Your ideal Interstellar vehicle/system (no FTL)

[Kertech]

The Axiom from WALL-E...

[AngelLestat]

23 hours ago, K^2 said:

You don't. You put a damper on your ship that covers 2π of the solid angle, and get 1/4 of max impulse that way. I'm perfectly happy with 25% thrust efficiency on an engine that has 100% mass-to-energy efficiency.

You'll need massive radiators to cool that damper, of course, but you can put some steam generators in between and generate all the power you could possibly need on a ship this side, including powering ship's magnetosphere for rad protection.

ok, so you mean absorb all the heat and release it in a collimated way?  The problem with that approach that your radiator mass increase because you can only radiate using one size of the surface.  But I guess it can be manageable if we reach to the point that we can create such SBH, besides the mass of the black hole will be >> than the damper + radiators I guess.

About electrical power, yeah that is the less of your concern, you can also use the rotation of the black hole with its magnetic field to be used as an electric generator.

18 hours ago, lugge said:

Generation ships require an unknown amount of cooperation between human individuals. An unknown amount of discipline. A management structure lasting for, say, 20000 years, thats more than huma history. For 20000  you need tens of thousands of human individuals working together for a single goal. No rebelions. I don't see this happening. Never, not in a distant future.

Not sure why PB666 wants a 50000 years ship.
But we have a new generation every 20 years, so a 50 year ship is a generational ship, those had more sense, although there are still many problems to solve, you can not harvest extra resources or power over the whole trip, sustain that close system over 50 years sounds a nightmare.  It will be easier to transport people in some kind of cryo frost or just embryos.  

Edited February 16, 2016 by AngelLestat
english errors

[sgt_flyer]

52 minutes ago, AngelLestat said:

ok, so you mean absorb all the heat and release it in a collimated way?  The problem with that approach that your radiator mass increase because you can only radiate using one size of the surface.  But I guess it can be manageable if we reach to the point that we can create such SBH, besides the mass of the black hole will be >> than the damper + radiators I guess.

About electrical power, yeah that is the less of your concern, you can also use the rotation of the black hole with its magnetic field to be used as an electric generator.

Not sure why PB666 wants a 50000 years ship.
But we have a new generation every 20 years, so a 50 year ship is a generational ship, those had more sense. Instead there are huge issues to overcome, you can not harvest extra resources or power over the whole trip, sustain that close system over 50 years sounds a nightmare.  It will be easier to transport people in some kind of cryo frost or just embryos.  

Mmh - on embryos, you would still need to keep them within the ship (once landed or during the final 20 years approach to raise and teach them from embryos to colonists - so you'd have to make sure nothing is going to break down before those people are trained enough to do the maintenance and sustain themselves.

[PB666]

 

8 hours ago, fredinno said:

http://www.scientificamerican.com/article/scientists-close-in-on-creating-black-hole-in-lab/

You can create black holes in giant particle accelerators- something which got conspiracy theorists riled up when they figured that out, saying it would destroy the entire world (in reality, it would just implode very quickly unless it quickly accreted more mass.)

Reactionless drives are impossible under the current laws of physics.

What- you can't use positrons in anti-matter reactors?

Voyagers and New Horisons are cheaters for using gravity assists to go faster.

ESA has something better- DS4G, with 30,000s ISP,

300000 m/s  at 1N =  F =   2 * EFF * MW/ISP,   1 = MW 1.6/300000  therefore  187500w per newton or 187.5 kw/N or .18 MW/N. So what ship out there has the capability of generating MW of power?

ISPv = ISPs x 9.8 m/s2

The rate limiting step in performance of ION drive systems is not the thruster, I repeat not the thruster, the problem in ION drive systems is the input power problem, this has been publically stated critique of the VASiMR system and is basic common knowledge, the solar panels on the space station IIRC only produce about 32.8 kW each that is enough to produce about 0.17N of power using that 30000 ISP system. If the ISSs solar panel has a mass of 14000 kg. THe solar arrays are the most efficient power source in the inner solar system. If you imagine a ship that had two of these for a weight of 28000 kg, and you discount the weight ot the rest of the ship, the maximum amount of acceleration a 30,000 ISP ship can generate is 0.000012N or 12 micronewtons. This is an unviable setup except for traveling outside of planetary orbits because the amount of time required to break orbits disallows efficient use of both sun and periapsis. A ION thruster that has the same two solar panels, but instead only has 1500 ISP can produce and acceleration of 2.4 millinewtons of thrust. From the way I see it, any ship that does not have a MW power supply (FEP) that is using high ISP is basically fail.

