Real exoplanets inspire Civilization: Beyond Earth pre-order deal

[Buster's Uncle]

Real exoplanets inspire Civilization: Beyond Earth pre-order deal
Polygon
By Colin Campbell  1 hour ago






A pre-purchase offer for Sid Meier's Civilization: Beyond Earth is now available on Steam, offering early-bird buyers the Exoplanets Map Pack, which includes six custom maps, inspired by real exoplanets.

The custom maps include the following exoplanets (list below), with added features from the imaginations of the development team at Firaxis. Publisher 2K Games is offering Sid Meier's Civilization: Beyond Earth for $49.99 and Sid Meier's Civilization: Beyond Earth Classics Bundle, which includes three previous Civilization games, for $69.99.

Civilization: Beyond Earth is a turn-based strategy game in which players settle an alien planet, while conquering or treating with neighbors and researching new technologies. It will be released on Oct. 24, 2014.


​Kepler 186f: One of the oldest known Earth-like planets. Featuring lush vegetation in the game world.
Rigil Khantoris Bb: Orbiting the closest star to our solar system.
Tau Ceti d: A planet of seas and archipelagos.
Mu Arae f: Tidally locked in orbit around a weak star, half the planet is frozen while the other half is always hot.
82 Eridani e: Tectonically unstable.
Eta Vulpeculae b: A mysterious new discovery with unknown terrain.

http://news.yahoo.com/real-exoplanets-inspire-civilization-beyond-200005850.html

[Geo]

Mmm...
In the scope of the game, Kepler 186f is too far out (500 ly) to reach with sublight starships, and Rigil Khantoris (Centaurus) Bb is too close to its star.

[NewAgeOfPower]

I dunno. Hitting 12% C with Thermonuclear Orion Drive becomes an engineering challenge, really...

Even Alpha Centauri would take over five decades (once acceleration and turn-over are figured in), so five centuries in cryo isn't too implausible.

[BlaneckW]

Assuming your ship isn't destroyed by a speck of dust.

[gwillybj]

Assuming your ship isn't destroyed by a speck of dust.

Maybe somebody will come up with a self-repairing composite, kind of like a self-sealing tire.

[Geo]

I dunno. Hitting 12% C with Thermonuclear Orion Drive becomes an engineering challenge, really...

Even Alpha Centauri would take over five decades (once acceleration and turn-over are figured in), so five centuries in cryo isn't too implausible.

500 ly at 12% C comes down to 4166 years (earth time) travel duration, give or take a season or two.

Maybe somebody will come up with a self-repairing composite, kind of like a self-sealing tire.

Its hard to repair/seal/bond particles when they've turned into plasma.

[t_ras]

Ill wait for the critics...

[Dale]

Publisher 2K Games is offering Sid Meier's Civilization: Beyond Earth for $49.99 and Sid Meier's Civilization: Beyond Earth Classics Bundle, which includes three previous Civilization games, for $69.99.

Until they remembered to add the Australia Tax and doubled the price.

Steam just lost a sale (and a LOT of other Aussies) as I sourced it from an overseas key-seller for normal US price.

[NewAgeOfPower]

Assuming your ship isn't destroyed by a speck of dust.

We'd need to advance our tech, but you could have a small fleet of drones (since 0 relative velocity to the 'mothership', very little delta-V is expended) with multiple radar/lidar/other sensor arrays, some drones armed with heavy lasers, others equipped with deployable whipple shielding, etc.

The ship itself could use some shielding material, like a thick caul of ice.

Anything too big to deflect with Whipple shields/vaporize with lasers could probably be dodged. Anything too small to be detected/intercepted can probably be absorbed by the ablative layers of ice.

Of course, this all means more mass to be accelerated, which means more mass to needed for bombs, which means more mass to accelerate more mass... but still an engineering challenge.

The ice itself could be gradually used as reaction mass after turnover (deceleration phase) to somewhat reduce fuel weight. One issue with this plan would be that during the beginning of turnover, your ship would be travelling at nearly .12C without an protective ice layer. As you decelerated, the risk from fast dust particles decreases dramatically, but during the initial phase of deceleration you'd have some significant vulnerabilities- perhaps possibly overcome with your drones preemptively deploying mobile Whipple shields to 'scour' the space in the path of the mothership.

