> The length of the day used for astronomical timekeeping reaches about 86,401 SI seconds. Under the present-day timekeeping system, either a leap second would need to be added to the clock every single day, or else by then, in order to compensate, the length of the day would have had to have been officially lengthened by one SI second.
Can you just imagine the amount of legacy code with DAY_SECONDS=86400 out there 50k years from now?
It's been suggested that perhaps one way to find evidence of extrasolar life, would be to find exoplanets whose years are integer multiples of their rotational periods, i.e. they've done what you describe just to eliminate leap years and make their calendars easier.
I think he might be sarcastic. There is no known method I know for measuring the rotational period of extrasolar planets, without having enough observational power to defiantly notice the astronomical engineering required to alter an inhabited planet’s rotation rate.
Actually I think if we follow the current trend in technology advances in astronomy, we will definitely be able to measure planetary rotation well before we have the angular resolution to spot anything of consequence on an exoplanet. We currently have the technology to measure stellar rotation bia Doppler shift. https://en.m.wikipedia.org/wiki/Stellar_rotation
This technique will definitely be applied to exoplanets as the angular resolution and spectroscopic sensitivity are improved. In fact, improvements to both if these numbers are being relentlessly pursued by a veritable army of scientists around the world.
Spectral broadening only needs one pixel, and enough spectral sensitivity that the broadening isn’t entirely in the margin of error. We are pushing For ever more accurate spectral sensitivity as we try to use Doppler measurement to hunt for exoplanets.
Meanwhile the ongoing efforts to obtain greater angular resolution, has basically been one of the core pursuits of the astronomical community for centuries. We are building massive telescopes and advanced compensation systems in the form of adaptive optics to get the very best out of these telescopes.
So yeah I think we’re going to have rotation rate measures before we see much more than a pale blue dot.
In the Three Body Problem series by Cixin Liu, the orbits of planets and moons in the solar system are altered to make colonization and terraforming easier.
Wrong. In the book they build the bunker stations behind Jupiter but NOT in orbit of jupiter or its moons and even that station keeping takes a tremendous energy.
Mathematically that's irrelevant to finding planets with an integer ratio of days per year. Integers are still integers no matter what base you express them in.
I would just change the duration of a second. It would be probably easier to change a few physics constants here and there than to fix all the broken code.
If only you were manipulating second only. You would also be manipulating metre, candela, and ampere, assuming old definition of SI, or metre, kilogram and kelvin assuming new definition of SI.
Not OP, but "The metre is defined as the length of the path travelled by light in a vacuum in
1/299 792 458 second"
- https://en.m.wikipedia.org/wiki/Metre
The duration of a second is defined using Caesium-133 [1], not using anything else like daytime or rotational speed. It's independent of such factors and will always be the same in a given frame of reference. No need to update those values.
edit: I think it will lead to the same or more problems because everyone would have to change all time-related constants. Easier to add a second to the day constant (because the day constant is a subset of the seconds constant, but the seconds constant affects many more aspects than just the day constant).
Unless these physics constants are, well, constants put in the same code. How many ballistical systems treat ‘standard g’ as a variable? (hint: it depends on seconds squared.)
In Vernor Vinge's A Fire Upon the Deep and A Deepness in the Sky novels, the characters in the far future track time using megaseconds (~11.6 Earth days) to sidestep the problem of days with different lengths. They still count from the 1970-01-01 Unix epoch, but the characters mistakenly think that date is when humans landed on the moon.
There's also such a thing as a Programmer-Archeologist, can you imagine dealing with 14,000 years of nested dependencies? One key plot point in one of the novels, a totalitarian group is running a omnipresent surveillance network but has no idea about the software running underneath it. They set it up using the GUI and are using it but never looked under the hood. The group attempting to get out from under the grasps of the totalitarians has a programmar-archaeologist who digs into the underpinnings of the software and hijacks it from a lower level of its operating system.
I forgot about the Programmer-Archeologist! Another point from (I think) these novels that stuck with me was Vinge's description of the "software midden heap". I'd like to think we can clean up some middle layers from our computing stack in the future, but with some old software only available in emulators (possibly running in WebAssembly in a browser), I am not so sure.
In fact, I realized I made an nearly identical comment here on Hacker News back in 2011. :)
The Matrix expanded-universe also has some surprisingly deep and complex lore regarding such interactions between the humans and machines and everything between and around them. Those movies and their spinoffs are worth revisiting now and then.
They're missing a bunch of possibilities. Maybe a second is lengthened? Maybe we decouple timekeeping from the rotation of the Earth? Maybe we spin the Earth back up?
Lengthening the second is unlikely: for every physical phenomenon with a duration (from the rotational period of other planets to the frequency of atomic transitions), you would forever after have to wonder, is that value quoted in"new seconds" or "old seconds"?
Redefining units leads to ultimate backwards compatibility problems.
> [...] a Boltzmann brain is a self-aware entity that arises due to extremely rare random fluctuations out of a state of thermodynamic equilibrium. [...]
That is __severely__ underestimating the true probability - it considers only random thermal fluctuations. But the universe is really powered by processes that dissipate energy across a gradient to fuel a structured, very low entropy state.
The math is the same as calculating the probability that the glass you just broke will spontaneously jump back onto the table and reassemble itself. Which is a standard introductory example in thermodynamics... but you add self-awareness and suddenly this rather mundane thing is spooky and amazing.
You should be far more interested in what's happening when you boil a pot of water and convection rolls spontaneously form.
Maybe some Boltzmann brains start out with rich fulfilling memories. And then a later (or earlier) Boltzmann brain happens to exist with a continuation of those memories. (Now I realize I'm just reciting a plot point from the excellent book Permutation City...)
Permutation City is the only recent hard science fiction books that I can fully embrace. It has novel and genuinely new thinking, it is realistic, and it's thoroughly entertaining.
Most modern sci-fi fails at one or more of those tasks. Indeed, most modern sci-fi fail's at not being mere fiction.