1 hour ago, AngelLestat said:

ok, so you mean absorb all the heat and release it in a collimated way?  The problem with that approach that your radiator mass increase because you can only radiate using one size of the surface.  But I guess it can be manageable if we reach to the point that we can create such SBH, besides the mass of the black hole will be >> than the damper + radiators I guess.

About electrical power, yeah that is the less of your concern, you can also use the rotation of the black hole with its magnetic field to be used as an electric generator.

Not sure why PB666 wants a 50000 years ship.
But we have a new generation every 20 years, so a 50 year ship is a generational ship, those had more sense. Instead there are huge issues to overcome, you can not harvest extra resources or power over the whole trip, sustain that close system over 50 years sounds a nightmare.  It will be easier to transport people in some kind of cryo frost or just embryos.  

Not want, I look at what is viable and what is fantasy, and in terms of 50000 years, if you can get the power density up for FEP then it need not be 10,000 years (what I said) if could be 3000 or 1000 years, but from my point of view, once you are fractional light speed you have a whole host of problems that we have no idea how to solve.

[PB666]

16 hours ago, K^2 said:

You don't. You put a damper on your ship that covers 2π of the solid angle, and get 1/4 of max impulse that way. I'm perfectly happy with 25% thrust efficiency on an engine that has 100% mass-to-energy efficiency.

You'll need massive radiators to cool that damper, of course, but you can put some steam generators in between and generate all the power you could possibly need on a ship this side, including powering ship's magnetosphere for rad protection.

Sensible. However, you were talking about containment failure. In this scenario, you still get an explosion before you can jettison the reactor. Yes, a smaller one, perhaps in just a few hundred ton range now, but it's going to be enough to breach containment on the next reactor, and a chain reaction is a go. You still have a single point of failure, except now you've reproduced it in every reactor.

Accidents will happen with this kind of ships. All we can do is make them infrequent.

Not even touching that one. My thesis is, "Maybe some day we'll figure out how to make a black hole. Then we can start building reasonably reliable, reasonably fast interstellar ships."

Yes, we can build generation ships either way, and we'll probably build them eventually. They just won't let us build an interstellar civilization. It will be many disjoint civilizations of common origin that might share knowledge with each other. To really call it going to the stars, we need ability for people to reach other worlds within their life times. And short of FTL, that requires torch ships. And there are only two things that can power an interstellar torch ship. Antimatter or black hole. Because these are the only two things known to human kind that allow for sufficiently efficient matter-to-energy conversion.

Virtual civilization live by sharing communications. What do you need, human x1ba23 has a new gene that is an improvement it can be found at chromosomal location 21p1.3_14531A>G. Civilization 2, great thanks will have it in the next embryo by tomorrow. Since we now can interpret that quantum entangled pairs can communicate (the issue is not making them stable), potentially you can communicate at near instantaneous speeds, and even if you can't you could send a communication probe every 10 years (without living being on board you prolly could get 0.01c. Since we can digitally transfer genetic information, the only limitation to virtual civilization is the speed of light. If we are using a FEP ship to seed new civilizations, by definition we are not traveling 100s of light years from a civilized starting point, so this means that you are no more than 100 ly for a transmission source, the solution to this problem is to improve communication with more powerful space receiving antennas and more powerful transmitters.

So there is nothing that states that a 100tonne fusion reactor will explode and blow up. Simply keep the reactor close to the surface, if their is a containment failure of the plasma simply open the ports into space. A second way, although not preferable is to have the reactors 10 to 100 meters off the side of the ship in a radial array, this allows better heat dissipation but does require more shielding. Problems that can be solved. Power supply - capacitors and batteries. Oscillators- redundancy and switching gears. HF generators - redundancy.

The biggest single problem with generational ship is this, in order to reduce risk targets must be within  a few light years. However there are no known potentially habitable targets within a few light years. But that was not a premise to the question, the basic assumption is that there are and we have not found them. I question the assumption to begin with. I think earth standard potentially habitable planets are few and far between, and more than likely to find one in the right stage of development you would need to travel 1000 ly. This is all fine and dandy but it may require a space phase of human evolution to reach them by hopping from survivable star with elemental resources, mining those resources, spawning new ships and repeating the process. And one has to beg the question if this is a requirement to reach habitable worlds, why make habitable worlds a target anyway. Simple set several ships out to the nearest stars, if there are no resources at close approach, change course and target the next closest star in the path until a habitable star is found, sure there will be mishaps were ships with 1000s of people perish, but OTOH you have now have occupancy of your neighboring stars, and stars like proxima Centauri will transport you to the stars in the interior of the galaxy.

