Freestetter's world of formulas: How hot is it at the most?
If you want to know the highest possible temperature that can exist in the universe, a thermometer won't help you. You still have to find the right physics for it.
© Nyonyo/Getty Images/iStock (details)
Sometimes the heat can take its toll on us. Is there an upper limit to the maximum temperature?
Water boils at 100°C. Melting occurs much earlier, at 0 degrees; Then solid ice becomes liquid. You have to heat the metals a little more if you want to melt them.
For example, lead can easily be liquefied using a candle flame, which can reach temperatures of over 1,000 degrees. 327 degrees is enough for that, as we saw on New Year's Eve, before lead smelting was banned. Iron, on the other hand, is difficult to melt with a candle flame – and if you want to liquefy tungsten, you need a temperature of more than 3,400 degrees. During all these processes, the substance changes only its physical state: liquid lead is still lead; The atoms that make it up have only changed their bonds to each other, not their structure.
All episodes of his weekly column, which appears every Sunday, can be found here.
To change this, much higher temperatures and therefore more energy are needed, which cannot be generated purely chemically. However, when atomic nuclei collide at high enough speeds and under the right conditions, they can fuse or disintegrate. Then they lose their original chemical properties and form new elements.
However, the maximum possible has not yet been reached. Atomic nuclei are made up of protons and neutrons, and fusion or fission only changes their number in the nucleus. Only when the temperature described by this formula is reached does something new happen:
Temperature, named after the German physicist Rolf Hagedorn, can be described rather simply as the “melting point of a substance.” This is the melting point of all matter: it is the temperature at which neutrons and protons “melt.” The Hagedorn temperature (which is determined by the reciprocal of the amplitude of the strong nuclear force sH can be rounded) about 1.7 trillion Kelvin.
A spoonful of quark soup
Of course, upon arrival, protons and neutrons do not become liquid. The building blocks of the atomic nucleus itself are made up of quarks, which according to current knowledge are elementary particles. The strong nuclear force binds quarks together, meaning they cannot exist as individual, free particles under normal conditions – unless the Hagedorn temperature is exceeded.
The protons and neutrons then melt, and the quarks exist with the gluons — the particles that mediate the strong nuclear force — in a state of matter called a quark-gluon plasma. It is assumed that shortly after the Big Bang the universe was filled with such a “quark soup” (as this state is often jokingly called in science). The quarks were unable to combine to form protons and neutrons until they cooled after a few milliseconds.
In order to artificially create such a situation, heavy atomic nuclei would have to be hurled at each other in particle accelerators at nearly the speed of light. For a very short period of time, there is so much energy that a quark-gluon plasma is formed.
By the way, Hagedorn's temperature is not the highest possible temperature. Even quark-gluon plasma can be heated even further. But here we are slowly leaving the area that can be described as the current state of knowledge. Neither physics nor mathematics are sufficient to properly describe such extreme conditions. Of course, research continues here and hopefully at some point we'll know just how hot it will be. And then we will also understand how the universe began.
Please allow Javascript to maintain the full functionality of Spektrum.de.
“Alcohol buff. Troublemaker. Introvert. Student. Social media lover. Web ninja. Bacon fan. Reader.”
More Stories
Fäkt aims to bring science closer to students through videos
Orca “attacks” science puzzle
This diet strengthens the psyche and emotional well-being – a healing practice