New interpretations suggest the "heat death" hypothesis might not hold (2023)

  As such, the second law appears to hold a chilling prophecy for humanity in the very long term.

The idea that our species is so uniquely capable of transcending extinction and surviving long enough for the fate of the universe to be relevant to it is optimistic to the point of absurdity. It fits the evidence better to suppose that we're particularly capable of self destruction.

Even if we don't self-destruct, we will likely have evolved into something else completely different by then. Or maybe a million years from now they will keep some humans (based on present-day DNA) in a museum exhibit somewhere. Or maybe that's us.

I'm somewhat familiar with Barbour's work, which tries to reformulate gravity as a theory of 3-geometries instead of 4-geometries. Basically, you can do this by moving additional complexity into the lagrangian. Barbour's work is hard to get into because he has had various versions of this theory (Shape Dynamics) over the years and some of them are classical models, some are curved spacetime, some are more effective at being totally relational than others, etc.

Anyway, its true that something he calls the complexity increases forever in his more recent models, this is just an expression chosen to make the dynamics work out. Even Barbour says this is not necessarily related to the sort of complexity life has. And it depends on the universe being an open systems.

I still maintain that we're not just a simulation, we're a screensaver on the computer of some extradimensional office worker who has been out of office for their version of a weekend.

You might like this: https://qntm.org/responsibilit

If the laws of thermodynamics don’t apply does that mean we can build our perpetual motion machine?

Slightly tangential, but does anyone know of a good layman's book on thermodynamics? I'm interested in the science and the history of it, but I'm not really trying to do a deep dive into the math -- I wasn't bad in stats or calc but that was decades ago now and I haven't really used them since...

> ... all believe that the universe is not destined to grow more disorganized forever, but more complex and rich with information.

Maybe it's just a problem of being loose with terminology, but this seems to be contrasting entropy and information content, which is backwards?

"Anything less than an infinite universe is a waste of space.

Anything less than an eternal universe is a waste of time."

~My Very Clever Dad. Miss you Dad.

Timescape model, arguably less magical than ΛCDM, also makes heat death seem less certain. The ultimate conjecture of all. Humans surely love closure.

Just as soon as you figure out what dark energy is and how to extract work from it. Easy, right?

Honestly, this is the type of stuff ChatGPT is really good at. Explaining overviews of a field, avoiding math if you want, focusing on concepts and explaining different schools of thought.

As long as you're sticking to the well-established stuff, it tends to be quite factually accurate. I think it's really underrated as a resource for good high-level overviews of fields where those overviews otherwise don't exist at all, are overly technical, or the existing overviews have a lot of author bias.

>>>>> Consciousness, creativity, love — all of these things are destined to disappear as the universe becomes increasingly disordered and dissolves into entropy.

Those are evolved traits, and it seems more likely that evolution will replace them with some other traits within a time frame that will be like the blink of an eye compared to the projected decay of the universe.

IANAP, but what I'm seeing here is a lot of very optimistic speculation about how life might survive, with no plausible mechanism. We have no idea what dark energy is, and it may well be impossible to extract energy from. Some of the quotes in the article suggest that life must physically go find additional energy sources, especially if dark energy doesn't work out. Interstellar travel is already prohibitively difficult, and getting to the next galaxy seems simply infeasible. Humanity's descendants are basically limited to the Milky Ways resources. Left to itself, the universe will eventually run out of hydrogen that can be economically fused. It will go dark eventually. The black hole power plants will eventually run out.

Wake me up when dark energy is more than a statistical anomaly, or we have a practical theory for a warp drive.

They evolved for pretty strong reasons that have been around a lot longer than a blink of an eye. Namely, collaboration and creativity are extremely good survival strategies.

Sprinkling pop physicists like Paul Davies in between name dropping prominent historical physicists doesn’t make for a convincing article

Entropy also has units of measure: Joules per Kelvin.

Loved it! Thanks!

Ugh, I couldn’t disagree more. Sure, LLMs can generate some really nice introductory summaries of topics. But, so far at least, they can’t even hold a candle to brilliantly written books and long form articles. Consider the classic book Cosmos. There is more insight into the universe in any few pages of that book than could be gathered by reading even a thousand ChatGPT results.