As you get closer to C, the problems become more and more difficult to solve, but at .12C the problems are hardly insurmountable.

[Geo]

We'd need to advance our tech, but you could have a small fleet of drones (since 0 relative velocity to the 'mothership', very little delta-V is expended) with multiple radar/lidar/other sensor arrays, some drones armed with heavy lasers, others equipped with deployable whipple shielding, etc.

The ship itself could use some shielding material, like a thick caul of ice.

Anything too big to deflect with Whipple shields/vaporize with lasers could probably be dodged. Anything too small to be detected/intercepted can probably be absorbed by the ablative layers of ice.

Of course, this all means more mass to be accelerated, which means more mass to needed for bombs, which means more mass to accelerate more mass... but still an engineering challenge.

The ice itself could be gradually used as reaction mass after turnover (deceleration phase) to somewhat reduce fuel weight. One issue with this plan would be that during the beginning of turnover, your ship would be travelling at nearly .12C without an protective ice layer. As you decelerated, the risk from fast dust particles decreases dramatically, but during the initial phase of deceleration you'd have some significant vulnerabilities- perhaps possibly overcome with your drones preemptively deploying mobile Whipple shields to 'scour' the space in the path of the mothership.

As you get closer to C, the problems become more and more difficult to solve, but at .12C the problems are hardly insurmountable.

Those 'defensive sats' are totally superfluous.
For starters, you can only deploy them once you reached cruising velocity. The whole acceleration -and deceleration phases they'll stay behind or cruise ahead. There's the extra mass you already mentioned. But most important, whether or not you 'evaporate' an incoming object doesn't matter. It damages your ship anyway, not because of the density of the object but of the speed of impact. So that leaves only a 'shield' to deal with incoming 'mass'.

[NewAgeOfPower]

For starters, you can only deploy them once you reached cruising velocity. The whole acceleration -and deceleration phases they'll stay behind or cruise ahead.

There's the extra mass you already mentioned. But most important, whether or not you 'evaporate' an incoming object doesn't matter. It damages your ship anyway, not because of the density of the object but of the speed of impact. So that leaves only a 'shield' to deal with incoming 'mass'.

What? Even factoring in relativistic dilation (which is very small, if noticable) at .12c, it doesn't take you more than 59 days to reach .12c at 1 g acceleration... you'd have expended about 80% of your fuel mass, but that's already accounted for in the ship design... The chance of smacking into an object

Your period of vulnerability could be further decreased if you sent out massive ice-caul "road clearing" craft to reduce the amount of dust present in the path of your starship for the next half light year- they'd have to be launched years in advance, but totally feasible.

And no, you'd almost never try totally vaporizing an incoming rock - the energy expenditure for vaporizing an entire rock is pretty high.

Perhaps I wrote it in an misleading way- but let me put it in different words- what happens to a rock if, say, 5% of it's mass in a certain direction is vaporized (by, I don't know, a pulsed laser?)

The remaining solid mass of the rock is accelerated in the opposite direction. And the fine mist of remaining vapor is far more easily absorbed by the ice caul than a solid rock- this is the entire principle behind Whipple shielding.

We'd need cryogenics or (god forbid, the mass increase would be stupendous) a generation ship design, but the stars have been in the reach of Mankind's hands should we develop the will to extend our reach to them.

[Geo]

For starters, you can only deploy them once you reached cruising velocity. The whole acceleration -and deceleration phases they'll stay behind or cruise ahead.

There's the extra mass you already mentioned. But most important, whether or not you 'evaporate' an incoming object doesn't matter. It damages your ship anyway, not because of the density of the object but of the speed of impact. So that leaves only a 'shield' to deal with incoming 'mass'.

