"Zarmina's World" -- Astronomer's Zeroing in On Habitable Extrasolars

[EyeKhan]

His Master's Voice is perhaps the best book I've read. Dunno if it'll resonate with you.

Cyberiad is humour and is hilarious!

The folks on Amazon are just gushing about these books.

[Wraith]

I'm thinking hybernation.

It'd be hilarious if half the people we sent woke up with brain damage, and the other half didn't wake up at all. Generation ship is probably safer. At least we know how to do everything involved in that. Let's go hollow out an asteroid and spin her up.

There's still potential for comedy when the destination turns out not to be habitable after all, or at least turns out like most of the planets in Known Space where there's one tiny part that's habitable and the rest isn't.

[Nessus]

The folks on Amazon are just gushing about these books.

The thing with His Master's Voice

I first read that book when I was maybe 13

It was awesome, it was an adventure, it opened many avenues of thought on how the Universe might work

I read it again when I was around 19

It spoke to an aspiring (and arrogant) young scholar about the life of a scholar. How there were the third-rate hacks and the first-rate geniuses. I figured I was the latter, when reality later showed me my error.

I read it again when I was 21, and again and again to this day, every six months or so. The story deepens with each reading, the deeper messages about humanity slowly open themselves up to my ponderously slow mental mastication. Every time I come a little closer, but I am left with the feeling that there's some deeper understanding there, something I'll get on the next go.

Much of my life philosophy has been shaped and/or articulated by that book. You may find it's rubbish, since we have very little common ground, but there you go all the same.

edit: Also, I don't like the English translation at all compared to the Finnish one. Don't know Polish so can't say which is truer.

[Khendraja'aro]

I'm thinking hybernation.

I'm half-tempted at this moment to calculate how long the actual trip would take at, say, 1G constant acceleration.

So, we have

v(T) = c tanh(a T/c)

which would mean that

s(T) = c²/a ln cosh(a T/c)

now we're solving the whole thing for T, since we want to know how long 10 lightyears at 1G will take

T = c/a cosh^-1 exp(sa/c²)

Setting c = 3E08 m/s, a = 10 m/s², and s = 10 ly = 9.461E16 m we get:

T = 2.4E23s = 7.8E12 a
("a" stands for "annum" or "years" in Latin for all you non-scientists :) )

In other words: Several eons (and that's only the acceleration phase! Halfway!). Unless my calculations are horribly wrong somewhere

[Nessus]

http://musr.physics.ubc.ca/~jess/p200/str/str13.html

[Khendraja'aro]

http://musr.physics.ubc.ca/~jess/p200/str/str13.html

Yeah, but I used the equation for an outside observer

[Nessus]

Yeah, but I used the equation for an outside observer

Who cares about Earth when you're on that ship though

[Khendraja'aro]

Who cares about Earth when you're on that ship though

Well, you've got a point there. And I didn't think the contraction would be that extreme. I mean, just look at the numbers: You've justgot a bit over 6 dainty years aboard the ship and outside millenia have rushed by.

[Nessus]

Well, you've got a point there. And I didn't think the contraction would be that extreme. I mean, just look at the numbers: You've justgot a bit over 6 dainty years aboard the ship and outside millenia have rushed by.

You should read Tau Zero if you haven't. Fun stuff.

[Khendraja'aro]

You should read Tau Zero if you haven't. Fun stuff.

Pushing Ice also dealt with the problem

[Wraith]

<snip>

That can't be right. C=299,792,458 m/s, 1g=9.8m/s^2, so to get to .5c dividing it would take 1.53E07 seconds = 2.55E05 minutes = 4.25E03 hours = 177 days = ~.5 years to reach that speed. Since you can cover the distance in 20 years at that speed, it can't possibly take 8 trillion years to get there.

edit: I did the math myself, using an equation I stole from here and came out with ~12 years assuming constant 1g acceleration & deceleration. I assumed I screwed something up because it's such a small number, but from the above calculation it actually seems believable. If it's right though, that still sidesteps the issue of where the hell we're going to get that much energy.

[EyeKhan]

It'd be hilarious if half the people we sent woke up with brain damage, and the other half didn't wake up at all. Generation ship is probably safer. At least we know how to do everything involved in that. Let's go hollow out an asteroid and spin her up.

Ok, if I'm going to participate as a colonist on a new planet, then its going to be ME, not my freaking great grand children. Who the hell would sign up for that??? Considering the arc of technology, there are several likely alternatives:

#1. Safe hybernation.