Practically stars are mostly burned out in another 50 billion years and radioisotopes that produce a heat gradient will also be mostly decayed by then. Eventually good tidal energy situations like

https://en.wikipedia.org/wiki/Tidal_heating_of_Io

will end as well since this kind of situation changes the orbits. So energy for life and usable thermal gradients will disappear even if entropy will continue to increase for a long time -- for instance, black holes will be slowly inspiralling and crashing into each other resulting in huge entropy increases on paper.

“From Eternity To Here” by Sean Carroll has some nice discussions of it. He can be a bit much at times and could stand to have better editing (the book is 25% too long), but he does have some of the most approachable modern writing on physics out there. Lots of videos on YouTube as well.

You and I are talking about totally different things.

I'm talking about general overviews of topics, where a good book form at the level you're looking for often doesn't even exist.

You're talking about a classic book that is recognized as a great work.

Nobody's claiming that what ChatGPT outputs is Cosmos. And most books written by people aren't Cosmos either.

And most of the time when you want a basic factual introduction to a field that is at your level, neither too popular nor too technical, ChatGPT is really good at providing that.

Not everything has to be Cosmos.

Edit: nevermind, I agree I misunderstood the parent comment.

It's a common response to any interest in the destiny of humanity: "what's so special about humanity? What about bacteria, huh?"

I don't know, I'm human and humans tend to be social and interested in their own species? Is that weird? Does that not apply to you? Do you consider it petty and parochial to be more interested in one's own species? Are you "above" that?

If any bacteria or humans are interested in projecting the future of bacteria and their probability of surviving humanity, they should absolutely go for it.

New thinking on physics... by a self-described neuroscientist. I think we already know how seriously to take this.

I've had plans for a sci-fi book I plan to never write that takes place in the ultra far future. The chapters' numbers would be the time dilation scale in a base 10 logarithm. The book would be made up of a series of short stories told from the point of view of a "time coast guard" rescuing idiots who refuse to time dilate from their creaking space hulks.

A later (set?) of chapters might just be in the 90+ scale; at that regime the characters can flit around the universe in the notional blink of an eye, even though their nanoships' velocity is only a few km/s. In my mind it'd be just a nuts-and-bolts 30's-style hard boiled detective story; but, set in the year 10^110.

Oh! Oh! And Charlie Stross would write this book for me, and it'd be a series.

I don’t think that’s that delichon is saying. It’s absurd to compare the lifetime of ANY species with the lifetime of the universe. The heat death of the universe is like 10^80 years away or something insane. Humans have been around for like… 10^5 years?

Even if something from earth lived that long, it wouldn’t be human. It probably wouldn’t be remotely recognizable!

That was freaking awesome

It’s also the plot of the show Devs

https://en.m.wikipedia.org/wiki/Devs_(TV_series)

Everything by qntm is phenomenal if a bit rough around the edges. Fine Structure was one of my favorites, along with There is No Antimemetics Division, which is now being published as a proper book!

> Boltzmann’s model also ignored the influence of gravity, which is often described as an anti-entropic force due to its clumping effects on matter.

I never heard something like that. Gravity follows the first and second laws of thermodynamics.

Flies do equally well, if not better.

The only problem for earth life is that anything less intelligent than a human cannot leave the planet with significant chances of survival. Bacteria can however take a ride in our space probes and get a minuscule chance to colonize e.g. Mars [1].

What will go to the end of the universe is self-replicating robots. We have already made the first step in that direction with the AI that makes the headlines currently.

No art, no love, no dreams, just brute force.

[1] https://astrobiology.com/2022/12/planetary-protection-killin...

That's not what the parent comment is saying at all. There's a difference between being interested in your own species and thinking your own species is somehow above the risk of eventual destruction.

Not to mention the existence fallacy - the human tendency to think that it's BETTER for the species to exist forever. I'm not sure that's true.

For anyone interested, Vernor Vinge does something like this but minus the massive scale, in Marooned in Realtime. Set 50 million years in the future. My all time favorite sci-fi fwiw.

I've not read this particular book but I like Arieh Ben-Naim's approach:

Four Laws That Do Not Drive The Universe, The: Elements Of Thermodynamics For The Curious And Intelligent

https://www.worldscientific.com/worldscibooks/10.1142/10531

Humans are the only species in the known* universe to have deliberately left their home planet. We may not be fully capable of it, but we are indeed more capable of transcending extinction than any other known species.

