Posted on 11/19/2020 5:51:14 AM PST by MtnClimber
First of all, what is the black hole information loss problem, or paradox, as it’s sometimes called. It’s an inconsistency in physicists’ currently most fundamental laws of nature, that’s quantum theory and general relativity.
Stephen Hawking showed in the early nineteen-seventies that if you combine these two theories, you find that black holes emit radiation. This radiation is thermal, which means besides the temperature, that determines the average energy of the particles, the radiation is entirely random.
This black hole radiation is now called Hawking Radiation and it carries away mass from the black hole. But the radius of the black hole is proportional to its mass, so if the black hole radiates, it shrinks. And the temperature is inversely proportional to the black hole mass. So, as the black hole shrinks, it gets hotter, and it shrinks even faster. Eventually, it’s completely gone. Physicists refer to this as “black hole evaporation.”
When the black hole has entirely evaporated, all that’s left is this thermal radiation, which only depends on the initial mass, angular momentum, and electric charge of the black hole. This means that besides these three quantities, it does not matter what you formed the black hole from, or what fell in later, the result is the same thermal radiation.
Black hole evaporation, therefore, is irreversible. You cannot tell from the final state – that’s the outcome of the evaporation – what the initial state was that formed the black holes. There are many different initial states that will give the same final state.
The problem is now that this cannot happen in quantum theory. Processes in quantum theory are always time-reversible. There are certainly processes that are in practice irreversible. For example, if you mix dough. You are not going to unmix it, ever. But. According to quantum mechanics, this process is reversible, in principle.
And your answer didn’t make sense at first because I thought “how would a piece of equipment that is used to listen to the heart be involved in this?”
Then i looked it up :)
Only 52 and sometimes those mistakes worry me.
That sounds like a real unsolvable problem!
Quite true. The best physicists earn their livelihood by trying to figure out answers to such questions. And quantum entanglement is the biggest unknown on their plate because it speaks to the very fabric of reality.
Matter cannot be destroyed? That’s false.
Matter is not conserved. What is conserved is mass.
Take the sun. As hydrogen burns to form helium, the mass of the matter decreases. The sun radiates away infra red, visible light, x-rays, etc. They have mass. The total of the mass of the matter, and the mass of the radiation stays the same.
Take an atomic reactor. As the fuel burns, the mass of the fuel is decreasing (at a rate equal to the square of the speed of light, or 19.7 trillion Btu’s per pound in US Standard units.) In a typical 1100 mw reactor, the mass of the fuel drops by about 5 pounds a year.
But mass is always conserved. So where does the mass go?
In water cooled reactors, it goes into the reactor coolant water.
When you add energy to something (heating water, lifting a weight, tightening a spring, charging a battery), its mass goes up. So as the water circulates through the reactor and it heats up from about 570 to 630 deg F, its mass goes up. When it loses its heat by boiling off steam in the boilers, the mass of the cooling water goes back down again, The mass of the steam goes up when boiling occurs, so mass is always conserved.
DANGER!
Warning!
This stuff can make your brain hurt.
About the author.
Sabine Hossenfelder (born 18 September 1976) is a German author and theoretical physicist who researches quantum gravity. She is a Research Fellow at the Frankfurt Institute for Advanced Studies where she leads the Superfluid Dark Matter group. She is the author of Lost in Math: How Beauty Leads Physics Astray, which explores the concept of elegance in fundamental physics and cosmology.
https://en.wikipedia.org/wiki/Sabine_Hossenfelder
Painfully, I now sometimes make spelling and grammar mistakes that I never made during my long ago school days.
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