What? Even factoring in relativistic dilation (which is very small, if noticable) at .12c, it doesn't take you more than 59 days to reach .12c at 1 g acceleration... you'd have expended about 80% of your fuel mass, but that's already accounted for in the ship design... The chance of smacking into an object

I bet you your starship drive won't give 1 g accel. The way to save on fuel mass is to increase your velocity slower. You may say 'only' .12c, but that's still 36,000 km/sec...

Your period of vulnerability could be further decreased if you sent out massive ice-caul "road clearing" craft to reduce the amount of dust present in the path of your starship for the next half light year- they'd have to be launched years in advance, but totally feasible.

Of course launching a 'shield' ahead is feasable, but since everything in space is continually in motion, any vessels' trajectory is going to be different if launched at another time. Your shield must be on your starship, or you simply miss the 'road cleared' by a 'shieldship' launched ahead. Simple trajectory mechanics.

Perhaps I wrote it in an misleading way- but let me put it in different words- what happens to a rock if, say, 5% of it's mass in a certain direction is vaporized (by, I don't know, a pulsed laser?)

The remaining solid mass of the rock is accelerated in the opposite direction. And the fine mist of remaining vapor is far more easily absorbed by the ice caul than a solid rock- this is the entire principle behind Whipple shielding.

Heh, the 'vapor' would still impact at .12c with your shield. In other words, the kinetic energy would be the same as if it collided with your iceshield as a solid object. Again, we're talking 36,000 km/sec here. And the tiny deceleration caused by your laser wouldn't be enough to avoid impact anyway. About dodging, you need RCS thrusters with enough punch to move your ship sideways in time. Detecting an object on a collision course at .12c and evading it in time might be less easily achieved then you think. It eats fuel, depending on the amount of 'dodges' you need to do, which relates to how 'dusty' the interstellar environment really is between Sol and your destination. And you detect objects with the delay of light lag. So, impossible to calculate beforehand how much 'spare' fuel you need.

[NewAgeOfPower]

I bet you your starship drive won't give 1 g accel. The way to save on fuel mass is to increase your velocity slower. You may say 'only' .12c, but that's still 36,000 km/sec...

Erm. You're thinking of tradeoffs present in chemical drives. A thermonuclear Orion Drive's delta V curve is more akin to a straight line; net delta V provided by nuclear explosions is practically the same no matter how you tune the burn rate (in this case, explosion rate). The only determining variables for total delta V is thermonuclear explosive device efficiency and total fuel % of the starship...

Of course launching a 'shield' ahead is feasable, but since everything in space is continually in motion, any vessels' trajectory is going to be different if launched at another time. Your shield must be on your starship, or you simply miss the 'road cleared' by a 'shieldship' launched ahead. Simple trajectory mechanics.

Duh. The cleared road doesn't have to extend far. Just long enough for your starship to reach cruising velocity. Afterwards, you move the road-clearing intrasystem ship off the cleared path, since it has a much weaker total delta V profile, and you can launch a handy flotilla of reconnaissance, defense, and shield drones ahead of the mothership.

Heh, the 'vapor' would still impact at .12c with your shield. In other words, the kinetic energy would be the same as if it collided with your iceshield as a solid object. Again, we're talking 36,000 km/sec here. And the tiny deceleration caused by your laser wouldn't be enough to avoid impact anyway.

First of all, particles in the interstellar medium are NOT accelerating. If you drones detect them, say, an AU or so ahead of the 'mothership', they only need to apply a minimal amount of thrust to move a small rock out of the way - remember, your ship has a small cross section.

Secondly, multi-megawatt mobile lasers already exist today.

Moving the rock out of your starship's path is not hard with this configuration.

Now, for the mass calculation. Let's assume an, I don't know, 10 kg object. Vaporizing 5% of its mass would require about 20 megajoules of energy, assuming it's similar to bedrock in thermal characteristics. The vapor consists of about 500 grams of matter behind.

At this moment, the relative KE of half a kilogram of rock-vapor would be equal to about 3.9 Hiroshimas- but we're assuming the vaporized mass doesn't expand (which gases/plasmas tend to do, in space). The 500g of hot plasma would contain at least 15 MJ in thermal energy.