Permutation City is still my favorite from him, which is a little disappointing since it's one of his older books. It touches the most subjects and makes the biggest sci-fi leaps. Diaspora scratches some of the same itch, going further with some of the ideas, and Schild's Ladder is in the same bucket. Distress and Incandescence are both something different, but Incandescence's subtlety took me a while to appreciate. Zendegi ... skip it. It seems to be written with outright disdain to sci-fi fans with weird author tracts and caricatures, and it doesn't really tread new ground otherwise. Is Greg Egan getting sick of the fan mail he's getting?
Diaspora is my favourite, and the first I read of his. Permutation City and Schild's Ladder are both really great. I thought Distress was really interesting, like you said it's different from the others. I haven't read Incandescence. I enjoyed Zendegi, I'm not sure what you meant by it being disdainful to sci-fi fans.
Incandescence is worth reading if you're an Egan fan. Its initial setting similarity to Diaspora and Schild's Ladder mislead me to believe that the story would progress similarly, but if you can reset your expectations, and can look forward to a lot of talk about relativity, then it's a good ride.
Part of what drove me crazy about Zendegi is that the guy funding the mind-uploading project is constantly portrayed as crazy and selfish for his goals of living longer through uploading, though as soon as one of the protagonists gets sick, suddenly the goal is an exciting possibility for that protagonist in particular (he's had a hard life, so it's noble for him I guess) ... and when the plan falls short because the tech isn't developed enough, the entire idea is back to being regarded as ridiculous and one of the other protagonists campaigns to stop more research from being done in the area. It felt like picking up a sci-fi book from someone known for writing space sci-fi, and then being expected to sympathize with the protagonist who wants NASA shut down after Apollo 1 burns.
Maybe it just bugs me a little extra because it's the apex of a weird pattern also in Permutation City and the short story Crystal Nights (which is a fun read!): the story's cool tech, the thing you came to the story for, is pushed by an unlikable character, and everyone else despises the character and everything they stand for including the tech. There's a lack of likable characters that sympathize with the reader in how cool the technology could be; it's harder to sympathize with the protagonists who seem too unimaginative to see how cool the tech could be. I get that the author is probably trying to make a point that technology can be abused by bad people and that most people aren't going to see the possibilities of new tech ... but I think he's getting worse at making that point, or the point is just getting grating being re-executed in the same way several times over.
And the other thing that drives me crazy about Zendegi is the time it spends with the lazy caricatures[0] of real people. It's a little personal given that Eliezer Yudkowsky is one of my favorite authors, but that's only part of it. The caricatures are lazy. Egan might as well have made each of the characters boast of having a small dick. And the bad caricatures aren't just a few unflattering introductions, but form a whole subplot that mostly doesn't affect the main plot or the protagonists at all; it exists just to take shots. And then the caricatures are mainly ridiculed for dreaming big (in ways the story cheaply makes out to be dumb or selfish), especially about AI. I come to Egan books to dream big. Egan's previous books were likely part of what taught many people to dream big in this!
I'm sure some of the things I call problems could be done well and aren't automatic disqualifiers, but the sum of all of them in one book with the execution they had just left a surprisingly terrible taste in my mouth.
As a dude-do-you-ever-think sidenote, this sort of thing keeps me from getting excited about any type of virtual reality that does anything with our brains. How do I know it won't simulate 10 years of torture, then at the end replace that memory with 10 minutes of an edenic golden field, so when I actually unplug all I have is a nice remembered experience that I'd like (incorrectly) to try again?
@Florin_Andrei: Sure, but we have reasonable expectations of how bad things can get and our capacity to learn from them. Alter your perception and memory and those things go out the window, and that's way scarier than normal organic life.
Does self-awareness presume the existence of emotion? I feel like Boltzman wouldn't have bothered to assert self-awareness if he'd had a real knowledge of the various gradations of consciousness and just how rare they are, even on Earth.
You don't even really need a sequence of closely-related brain states encoding a coherent stream of consciousness. Maybe you only exist right now, and nothing else ever happens in your life. All you need is a single brain state with all of the right memories loaded up and you'd have a person who thinks they're going about their day.
If you consider the likelihood of a one-brain-state person spontaneously arising in thermal noise versus the likelihood of many similar brain states spontaneously arising in thermal noise, the probability that a given person is going to continue living beyond the current moment seems very low, assuming a finite age for the universe.
Hopefully there's some better, lower-entropy mechanism out there for generating brain states. Maybe it's even an objective physical reality and human evolution producing physical brains. :)
(I loved Permutation City, by the way. I don't think any other novel has made me think so much.)
>You don't even really need a sequence of closely-related brain states encoding a coherent stream of consciousness. Maybe you only exist right now, and nothing else ever happens in your life. All you need is a single brain state
Agreed mostly, though personally I think Permutation City was dancing around trying to imply something one step further than that: maybe you don't even need that single brain state to exist in some objective reality for it to have a coherent stream of consciousness. In other words, the Mathematical universe hypothesis[0].
But given sufficiently enough time (i.e. infinity) the 'same' brain (spawned with a start-state which is an exact copy of the end-state of the last time) will keep re-appearing again and again, allowing for a continuous stream of thought. In fact, with infinity at our disposal, infinite repetitions of all states is guaranteed.
(+10^10^59 years) "Ah, good, awake again, shame the universe has gone dark, I wond-"
(+10^10^122 years) "er what the other copies are thinking. After all, there isn't really-"
(+10^10^185 years) "anyway to tell how much time is passing, I wish I still had stars and eyes to see them."
Just spent some good hours reading about Boltzmann brain related stuff...it's indeed a fascinating topic.
The most interesting part is the related Boltzmann brain paradox: we are far more likely to be isolated brains randomly popping out of chaos and imagining a universe, than actually living in a real universe.
"Around this vast timeframe, quantum tunnelling in any isolated patch of the vacuum could generate, via inflation, new Big Bangs giving birth to new universes [...] this is also the time required for a quantum-tunnelled and quantum fluctuation-generated Big Bang to produce a new universe identical to our own, assuming that every new universe contained at least the same number of subatomic particles and obeyed laws of physics within the range predicted by string theory."
