Thermodynamics : https://www.youtube.com/watch?v=uc9P5yb3Xtc

[TheAnt]

Hi I had a question about this video. Indeed if I understand the video correctly it states that energy is linked to information. But how does that work indeed knowing that energy is constant, that more entropy = less information and that entropy increases. It seems that the universe will end with less information but the same amount of energy.
Thank you.

 

[Lucas SV]

Entropy can be given by
$$
S=k_B \ln\Omega
$$
where $\Omega$ is the number of microstates that correspond to your known macrostate, and $k_B$ is the Boltzmann constant. This formula holds for a microcanonical ensemble, which means that states close to the energy of the system have prety much the same probability. If you try to combine two such systems, so that they interact, you will see an increase in entropy, which means there are more microstates with the total energy.

So yes by conservation of energy the total energy of the universe will not change (ignoring quantum fluctuations), even though entropy increases due to interactions of subsystems.