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White House Wants Ideas For "Bootstrapping a Solar System Civilization"

MarkWhittington writes Tom Kalil, the Deputy Director for Policy for the White House Office of Science and Technology Policy and Senior Advisor for Science, Technology and Innovation for the National Economic Council, has an intriguing Tuesday post on the OSTP blog. Kalil is soliciting ideas for "bootstrapping a solar system civilization." Anyone interested in offering ideas along those lines to the Obama administration can contact a special email address that has been set up for that purpose. The ideas that Kalil muses about in his post are not new for people who have studied the question of how to settle space at length. The ideas consist of sending autonomous robots to various locations in space to create infrastructure using local resources with advanced manufacturing technology, such as 3D printing. The new aspect is that someone in the White House is publicly discussing these concepts.

49 of 352 comments (clear)

  1. Biggest motivation? by Anonymous Coward · · Score: 2, Funny

    Prison colonies!

    1. Re: Biggest motivation? by Anonymous Coward · · Score: 2

      How to bootstrap a solar System civilization: Take all military dounds and give them to nasa.

    2. Re:Biggest motivation? by K.+S.+Kyosuke · · Score: 2

      I have an idea...we could name a ship Botany Bay and send the worst criminals into space.

      --
      Ezekiel 23:20
    3. Re:Biggest motivation? by z0idberg · · Score: 5, Funny

      The only problem with that is that their descendents will then come back in 200 years and beat our descendents in all the sports we invented.

  2. so...... by Anonymous Coward · · Score: 2, Funny

    where did they find oil now?

    1. Re:so...... by tloh · · Score: 4, Insightful

      I won't speculate on the intentions of OC. But bringing up oil does raise a very legitimate item of concern. For much of the 20th century, petroleum has been the critical resource that drove or enabled much of our civilization and technical infrastructure. If we are going to look skyward, we have *GOT* to start thinking differently about the resource(s) that we are going to use. Unless big oil is willing to shell out the cash for researching the exploration and mining of hydrocarbons in the Jovian system, our government has got to step up and look at what we need to power space travel on an industrial scale.

      --
      Stay sentient. Don't drink bad milk.
    2. Re:so...... by Doubting+Sapien · · Score: 2

      Why is this comment modded off topic? Anyone who has bothered to read the linked webpages would know they are not talking about photovoltaics. What perhaps *IS* off topic is that examiner.com is usually a really poor source of good science. The feed they provide to YAHOO is almost always filled with sensationalist nonsense.

      --
      ========== "Hello World" in my programming language of choice: ATG - LET THERE BE LIFE - TAG ==========
  3. One word: by penguinoid · · Score: 5, Insightful

    Start.

    --
    Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
    1. Re:One word: by JonathanR · · Score: 4, Funny

      I think we would be better off going 100% silver bullets. That would instantly fix everything.

    2. Re:One word: by BoogieChile · · Score: 2

      This map begs to differ, even at only 10 percent efficiency.

    3. Re:One word: by GNious · · Score: 3, Insightful

      Comments like your always scare me - the last thing we need is for people to think that "100% solar" (or, "100% some powersource") is in any way relevant to meeting our powerneeds.

    4. Re:One word: by aquabat · · Score: 2

      If someone would pay for it, and build it right, I would let them build it in my house.

      --
      A republic cannot succeed till it contains a certain body of men imbued with the principles of justice and honour.
  4. Step one by SlowMovingTarget · · Score: 3, Funny

    Step one: corner the maple syrup market.

    1. Re:Step one by Lawrence_Bird · · Score: 2

      some one tried to steal the strategic maple syrup reserve a few years ago. probably was you

    2. Re:Step one by smallfries · · Score: 2

      If you want to make the serious money, look into frozen concentrated orange juice futures.

      --
      Slashdot: where don knuth is an idiot because he cant grasp the awesome power of php
  5. Baby steps by __aaltlg1547 · · Score: 4, Interesting

    Step 1: research on the ISS focused on biosphere components and food production.
    Step 2: build a new station to experiment on establishing a small biosphere
    Step 3: Expand it to the point that it's food and air sufficient for humans
    Step 4: Build a moon base and apply what you learned in LEO to make it self-sufficient

    At the same time, work on high efficiency, low reaction mass propulsion systems. This is the real killer. If you can't crack the problem of long distance propulsion systems, we're stuck near earth where we can or make fuel.

