Water found on a potentially life-friendly alien planet • Hacker News Board

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

#301

Post by IggleSniggle » Thu, Sep 12, 2019, 7:40 AM UTC

vermilingua wrote: post #246

gisely wrote: post #242

Earlier quoted context omitted.

The speed of light is just a compute constraint imposed on the physics simulation that is our universe. If we can just get the gods who are running that simulation to give us a little extra compute time in our neck of to woods then we can all be galactic explorers.

Just for the sake of argument, let's run with that. If we're in a physics simulation, we don't experience at the rate that the simulation is processed. One "tick" of the simulation could be processed in one second of the host universe, or one hour: and we wouldn't feel the difference. We are processed at the same tickrate as the rest of the universe, so we experience the passage of time at the same rate that the simu…

The short story “Dust” (1992) by Greg Egan explores these ideas in a pretty entertaining way.

Here, I found a copy: https://emperybooks.com/wp-content/uploads/2018/06/Greg-Egan...

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

#302

Post by alexgmcm » Thu, Sep 12, 2019, 7:47 AM UTC

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…

Why is annual energy growth rate or industrial growth rate assumed to correlate to the speed of space travel?

Just because we build more power plants or sell more tractors doesn't imply a corresponding improvement in spacecraft technology.

The Wait Calculation seems to make even less sense than the Drake Equation - which is at least correct in theory even if the actual variables have so much uncertainty it is useless.

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

#303

Post by nonsapreiche » Thu, Sep 12, 2019, 7:47 AM UTC

po1nter wrote: post #160

swarnie_ wrote: post #152

Earlier quoted context omitted.

Probably tiny? Lloyds bank founded 1765 Barclays founded 1736 I doubt any banks in the new world are as old.

Berenberg Bank founded 1590 (429 years ago)

Monte dei Paschi di Siena 1472 (547 years ago)

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

#304

Post by neuronic » Thu, Sep 12, 2019, 7:59 AM UTC

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…

This completely dismisses any tangential factors, of course. Going earlier might be an advantage, as new ways to kill each other (or kill Terran ecosystems) emerge.

Going later to optimize for time is one aspect of deciding how to spread throughout the galaxy. Another question might ask, which is the most risk reducing strategy? And the answer might be completely different.

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

#305

Post by simon1573 » Thu, Sep 12, 2019, 8:05 AM UTC

vermilingua wrote: post #275

SRTP wrote: post #268

Earlier quoted context omitted.

Any book in particular you'd recommend?

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.

Is Pandoras Star worth the effort?

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

#306

Post by gradschool » Thu, Sep 12, 2019, 8:14 AM UTC

methodover wrote: post #170

gradschool wrote: post #150

Earlier quoted context omitted.

Not a physicist, but I think it might not be that simple. From our point of view, a ship with constant 1g acceleration increases its speed by 9.8 m/s every second, but people on a ship moving at a significant fraction of c take more than one of our seconds to experience one of their seconds. During the time they experience one of their seconds, the speed increases more than 9.8 m/s, so they must experience greater th…

Err, that isn't a correct understanding of physics, I believe. The ship wouldn't need to reduce its output as it gets faster relative to some other object in the universe. It can happily keep accelerating at 9.8 m/s for as long as it likes (or has fuel). No passengers would get squashed.

If the ship's means of propulsion is set to impart a constant force, then I understand that the passengers could experience a constant acceleration indefinitely, but that constant acceleration would be with respect to the ship's reference frame, not ours. A constant acceleration of 1g in our reference frame would mean by definition that the speed reaches 2c in two years, which can't be right. Subject again to the disclaimer that I'm not a physicist and haven't done the math, the only outcome I can picture is that in our reference frame the speed asymptotically approaches c in some interesting way.

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

#307

Post by arethuza » Thu, Sep 12, 2019, 8:23 AM UTC

SRTP wrote: post #268

ddingus wrote: post #257

Earlier quoted context omitted.

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.

Any book in particular you'd recommend?

"reality is so limiting compared to what we can imagine"

This is actually a central theme of the Zones of Thought novels by Vernon Vinge where a character in the far future describes our current time as the "Age of Failed Dreams" (GAI, nanotech etc.) - turns out that he is wrong but for rather neat reasons....

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

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

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

#308

Post by username90 » Thu, Sep 12, 2019, 8:24 AM UTC

vermilingua wrote: post #246

gisely wrote: post #242

Earlier quoted context omitted.

The speed of light is just a compute constraint imposed on the physics simulation that is our universe. If we can just get the gods who are running that simulation to give us a little extra compute time in our neck of to woods then we can all be galactic explorers.

Just for the sake of argument, let's run with that. If we're in a physics simulation, we don't experience at the rate that the simulation is processed. One "tick" of the simulation could be processed in one second of the host universe, or one hour: and we wouldn't feel the difference. We are processed at the same tickrate as the rest of the universe, so we experience the passage of time at the same rate that the simu…

We could ask the host to update their algorithm to let c be a property of objects and then just do spaceship.c = 1000 * c.

Would probably be a heck of a refactor to get it working without bugs though.

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

#309

Post by known » Thu, Sep 12, 2019, 8:32 AM UTC

If water is found can we assume fish like life in that planet?

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

#310

Post by Tepix » Thu, Sep 12, 2019, 8:35 AM UTC

manicdee wrote: post #134

Some caveats per Marina Koren https://twitter.com/marinakoren/status/1171873631808438273 1. This planet probably doesn’t have a solid surface 2. Being in the “habitable zone” doesn’t mean a planet is habitable 3. The detection is of water molecules, chances are the water only exists as vapour in the atmosphere of this small gas giant. 4. If you ask 10 astronomers about this you will get 11 opinions

> 2. Being in the “habitable zone” doesn’t mean a planet is habitable