Quantum shot noise, where light particles, or photons, hit the microscope’s detection device randomly, can obscure tiny objects (Source: chaoss/iStockphoto)

Quantum physics sheds light on cells

Monday, 4 February 2013
Stephen Pincock
ABC

For the first time, Australian scientists have explored the inner workings of a living cell using a new kind of laser microscopy that harnesses the laws of quantum physics.

The technique could shed light on new biological processes, the motion of microscopic particles, and even allow quantum mechanics to be studied at a scale visible to the naked eye, says the study’s lead author, physicist Dr Warwick Bowen from the University of Queensland.

When scientists want to study the miniscule goings-on within a living cell, they come up against a limit known as “quantum shot noise,” Bowen and colleagues explain in the latest issue of the journal Nature Photonics.

This phenomenon is a result of the fact that light particles, or photons, hit the microscope’s detection device randomly.

“You can get the idea if you imagine the photons are raindrops falling on a square of ground, and you were to count the number hitting the ground in a given time interval,” Bowen explains. “Obviously, there’ll be some randomness in the number hitting the ground in a given time – this is shot noise.”

To study biological systems such as cells, scientists aim to detect very small levels of scattered light from an object within the biological specimen. Because the level of scattering from these tiny objects is so small, it can easily be obscured by shot noise.

Read more: Quantum physics sheds light on cells › News in Science (ABC Science).

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