    1. Re:Baby steps by Anonymous Coward · · Score: 2, Insightful

      Um, because one way you've got a chance to engineer your process until you get it right, and the other way you're a loser? Because "has exhausted itself" is loser thinking all by itself?

  6. Sheesh. Five cases of Ebola and by jpellino · · Score: 3, Funny

    they start asking how to get off the planet? Lightweights.

    --
    "Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
  7. Begin planning use of Lockheed's fusion power by BenJeremy · · Score: 3, Insightful

    Fund NASA to explore the advantages (and mitigate issues, such as waste heat) of using fusion in space vehicles. Let's get new designs in play now, so we can get the ball rolling fast when these compact generators are practical and real. Ion thrusters, magnetic fields, life support... having hundreds of megawatts of power makes the entire solar system within reach for manned space travel.

    1. Re:Begin planning use of Lockheed's fusion power by arth1 · · Score: 2

      They do on a shoestring in a month what NASA does for billions in 20 years.

      ... using NASA designs as the foundation.
      If they had to research everything from scratch, they would go nowhere. It wasn't a public company that sent up the first space vessel, nor the first satellite, nor the first manned spacecraft, nor the first satellite, nor the first interplanetary vessel, nor the first manned trip to another world, nor.... Catch my drift?

      Private enterprises are good at cashing in money on other people's work. But they seldom push the envelope or break boundaries.

    2. Re:Begin planning use of Lockheed's fusion power by able1234au · · Score: 3, Insightful

      Those wimpy environ-liberals are so weak they fear being irradiated by exploding rockets. Where is the fun in that. I look forward to having three eyes and a tail.

    3. Re:Begin planning use of Lockheed's fusion power by Rei · · Score: 2

      Great! Now you just need to invent an actually functional confinement method for the absurdly-hot gaseous/plasma nuclear fuel to stop it from destroying its containment vessel or leaking out its fuel in short order. And while you're at it, you should probably go ahead and invent a way to stop the quartz / fused silica bulb from undergoing blackening when exposed to a neutron flux, something it's so prone to doing that people deliberately expose quartz to nuclear reactors to make opaque black quartz for jewelry. And of course, a way to start the whole thing, a process that's been so problematic that they've been investigating bombardment by sizeable amounts of bloody antimatter as a potential solution.

      Easy as pie, surely! Riiight around the corner.

      What isotope are you thinking of as fuel? Unicorn-235?

      --
      You people make me envy the deaf and the blind!
  8. You want an idea? How about we fund NASA? by bobbied · · Score: 4, Interesting

    You want to encourage exploration/exploitation of space? Fund NASA and point them in the desired direction..

    Fully fund a manned mission to Mars and set a 10 year goal. Dig up a pile of past interplanetary missions and let's start funding them too. Saturn and Jupiter all have possibilities that we need to go look at. How about making a survey of near earth asteroids? What are they made of, is there something there we can use, refine or utilize so we don't have to get it all off the surface of the earth and into orbit? NASA has already suggested all these things and more.

    Why are you asking the public for ideas, just FUND NASA and let NASA collect ideas and run with the good ones. All they need is the money....

    --
    "File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
  9. Re:You want an idea? How about we fund NASA? by AdamThor · · Score: 5, Insightful

    Indeed! The actual key in our current generation is to provide consistent direction and funding to NASA. As it is, every president comes in, makes some big talk about the Moon or Mars or something, no resources are allocated, and the next president in line makes a different set of commitments.

    A framework for a large-scale goal that is capable of withstanding our political situation is the thing we lack.

    --
    -- "Oh. This guy again."
  10. Re:Replace rockets with something reasonable. by peragrin · · Score: 2

    it isn't just rockets in space that is the problem. when you need 20 pounds of fuel to carry every pound of material to orbit you have a design limitation that needs to be changed.

    We need better earth to orbit tech. once we have that the rest becomes much much easier. The ISS took 36 separate launches and we basically have a 10,000 sqft house.

    Solve SSTO and watch as we can suddenly start launching more stuff up there.