Assuming that time moves forward, probability of all events that have already happened is 1. Probability of all events that could have happened, but did not 0. There is an interesting parallel that could be made to quantum states collapsing.
Given that the question asks about 'current' universe arising spontaneously from vacuum the probability is 1 because that has already happened.
The more interesting question, what is the probability of a new universe similar to our own arising. To the best of our knowledge (which for this type of extrapolation is admittedly flimsy) this is also 1, this just takes a very long time. The expected time it would take (10^10^10^56) is specified on the last row on the "Future of the Earth, the Solar System and the Universe" table.
I am hardly a mathematician, so I'm probably missing something, but I think it makes sense?
I believe it's well-established that elementary particles can spontaneously generate through quantum fluctuation. Assuming that this process is uniformly distributed, the probability per unit time of any given structure self-generating is nonzero (if fantastically small). Over a long enough timescale, the probability of any possible event occurring approaches one. If time is infinite, the probability is one.
I meant it more tongue-in-cheek than as a real critique. That being said, such a strong statement should have some backing other than anecdotal evidence I agree with. I'm assuming @eanzenberg said the answer is "1" because our universe clearly exists (from my perspective at least). I'd expect the formula to be similar in nature to the Drake equation [1]. However, I'm neither a mathematician nor a physicist.
My all-time favorite wikipedia article, great to see it getting some attention. I find that along with providing great fodder for small-talk (among certain types), it causes me to experience a psychological effect analogous to the so-called "overview effect" experienced by astronauts. Attempting to conceive of one's place in cosmological time is great exercise.
I am glad to read I wasn't the only one feeling a deep feeling. The facts about past and present gives one an overview effect already, but man the future... makes you feel really insignificant. I am mostly shocked by how all the predictions about Antares etc. show their death pretty soon. We look at these major big stars with awe and inspiration putting great significance to them, yet in the long scale...; their death is closer to us than that of T-rex... much closer.
If you're into role-playing games, you might enjoy Numenera [0].
A setting that takes place a billion (!) years in Earth's future, after several civilizations have peaked and gone, each building upon the remains of the ones before it and then reshaping the planet yet again to it will, to the point that even the layers of accumulated detritus from the past seem unfathomably magical to future inhabitants (e.g. soil that can reshape itself, or windstorms made up of nanomachines that reshape anything they engulf.)
Consider how mines from wars that took place a hundred years ago are still killing people. [1] Imagine some nomads from a hundred years in the future accidentally coming upon these. After a point, technology simply becomes a feature of the terrain, and indistinguishable from nature (another example would be our selective-breeding and cultivations of animals and plants over centuries to develop new hybrids that are now commonplace.)
All of this really piques my interest in what this world will be like in a few thousand years.
As for man, his days are as grass; as a flower of the field, so he flourishes.
For the wind passes over it and it is gone, and its place shall know it no more.
-Psalm 103:15-17
Yes, being aware of the scale of any sorts is tremendously valuable. The scale of suffering, complexity, culture (having travelled the world makes it smaller), time, distance puts things in perspective. Knowing the extremes, it's warm and fuzzy in the middle, most of the time.
I came here to say this. I peruse this article every once in a while; not intentionally, but I end up coming around to it from time to time, often during Wikipedia binges.
#mefour. I have recommended this article in various conversations over the years. I love how it's grown to include projections from various diverse fields. I feel I have lived forever after reading through it. And the mind-numbing scale eases fears over death for me.
>Goldstein, Natalie (2009). Global Warming. Infobase Publishing. p. 53. "The last time acidification on this scale occurred (about 65 mya) it took more than 2 million years for corals and other marine organisms to recover; some scientists today believe, optimistically, that it could take tens of thousands of years for the ocean to regain the chemistry it had in preindustrial times."
In my opinion, this is the greatest threat to humanity of continuing to pump CO2 into the atmosphere.
One should maintain some perspective: Coral reefs have gone through enormous variations in extent and location, and near extinction, many times since 500 million years ago. Not even the last Ice Age or CO2 levels 10x higher than what we have today managed to cause the extinction of coral.
The claim that, for instance, the Great Barrier Reef is dying due to massive bleaching is based on selective data and contradicts the evidence: "Monitoring data collected annually from fixed sites at 47 reefs across 1300 km of the GBR indicate that overall regional coral cover was stable (averaging 29% and ranging from 23% to 33% cover across years) with no net decline between 1995 and 2009. Subregional trends (10–100 km) in hard coral were diverse with some being very dynamic and others changing little. Coral cover increased in six subregions and decreased in seven subregions. ... Crown-of-thorns starfish (Acanthaster planci) outbreaks and storm damage were responsible for more coral loss during this period than either bleaching or disease ... we found no evidence of consistent, system-wide decline in coral cover since 1995. Instead, fluctuations in coral cover at subregional scales (10–100 km), driven mostly by changes in fast-growing Acroporidae, occurred as a result of localized disturbance events and subsequent recovery." [1]
We have scientific observation of corals, and of coral reefs, that goes back just a few decades. We also have their fossil record of the last 500 million years, including huge climate changes and the documented extinction/rise of various coral subspecies. And then we have people who claim to know with dogmatic certainty that corals are massively dying right now, that they cannot adapt to any climate change -- regardless of the full scientific context.
If we know so much as to make such gloomy, specific predictions -- please show me detailed scientific documentation of the diurnal cycle of corals and their symbionts, with exact minute-by-minute measurement of the day-and-night changes in the photosynthesis, the amount of CO2 in the water, and the productivity of each coral and symbiont. Then provide the same for each day across seasonal changes in water temperature, abundance of sunlight, and CO2 fluctuations. After that, can you indicate this: what are the specific concentration of atmospheric CO2, global sea levels, and ocean temperatures that you will accept as the standard to declare there is no risk of extinction? can these numbers ever change over time and corals would continue to thrive?
The actual science directly contradicts the alarmist speculation spread by unscientific media reports and professional purveyors of modern eschatology.
