Live data from Hacker News

Timeline of the far future

en.wikipedia.org

111–120 of 272 posts

Re: Timeline of the far future

#111
post #13

Earlier quoted context omitted.

It will be easier to boost the Earth’s spin back to a 86,400-second day than to fix all the code.

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.

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.)

Re: Timeline of the far future

#112

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 i…

Now, here's the interesting part.

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.

Ah, patterns.

Re: Timeline of the far future

#113
post #98

Can someone explain: > 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]

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.

https://arxiv.org/pdf/0912.2482.pdf

There's more on the compensation point here:

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

Re: Timeline of the far future

#114
post #8

> 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 5…

Could you just add a leap day every 86,400 days?

Re: Timeline of the far future

#115
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.

What is the fallacy in that thinking?

Re: Timeline of the far future

#116

Earlier quoted context omitted.

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.

But how do we know which base number system they're using!?

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.

Re: Timeline of the far future

#117
post #115

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.

Re: Timeline of the far future

#119

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 accu…

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!

Re: Timeline of the far future

#120

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.

Would you mind making your comments more thoughtful and informative?

https://news.ycombinator.com/newsguidelines.html

Post reply on HN