    --
    i thought once I was found, but it was only a dream.
  11. Re:You want an idea? How about we fund NASA? by arth1 · · Score: 4, Interesting

    NASA is terrible. They take too long to do anything,

    Yet, they actually do something.
    Once companies takes pictures of Neptune or puts a man on the moon, I'll be suitably impressed.
    Until then, they're leeches riding on NASAs skirt, playing around in LEO using NASA-derived designs, and not pushing any boundaries except executive bonuses.

  12. Re:Get real by Connie_Lingus · · Score: 2

    Unless you have a few trillion dollar coins stashed away somewhere that'll fund thousands upon thousands of chemical rockets, it's just not possible to do this

    this is, of course, 100% true.

    but, in light of this administrations total incompetence on so many issues, i think the plan is just...

    "hey, dream whatever ideas, we will get funding and then make announcements and speeches about how smart we are, and it doesn't even matter if they ideas succeed or not, we will just say they did!

    it's our intentions that count, not results."

    --
    never bring a twinkie to a food fight.
  13. Power Source by sycodon · · Score: 4, Insightful

    Nothing will happen until you can build and loft a real power source that can generate hundreds of megawatts of energy to drive the ships and once there, power the outposts.

    Solar can be part of that but putting up a solar farm to generate enough power to provide for an actual colony would take hundreds of tons of material as compared to a compact nuke or a fusion device like recently discussed by Lockheed. Think Nuke Sub reactors.

    --
    When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
    1. Re:Power Source by FatLittleMonkey · · Score: 2

      Trade studies have suggested that out to the main asteroid belt, aerospace grade solar panels have a higher power/mass ratio than nuclear systems. Only out near Jupiter does the equation shift (but even that is only counting the direct reactor mass. The added mass of shielding, trusses for distance, etc, is usually not included.) And every year, the cross-over distance shifts further out.

      The exception is where sunlight is unavailable — Lunar night, Mars winter — where the length of darkness exceeds likely storage capacity. However, the most likely location for early development on the moon is the poles, where there are Peaks of Eternal Light. (How can you not capitalise that?) OTOH, for Mars, you are probably going to avoid the poles due to the severity of those winters, staying within 30 deg of the equator, avoiding that problem too.

      So it'll be a fair while before we need nukes, better to focus available funding on something else.

      --
      Science is all about firing a drunk pig out of a cannon just to see what happens.
    2. Re:Power Source by Rei · · Score: 3, Interesting

      On the other hand, when it comes to propulsion, nukes are the bees knees. No form of currently-achievable propulsion yields a higher Isp than a fission fragment rocket, with the exception of photonic / magnetic sails, which are impractically low thrust for interplanetary travel. Some day I'd love to run some simulations as to whether you could have a spallation-driven subcritical dusty fission reactor get rid of much if not all of the moderator mass (power to drive the accelerator should be copious from a fission fragment reactor), and whether you could run one in an infrared nuclear lightbulb mode (making use of the electrostatically-contained dust's extreme surface area and low IR absorption spectrum to get high output, rather than using extreme, unmanageable temperatures to get high output as in a traditional nuclear lightbulb concept), thus opening up non-dirty high thrust power modes for surface operation (airbreathing, simple fuel heating, etc, including using electricity from fragment deceleration to run a microwave beam to help ionize the air/fuel and make it more opaque to IR) and a few other space options (such as a nuclear VASIMR-like mode)

      --
      You people make me envy the deaf and the blind!
    3. Re:Power Source by FatLittleMonkey · · Score: 3, Interesting

      No form of currently-achievable propulsion yields a higher Isp than a fission fragment rocket

      We're so far from FFR, we might as well talk about fusion drives, or Harold White's warp drive.

      and a few other space options (such as a nuclear VASIMR-like mode)

      My previous comments apply to NEP vs SEP. SEP has better power/mass ratios until you are somewhere near Jupiter, and realistically probably somewhere past Jupiter.

      --
      Science is all about firing a drunk pig out of a cannon just to see what happens.
    4. Re:Power Source by FatLittleMonkey · · Score: 2

      Very large radiators.