There are wide varieties of corals and of their symbionts. To claim that they are all simultaneously going extinct in all seas and microclimates is absurd, and contradicts the evidence of their repeated adaptations to past climate variations over 500 million years as well as ignores the observation of their thriving across countless local seasonal and weather variations.
Straw man, no one claimed that there will be a complete extinction of coral, only that it will be 2 million years for coral to recover to pre-industrial levels.
Indeed. Coral reefs are important nursery's for many fish species, and reducing the areas for fish to safely grow up puts yet another pressure on declining fish stocks. Not to mention marine crustaceans that are also affected by rising acidity, and the overall warming trend of the ocean itself is pressuring all kinds of marine life that humanity depends on as a major food source.
Not only that, but the ocean is rising due to land-based glaciers/ice melting, the continental rebound involved from the reduced ice load, and yet more: the warming ocean is less dense and expands. The rising seas along with other factors mentioned also puts pressure on coral reefs, as they often cannot grow fast enough to catch up with that sweet-spot near the ocean surface!
While the topic is on. I am trying to find a short story I read some years ago (4-5) about the evolution of life on our planet in the far future.
Warning, massive spoilers:
There are like 5 or 6 mass extinction events followed by a new civilization each time built by a different specie. At some points a raven civilization goes on the moon (they always had an innate tendency to go higher) and find an old rover, then it jumps to another civ. and the earth is totally smooth and people are living in holes in the ground (this might be another story from Baxter). Then it's some earth inner core creatures fungi-like. It ends with the sun expansion making life on earth impossible and a mars creature pondering all that.
Could it be Last and First Men by Olaf Stapledon? It's a novel, not a short story, but it has the same structure you've described involving successive sentient races (including bird-like people) and the planets gradually becoming uninhabitable.
Thanks, I checked both but it's not it. It really was a short story, no more than ten minutes of reading. Also I distinctly remember the moon rover reference and emphasis that wouldn't likely be depicted as I remember it considering the 1927 date of publication of the short story.
I am pretty sure the author wasn't a published author. It was a blog post.
I was sure I first read that story when it was first submitted on HN. Sure enough here it is https://news.ycombinator.com/item?id=6860839, I even put out a comment in a discussion.
The funny thing now is that someone mentioned the very wikipedia article `Timeline of the far future` in that short story submission.
I came across this article by looking up Neptune and going down a wikipedia rabbit hole after seeing another submission that's currently on the front page: `Supersharp Images from New VLT Adaptive Optics`
I always thought the style was part of the intention to express the enormous amount of time described. When you get to the end of the book you are left with the feeling like you have lived a billion years :)
Extreme weather with atmospheric acidification that slowly eats away at everything on the surface like a polishing a rock. It would take hundreds of thousands or millions of years but it's plausible as the sun slowly expands, which causes tidal stresses and significantly increases surface temperatures making the landscape a lot more dynamic.
Dunno. Also, the author hints than the night is endless and cold and the child, which the author uses to convey that part of the story, is scolded by his parents and ordered to get back underground where it's warmer.
Hmm... maybe it only looks smooth from space, like Venus or Uranus? An impenetrable cloud layer (like in The Matrix) would explain the cold on the surface and the endless night.
> Current data suggest that the universe has a flat geometry (or very close to flat), and thus, will not collapse in on itself after a finite time, and the infinite future allows for the occurrence of a number of massively improbable events, such as the formation of Boltzmann brains.
I always thought that the universe will just reach zero Kelvin and the party is over. That it will just continue to do improbable stuff was beyond my imagination. I don't really understand how it should be possible that effects like the emergence of virtual particles still work if all the energy is now in a form which can't be used for energy transformations anymore (entropy) - I know that annihilation of anti-particles of virtual particles (which causes them to exist - that was the amazing finding of Hawking with the Hawking radiation where the anti-particles of virtual particles get annihilated at the event horizon and his counterpart is happily living on because he got lucky that he wasn't too close) is a way to form new particles "out of nothing" (using quantum effects), but I still can't believe that this still works when nothing's moving because we're at absolute zero.
Could someone explain why those quantum effects still continue to work (and sometimes even spawn particles and even brains if we get lucky) even if the universe is at absolute zero?
My understanding of it is that it wouldn't reach zero Kelvin. The heat only becomes uniformly distributed. Everything becomes maximally disorderly. Things move, but all interesting information is gone.
But order is probabilistic. It's not physically impossible for order to increase, it's just ridiculously unlikely. If you wait long enough (really long) it'll probably happen some time.
I don't think quantum effects are especially related, except to the extent they relate to everything.
That’s the crazy thing about large numbers like these. Even Entropy’s Heat Death are swallowed up by them. Not only do such events become probable but they become inevitable an endless number of times over a long enough timescale. Infinity kills even Heat Death.
I will start to use this in rock-paper-scissors-infinity.
But first I have to deeply realize that I'm just one out of all possible ones and that I exist infinitely times and also infinitely times where I finally have a beard.
Ok, thanks guys. Quantum uncertainty is the reason we can't reach zero Kelvin, so it's kind of nonsense to ask why quantum effects still work at absolute zero.
> It's not physically impossible for order to increase, it's just ridiculously unlikely.
Would love to see resources that explain this (I think it comes down to quantum uncertainty again).
> the basic idea is that the probability for anything to happen is different than 0
Yeah, quantum uncertainty.
Still can't wrap my head around it, but in conversations with physicists, they also weren't sure why the heck it works that way. Gonna read my quantum mechanics book, but the math is not easy-going and especially quantum logic with its 3 states (true, false and flying spaghetti monster superposition) is extremely difficult to grasp using intuition. It contains a lot of thinking from statistics which essentially is just extremely unintuitive as well.
- - -
Edit: I really wonder if something like a "gravitational quantum electrodynamics" (don't know if we achieve it with this specific theory) or string theory (I don't really like it due to its unscientific nature) - in essence a Theory of Everything - will really explain everything like it really is or just happens to be a fitting model without being any meaningful representation of reality (in the sense that it explains how the underlying reality really looks like).
