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Water found on a potentially life-friendly alien planet

nationalgeographic.com

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Re: Water found on a potentially life-friendly alien planet

#281

Post by tunesmith »

radeklew wrote: post #278
tunesmith wrote: post #204

I got into the Wait Calculation[1] a few weeks back and made a Jupyter notebook out of it. At our current max speed (692,000 km/hr, stated max speed of Parker Space Probe), it would take about 173,000 years to get to that planet. We could instead choose to Wait and grow our tech. By picking a constant annual growth rate and then doing some calculus to find the minimum, we can calculate the shortest possible time it w…

As others have said, E=mv^2/2 only holds at very small fractions of the speed of light. I believe the equation you need is E=mc^2/sqrt(1-v^2/c^2)-mv^2. https://en.wikipedia.org/wiki/Kinetic_energy#Relativistic_ki...

Can you explain this further? It seems this is relevant more for something other than the Wait Calculation. The original Wait Calculation doesn't factor in mass at all. I'm having trouble understanding what this impacts. Is this more about relativistic time passage, like from the ship traveler versus the observer?

Most scenarios I've explored - low velocity growth rate, nearby planets/stars - the Wait Calculation tells you to stop researching and start launching long before your tech gets to significant fractions of light speed.

Re: Water found on a potentially life-friendly alien planet

#282

Post by gregmac »

tunesmith wrote: post #204

I got into the Wait Calculation[1] a few weeks back and made a Jupyter notebook out of it. At our current max speed (692,000 km/hr, stated max speed of Parker Space Probe), it would take about 173,000 years to get to that planet. We could instead choose to Wait and grow our tech. By picking a constant annual growth rate and then doing some calculus to find the minimum, we can calculate the shortest possible time it w…

Does that include slowing down and stopping, or would you be at max speed by the time you got there?

I always thought that was a very well thought out aspect of The Expanse: spend half the trip accelerating, then flip the ship around and spend the other half slowing down (aka accelerating in the opposite direction).

Re: Water found on a potentially life-friendly alien planet

#283

Post by vermilingua »

SirHound wrote: post #280
vermilingua wrote: post #275

Earlier quoted context omitted.

Anything in the Culture series by Iain M. Banks; The Expanse series by James S. A. Corey; The Commonwealth and Void trilogies by Peter F. Hamilton, and the Night’s Dawn trilogy also by Peter F. Hamilton; The Dune saga by Frank Herbert.

Hamilton’s The Reality Dysfunction was the stupidest book I’ve ever read and took hundreds of pages to expose itself. Are his others any more grounded (like your other suggestions)?

Yeah the Night’s dawn series was a bit out there compared to the genre average. The Commonwealth series is considerably closer to baseline, and his best books IMO. The void trilogy (and the newer trilogy whose name escapes me) follow on from the Commonwealth books, and while good, don’t hold up to the first three.

Re: Water found on a potentially life-friendly alien planet

#284

Post by temporalparts »

tunesmith wrote: post #263
temporalparts wrote: post #241

Earlier quoted context omitted.

Does this take into consideration that your mass increases as you travel closer to the speed of light?

No, I'm not sure what that would suggest - how would that need to be accounted for? Maybe some fraction of light speed would need to be the upper bound, low enough that mass increase wouldn't have a material impact? I'm having trouble understanding what impact the mass increase would have in the first place.

It's a cool project! Just as others say, once you get to a notable fraction of the speed of light, you need to account for relativity.

Re: Water found on a potentially life-friendly alien planet

#285

Post by wahern »

dragonwriter wrote: post #142
stickfigure wrote: post #73

Earlier quoted context omitted.

If you put some money in an interest-bearing account you could at least buy a new home when you got back.

