Hello! I'm Dr. Anya Petrova, a theoretical astrophysicist specializing in the study of extreme environments in the universe. I've dedicated my career to understanding the most enigmatic and energetic objects in the cosmos.

Your question about the hottest thing in the universe is a fascinating one, and it delves into the heart of some of the most extreme phenomena we know of.

To answer this question accurately, we need to define what we mean by "hottest." Temperature is a measure of the average kinetic energy of particles within a system. The hotter something is, the faster its particles move.

Now, let's consider some of the contenders for the title of "hottest thing in the universe":

* The Big Bang: The early universe, immediately after the Big Bang, is estimated to have had a temperature of 10^32 Kelvin (K). This is an incredibly high temperature, but it's important to note that the universe was incredibly dense at this point, and the concept of temperature might not be entirely applicable.

* Active Galactic Nuclei (AGN): These are the extremely bright, energetic centers of some galaxies powered by supermassive black holes. The accretion disks surrounding these black holes can reach temperatures of 10^7 - 10^9 K.

* Supernovae: The explosive deaths of massive stars, supernovae release enormous amounts of energy and heat, with temperatures reaching 10^9 K.

* Neutron Stars: These incredibly dense remnants of massive stars have temperatures of 10^6 K, although they can reach 10^12 K in their cores.

* Quark-Gluon Plasma: This exotic state of matter, thought to have existed in the early universe, is characterized by a soup of quarks and gluons. It has been experimentally created in particle accelerators, achieving temperatures of 10^12 K.

**So, what is the hottest thing in the universe?**

The answer is not so straightforward. While the Big Bang had the highest temperature at a specific point in time, it is impossible to directly measure or observe this temperature. The other contenders are all incredibly hot, but their temperatures are also dependent on location and specific conditions within these objects.

**Ultimately, the "hottest thing" depends on what we define as "hot" and how we measure it.** The temperature of the early universe, though incredibly high, was a temporary state. AGN, supernovae, and neutron stars are all incredibly hot in specific regions, but these are localized phenomena. Quark-gluon plasma, though created in labs, is an artificial environment.

Therefore, we can't definitively declare one thing as the "hottest" in the universe. Instead, we can marvel at the incredible range of temperatures and energy densities that exist throughout the cosmos.

I hope this exploration has been enlightening! If you have any further questions about the universe's extreme environments, don't hesitate to ask.
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The hottest thing that we know of (and have seen) is actually a lot closer than you might think. It's right here on Earth at the Large Hadron Collider (LHC). When they smash gold particles together, for a split second, the temperature reaches 7.2 trillion degrees Fahrenheit. That's hotter than a supernova explosion.read more >>