As far as we know there are no other sentients out there, so we do not need to speedy Gonzales across the galaxy to find those civilization and death star them, we can instead bide our time and create a network of travel stations and terraforming stops every here and there.

here is what an outmounted fusion electric/ion thruster pod might look like

Edited February 15, 2016 by PB666

[K^2]

1 hour ago, AngelLestat said:

ok, so you mean absorb all the heat and release it in a collimated way?  The problem with that approach that your radiator mass increase because you can only radiate using one size of the surface.  But I guess it can be manageable if we reach to the point that we can create such SBH, besides the mass of the black hole will be >> than the damper + radiators I guess.

Oh, man, that totally slipped my mind. I was just thinking of impulse received, but with radiators you have to expel the same amount. On one hand, great! You can double your impulse with directed beam! So you'd get 50% efficiency instead of stated 25%. On the other, it means you effectively need to build an incandescent light bulb that generates half of your impulse. :/

I'm not even going to do the math for it. That's silly. What might not be silly is active radiators containing hot plasma in magnetic confinement. Hawking radiation of a tiny black hole is extremely hot, putting output firmly in gamma ranges, so even at a temperatures of a hot star in the radiator, there should be organize net wins on energy. I'll run the numbers for that to see what's actually plausible.

[AngelLestat]

5 hours ago, sgt_flyer said:

Mmh - on embryos, you would still need to keep them within the ship (once landed or during the final 20 years approach to raise and teach them from embryos to colonists - so you'd have to make sure nothing is going to break down before those people are trained enough to do the maintenance and sustain themselves.

The main point of this, is to reduce the amount of population that you need to keep alive over the whole journey.
That reduce by a lot the complexity of the ship.  
 

5 hours ago, PB666 said:

Not want, I look at what is viable and what is fantasy, and in terms of 50000 years, if you can get the power density up for FEP then it need not be 10,000 years (what I said) if could be 3000 or 1000 years, but from my point of view, once you are fractional light speed you have a whole host of problems that we have no idea how to solve.

Keep a population alive over more than 10 years without external power source or resources in a closed system is away our reach today.  Now if you want 1000 or 50000 years, is easy to said that is "impossible".
Why fractional light speed give you problems?  Due collisions?   The good news of going fast is that you know that all collisions will be in the front of your ship, so you only need a good shield in front.
But a ship that makes the travel in 25 year will receive 2000 times less collisions than a ship with a trip of 50000 years. Those collisions you receive produce more damage, but no until the point of increase your risk or damage.
What is your power source that will last more than 1000 years?   What thing made in earth last more than 1000 years of duty?
You did not thought in all possible problem that you need to solve in a long time mission, you should do it.

 

4 hours ago, K^2 said:

Oh, man, that totally slipped my mind. I was just thinking of impulse received, but with radiators you have to expel the same amount. On one hand, great! You can double your impulse with directed beam! So you'd get 50% efficiency instead of stated 25%. On the other, it means you effectively need to build an incandescent light bulb that generates half of your impulse. :/

I'm not even going to do the math for it. That's silly. What might not be silly is active radiators containing hot plasma in magnetic confinement. Hawking radiation of a tiny black hole is extremely hot, putting output firmly in gamma ranges, so even at a temperatures of a hot star in the radiator, there should be organize net wins on energy. I'll run the numbers for that to see what's actually plausible.

ah I thought you already counted on that, because I did not put much attention on how much 2π represented in the sphere area, this might help for those who had my same doubt.

The first I've heard of using plasma as a radiator...  I guess it could work, I like the idea.
It needs a lot of density or scale to not let pass the gamma rays and to obtain a good heat capacity.
The damper will be made by a mirror,  maybe it can reflect the whole range of 7000K plasma at certain distance.

So it will be like a black hole that creates a sun behind us, and we use a solar sail for propulsion. 
Then we need a particle accelerator (with a really good accuracy) to feed this black hole once we reach our destiny with at least 2kg of matter by second.

[K^2]

Ooo. That gives me all sorts of ideas. We've decided on a charged black hole, right? What if we shield it partially by dropping in a bunch of electrons? They will form countless shells, with potentially an absurd energy spectrum. These can block nearly all of the gamma and convert it down to something much more manageable. Perhaps to the point where, yeah, you'll really just have a solar sail. Powered by its own tiny sun.

I really need to run at least some rough estimates on all of these, though. Otherwise I'm just going to carry on making stuff up.

[HebaruSan]

Can you reflect the "wrong" directions of emissions back into the black hole?

When actually operating the thing, would there be a lag time when you try to throttle the mass input, from relativistic effects near the event horizon?

Edited February 16, 2016 by HebaruSan
too many "in terms of"

[Shpaget]

When I read about generation ships, especially the ones taking thousands of years, I can't help but thinking about Orphans of the Sky by Heinlein.

