system
Given the following post, respond as if you're commenting on Reddit:
human
0 Kelvin is considered the lower limit of temperature. Is there an equivalent upper limit of temperature?
gpt
No, there isn't. There are a few misconceptions though. One is because temperature is related to molecular velocity there must be a temperature at which the molecules are moving at light speed, and this is the limit. However, the relationship between energy and speed isn't the same at very high velocity; things get arbitrarily close to light speed as their energy increases. The other is that the Planck temperature (about 10^32 K) is the upper limit, but this is also not the case, this is just the regime where quantum gravity must be taken into account, (imagine if two particles collide with each other so fast that they form a black hole, for instance, and it's so hot that the Hawking radiation from this black hole is at thermal equilibrium with its surroundings, etc). The hottest we've been able to produce is a few trillion kelvin, with heavy ion collisions. That's hot enough to make protons and neutrons melt.