Weird side of thermodynamics | Negative Temperatures

Negative absolute temperatures are a fascinating and counterintuitive concept. 🌡️❄️
Negative temperatures do not occur in classical systems; they are seen only in certain quantum systems.
We've used the Boltzmann distribution framework to explain temperature and thermal distribution because it provides an easy-to-understand basis and avoids going into complexities. However, the distribution will be based on Bose-Einstein or Fermi-Dirac distributions in quantum systems with negative temperatures. The discussion of negative temperatures in terms of the Boltzmann distribution is still relevant because it provides a simplified framework for understanding the concept of negative temperatures.
This video is heavily based on information provided in the article www.quantum-munich.de/119947/....
Music by Aleksey Chistilin from Pixabay
Audio File URL:
pixabay.com/music/beautiful-p...
0:00 Introduction to video
1:03 Entropy and temperature
7:10 Is our universe at Negative temperature?

[@qazinoorwasi]

And so the wait was worth it. ❤️

[@RoshanKapoor-rl3ul]

Man liked the end part of the video as it questions a wider aspect of this topic.
Loved the background music.
7:10

[@poralekhadotkom]

sir please refer some good books for jee and olympiads

[@krushnamali6183]

which class r u in?

[@SwayamKrishnaartsandcrafts]

@@krushnamali6183 im JEE 2025 aspirant pls recommend some good physics books. i score around 30-40 marks in physics jee adv mocks of allen

[@krushnamali6183]

@@SwayamKrishnaartsandcrafts i am also a 2025 aspirant, i suggest you PG books and hcverma(or allen module). Do illustration and numerical section jitna ho ske utna

[@SixTough]

How can particles have maximum possible energy?

[@apq3710]

It depends on the system they are in. For example, you can imagine a room with balls in it. While it's true that their kinetic energy is not bounded, they can't have arbitrarily big potential energy because of the ceiling.
There are examples of such systems where the total energy of particles is bounded but none come to mind right now.

[@SiddhavHegade]

Good question. Atoms can be trapped in an optical lattice which consists of periodic potential (Quantum mechanics), which can be created by laser beams. It creates a band structure. This means the energy splits up in bands like for eg: Valence and conduction bands in a metal or semiconductor. Bands are separated by band gaps - Energy regions without any states for particles (particles cannot accommodate these gaps- quantum mechanics). Therefore, each band naturally has a lower as well as an upper bound for energy. While there is more to it, you can read about it more.