No majors spoilers ahead.

Any such long lasting generation ship, even if mechanically robust enough to survive the long journey, will face issues with the crew. To sustain the large population needed for genetical diversity (assuming no cryosleep, for whatever reason), will necessarily have a large population not involved with the operations of the ship, and be support crew (medical professionals, food growers, education workers, even the plumbers and vacuum cleaner repair men will be needed). A very large community of such individuals will over just a few generations lose the perspective and spend all their time worrying about their job, not thinking about the final mission. It is entirely likely that the majority of the population will not be willing to stop and abandon their established lives once the ship finally arrives at its destination.

A mutiny and the breakdown in function of the ship, as described in Orphans of the Sky, is equally plausible. Thousands of years is just too long period to maintain any predetermined social structure. Look at the history. Even decades are too long a period to predict the social future. Who could have guessed in 1925, that in just 15 years the world would be boiling in war? People witnessing the Cuban missile crisis lived to see American astronauts sharing a rocket ride with their Russian colleagues.

Long term social stability of a generation ship is just too questionable.

[lugge]

16 hours ago, PB666 said:

Virtual civilization live by sharing communications. What do you need, human x1ba23 has a new gene that is an improvement it can be found at chromosomal location 21p1.3_14531A>G. Civilization 2, great thanks will have it in the next embryo by tomorrow. Since we now can interpret that quantum entangled pairs can communicate (the issue is not making them stable), potentially you can communicate at near instantaneous speeds, and even if you can't you could send a communication probe every 10 years (without living being on board you prolly could get 0.01c. Since we can digitally transfer genetic information, the only limitation to virtual civilization is the speed of light. If we are using a FEP ship to seed new civilizations, by definition we are not traveling 100s of light years from a civilized starting point, so this means that you are no more than 100 ly for a transmission source, the solution to this problem is to improve communication with more powerful space receiving antennas and more powerful transmitters.

 

16 hours ago, PB666 said:

The biggest single problem with generational ship is this, in order to reduce risk targets must be within  a few light years. However there are no known potentially habitable targets within a few light years. But that was not a premise to the question, the basic assumption is that there are and we have not found them. I question the assumption to begin with. I think earth standard potentially habitable planets are few and far between, and more than likely to find one in the right stage of development you would need to travel 1000 ly. This is all fine and dandy but it may require a space phase of human evolution to reach them by hopping from survivable star with elemental resources, mining those resources, spawning new ships and repeating the process. And one has to beg the question if this is a requirement to reach habitable worlds, why make habitable worlds a target anyway. Simple set several ships out to the nearest stars, if there are no resources at close approach, change course and target the next closest star in the path until a habitable star is found, sure there will be mishaps were ships with 1000s of people perish, but OTOH you have now have occupancy of your neighboring stars, and stars like proxima Centauri will transport you to the stars in the interior of the galaxy.

This all sounds a lot mor like sci-fantasy than the usual "Magic-Propulsion" or "Unlimited-Energie" devices.
 A LOT.

We can master technology and physics, but we cannot change human behaviour. Anything requiring humans working together for one goal for thousands of years is, well, sci-fantasy.

[K^2]

10 hours ago, HebaruSan said:

When actually operating the thing, would there be a lag time when you try to throttle the mass input, from relativistic effects near the event horizon?

You can't throttle a black hole. Its output grows as it evaporates. You feed it matter to prevent it from exploding. Although, you will have a few years between the time you've stopped feeding it and the time it actually explodes, so this isn't a safety factor.

[sgt_flyer]

@K^2 @HebaruSan

mmh. even if you can't 'throttle' the black hole's power output easily, you should be able to have control over the thrust, if you can rearrange the radiation mirrors to split the exhaust in two with varying angles (the more open the angle from full rear, the less the resulting thrust - till you get a 180° split, so your resulting thrust is 0). - in fact, if you have various exhausts ports that can be opened / closed at will an rearranged the same way, you could even use it as the ship's RCS. - which would be interesting, given the mass of the spaceship.

 

[AngelLestat]

13 hours ago, K^2 said:

Ooo. That gives me all sorts of ideas. We've decided on a charged black hole, right? What if we shield it partially by dropping in a bunch of electrons? They will form countless shells, with potentially an absurd energy spectrum. These can block nearly all of the gamma and convert it down to something much more manageable. Perhaps to the point where, yeah, you'll really just have a solar sail. Powered by its own tiny sun.

I really need to run at least some rough estimates on all of these, though. Otherwise I'm just going to carry on making stuff up.