      And the radiators must be protected behind a heavy shield, because the radiation degrades them too quickly. Most designs have the reactor, then a heavy shield, a long truss and then the rest of the ship. Running down the length of the truss, carefully shaped to remain in the shadow of the shield, you have huge radiators to dump the heat from the reactor. The truss, the radiators and the shield are all additional mass required for a nuclear propulsion on top of the reactor mass. Solar arrays require radiators too, but only a fraction of the size, see the ISS.

      --
      Science is all about firing a drunk pig out of a cannon just to see what happens.
    5. Re:Power Source by Rei · · Score: 2

      I totally disagree. A dusty fission fragment reactor has been demonstrated using a non-nuclear substitute fuel, which demonstrated proper containment and thermal management. And modelling shows that such a configuration should produce a collimated fission fragment beam. So what's so grossly impractical? Have you come across a paper indicating that it's impractical? Because I sure haven't.

      My previous comments apply to NEP

      I'm not talking about NEP. I'm talking about generating a RF plasma and funnelling it through a nozzle, like in VASIMR, but with primary heating being from an IR nuclear lightbulb. And even if I wasn't, commentary on conventional nuclear reactors vs. solar is inapplicable when one is talking about totally different type of reactor.

      --
      You people make me envy the deaf and the blind!
    6. Re: Power Source by sycodon · · Score: 2

      Funny you mention Subs. I was thinking about that this morning.

      Subs are built for very hostile environments, and that's without people shooting at them. Take the principals of sub building and modify them appropriately...aluminum instead of steel, structures to hold air in instead of water out, etc. and you have a pretty good game plan for building an actual space ship instead of a soda can with windows.

      --
      When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
    7. Re:Power Source by Immerman · · Score: 3, Insightful

      Oh, and meant to mention: solar panels are really only promising in the inner solar system, and there's just not much worth colonizing inwards of Earth and its L-points. On Mars you only have 43% of the solar intensity, so you'll be getting only 130W/kg. At about 2 AU the asteroid belt will only see ~25%, and at over 5 AU the Trojans and Jovian moons are seeing less than 4%. And then there's everything beyond Neptune, where the sun is little more than a particularly bright star - lots of mineral wealth floating out there - I've heard estimates that the Oort cloud might extend as far as a light year from the sun.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
    8. Re:Power Source by Immerman · · Score: 2

      >where does the heat go?

      Well, if you're on a planet, moon, or sufficiently large asteroid you can dump it into the ground. I free space, as others have said, honking big radiators.

      Or... you use p-B fusion. The energy is released as high-speed He4 ions with a narrow range of kinetic energies, which can easily be converted directly to electricity with near 100% efficiency. Plus with negligible radiation you don't need much shielding. We're a ways away from a break-even reactor yet, but the Polywell will supposedly be able to perform p-B fusion at only a slightly larger scale than an energetically comparable D-T reactor (and if the sparse Navy milestones and status reports are to be believed then they have probably already demonstrated the ability to initiate p-B fusion at non-breakeven levels)

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
  14. Re:Get real by khallow · · Score: 2

    You do realize that a thousand Falcon 9 flights would fall well short of 100 billion dollars at current prices? That would be enough launch capability to get a modest number of people or gear to Mars and about an order of magnitude more to the Moon. Most of that mass would be propellant, water, and air/food, meaning little additional cost beyond the launch costs for significant parts of the missions.

    What will enable exploration and development on a modest budget scale is use of local resources or (ISRU - In Situ Resource Utilization). For example, once the local infrastructure is in place to extract propellant, you don't need to bring your own return trip propellant.

  15. Insurance by Boronx · · Score: 3, Insightful

    Provide low-cost federal insurance for colonization and asteroid mining missions, like we do for nuclear power plants.

  16. Re:You want an idea? How about we fund NASA? by penguinoid · · Score: 2

    To be fair, they are pushing economics boundaries. Which are the only boundaries really holding us back from colonizing the system (and then galaxy).

    --
    Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
  17. Re:Replace rockets with something reasonable. by AJWM · · Score: 2

    We already had a SSTO it was called the Saturn V.

    Uh, no. You're confusing HLLV (heavy lift launch vehicle) with SSTO (single stage to orbit). Saturn V dropped two stages on the way to orbit.