From an quick search, this paper gives the expected expansion of gas into a vacuum at a speed of ~1700 m/s.

Our starship is travelling at .12C. It would take over 66 minutes, 39 seconds to travel to the site of the rock-plasma cloud (1 AU). The cross section of your starship is almost certainly under 200 meters in diameter.

At the time of arrival, the cloud of hot gas has diffused into an rough sphere with radius approximately equal to 6.8 million meters. Volume is equal to about 1.32x10^21 meters.

Half a kilogram of rock dispersed into a volume of 1.32 billion kilometers is... Wolfram is acting up on me. Our 200m cross section of the hull is intercepting less than 1.5e^-19 percent of the original dust...

Needless to say, I am not worried.

About dodging, you need RCS thrusters with enough punch to move your ship sideways in time. Detecting an object on a collision course at .12c and evading it in time might be less easily achieved then you think. It eats fuel, depending on the amount of 'dodges' you need to do, which relates to how 'dusty' the interstellar environment really is between Sol and your destination. And you detect objects with the delay of light lag. So, impossible to calculate beforehand how much 'spare' fuel you need.

Again, you have a flotilla of drones scanning the space in front of them. These drones maintain a large seperation between the scouting formation and your starship. Only when they detect an object too large to move out of the way, does your starship decide it needs to dodge. Given that your starship has a cross section of probably under 200 meters wide, and that you have an AU (or more) of distance to deflect said rock, the rock would have to be pretty big... So big you could see it coming multiple AU's out.

How many such rocks exist floating around in interstellar space between Sol and our destination? How many of them are in the path of my 200 meter (or less) wide starship?

I'm willing to bet the number is quite, quite small.

[Geo]

You want to construct and launch enough nukes into Earth's orbit to give a starship a .12c velocity? How many are we talking here? Besides, current feasability projections about an Orion's performance (except the M-AM option) is well short of .12c
And it seems you are overtly optimistic about detecting particles on long distances. 150 million km ahead? Forget it!

All the rest of your dissertation fails on those two topics.

[NewAgeOfPower]

Besides, current feasability projections about an Orion's performance (except the M-AM option) is well short of .12c

M-AM? Matter-Antimatter drive? With 90% fuel mass, it would be feasable to exceed .8C... But humanity is probably centuries away from mass producing anti-matter. No, a 90% fuel mass thermonuclear fusion drive is plenty to exceed .1c. As we lower the payload% and increase the nuclear fuel %, you get closer and closer with a deceleration profile-enabled starship to peak envelope velocity for a non-deceleration enabled starship.

You want to construct and launch enough nukes into Earth's orbit to give a starship a .12c velocity? How many are we talking here?

*beautific smile appears on my face* millions 

In all seriousness, you would need millions of nukes, as there is a nice ratio between current mass of starship and nuclear impulse efficiency. You can use bigger nukes than optimal, but humans tend not to like experiencing more than 1g for extended periods of time.

To even feasibly construct such a large spacecraft, we'd probably need to build an L2 shipyard... Well, the Earth-Moon L4 might work too, but its not quite as optimal as Earth-Sun L2.

Yes, the cost is tremendous. Yes, even ignoring monetary costs, it would consume decades of Earth's industrial output to build an multi-million ton starship. In fact, we'd need to build a skyhook first (need to research macroscale production of carbon nanotubes) or just build an electromagnetic rail launch system (achievable today, but at extreme capital cost) to even get the material to L2.

Again, this requires no new fundamental knowledge, engineering breakthroughs; definitely, new discoveries in physics; no.

And it seems you are overtly optimistic about detecting particles on long distances. 150 million km ahead? Forget it!

You know, if you actually bothered to read my posts, I never said anything about directly detecting fine objects at 8 light minutes. The energy loss from most practical laser arrays would be enormous at that range as well.

That's the entire purpose of launching a flotilla of drones once you hit cruising velocity.

All the rest of your dissertation fails on those two topics.

This isn't a dissertation. And you have failed to point out a single thing I haven't already thought about. Or planned for.