I lost you there, I can not make a mental picture of the electron shell  because I don't understand the physics involved.
You mean a super dense cloud of electrons orbiting the SBH as it were a super atom?
Or the electrons orbit at higher distance?  Even in that case no sure how they can shine in the visual wavelength or stop all the gamma radiation..
That seems a very hard mental exercise. I can imagine from that example that pair production and many other hard physics will happen there. 

13 hours ago, HebaruSan said:

Can you reflect the "wrong" directions of emissions back into the black hole?

When actually operating the thing, would there be a lag time when you try to throttle the mass input, from relativistic effects near the event horizon?

The black hole is super tiny, hard enough is to try to absorb and redirect some % of that energy in opposite direction, no even imagine focus all those elusive gamma rays back to the black hole which is not perfectly still.
Even if you convert the energy in the visual or ultraviolet range, I guess this wavelength is bigger than the black hole radius.
Also.. not sure what you win with that..    You are wasting a lot of the black hole power.  

2 hours ago, sgt_flyer said:

@K^2 @HebaruSan

mmh. even if you can't 'throttle' the black hole's power output easily, you should be able to have control over the thrust, if you can rearrange the radiation mirrors to split the exhaust in two with varying angles (the more open the angle from full rear, the less the resulting thrust - till you get a 180° split, so your resulting thrust is 0). - in fact, if you have various exhausts ports that can be opened / closed at will an rearranged the same way, you could even use it as the ship's RCS. - which would be interesting, given the mass of the spaceship.

It will be possible to do that placing the black hole in a different point of the focal point.
Like a normal engine in neutral gear. 

Edited February 16, 2016 by AngelLestat

[K^2]

Just now, AngelLestat said:

You mean a super dense cloud of electrons orbiting the SBH as it were a super atom?

This, basically. But I'm a little worried about the overlap between electron cloud and the Schwarzschild radius. S-orbitals will partially overlap with the actual black hole, just like they overlap nucleus in ordinary atoms. That means the black hole will be munching on these electrons. I just don't know how fast.

It's an interesting problem. Ground state should have cylindrical symmetry to within a phase, at least. So I should be able to get the actual electron distribution around the black hole with a lattice QED approach. And since it's going to be 2+1 dimensional, instead of 3+1 dimensional, I should be able to run it on ordinary PC instead of needing a cluster.

I'm going to give it a shot.

[HebaruSan]

2 hours ago, AngelLestat said:

The black hole is super tiny, hard enough is to try to absorb and redirect some % of that energy in opposite direction, no even imagine focus all those elusive gamma rays back to the black hole which is not perfectly still.
Even if you convert the energy in the visual or ultraviolet range, I guess this wavelength is bigger than the black hole radius.

Good point, I kept picturing it as basketball-sized for some reason.

[PB666]

17 hours ago, AngelLestat said:

The main point of this, is to reduce the amount of population that you need to keep alive over the whole journey.
That reduce by a lot the complexity of the ship.  
 

Keep a population alive over more than 10 years without external power source or resources in a closed system is away our reach today.  Now if you want 1000 or 50000 years, is easy to said that is "impossible".
Why fractional light speed give you problems?  Due collisions?   The good news of going fast is that you know that all collisions will be in the front of your ship, so you only need a good shield in front.
But a ship that makes the travel in 25 year will receive 2000 times less collisions than a ship with a trip of 50000 years. Those collisions you receive produce more damage, but no until the point of increase your risk or damage.
What is your power source that will last more than 1000 years?   What thing made in earth last more than 1000 years of duty?
You did not thought in all possible problem that you need to solve in a long time mission, you should do it.

 

ah I thought you already counted on that, because I did not put much attention on how much 2π represented in the sphere area, this might help for those who had my same doubt.

The first I've heard of using plasma as a radiator...  I guess it could work, I like the idea.
It needs a lot of density or scale to not let pass the gamma rays and to obtain a good heat capacity.
The damper will be made by a mirror,  maybe it can reflect the whole range of 7000K plasma at certain distance.

So it will be like a black hole that creates a sun behind us, and we use a solar sail for propulsion. 
Then we need a particle accelerator (with a really good accuracy) to feed this black hole once we reach our destiny with at least 2kg of matter by second.

First off Interstellar - period - is currently out of our reach, so your argument is just silly and stupid. The argument is given the current limitations what is the most feasible, this is it, K2 as you note abdicated on his responsibility to tell us how he was going to produce a black hole at 10^-19 meters in diameter. Everyone else has methods that are fail.