> If you put some money in an interest-bearing account you could at least buy a new home when you got back. If you do it in a country that doesn't allow you to be declared legally dead when you are out of contact for a couple centuries, and if the institutions involved don't collapse, and if the interest on the account outpaces inflation, sure. What percentage of the banks that were around 222 years ago have not fail…

That's not the right question, though, because the expected rate of failure isn't constant throughout the lifetime of a bank. See, e.g., https://en.wikipedia.org/wiki/Lindy_effect

Seems like your best bet would be to park your money with several very old banks: https://en.wikipedia.org/wiki/List_of_oldest_banks_in_contin...

Also might want to think about purchasing bonds: https://en.wikipedia.org/wiki/List_of_oldest_banks_in_contin...

Re: Water found on a potentially life-friendly alien planet

#286

Post by _imba_ »

narrator wrote: post #230
tunesmith wrote: post #204

I got into the Wait Calculation[1] a few weeks back and made a Jupyter notebook out of it. At our current max speed (692,000 km/hr, stated max speed of Parker Space Probe), it would take about 173,000 years to get to that planet. We could instead choose to Wait and grow our tech. By picking a constant annual growth rate and then doing some calculus to find the minimum, we can calculate the shortest possible time it w…

Progress in physics was much faster in the early 20th century when it wasn't so fascinated with deep space. Yes, you needed to observe eclipses to verify relativity, but that was a tool, not the end in itself. Cosmology involves distances that are so great that it seems like it's pouring a whole bunch of smart people's efforts down the drain in an ultimately futile waste of brain power that will never amount to anyth…

> Progress in physics was much faster in the early 20th century when it wasn't so fascinated with deep space.

I don't think measuring progress is tivial enough to make that assumption. It's also unfair to blame a fascination with deep space for any slower progress, things are more complicated than that.

Getting humans onto anther planet asap is one of the most important things one can pursuit for humanity. The earth is a giant single point of failure

Re: Water found on a potentially life-friendly alien planet

#287

Post by babuskov »

tunesmith wrote: post #204

I got into the Wait Calculation[1] a few weeks back and made a Jupyter notebook out of it. At our current max speed (692,000 km/hr, stated max speed of Parker Space Probe), it would take about 173,000 years to get to that planet. We could instead choose to Wait and grow our tech. By picking a constant annual growth rate and then doing some calculus to find the minimum, we can calculate the shortest possible time it w…

> One common recommendation for annual energy growth rate is 1.4%

Where does this come from? Does it even hold water when compared to past data? Looking at some Wikipedia data for the past 20-30 years, it seems that the increase in speeds is much higher:

https://en.wikipedia.org/wiki/List_of_vehicle_speed_records#...

Re: Water found on a potentially life-friendly alien planet

#288

Post by de_watcher »

ddingus wrote: post #257
glup wrote: post #240

Earlier quoted context omitted.

...crushing all my dreams of being a starship captain, thanks.

I am reading big space operas right now. What we know of this reality is so limiting compared to what we can imagine. Good dreams. Many of us have them. I also like to dream the knowable remains much larger than the currently understood too.

Funny thing is that the imaginary worlds in books are way less weirder compared to what reality has to offer. Apparently because it's harder to develop the story.

Re: Water found on a potentially life-friendly alien planet

#289

Post by de_watcher »

blencdr wrote: post #271
skrebbel wrote: post #267

Earlier quoted context omitted.

As a startup founder, I learned the hard way to not assume progress will ever be exponential.

As a guy who lives in a finite world where energy comes mainly from fossil fue in a way or another, I do not assume that any constant progress in energy supply is something achievable.

As soon as you get fusion the game drastically changes. And fusion is only 30 years away.

Re: Water found on a potentially life-friendly alien planet

#290

Post by archgoon »

Swizec wrote: post #218
peteretep wrote: post #180

Earlier quoted context omitted.

I mean that sounds pretty awesome if you invested your funds well. I'd definitely be willing to be the first person who did that.

Where can you invest that would still recognize those funds as yours after 222 years?

It's been done actually. Ben Franklin established a trust that lasted over two hundred years by design.

https://www.nytimes.com/paidpost/franklin-templeton/investin...

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