We won't be able to verify if our models are actually representing reality anyways (any theory that explains all observed events and which has some plausible and strong predictions can be treated as a possible reality), but would be nice to know. Guess it can't physically happen, unfortunately.
Imagine you have a box with red marbles and blue marbles. You start shaking it. The marbles get mixed up. Pretty soon, they're completely mixed up. That's maximum entropy.
Now imagine you keep shaking the box for a few years or so. Just by sheer coincidence, they might end up neatly sorted for a few seconds every now and then. That's like a Boltzmann brain.
I think that's all there is to it in principle, but I'm not very informed.
That was the part I was unsure about: Does the universe keep on shaking? The answer seems to be: Due to quantum uncertainty - yes. Why? No one really knows because we don't have a god-damn clue about why the universe works the way it works (although we have a good understanding how the universe works in many points, but not a coherent theory or framework that gives a conflict-free explanation).
I thought that an equilibrium in which the energy is distributed evenly is a state which the universe can reach. In that state, there wouldn't be something that shakes after a long while.
But yeah, maybe energy conservation principles alone can explain that it keeps shaking. But it still feels so unintuitive that it doesn't slow down or cool down.
I still have those other models in mind that the universe expands and then collapses or it keeps on expanding (which seems to be the case) or simply stop to expand but also doesn't collapse (and proceed to have maximum entropy level). Those were the three models I got taught. It seems that the universe is flat and will expand endlessly, so the model I thought is right (the universe just stops to expand) isn't true and my related assumptions (that maximum entropy levels get reached and absolute zero) are also not true (for some different reasons like quantum certainty and - it seems - even simple Newtonian mechanics).
Not a physicist, but the basic idea is that the probability for anything to happen is different than 0, even if extremely small.
The quantum fields can't ever be zero, from my understanding. And thus stuff can still happen:
> According to Fowler & Guggenheim (1939/1965), the third law of thermodynamics may be precisely enunciated as follows: It is impossible by any procedure, no matter how idealized, to reduce any assembly to the absolute zero in a finite number of operations.
The thing that confuses me is, if the universe were to reach any type of steady state over infinite time, my question would be, what caused it to be in any other state than steady to begin with? Almost feel like this is a causality question.
Well, one of the last timeline events is "Around this vast timeframe, quantum tunnelling in any isolated patch of the vacuum could generate, via inflation, new Big Bangs giving birth to new universes.[108]"
Thus, the cycle of new big bangs continue on forever.
Granted, the timeline for that is 10^{10^{10^{56}}} which is beyond comprehension soooo.
But these numbers are still tiny compared to numbers mathematicians have created, like Graham’s Number. Which is crazy. These numbers are still finite, still nothing compared to infinity, but they’re plenty big enough to kill Heat Death an almost innumerable number of times.
If there is no variance in the position of a particle (it is in a position eigenstate), then there must be an infinite variance in the momentum, which means the particle necessarily has kinetic energy.
Some of these are ironically myopic: "10,000 years: If globalization trends lead to panmixia, human genetic variation will no longer be regionalized, as the effective population size will equal the actual population size. This does not mean homogeneity, as minority traits will still be preserved, e.g. the blonde gene will not disappear, but it will be rather evenly distributed worldwide."
That prediction makes the rather questionable assumption that humans will still be primarily, if not entirely, on Earth in 10,000 years! Interplanetary colonization will likely dwarf the regional evolutionary isolation we've experienced on this planet. In the longrun it will likely even trend towards speciation (as a more reasonable prediction further on does hit on.) Consider that a European, an African, and a Japanese all share an incredibly recent ancestor.
The exciting thing about interplanetary colonization is once the technology starts to become robust, our potential growth and expansion is effectively unlimited. It would be like if the western frontier in the US was uninhabited and somehow went on to infinity. The implications of this are difficult to even imagine.
> our potential growth and expansion is effectively unlimited
It's still finite. I recommend this famous Asimov story [1]. I don't think that it makes humanity "more meaningful" or something similar if we start interplanetary colonization.
Really, it doesn't matter even if we inhabit the whole observable universe. We will die and it doesn't matter if I die on an exoplanet as a 1500y/o guy in a young body or if I die on earth as a 80y/o. Maybe I will experience more and whatever, but I don't really give a sh*t because life will always be finite (even if you can be billions of years old). And the implications of becoming so old can be seen in the Netflix series "Altered Carbon": You will develop weird sexual fetishes because you're bored af. And if we "overcome humans" and become some other weird sentient being it's still limited and if it's not limited it still doesn't matter from some other angle.
I don't understand why everybody is excited about interplanetary colonization and immortality. There's this quote: "To philosophize is to learn to die" - I think this is more important than trying to increase your life span or do some other stuff to delay death or even become immortal. I think most of those Silicon Valley tycoons who want this, e.g. Peter Thiel, just like the thought of accumulating power over hundreds of years. Sounds hedonistic to me + all that "will to power" ego talk.
We each have to find our own personal meaning to life. For myself it's simply knowledge. And starting to colonize other planets, and more generally become a genuinely space faring civilization, is going to revolutionize our knowledge and understanding of this universe. To what end? Well, I'll tell you when we run out of things that we don't know. I expect, even if immortality should come to pass, this is a question I will not have to answer.
It's a bit ironic because you made the exact same mistake they made. Interplanetary colonization only makes sense if humans are even around in 10,000 years. It's possible they will not be -- the speed of light being finite makes interplanetary colonization much less probable. Making any kind of 10,000 year prediction on a population thousands seems myopic.
Interplanetary is not the same thing as interstellar. Interplanetary just means different planets. E.g. after we colonize Mars we will be an interplanetary species. That's also where the divergence will begin. The development and evolutionary characteristics of individuals that grow up in low g will likely quickly begin to create a group of people radically different from anything on Earth.
You're making a common mistake on the speed of light. Understandable as relativity is really really weird. We can get into the hows/whys if you like, but the long and short is that if we can, somehow, develop technology to be able to consistently accelerate at just 1g then we can colonize places that are billions of light years away, all in a single human lifetime. Of course indeed billions of years will have passed for everybody else. It's going to make notions of time, progress, and even extinction get really really weird.