Second on a ship that is .32 km in diameter there is ample enough room to grow food, to build factorys that can build fusion reactors, store dueterium and hydrogen (tritium cannot be store because it has a half life of only 12 years) or whatever the ship needs. One assumes that the ship is dominated by multitasking robots, that the supplies of raw materials are stocked on board, In addition in the center of the ship one could have a rotating habitation area capable of producing 1g for the inhabitants to work out or do other gravity requiring tasks (again at 0.32 km, this is not a particular problem).

Third, given a fusion power reactor capable of producing 100 MW of power, you have a power supply that can potentially last generations, therefore all you need is a capacity to produce LEDs in the red and blue spectrum and you have food and oxygen. Fusion power gets its fuel from hydrogen, very little hydrogen is needed and potentially can be extracted from space using a collector at the front of the vessel, or could be carried on board. Product Helium would be used for impulse production. Again on a ship of 0.32 kilometers you can have several of these, so if one reactor goes down you have back ups.

Forth, since current energy requirement prevent speed of light, most you are going to see for a start/stop (which BTW even optimistically is impossibility) of 0.1C the collisions even a grain of sand or space dust in space, would be catastrophic. E = 1/2mv² our dust weighs .0000001 kg = 45000000 Joules. A 50 calibre car killing rifle bullet is 18,050 Joules, In other words you have 2500 times the amount of energy hitting 1/1000 th amount of space. The RML 8 inch howitzer (The type of artillary that can tear down a 12 inch concrete wall) produces a 26900100 is only half the amount of energy as that piece of space dust. So, yeah, fractional c has a big impact problem. At a million meters per second, that is 1/300th of C (1/30th of 0.1c) the relative kinetic energy of impacts is 0.1% so instead of that grain of dust hitting with a force of 2 howizter bullets it hits with about three times the energy as a a 50 calibre bullet, A covering of solid titanium about an inch thick can stop this. Somewhere around 5 million meters velocity relative to intergalactic medium is the practical safe limit of space travel, everything faster is risking almost certain catastrophe. Solve the howitzer shell impactor problem and we can talk about the other non-functionalities of your ideas. 

 

 

Fifth, No one has any idea how to safely create a black hole of 660 tonnes. Its a fantasy, chances are if you created it here on earth, it would destroy the earth, so. . . . Far as I know fusion reactors don't have that problem. Solar sails are toilet paper pretending to be a source of force.

Edited February 16, 2016 by PB666

[fredinno]

On February 15, 2016 at 1:02 AM, K^2 said:

A 660,000 ton black hole, which is considered a "sweet spot" for a black hole drive, would have a Schwarzschild Radius of 2.2x10^-19 meters. This is smaller than a single proton. It's not just subatomic. It's sub-nuclear.

I meant not subatomic in mass.

[More Boosters]

6 minutes ago, fredinno said:

I meant not subatomic in mass.

Which makes zero sense in this context.

[AngelLestat]

6 hours ago, K^2 said:

This, basically. But I'm a little worried about the overlap between electron cloud and the Schwarzschild radius. S-orbitals will partially overlap with the actual black hole, just like they overlap nucleus in ordinary atoms. That means the black hole will be munching on these electrons. I just don't know how fast.

It's an interesting problem. Ground state should have cylindrical symmetry to within a phase, at least. So I should be able to get the actual electron distribution around the black hole with a lattice QED approach. And since it's going to be 2+1 dimensional, instead of 3+1 dimensional, I should be able to run it on ordinary PC instead of needing a cluster.

I'm going to give it a shot.

I dont know, all that seems very hard to know even for a simple estimation.
Not sure how powerful is the software you are using, but at those distances, particles that leave the black hole might not even had time to decay on gamma rays, then not sure the effect on pair production or the outgoing radiation pressure over the orbitals.
I think you can figure out with enough time, but no just now.
  

3 hours ago, PB666 said:

First off Interstellar - period - is currently out of our reach, so your argument is just silly and stupid. The argument is given the current limitations what is the most feasible, this is it, K2 as you note abdicated on his responsibility to tell us how he was going to produce a black hole at 10^-19 meters in diameter. Everyone else has methods that are fail.

I need to search it, but if I remember right, if you can manage to harvest all that energy and then emit all that power in gamma rays in the same instant on the same tiny tiny point.  you create the black hole (in theory). 
We are talking of 700000 tons of E=Mc2.  My garage is not big enough to realize that experiment, but I will see what I can achieve.
Or.. be lucky enough to find one black hole of this type and capture it
The good news, that once you have a black hole, you can use it to make other black holes.
Smaller black holes require less initial energy, but it is harder to feed them to make them big. 