    The original Atlas was the closest we've come to an actual flying SSTO, it only dropped the two outboard engines, the tankage and sustainer engine made it the rest of the way.

    Now, as a thought experiment you could take the Saturn V second stage and replace its five J2 engines with a Shuttle SSME (and move a bulkhead to allow for the different LH2/LOX burn ratio) and it would make orbit as a single stage. Ditto with the Shuttle External Tank and six SSMEs. But none of those would have reentry and landing capability, and if it's not reusable there's not much point to SSTO.

    As for not seeing the point, it must be sad to live in a mind with such limited imagination. My condolences.

    --
    -- Alastair
  18. Re:Replace rockets with something reasonable. by cbhacking · · Score: 2

    The propellant, by itself, is not costly.
    The rocket big enough to launch a meaningful mass of payload when only 5% of what it carries actually makes it into orbit is absurdly, exorbitantly expensive.

    Launching tiny payloads isn't that hard. It still costs a lot, per unit mass, but the absolute costs are affordable.

    Launching small payloads (a few tons) is pretty bad, price-wise. You may be able to combine your launch with a few others on a medium-sized launch vehicle, but it's still not something that can be done lightly.

    Launching medium payloads (a few dozen tons) is basically the state of the art. Actually, nothing flying today can loft even two dozen metric tons, and the best launch vehicles under construction right now can only manage a few times more than that. Even these barely-into-double-digit-payload-tonnage launches are expensive enough that a company can do well making a few such launches a year, while undercutting all their competition and plowing a ton of money into R&D. Governments and large corporations are pretty much the only clients.

    Launching large payloads of over a hundred tons hasn't been possible since the Saturn V stack lofted an entire mobile-home-sized space station into orbit. We have nothing that could manage this today, or even on the near horizon; we might have such a thing within two decades.

    Launching something huge - for example, anything even close to the size of the ISS, much less anything bigger - will require either an extraordinary breakthrough in rocketry or a completely new launch system.

    The biggest human-built object in space right now is the size of a large house, and sleeps six. It took dozens of launches over more than a decade to get it this far, at a cost exceeding the GDP of many nations. It has almost no propulsive capability and is not self-sufficient over long periods. If we ever want to put something much bigger and better in space - even just as a series of small-to-medium launches, like it was - we are going to need to bring the cost to orbit *WAY* down.

    Now, in fairness, SpaceX has a pretty good angle on that. As you say, the propellant isn't terribly costly. If we can avoid throwing away the entire rocket with each launch, that will have an enormous effect on the cost of getting stuff to space. With that said, though, we'll still be stuck with a max payload to orbit barely in the triple digits until we come up with a better way to reach orbit than relying on chemical rockets.

    --
    There's no place I could be, since I've found Serenity...
  19. Re:How about... by Will.Woodhull · · Score: 4, Funny

    Republicans.

    Tell them the space program is an effort to protect the one percent from ebola, and to get away from all them do-gooder, pesky Democrats. And all them immigrants. That would shake the money tree.

    --
    Will
  20. Solar insolation is 150,000 TW, we need 22 TW by Anonymous Coward · · Score: 2, Informative

    The subject line says it all, but just to clarify it a bit more, the global power requirement for 2020 is projected to be under 22 TW (we use 20 TW or so right now, depending on how you measure it).

    In contrast, mean solar insolation on the planet is around 150,000 TW at ground level. It doesn't take a mathematical genius to work out from this that our civilization's power needs are completely insignificant compared to the power arriving from the Sun, by orders of magnitude.

    Of course we can't harness those 150,000 TW, but 22 TW could be captured using very little acreage (0.015% of the Earth's surface) in any sunny desert, and there are lots of those available. Only a tiny fraction would be needed.

    So, I don't know where someone got the idea that solar energy cannot meet our needs, it's so hugely wrong that it's funny.

    But wait, the above figures are at ground level . Do you realize how much power could be harnessed in Low Earth Orbit and beamed down safely at low power density? (Design studies for this have already been made.) The amount of power available in LEO is so mind-blowingly enormous that doing a calculation becomes completely pointless. It's astronomic. And we don't have to stop at LEO.

