0 Members and 1 Guest are viewing this topic.
What would happen if they interact?What do you mean by "they"?
Could you at least try to think about your questions a bit before you ask them?
Quote from: Bored chemist on 01/08/2022 14:43:32What would happen if they interact?What do you mean by "they"?Those two objects with negative temperature but different magnitude. Quote from: Bored chemist on 01/08/2022 14:43:32Could you at least try to think about your questions a bit before you ask them?
It depends on the objects and what sort of negative temperatures they have.
In a HeNe laser the electronic temperature is negative.In the ammonia maser the rotational (I think- might be something odd like a spin flip) temperature is negative.In the hydrogen maser the electron spin temperature is negative.There are other sorts too.
NASA’s Cold Atom Lab aboard the International Space Station cools atoms down to a billionth of a degree above absolute zero, or the temperature at which atoms should stop moving entirely. Nowhere in the universe are there atoms that reach this temperature naturally. But how do scientists accomplish this feat? It’s a three-step process that starts with scientists hitting the atoms with precisely-tuned lasers to slow them down. The colder atoms are, the slower they move, and the easier they are to study. Ultracold atoms can also form a fifth state of matter, called a Bose-Einstein condensate (BEC). Learning about the fundamental properties of atoms has laid the foundation for technologies that most of us use every day, such as computers. As the first ultracold atom facility in Earth orbit, Cold Atom Lab is opening up new avenues for investigation.
Negative value can be assigned to a physical parameter if it negates or cancels out the positive value of the same physical parameter.
Which means that it doesn't always have negative temperature.
Using a laser is by far the most sensible way but, in principle you could use a different light source.
The concept of negative temperature derives from a definition of temperature in terms of entropy. All it means is a condition where adding energy to a system decreases its entropy.
Gravitational potential is very real and always negative.
In classical mechanics, the gravitational potential at a location is equal to the work (energy transferred) per unit mass that would be needed to move an object to that location from a fixed reference location. It is analogous to the electric potential with mass playing the role of charge. The reference location, where the potential is zero, is by convention infinitely far away from any mass, resulting in a negative potential at any finite distance.https://en.wikipedia.org/wiki/Gravitational_potential
Quote from: hamdani yusuf on 08/08/2022 11:11:55Negative value can be assigned to a physical parameter if it negates or cancels out the positive value of the same physical parameter.So what?
In a HeNe laser the electronic temperature is negative.
Do laser cutters decrease entropy?
Quote from: hamdani yusuf on 09/08/2022 03:03:44Do laser cutters decrease entropy?no.
Quote from: Bored chemist on 08/08/2022 12:49:24Quote from: hamdani yusuf on 08/08/2022 11:11:55Negative value can be assigned to a physical parameter if it negates or cancels out the positive value of the same physical parameter.So what?If it cannot negate positive value of the same parameter, it should not be assigned a negative value.
Quote from: Bored chemist on 03/08/2022 14:27:05In a HeNe laser the electronic temperature is negative.What's the magnitude, in Kelvin?