#2. Arrested aging - with this you have a reasonable chance of getting to the destination alive. You just better make sure its a big honkin' asteroid because its going to be a long, boring trip. Of course, that's what full immersion VR is for. Everyone can spend most of their time in the box until they get to the destination.

#3. Just send frozen embryos and some decent robots. When the ship is within 20 years of destination, put the embryos in artificial wombs and have the human appearing robots raise them to adulthood. They'd probably be the best adjusted kids in human history - what are we if not forged by the flaws of our parents, siblings and friends?

There's still potential for comedy when the destination turns out not to be habitable after all, or at least turns out like most of the planets in Known Space where there's one tiny part that's habitable and the rest isn't.

Whatever goes out would have to be able to make use of a number of means of colonizing. Likely there'll be some barren moons, if all the planets are like Venus or worse.

[Nessus]

If it's right though, that still sidesteps the issue of where the hell we're going to get that much energy.

Teller's brainchild, atomic bombs.

[EyeKhan]

The thing with His Master's Voice

I first read that book when I was maybe 13

It was awesome, it was an adventure, it opened many avenues of thought on how the Universe might work

I read it again when I was around 19

It spoke to an aspiring (and arrogant) young scholar about the life of a scholar. How there were the third-rate hacks and the first-rate geniuses. I figured I was the latter, when reality later showed me my error.

I read it again when I was 21, and again and again to this day, every six months or so. The story deepens with each reading, the deeper messages about humanity slowly open themselves up to my ponderously slow mental mastication. Every time I come a little closer, but I am left with the feeling that there's some deeper understanding there, something I'll get on the next go.

Much of my life philosophy has been shaped and/or articulated by that book. You may find it's rubbish, since we have very little common ground, but there you go all the same.

edit: Also, I don't like the English translation at all compared to the Finnish one. Don't know Polish so can't say which is truer.

Do I have to ask about OCD? I serioulsy doubt I'll be able to get much below the surface. And multiple readings? Maybe when the kids are off to college and I'm retired. But I admit I'm feeling a bit of anticipation now.

[Nessus]

Do I have to ask about OCD? I serioulsy doubt I'll be able to get much below the surface. And multiple readings? Maybe when the kids are off to college and I'm retired. But I admit I'm feeling a bit of anticipation now.

I don't have OCD, I'm lazy to a disaster, it's just a book that helped fuel my monomania.

[EyeKhan]

Well, you've got a point there. And I didn't think the contraction would be that extreme. I mean, just look at the numbers: You've justgot a bit over 6 dainty years aboard the ship and outside millenia have rushed by.

There will likely be humans waiting for them when the generation ship arrives; humans who over the intervening millenia perfected ftl travel.... THAT would piss me off.

[Wraith]

Teller's brainchild, atomic bombs.

As big a fan I am of Project Orion, that's a shit ton of mass for all the bombs needed for 12 years of near continuous nuclear explosions, which increases the energy needed further. Probably not feasible, and definitely not a fun ride. I don't think a top speed of anything more than .1c is remotely reasonable, and even .1c is a damn hard target to hit.

[EyeKhan]

I don't have OCD, I'm lazy to a disaster, it's just a book that helped fuel my monomania.

I've only read maybe two dozen books twice. And a handful at most 3x. But every 6 months? That's crazy. Obsessive even.

As big a fan I am of Project Orion, that's a shit ton of mass for all the bombs needed for 12 years of near continuous nuclear explosions, which increases the energy needed further. Probably not feasible, and definitely not a fun ride. I don't think a top speed of anything more than .1c is remotely reasonable, and even .1c is a damn hard target to hit.

We need an easy way to produce anti-matter.

[Nessus]

As big a fan I am of Project Orion, that's a shit ton of mass for all the bombs needed for 12 years of near continuous nuclear explosions, which increases the energy needed further. Probably not feasible, and definitely not a fun ride. I don't think a top speed of anything more than .1c is remotely reasonable, and even .1c is a damn hard target to hit.

You're not thinking in four dimensions, Marty!

[Nessus]

I've only read maybe two dozen books twice. And a handful at most 3x. But every 6 months? That's crazy. Obsessive even.

You've stated your opinion on my life-style several times before.

[Illusions]

Who cares about Earth when you're on that ship though

If it hasn't destroyed itself, and technological progress continued at its usual rate, you'd likely be aiming your ship at a planet that is still going to be of interest to future Earth and with the time dilation and your leaving much earlier than ships sent after you, you could be, technologically, culturally and perhaps even biologically, decades to millenia behind whatever human or human-species offshoots you might find there. Although that would be one giant mind-fuck.