* - which is certainly a small sample

dark energy is the ultimate free lunch. it's like the more you spread butter on your toast, the more toast you get and the more butter gets spread out.

It's quite a bit different from that description, but Diaspora by Greg Egan deals with some impressive scales of time and space. The tone is nothing like you're describing, but the ideas and scale in it totally changed how I think about about im/mortality.

> Charlie Stross would write this book for me, and it'd be a series.

Sounds like Stephen Baxter's cup of tea. Hell, the detective could even be Reid Malenfant himself (maybe a cameo for Sheena 5 in a later book in the series?)

Then again, if there was an ultradeep-time Saturn's Children book, I'll place the preorder so fast it'll be blueshifted.

Due to the expansion of the universe, we're also going to lose access to the rest of the universe in that time.

  Time - Galaxies lost to us forever 
  1 million years ~ 0.02%
  10 million years ~ 0.2%
  100 million years ~ 2%
  1 billion years ~ 20%
  10 billion years ~ 80%
  150 billion years ~ 99.9999997%

So we'll have to find somewhere to hunker down for the last forty billion years or so as we wait for all energy to dissipate.

That's all assuming we can't "break physics" and nucleate something new, find a tear in our current manifold, etc. Our peon brains are too small to reason about this and any claims that we're stuck are insufficiently computed.

Given our limited sensing capabilities and tiny time sample, I'm skeptical of our current understanding. Claims of current model predictions feel premature.

Some will evolve, some will stay. We are evolved from 1 billion year old bacteria, which still there, on Earth.

Black holes are perpetual motion machines.

In my mind his work was the best of the 1980s and that's a decade that produced some pretty powerful stuff like Ender's Game and Forge of God. Vinge coined the term "The Singularity" which is now almost a given to be a future event in some circles. His then wife also wrote some pretty good sci-fi such as The Outcasts of Heaven Belt I liked Vernor's A Fire Upon the Deep a lot but not his later books.

If it could be the Charlie Stross who wrote Accelerando and the Iron Sunrise than yeah but I feel like he went downhill after that.

>> gravity, which is often described as an anti-entropic force

I don’t know about that but it’s also sometimes described as an entropic force https://en.wikipedia.org/wiki/Entropic_gravity

Your comment reminded me of this Asimov short story:

https://en.wikipedia.org/wiki/The_Last_Question

So you’re saying there’s a chance

He's changed the focus of his stories, for sure; I get that it's not everyone's cup-of-tea. But, his prose & storytelling is still just as strong. (I agree, though.)

It's amusing to see such grandiose predictions about the fate of the entire cosmos when our science doesn't hold water even at the galactic scale, I mean its dark matter band aid. If the accuracy is only 10% at the galactic scale, it must be less than 1% at the scale of galaxy clusters, and beyond that it's no better than tea leaves reading.

Thanks for the spoilers

>a bit rough around the edges.

You're right. It almost lost me with this nonsense

>Pi to the last digit? A triviality

Cool stuff though

As soon as the article mentioned Ray Kurzweil, I knew there was no scientific basis for the claim.

If you look at who supports this theory, it's all ego-driven software engineers who believe they can solve physics from first principles, ignoring hundreds of years of evidence that these laws do apply.

Highly recommend reading this book for how these sci-fi theories are being used to promote eugenics, climate destruction, and pseudoscience: https://www.amazon.com/More-Everything-Forever-Overlords-Hum...

You will like this shorty story from Stephen Baxter

https://www.infinityplus.co.uk/stories/gravitymine.htm

Loved this story.

Although, *spoiler*, my mind is still having a hard time understanding how the characters could exist before their simulation started.

Did they just not realize that their reality was sped up before the moment where the simulations began?

The usual handwaving for entropy v. information/complexity is to observe that our universe goes from simple low entropy state (Big Bang) to a simple maximum entropy state (Heat Death).

Both have low information. The complexity rises and falls, peaking somewhere in the middle, as energy from the gravitational field is turned into structure.

https://en.wikipedia.org/wiki/Weyl_curvature_hypothesis

Penrose likes zero initial Weyl curvature because it provides low entropy, but also conformal flatness, thus enabling his CCC theories.

Another consequence is that the Big Bang is not a reversed black hole (white hole). Black holes have high Weyl curvature. The Big Bang is the lowest entropy configuration, but a Black Hole is the maximum entropy configuration (just mass, spin and charges).