Quote

Second on a ship that is .32 km in diameter there is ample enough room to grow food, to build factorys that can build fusion reactors, store dueterium and hydrogen (tritium cannot be store because it has a half life of only 12 years) or whatever the ship needs. One assumes that the ship is dominated by multitasking robots, that the supplies of raw materials are stocked on board

Ok. take a look to the 3 experiments like biosphere2 that was done, they all fail. And they fail in less than 2 years (no even 2 season cycles).
So now you add magic robots that will solve with magic any possible problem that the ship will have..   thanks for the details.

Quote

Third, given a fusion power reactor capable of producing 100 MW of power, you have a power supply that can potentially last generations, therefore all you need is a capacity to produce LEDs in the red and blue spectrum and you have food and oxygen. Fusion power gets its fuel from hydrogen, very little hydrogen is needed and potentially can be extracted from space using a collector at the front of the vessel, or could be carried on board. Product Helium would be used for impulse production. Again on a ship of 0.32 kilometers you can have several of these, so if one reactor goes down you have back ups.

So now we can fuse hydrogen atoms?  I didn´t knew..   I guess it was deuterium and tritium, good luck searching enough of that in empty space, if you want to carry that on board you will need 150000 tons for the 50000 year trip.
But yes, lets said that you can carry that, what about all the other spares you will need in 50000 years?  Or even 1000 years if you want to short numbers now.
By the way, all nuclear plants last only 40 years before decommission, and this only with full maintenance and spare parts over all its lifetime.

Quote

Forth, since current energy requirement prevent speed of light, most you are going to see for a start/stop (which BTW even optimistically is impossibility) of 0.1C the collisions even a grain of sand or space dust in space, would be catastrophic. E = 1/2mv² our dust weighs .0000001 kg = 45000000 Joules. A 50 calibre car killing rifle bullet is 18,050 Joules, In other words you have 2500 times the amount of energy hitting 1/1000 th amount of space.

You said that traveling at 0.1 you get 2500 times more damage, but I prove you that you get 2000 times more collisions with your 50000 year ship.
Now if you add that your ship is much much bigger (you need to sustain a big population a lot of time so this mean a lot of extra area), and you dont know the place and angle in which you will be hitted, is easier to conclude that you receive a lot more damage.
One more thing.
With a fast ship, you know that all the hits will be in front, so your ship can be long and thin, then you will add as shield several graphene layers (separated by some amount), this will slow down and ionize all the incoming particles or dust, then you can use a magnetic shield to divert all those new particles generated away of the rest of the ship.
You can not have a magnetic deflector in your case because you don't know the angle or direction of the incoming particles.

Quote

Fifth, No one has any idea how to safely create a black hole of 660 tonnes. Its a fantasy, chances are if you created it here on earth, it would destroy the earth, so. . . . Far as I know fusion reactors don't have that problem. Solar sails are toilet paper pretending to be a source of force.

Correction: 660000 tons.
Even if the black hole falls in the center of earth, nothing will happen.  It is too tiny to interact with matter, and the outgoing pressure of its radiation makes that impossible.
It will just heat up a bit more the earth core, and that heat will take thousands of year to reach surface, and when it does, nobody will notice the difference.

1 hour ago, fredinno said:

I meant not subatomic in mass.

Good try

[HebaruSan]

32 minutes ago, AngelLestat said:

You said that traveling at 0.1 you get 2500 times more damage, but I prove you that you get 2000 times more collisions with your 50000 year ship.

How does that work? I would naïvely expect that the number of collisions traveling through a field of randomly floating particles would be proportional to the volume swept out by the ship on its journey, and that that volume would be independent of the speed of the craft. Which part of that intuition is mistaken?

[Bill Phil]

57 minutes ago, HebaruSan said:

How does that work? I would naïvely expect that the number of collisions traveling through a field of randomly floating particles would be proportional to the volume swept out by the ship on its journey, and that that volume would be independent of the speed of the craft. Which part of that intuition is mistaken?

There's also things coming from other directions. Maybe not severe, but it is there.

[K^2]

2 hours ago, AngelLestat said:

Not sure how powerful is the software you are using, but at those distances, particles that leave the black hole might not even had time to decay on gamma rays, then not sure the effect on pair production or the outgoing radiation pressure over the orbitals.

The software I'm using is called a C++ compiler. Also some Mathematica to help avoid stupid mistakes in algebra where relevant. This isn't something you can just plug into standard simulation software. Especially, since I'm planning to have a curved metric. Although, there are certainly libraries that make working with lattice QED/QCD way easier.

Because this is a lattice computation, it would inherently look at the ground state of the system. I'm not going to look at how outgoing flux of gamma radiation is going to affect the system. What I'm worried about is black hole munching on the electron cloud, which can be determined from the ground state. Since everything is far above Plank scale, QED is sufficient to describe it. Whether or not the flux is going to be sufficient to blow away the electron cloud is a separate question, but that can be estimated separately from ionization energy, which this computation will provide me.

