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Does the Universe Have a Maximum Temperature? What determines the highest possible energy a particle can have? And why does temperature, of all things, take us to the very edge of physics? In this video, we explore the deep connection between confinement, energy, gravity, and the Planck temperature — the theoretical upper limit of temperature in our universe.
In the first part of the video, we investigate how squeezing a particle into smaller and smaller spaces causes its energy to rise — first through quantum mechanics, then relativity. We show how the minimum energy scales as ℏc/L and how this links directly to temperature via Boltzmann’s constant.
In the second part, we introduce gravity and show that extreme confinement leads to gravitational collapse, defining a minimum meaningful length: the Planck length. From this, we derive the Planck temperature and explore its meaning as a fundamental boundary beyond which our current theories break down.
Finally, we link this result to black hole thermodynamics and Hawking radiation, showing that a black hole with Planck-scale mass and size radiates at the Planck temperature — a beautiful unification of quantum mechanics, relativity, and thermodynamics.
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