> You're making a common mistake on the speed of light.
Correcting for my mishap, all I said was that finite c makes interstellar travel much less probable, which isn't wrong. It would take infinite energy for your spaceship to arrive at c as the Lorentz factor blows up.
> if we can, somehow, develop technology to be able to consistently accelerate at just 1g
This is exactly the kind of long-shot assumption you are forced to make because c is finite. I would say that reduces the probability. Plus, once we start talking about billions of years of time-dilation, we aren't really in the 10,000 year scope we set up earlier, so it's not even wrong.
You're completely right that we observe it taking an amount of energy approaching infinity to accelerate a particle as it approaches the speed of light. But what the particle experiences is quite different. Imagine the speed of light is 10 units and you had a thruster on you that, in a vacuum, could generated exactly enough thrust accelerate you 1/10th that speed each time you pressed a button. Nothing suddenly happens causing the thruster to completely fail on the 10th, 11th, or 500th push of that button.
All that would happen is that you'd start to experience things getting quite weird. The two biggest things would be that time for everybody would seem to be speeding up and distances would physically contract. This would prevent you from ever perceiving yourself as moving faster than 10 units. The distance from A to B might be 1000 units at rest, but through length contraction it might be perceived to instead only be 15, traversing that distance in thus 1.5 units of time would not be perceived as exceeding the speed of light. However, an outside observer would see you passing through those 1000 units at some speed asymptotically approaching 10 units of speed, but never getting there. They see you taking approximately 100 units of time, you see yourself doing it in 1.5 units of time. Both are right.
A really cool (and handy) area where these two worlds of observer and observed intersect is in particle decay. For instance in particle accelerators we can observe particles that decay after 1 units of time, yet the odd thing is we get observe these particles existing for 4 or 5 units of time! Actually the same effect also applies to things in nature. Muons are created as a product of atmospheric particle collisions, and these muons do make their way down to Earth's surface, yet their lifetime (before decay) is less than the time it would take to get from our atmosphere to the surface of earth at the speed of light! Our universe is seriously weird.
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These are all very practical problems, or solutions, depending on how you look at things. You can travel billions of years in a human lifetime. Here [1] is a handy converter. It'd take about 45 years at 1g accelerator for a person to travel 15 billion light years - to the ends of the currently observable universe. So the only question is how long it will take us to develop or discover such technology. This is one of the many reasons the possibility of an EM drive, though improbable, was so tantalizing! Forget infinite energy, we're going exploring!
These are also the reason I said that things like extinction become quite difficult to define. For instance, imagine in 200 years that we send out 1000 exploration+colonization ships each with some 5,000 people on them (or whatever the magic number to create a genesis population without inbreeding is). And then 1000 years later humanity on Earth kills itself off. Are humans extinct? Well, we still have those 5 million humans traveling not only in different places in space but in different times in space. So you'd probably say no, but once again... it's weird.
A number of Science Fiction works talk about how prediction is more accurate the further out you go into the future, but how predictions in the short term are not so much.
Like the episode of Deep Space 9 where Bashier works with the other genetically modified humans. They talk about how eventually the galaxy will come to an end due to entropy, but their predictions for the Dominion War had too many variables to accurately predict close up.
Psycho-history and Foundation is sorta like this, but I think Issac Asimov doesn't do as good a job with this story/theory/believably.
There is an absolutely delightful short story by -- who else? -- Robert Silverberg about predictions of the far future, "When We Went to See the End of the World". You'll be amused and you'll laugh, though perhaps you'll need a dark sense of humor for that!
Amazing that the entirety of human civilization as we know it fits in a smaller time scale than the very first event on this timeline (10,000 years from now).
So while these time spans are minuscule on an astronomical scale, they are enormous on a human scale.
Indeed. In Neil DeGrasse Tyson's version of "Cosmos" there is a great illustration where he says that if we visualize the entire history of the universe as being scaled to one calendar year then every human being that has ever lived has essentially existed somewhere within the last 12 seconds of that year.
Even better, when you stretch those 12 seconds to a few minutes and where to watch a slideshow of human progress, all of modern history would be over in a few seconds too, stuff like the invention of steam machines up to the moon landing would be in the last two or three frames, flashing by in the blink of an eye.
It really puts into perspective how insignificant we really are on this tiny blue dot. On the grand scale, nothing we do will matter, in either time or space. We're too small and shortlived. Probably means we should make the most of it :)
> In Neil DeGrasse Tyson's version of "Cosmos" there is a great illustration where he says that if we visualize the entire history of the universe as being scaled to one calendar year then every human being that has ever lived has essentially existed somewhere within the last 12 seconds of that year.
Was that in the original Carl Sagan version of Cosmos as well? I seem to recall it, but I've never seen the Neil DeGrasse Tyson version.
the entirety of human civilization as we know it fits in a smaller time scale than the very first event on this timeline (10,000 years from now).
Well, it depends how you define civilization. Humans reached Australia 60,000 years ago. Many substantially complex settled civilizations existed 3,000 years ago. Ancient Egypt's dynastic period began 5,000 years ago.
So you could say it's 1/6th of Australia's habitation time, or merely two Egyptian stories.
This reminded me of a question I've had knocking around in my head since I've heard of hawking radiation- the prediction is that the black holes slowly evaporate into subatomic particles.
However, it seems to me at some point a critical juncture would be passed and the black hole would cease being bound gravitationally and the matter would be released similarly to a supernova or just spontaneously form a neutron star.
Theoretically, a black hole can exist at any mass as long as it is dense enough. It is true that a black hole won't form without enough mass to cause it to collapse, but once formed, it can evaporate down to nothing without ever becoming gravitationally unbound.
Theoretically it could evaporate but is there any necessity of that? Is exploding a theoretical possibility or once a stellar mass black hole forms is it thereafter in such a small circumference that it is stuck in that form until it evaporates?
Well, evaporation is simply a conclusion from hawking radiation.
The black hole losses energy over this radiation, energy it produces from it's own mass.
