Thermodynamics: The 2016 advent calendar
Day 9

What the first law means to a particle physicist

Dr Suzie Sheehy explains how the first law of thermodynamics helps particle physicists understand our world.

The four laws of thermodynamics touch almost every type of science, and impact on research and understanding in different ways. In this animation, particle accelerator physicist Suzie Sheehy discusses why the first law of thermodynamics is so important to particle physics.

To describe the motion of almost any system, from a car on a road to particles in an accelerator, you have to be able to trust that certain quantities are conserved. From the simple rule that energy is conserved, you can deduct incredible information.

In a particle accelerator, particles are collided with each other, or with other matter. The result is a spray of the component particles, but some of these can’t be detected by modern machines. For example, neutrinos have almost no mass and as such are almost impossible to directly detect. But because energy is always conserved, the physicists can tell what properties they haven’t detected by calculating the difference between the initial input and the output they find.

The first law of thermodynamics gives a predictive power that lets scientists understand the world.

This video was supported by the Science and Technology Facilities Council. Watch more from our series on particle accelerators.

Watch our series on particle accelerators

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