Developing a Theoretical Quantum Effect and Experimental Methods for 'Heat Death' in a Science Fiction Universe

Question

I am currently crafting a science fiction story in which humanity confronts an unprecedented threat: a novel form of 'heat death' that causes matter to cease to exist when it reaches certain temperatures. This event, initially manifesting with the disappearance of stars and the darkening of one half of the sky, eventually extends to Earth, transforming our lush home into a frozen wasteland.

In this narrative, a mysterious quantum effect is driving this scenario. With the temperature threshold for this disappearance effect gradually reducing from stellar levels to the temperature at the Earth's core, it accelerates the universe towards a unique and imminent demise. As the Earth loses mass, humanity scrambles to innovate survival strategies and ultimately succeeds by creating pocket-dimensions. Within these pocket-dimensions, the laws of physics are not immutable, and they offer humanity a refuge from the advancing heat death.

To ensure my story remains engaging and at least semi-plausible to readers with a rudimentary understanding of physics, I am seeking scientific and creative advice on two key plot points:

1. Hypothetical Quantum Effect: Can you help me outline a theoretical quantum effect that would cause objects reaching certain high temperatures to vanish from existence? While we are venturing into the realm of speculative science, are there existing quantum theories or principles that could give my narrative's phenomenon a semblance of believability? How might such an effect relate to current theories about the nature of matter, energy, and the fabric of the universe?

2. Identifying the Root Cause: In the context of my story, how might scientists piece together the truth behind these bizarre events? What kind of experiments or observations might lead them to deduce that heat is the root cause of the universal cataclysm? How could they theoretically measure that the universe's maximum permissible temperature is decreasing?

Please bear in mind that while the story assumes an alternate universe with some differing laws, it should still retain a sense of coherence and intelligibility.

Answer 1

Frame challenge: Humanity's first indication is its sudden death

Assuming that:

1. this effect is affecting the entire universe simultaneously; and
2. the decrease in maximum available temperature from hottest stars to Earth's core happens over a normal human lifespan,

then the speed of light will mean that Earth's sun will have gone "nova" (see below) and destroyed the Earth before the light from other stars reaches our solar system.

The problem is that the temperature of the sun's core is about 15 million K, while the Earth's core is around 5,000 K. As soon as the maximum "allowable" temperature for matter drops to around the sun's core temperature the interior will suddenly collapse and a variety of exciting effects will result in it exploding, destroying pretty much everything in the solar system and possibly well beyond, long before the Earth core temperature can be affected. Read Charles Stross' Iron Sunrise for a description of how this goes down (the root cause there is slightly different - coincidentally also involving a pocket universe - but the effects are largely similar). Astronomers may be able to observe a few minutes of changed solar activity before the near-lightspeed shockwave obliterates Earth.

(An alternative scenario is that a nearby, larger and hotter star with a much higher core temperature goes supernova sufficiently long before our sun goes nova that its shockwave reaches and obliterates us first, but the practical result is identical.)

In summary, rather than the sky slowly going dark, this effect will destroy solar systems. The only way that we could gain information about this effect before being destroyed by it would require that the area affected by quantum/handwavium destruction is propagating through the universe at much less than lightspeed - this might allow Earth astronomers to detect enough novae and supernovae that are far enough away from Earth for detection not to be accompanied by destruction. With enough data points they might be able to figure out what is going on. If that premise is adopted, then note that the race is to get into a pocket universe before the sun goes nova, not a race against Earth getting cold.

Answer 2

False vacuum decay has some history in doomsday fiction. https://en.m.wikipedia.org/wiki/False_vacuum_decay

Basically a bubble forms and grows in the universe ripping a new set of physics rules in the universe.

Now if you want to mess up a huge chunk of the universe simultaneously (Though note there's no way to observe that it you stick to real physics)

A brane collision will be rather catastrophic and energetic and you can fictionally do whatever you want since this is so theoretical. Want to get rid of mass - maybe have it get dragged into the other brane.

https://www.science.org/content/article/cosmic-radiation-features-could-suggest-our-universe-not-alone

https://www.sciencenews.org/article/when-branes-collide

Of course in reality if you alter the laws of physics even slightly it probably means instant death because life is chemistry following those laws.

Edit: on further thought since you want heat to play a role. Let's say that brane collision between universes happens. You could then claim that high energy particles are quantum tunneling into the other universe. This would mess up the insides of a star but leave regular chemistry alone. You could further claim that as the collision proceeds the energy to cross the barrier is decreasing. So maybe it gets to the point where a planet's core is losing particles.

This is very much an abuse of tunneling but then again tunneling isn't meant to cross universe boundaries either.
https://en.m.wikipedia.org/wiki/Quantum_tunnelling

Edit 2 Also note tunneling is a statistical event for each particle. So you can define the rate of loss to suit the plot. That is for something at 5000 degrees you lose 0.01% per year.

Answer 3

As said in Lucasbachmann's answer I think you want a False Vacuum decay. (copy his link: https://en.m.wikipedia.org/wiki/False_vacuum_decay)

Vacuum, in quantum physics, is supposed to be the lowest energy state of a system. False Vacuum decay is a hypothetical situation, where what we call "vacuum" is not in fact the lowest energy state, and is thus a "false vacuum". If this hypothetical were true then a phase transition is possible, where a bubble of true vacuum forms (somehow) and then spreads outwards in all directions (probably at lightspeed). Everywhere inside the bubble physics would be quite different, with different particles and forces.

However, importantly for your scenario, heat would (to some extent) resist the vacuum phase transition. A lower energy state is only an attractor at low temperatures. So hot stuff could (handwavy) be made resistant to the transition.

Given that the expansion speed is lightspeed I think it would very much feel like it was happening everywhere at once, as one second we would not be in the bubble. Then a second later the whole Earth would be, the vaccum outside earth changes in some mad way but the Earth itself (hotter) only starts to change slowly* (out from the edges of the atmosphere).

* I think this aspect is not really physically right, but suits the stroy and the "heat protects" handwave.

Answer 4

I dont think you would need something that fancy, energy excites matter, if matter gets too excited it will most likely try and desperse (Explode) due to high internal tension/pressure.Explosions in space are pretty mild compared to inside an atmosphere, and there you have an explanation that fits the story,people stop seeing light but nothing catastrophic happens (for now).

I cant explain any effect that would do that, but since we can bend physics a little (Various things explode when too hot,why not a star ?) but that does lead to something making the stars spontaneosly get warmer and cross the threshold to go BOOM.

Quantum mechanics are way to complicated to explain something that simple IMO, but its your story