Tuesday, April 16, 2019

Seven common myths about quantum physics

I have been popularising quantum physics, my area of research, for many years now. The general public finds the topic fascinating and covers of books and magazines often draw on its mystery. A number of misconceptions have arisen in this area of physics and my purpose here is to look at the facts to debunk seven of these myths.
Don't worry, you don't need to know much about  to read this article. I will mostly be explaining what quantum  isn't, rather than what it is…
1. "Quantum physics is all about uncertainty"
Wrong! Quantum physics is probably the most precise scientific discipline ever devised by humankind. It can predict certain properties with extreme accuracy, to 10 decimal places, which later experiments confirm exactly.
This myth originated partly in Werner Heisenberg's "uncertainty principle". He showed that there is a limit to how accurately two quantities – for instance a particle's speed and its position – can be measured simultaneously. When quantum physics is used to calculate other quantities, such as the energy, or the magnetic property of atoms, it is astounding in its precision.
2. "Quantum physics can't be visualised."
Quantum physics describes objects that are often "strange" and difficult to put into pictures: wave functions, superimposed states, probability amplitude, complex numbers to name but a few. People often say that they can only be understood with mathematical equations and symbols. And yet we physicists are always making representations of it when we teach and popularise it. We use graphs, drawings, metaphors, projections and many other devices. Which is just as well, because students and even veteran quantum physicists like us need a mental image of the objects being manipulated. The contentious part is the accuracy of these images, as it is difficult to represent a quantum object accurately.
Heisenberg’s ‘uncertainty principle’. Credit: Margaux Khalil and Janet Rafner, Author provided
Working together with designers, illustrators and video makers, the Physics Reimagined research team seeks to "draw" quantum physics in all its forms: folding activities, graphic novels, sculptures, 3-D animations, and on and on.
3. "Even scientists don't really understand quantum physics"
One of the leading lights in the field, Richard Feynman himself said: "I think I can safely say that nobody understands quantum mechanics." But he then immediately added: "I am going to tell you what nature behaves like." Niels Bohr, one of the founding fathers of the discipline, gives a good summary: "Those who are not shocked when they first come across  cannot possibly have understood it."
Physicists do understand what they're doing when they're manipulating the quantum formalism. They just need to adapt their intuitions to this new field and its inherent paradoxes.

4. "A few brilliant theorists came up with the entire concept of quantum physics"

1 comment :

  1. I believe the spiritual mind moves the physical body. So there presumably is a point of contact between the spiritual realm and the physical realm. Furthermore, nature is controlled by G-d. So logically there must be a point of contact between the physical realm and the spiritual real. It maskes sense that this would happen at the quantum level.


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