I might be completely wrong about being able to reduce degrees of freedom for this problem, though. If I have to run an actual 3+1 dimensional simulation, I won't have sufficient computing power. And I don't think I have access to any super clusters anymore. I miss being able to just SSH into a system that gives me access to 800+ GPUs for parallel computing. *sigh*

Edited February 16, 2016 by K^2

[PB666]

5 hours ago, AngelLestat said:

I dont know, all that seems very hard to know even for a simple estimation.
Not sure how powerful is the software you are using, but at those distances, particles that leave the black hole might not even had time to decay on gamma rays, then not sure the effect on pair production or the outgoing radiation pressure over the orbitals.
I think you can figure out with enough time, but no just now.
  

I need to search it, but if I remember right, if you can manage to harvest all that energy and then emit all that power in gamma rays in the same instant on the same tiny tiny point.  you create the black hole (in theory). 
We are talking of 700000 tons of E=Mc2.  My garage is not big enough to realize that experiment, but I will see what I can achieve.
Or.. be lucky enough to find one black hole of this type and capture it
The good news, that once you have a black hole, you can use it to make other black holes.
Smaller black holes require less initial energy, but it is harder to feed them to make them big. 

Ok. take a look to the 3 experiments like biosphere2 that was done, they all fail. And they fail in less than 2 years (no even 2 season cycles).
So now you add magic robots that will solve with magic any possible problem that the ship will have..   thanks for the details.

So now we can fuse hydrogen atoms?  I didn´t knew..   I guess it was deuterium and tritium, good luck searching enough of that in empty space, if you want to carry that on board you will need 150000 tons for the 50000 year trip.
But yes, lets said that you can carry that, what about all the other spares you will need in 50000 years?  Or even 1000 years if you want to short numbers now.
By the way, all nuclear plants last only 40 years before decommission, and this only with full maintenance and spare parts over all its lifetime.

You said that traveling at 0.1 you get 2500 times more damage, but I prove you that you get 2000 times more collisions with your 50000 year ship.
Now if you add that your ship is much much bigger (you need to sustain a big population a lot of time so this mean a lot of extra area), and you dont know the place and angle in which you will be hitted, is easier to conclude that you receive a lot more damage.
One more thing.
With a fast ship, you know that all the hits will be in front, so your ship can be long and thin, then you will add as shield several graphene layers (separated by some amount), this will slow down and ionize all the incoming particles or dust, then you can use a magnetic shield to divert all those new particles generated away of the rest of the ship.
You can not have a magnetic deflector in your case because you don't know the angle or direction of the incoming particles.

Correction: 660000 tons.
Even if the black hole falls in the center of earth, nothing will happen.  It is too tiny to interact with matter, and the outgoing pressure of its radiation makes that impossible.
It will just heat up a bit more the earth core, and that heat will take thousands of year to reach surface, and when it does, nobody will notice the difference.

Good try

You cannot focus 600,000 mas equivilance of gamma ray energy on a single point 10-19 radius because of heisenberg uncertainty. 600,000 kg of mass equivilant of gamma itself exceeds the amount of electrical energy humans have ever produces by 10s of magnitudes. We can fuse hydrogen atoms after they have absorbed neutrons, this occurs during the breeding reaction. Dueterium. Fusion energy works the current thermodynamics of the reactors do not, this is because heat and plasma containment are quickly lost. 

I watched a guy pummel a one inch thick piece of titanium with justa about every form of high powered rifle even a fifty calibre coukd not break it. You body is constantly being bombarded and you survive, Mars on the other hand withou a magnetic field bombarded by 250000 m/s solar wind lost all its hydrogen. More is very different from more poweful. I can drop a bullet 1700 times on your arm from a few inches up with a contact velocity of 1 mph, you would have a bruise and contact dermatitus, however if i fire a 50 at your arm you might find some of its remains. When that 50 cal bullet hits your bone, the bone fragments become the projectiles that tear off the rest of your arm. 

At close to c collision between molecules and larger atoms will then to create a shower of atoms some that can even pass through metal, to give an example when asteroids strike the earth a 25000 m/s there is radioactivity released depending on the composition of the soil and meteor, typically there is an iridium signsl associated with soil layers. The faster moving the object the more high energy particles will be produced. 

 

[kunok]

Serious question, how do you suppose to feed a sub-nuclear size black hole? Aiming very hard atomic nucleus to it?

Edited February 17, 2016 by kunok
grammar