantum sensing. This umbrella term encompasses any device that makes use of quantum properties to measure a variable( for example, atomic clocks measure time, and NV centres measure magnetic fields). The use of quantum sensing is all around us, with perhaps the most important example being GPS. When a device uses GPS to gauge location, it sends signals to several satellites and the time it takes the satellites to receive these signals is recorded and sent back. From this data the position of the device can then be triangulated, which of course requires incredibly accurate clocks. Atomic clocks use the hyperfine transition of a caesium-133 atom to measure time to an incredibly exact level.
A photo from the 1927 Solvay conference, where there was much debate between the greatest physicists of the time over new ideas relating to quantum physics. Those pictured include Marie Curie, Einstein, Schrödinger, Heisenberg and Bohr.
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