    Sorry to burst the bubble of your misconceptions, but you're wrong. Solar energy is, for all human intents and purposes, limitless.

  21. space gets defunded all the time... by Karmashock · · Score: 2

    I don't find such statements credible unless they put the money where their mouth is on the issue. If they blew what they've blown on the war on drugs on the space program we'd have a colony on mars. Think about that.

    --
    I've decided to stop wasting my time responding to AC trolls/sockpuppets... so if you want a response from me... login.
  22. Just impractical by fyngyrz · · Score: 5, Funny

    I have an idea...we could name a ship Botany Bay and send the worst criminals into space.

    I don't think we can make a spaceship large enough to hold congress and the supreme court at this time. Your idea will have to wait.

    --
    I've fallen off your lawn, and I can't get up.
    1. Re:Just impractical by Immerman · · Score: 2

      We don't have to send them all at once, and we can boost payload by leaving out nonessentials like air and water.

      --
      --- Most topics have many sides worth arguing, allow me to take one opposite you.
  23. Re:Replace rockets with something reasonable. by Rei · · Score: 2

    Presently working or theoretical? If you want "presently working", then that would defeat the point of asking for suggestions, would it not? If you want theoretical, there's tons. I kind of like the Launch Loop concept - sort of like a space elevator except that it doesn't require unobtanium, avoids or reduces the countless other problems with space elevators (micrometeorite damage, oscillation modes, power transfer, lightning and ionospheric discharge, and about 50 other things), and it gives you much more ideal/customizable orbital momentum, plus is 1-2 orders of magnitude more energy efficient at lifting cargo (space elevator climbers have to rely on beamed power, there's no practical way to send it through the cable, and beamed power over great distances where one receiver is only a few square meters at best is very low efficiency) AND offers a far higher launch rate.

    Earth-based space elevators, the stuff of sci-fi nerd dreams, really are an awful solution when you start looking at the details. There's far better solutions out there.

    --
    You people make me envy the deaf and the blind!
  24. Basic plan by Chas · · Score: 3, Interesting

    Step 1: Build permanent habitation in orbit. In a way that can easily be converted to a "space dock".

    Step 2: Use it as a launch pad for permanent habitation on the Moon. Build the infrastructure, build large (mega-engineering projects). Once it's done, THEN move people in permanently. Use this method as the basis for expansion elsewhere in the solar system.

    Step 3: Once permanent habitation has been done within Earth-orbit, send out automated devices to construct a similar space dock in Mars orbit, and possibly one in Venus orbit.

    Step 4: Use the Mars dock as a launch pad for permanent habitation on Mars using the Moon's habitation as a template. Due to Venus' EXTREMELY unfriendly atmosphere, I'd likely say convert the Venus station into a solar power-to-battery facility.

    Step 5: Once the Moon and Mars colonies are firmly established, use the template for occupying the moons of the outer planets.

    Basically the orbital facilities would be staging areas for occupation of the various planets/moons. They serve as fall-back points in case of catastrophe. And, once the colony was safely established, they'd become fuel depots.

    Going with a "launch from orbit" model also saves fuel and wear and tear on interplanetary vehicles.

    --


    Chas - The one, the only.
    THANK GOD!!!
  25. Satellites were Once Considered Crazy by catchblue22 · · Score: 2

    This article argues that Elon Musk is in many ways like Werner Von Braun or the Soviet scientist Sergei Korolev (who pushed the Soviets into space). One thing I got from this article was that the original and primary motivation for building rockets was to make weapons. Von Braun and Kovolev almost singlehandedly pushed their own countries into building rockets to put people into space. Without them, we might not have had satellites as quickly or at all. Placing satellites into orbit and putting humans into orbit was once considered crazy. American government officials considered Von Braun to be eccentric, but they didn't care as long as he gave them better ICBM's. Now our entire civilization is built around satellite technology, and our moon shots have brought us technology advances such as the microchip.

    When we talk about putting more humans it can sound a little crazy. However I don't think it is any more crazy than having people climb Mt. Everest, having bases in Antarctica, or sending three small ships westward into the unknown ocean to find a new world. We humans have an inbuilt desire to explore. To ignore that is to go against our fundamental nature.

    --
    This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)