I dare say that even for such a "tiny" trip as 20 lightyears, we'd still need a Generation ship. Reaching .5 c is a fantasy value as the ship would simply lack the reaction mass to reach this velocity. And you also have to consider the time spent decelerating.

I was merely using that value to show that developing Axe body spray and talking pens wasn't what was holding us back from being able to launch a starship to Gliese anytime soon, and I did factor in deceleration, hence the "at least" after the 40 years.

I forgot to factor in time dilation for the rest of it though, and don't know that off the top of my head...

[EyeKhan]

You've stated your opinion on my life-style several times before.

I don't recall having any real issues with your life-style... I might have pulled your leg here and there just foolin' around, but not serious....

[Khendraja'aro]

That can't be right. C=299,792,458 m/s, 1g=9.8m/s^2, so to get to .5c dividing it would take 1.53E07 seconds = 2.55E05 minutes = 4.25E03 hours = 177 days = ~.5 years to reach that speed. Since you can cover the distance in 20 years at that speed, it can't possibly take 8 trillion years to get there.

edit: I did the math myself, using an equation I stole from here and came out with ~12 years assuming constant 1g acceleration & deceleration. I assumed I screwed something up because it's such a small number, but from the above calculation it actually seems believable. If it's right though, that still sidesteps the issue of where the hell we're going to get that much energy.

12 years can't be right either, since you're talking about acceleration and deceleration, I'm going to assume that you're talking about doing 20 ly in 12 years. That would involve superluminal speeds.
12 years for 10 ly would be fun as well, since that means that you're pretty close to c the whole time, on average you'd have to go at ~0.83 c.

So, your solution ain't right either. And your original approach used Newtonian physics, which for obvious reasons are not exactly cut out for the problem at hand.

[Nessus]

I don't recall having any real issues with your life-style... I might have pulled your leg here and there just foolin' around, but not serious....

I wasn't very serious, either, just the usual joshing around obsession and reading material

[Wraith]

12 years can't be right either, since you're talking about acceleration and deceleration, I'm going to assume that you're talking about doing 20 ly in 12 years. That would involve superluminal speeds.

There's part of the problem; I thought we were talking about 10 ly. I'm guessing the same equation would come out to ~22 years with that one, since it looks like it's just 1 year accelerating and decelerating, and the rest of the time cruising at near c. (edit: yep, 22 years, assuming I didn't fuck it up)

So, your solution ain't right either. And your original approach used Newtonian physics, which for obvious reasons are not exactly cut out for the problem at hand.

I used .5 c instead of something closer to c because IIRC the relativistic differences still aren't too huge (should at least ballpark things, and I don't remember the relativisitic equations of the top of my head and don't have my physics books here), and I'm going to use the same outside observer excuse you used earlier and hand-wave away the increasing energy costs to maintain that same acceleration at high speeds.

[EyeKhan]

I wasn't very serious, either, just the usual joshing around obsession and reading material

Its still weird to read the same damn book every six months. (Unless its the New Testament or something....) ((excited to get it though - now I'm thinking I should have paid for the 2 day freight...))

[LittleFuzzy]

He's right - there are going to be constant wind speeds on tidally locked planets with atmospheres. Also remember that hot air rises, and what happens is that in the upper atmosphere air flows from the day side to the night side, where it cools down and sinks, and the pressure causes the cold air to flow from the night side to the day side at ground level. On many planets like that, it's supposed to actually keep the temperature relatively consistent across the planet that way.

supposed to

The fact is that the geophysics of the situation is highly speculative.

[littlelolligagged]

I've only read maybe two dozen books twice. And a handful at most 3x. But every 6 months? That's crazy. Obsessive even.

There is something seriously wrong with you.

[Khendraja'aro]

There's part of the problem; I thought we were talking about 10 ly. I'm guessing the same equation would come out to ~22 years with that one, since it looks like it's just 1 year accelerating and decelerating, and the rest of the time cruising at near c. (edit: yep, 22 years, assuming I didn't fuck it up)


I used .5 c instead of something closer to c because IIRC the relativistic differences still aren't too huge (should at least ballpark things, and I don't remember the relativisitic equations of the top of my head and don't have my physics books here), and I'm going to use the same outside observer excuse you used earlier and hand-wave away the increasing energy costs to maintain that same acceleration at high speeds.

Sorry, but at .5c you can't use Newtonian anymore.

[Nessus]

Its still weird to read the same damn book every six months. (Unless its the New Testament or something....) ((excited to get it though - now I'm thinking I should have paid for the 2 day freight...))

You're weird too, fungi-poop-boy