Since hawking radiation output increases relative to the size of the black hole as it gets smaller, eventually you end up with an explosion. I do believe that Kurzgesagt made a video that details what would happen with a blackhole with the mass of a coin in your pocket (short version: you die)
The intensity of Hawking radiation is inversely proportional to the size of the black hole. It shrinks as it radiates and its output increases. Once the black hole is tiny, the level of radiation is intense enough that you could call it an explosion. This is why small black holes are excellent generators. You just dump some mass into them and they convert it rather quickly to radiation.
The temperature of a black hole decrease as it gets larger. A black hole colder than 2.7K will absorb energy from background radiation faster than it emits Hawking radiation. So it will get larger and cooler. Any black hole warmer than 2.7K will emit energy faster than it absorbs. This means it will get smaller and hotter, leading it to lose energy at an increasing rate until it has lost all its energy and evaporates.
The cutoff is at around 4.5×10^22 kg (about the mass of the moon). The event horizon at this mass is only 0.13 mm.
I've always wondered, what would happen if we were able to create a black hole of this small a scale and it didn't evaporate? Something with an EH of a fraction of a millimeter.
If we created it on earth? It would swallow the earth and destroy us. But to create one we would have to gather a mass greater than the moon onto the earth, so the gravitational effects would probably destroy us before the black hole formed.
Black holes aren't as scary as people think. If being next to a black hole of mass M is bad, then being next to a rock of mass M is probably just as bad.
The Total Perspective Vortex is allegedly the most horrible torture device to which a sentient being can be subjected.
When you are put into the Vortex you are given just one momentary glimpse of the entire unimaginable infinity of creation, and somewhere in it there's a tiny little speck, a microscopic dot on a microscopic dot, which says, "You are here."
Well in that specific case the universe was actually centered around Beeblebrox since he was in the boss office who was on a cruise vacation. In his office.
I dunno man. I'm already quite aware of how insignificant I am on a cosmic scale. So it would be interesting to gain a proper sense of scale of the ridiculous vastness of space.
I recommend watching the Numberphile Video on Grahams Number.
I think once you start to grasp how truly unimaginable large this number is, you get a comparable feeling to how the cosmic scale compares to us in an emotional way.
The further I read, the smaller some of the issues we face today seem. I could spend my life fighting to prevent global warming or fix the world, but this list just makes me want to enjoy the time I have here with my loved ones... I don't know how I feel about these feelings.
> According to Berger and Loutre, the current interglacial period ends[14] sending the Earth back into a glacial period of the current ice age, regardless of the effects of anthropogenic global warming.
According to that guy, there will be a new ice age in 50k years regardless of the current global warming being stopped or not.
I agree, I guess I'm just expressing my feeling as I read this list. It is about balance, and I do my best, but thanks for reminding me of the connection between the two.
Well... the odd thing about humans is we actually can do things about the events here, at least in the beginning of the timeline. Not us, but our descendants formed and molded by us today, just as you and I are the direct descendants of some microscopic organisms, actually a continuous living organism alive since life first sprung on Earth. Things like moving the Earth, moving to other Star Systems and galaxies, and more exotic ideas like engineering the course of the cosmos itself. You and your loved ones are part of that.
It's truly a shame that more people don't realize how much better you can feel about life and humanity when you stop getting drawn into arguments on social media.
Well, if you take the long view then the earth will be consumed by the expanding sun and the entire history of everything on it will be erased as if it never existed. So nothing any human has done or likely will do matters. Hitler is as insignificant as gandhi.
But ... there are many lifetimes between now and then, and the quality of those lifetimes (at least the earliest ones) is something we can have an influence on, so what we do matters a lot.
So, really, it boils down to what scale you choose to measure the consequences of your actions by.
The "Humanity" section has left me with a deep chill. I've already been in an existential mood the nature of life in the modern age, and now I've got the end of humanity to think about too...
Java is still at the top of the TIOBE index. Moreover, the familiar Java update progress dialog will display "100 Trillion Devices Run Java Across Thousands of Galaxies".
Reading that timeline was quite a trip. Humanity is really just a tiny blip in the grand scale of time.
They don't talk much about AI and other synthetic replacements for humanity. Maybe it's just too difficult to extrapolate.
One can guess, though, that long before another 10,000 years have passed, we will have developed artificial beings that are billions of times smarter than we are.
By then, we probably will have augmented our minds and bodies to the point where we are vastly more intelligent and powerful as well, so perhaps we will survive in some form or other.
Or we will have unleashed highly lethal, self-replicating nanobots in the prosecution of a devastating global war, and the human race will be crawling along with a population at extinction levels. (Or maybe just a good old fashioned series of nuclear exchanges?)
The future can be more brilliant than we could imagine, or darker than our worst fears can conjure. Likely, it will be somewhere in the middle.
One of my favorite Wikipedia pages of all time. A little sad that there are only three Biology events there though: North American earthworms spreading to Canada, coral reefs recovering, and C4 photosynthesis no longer possible. Can anyone think of more possible biology events?
Actually, the prediction accuracy here is more like "may go off any time". Likewise, for Betelgeuse (the brightest star of Orion), which would also be visible in daylight.
It’s very interesting to speculate about all this, and also crazy to think all these predictions were only made in the last century. I wonder how much different this list will look in another 100 years (if at all).
> 230 million - Prediction of the orbits of the planets is impossible over greater time spans than this, due to the limitations of Lyapunov time.
> [...]
> 3.3 billion - 1% chance that Jupiter's gravity may make Mercury's orbit so eccentric as to collide with Venus, sending the inner Solar System into chaos. Possible scenarios include Mercury colliding with the Sun, being ejected from the Solar System, or colliding with Earth.
Are these statements contradictory or am I missing something?
After 230 million years we lose the ability to make accurate predictions. The second statement says that we are guessing (odds 100 to 1) that Jupiter might do that.
There's no agreed upon definition of "Prediction" "the planets" or "the orbits", so its any random number between 1M and 10B years under wildly divergent criteria.
Orbits have a large number of degrees of freedom and the chaos noise amplification effect is different for each, so given 15M of noise in starting conditions the point along the orbit of the earth is completely unconstrained in about 100M years, but the diameter of the orbit is very tightly constrained in comparison. In 100M years it'll be pretty easy to draw an ellipse and completely impossible to predict where along that ellipse the earth will be, but it'll be somewhere along that ellipse.
There's no analogy in physics, but there is an analogy in numerical simulation, that its like predicting electron orbits. I can do organic chemistry and build lasers all day without knowing where any specific electron is located, does that mean prediction of electron orbits is impossible or that its irrelevant to most practical issues? The specific mechanism for electron orbits is a quantum mechanical limitation whereas the orbit problem is statistical undersampling of noisy data.
Given the services of a measurement calibration lab and sufficient budget I can predict very accurately what comes out of a screw making factory tomorrow given today's sample data without continuously supervising the factory overnight, but I can't calibrate the screw making factory today, let it run 100M years, and usefully statistically predict what the factory will try to ship on one given day 100M years from now.
It's more like the first says we can't know exactly where the planets will be while the second is talking about some of the extremes that divergence will go.
This is extremely interesting, but couldn't it be that in 10.000 our technology has advanced so much that we are able to "refill" dying stars for example? I mean, look at how much we have achieved in the past 1000 years, exponential technology growth over a timefrime 10x that can be unimaginable now.
These are cool predictions but they need not be true
> 800 million Carbon dioxide levels fall to the point at which C4 photosynthesis is no longer possible.[57] Without plant life to recycle oxygen in the atmosphere, free oxygen and the ozone layer will disappear from the atmosphere. All multicellular life will die out.[58]
The general idea, I believe, is that the carbonate-silicate cycle will shift more toward carbonates over time. The Earth will warm substantially as the sun's luminosity increases over millions of years. Warmer conditions will accelerate the reaction of water and carbon dioxide with silicate minerals like magnesium and calcium silicates, shifting the equilibrium to favor more carbon-as-insoluble-carbonate and less carbon-as-available-CO2. Plant life will eventually go extinct from insufficient atmospheric CO2. I haven't spotted a discussion of oxygen loss in either citation 57 or 58. But "just" losing plant life would be enough to drive the extinction of most other multicellular life on Earth.
Photosynthesis produces oxygen at a rate faster than the rate of depletion due to oxidation of the Earth's crust (think rust). Without plants there's nothing left to spew oxygen back into the atmosphere.
Photosynthesis converts CO2 into carbohydrates. Lowering the concentration of atmospheric CO2 slows this reaction. Plants also metabolize carbohydrates, producing CO2. So photosynthesis requires the right balance of CO2 concentration and light.
The estimate for when CO2 levels would fall too low appears to come from the following linked article:
The latter authors feared that
photosynthetic production would cease ~ 0.1 Gyr from now when just 150 ppm CO2 remained in
the atmosphere. The latter figure corresponded to the CO2 compensation point, at which
photosynthetic carbon fixation would exactly balance losses through respiration. We stress that _
this must not be confused with the CO2 value at which healthy metabolism ceases; with zero net C
fixation available, a plant could not repair itself, produce seeds, or even grow.
While I'm not totally on board with outlooks on a technological singularity a la Kurzweil and peers, what does it mean that there is no real representation of that idea here? For example, Kurzweil's "law of accelerating returns" where the speed of technological change increases exponentially has many flaws according to scientists I respect greatly, yet also has many hints at possible futures, ironically also according to scientists I respect greatly.
It is a controversial idea, and most people can only imagine a future for humanity where things look pretty much as they do now, but with slightly better technology (cf Star Trek, where meat bags are flying among the stars, mostly unchanged from present humanity).
I'm fairly certain we're looking at the end of human civilization one way or the other within the next 100 years max. The Global Pollution Epidemic, robot uprising, and nuclear war are the more likely bad scenarios for the end of civilization.
We might instead be able to develop technology which solves all present problems (like pollution and energy production) and then use it wisely to bring wealth and enlightenment to everyone.
I wouldn't care to estimate what outcome is more likely.
Even Kurzweil's updated ideas and projections in The Singularity is Near from around 2005 still make assumptions of humanity having a longer technology maturation period than 100 years. I actually have the same opinion as you when it comes to our time left if we can't make some global changes; it bums me out, having two girls who are not even in High School yet.
The Timeline talks about Nuclear waste but what about cumulative effect of daily garbage, solid waste, plastic degradation until human beings survive on earth...
Whoever thou mayest be, beloved stranger, whom I meet here for the first time, avail thyself of this happy hour and of the stillness around us, and above us, and let me tell thee something of the thought which has suddenly risen before me like a star which would fain shed down its rays upon thee and every one, as befits the nature of light.
Fellow man! Your whole life, like a sandglass, will always be reversed and will ever run out again, - a long minute of time will elapse until all those conditions out of which you were evolved return in the wheel of the cosmic process. And then you will find every pain and every pleasure, every friend and every enemy, every hope and every error, every blade of grass and every ray of sunshine once more, and the whole fabric of things which make up your life. This ring in which you are but a grain will glitter afresh forever. And in every one of these cycles of human life there will be one hour where, for the first time one man, and then many, will perceive the mighty thought of the eternal recurrence of all things:- and for mankind this is always the hour of Noon.
Is someone aware of any non-fiction book that imagines the far future? There're plenty of good books about the past, but I'm not aware of something that spins a tale similar to this article, it could make a great read.
Fascinating reading, but does anybody else find it incredibly depressing? Everything we've seen, every place we loved, everything we've produced, every bit of our history, literature, arts, every smallest trace of our passage in the universe, and every living being, species, descendant or distant cousin, is going to be pulverized, baked, incinerated and atomized. Not even too far from now, in geological terms- much before the universe has stopped producing new stars and planets and new life.
Anyone who was holding their breath waiting for coastal California to fall into the ocean is going to be disappointment to find out it's not happening in their lifetime.
Can you just imagine the amount of legacy code with DAY_SECONDS=86400 out there 50k years from now?