Finding Over 100 Million Exoplanets By 2050

69 thoughts on “Finding Over 100 Million Exoplanets By 2050”

1. What you say is true. It is a reason that what I do is so important. There is great ignorance out there.

2. The average person parrots whatever TV says. Today it is one thing, tomorrow it is another. TV can make an average person love, hate or ignore anything – it is called opinion leadership, or something to that effect. You can try it yourself this way. Approach 10 random people with a ‘simple question’: “do you agree that O’Neill habs are a better long-term solution than Mars?” Then another 10 random people, with the opposite: “do you agree that Mars is a better long-term solution than O’Neill habs?”

   I have seen that done in so many ways, with questions like “when did the Russians first land on Mars?” And the average people poured on the dates, or said they don’t know, which is another way of saying “I have slept through my whole life”.

3. The *average* person seems quite concerned about the things O’Neill plan would help, things on the Earth such as global heating, compared with anything Space, as you point out. It is not Mars that will get such peoples’ support, it is things that will work! O’Neill supporters are far more rabid than Mars supporters, as they do not include those with a preexisting bias who are just going along. And, they are correct. Settlments/stations in O’Neill Space will always be easier than settlements/stations on Mars. They are where the Mars dwellers will get much of their food, material and energy as they try to get started. The Mars stuff will always be smaller than O’Neill habs, as has been true since the ISS was first populated. Mars pops should catch up with the existing orbital stuff, then relative costs will be known.

4. That is exactly what Bezos wants. As for average people, the difference between planets and stations is non-existent from their perspective – so far are they from all this in their minds. That is why I doubt the Bezos way. Musk, on the other hand, relies on people who are determined or fanatical about Mars, and is one of them. That is how people got things done before. It was not avarage people who crossed oceans for whatever reason. I think Musk wants to leave the average people behind – cut off the fat tail (that is exactly “Expanse” story!). From that perspective, Mars is sufficient. Then, in some distant future, martians may start building orbital stations instead of planetary stations, or terraforming Mars. If stations look good to you from Terra, they look perfect from Mars.

5. Please read what you have written, but with the stipulation, true or not, that O’Neill is correct. That is, do a thought experiment in which it is a given that it is inherently easier to live , work and play in (O’Neill) Space than on the Earth, where we have evolved. Let alone places hard to get to, with no existing infrastructure, yet all the disadvantages of any planet, Earth or other. You will find that most of your conclusions will be reversed, on these planet v Space questions. The purpose of the thought experiment is not to decide whether O’Neill is correct, but to realize how important the question is. It changes the whole outlook. We need to populate cislunar with billions before we *need* to go further, from a practical standpoint. Many will go further, but average people see nothing at all in Mars or even farther out plans. They don’t see O’Neill at all, given the natural Earth bias.
   As an example of this, Musk’s Mars focus rather than Globus ELEO. It is clear which is easier from where we are. I don’t blame Musk for not seeing this, but it does not make him right! Planets are a dead end idea. They are so tiny.

6. I think you are missing one factor in your logic: human factor. Musk and Bezos are humans, and human factor is inseparable from their logic and decisions. They are also businessmen. Part of human factor is time limit on everything humans do. On the scale of short, medium, long and timeless terms, the human factor affects decisions differently.
   1. Short term: both of them want to live to see some deliverables. Must wants to die on Mars. Bezos has not expressed any such wishes, but he knows he will not live to see station-cities around cleaned up Terra.
   2. Medium term, measured in centuries. Basically an “Expanse” scenario, where planets are a shortcut to greater possibilities and fewer limitations than any space outposts at any scale.
   3. Long term, measured in kilo-annum. Assumptions can be made about space industry, which work both for planetary and station-city plans. They are about equal in value.
   4. Timeless term, planets are a limitation, as terrans have already learnt. Bezos plan is based on this premise, and station-cities plan is better, limited by star system, not by any planets in it.
   In Musk’s lifetime, the probability of sum of tech necessary for building a Mars outpost is high. So it is a matter of live-long risk management and effort allocation: Musk knows he has a good chance with Mars, and he is committed to that. That is the best choice for Musk, not “humanity”. I don’t blame him at all.

7. Shortly after posting the above, I saw an article blaming both Musk and Bezos for their plans to despoil other planets, not being satisfied with destroying merely the Earth. You know the type of story. No hint whatsoever the author had any clue O’Neill ever lived. Certainly not that Bezos had featured O’Neill in the Blue Moon video the author claimed to have watched. This needs to be corrected, the total ignorance of O’Neill. We hear about Mars all the time.

8. I agree with your last sentence!
   We are both seeing the problem with Mars, but I see a simple, correctable mistake in Musk, he does not understand O’Neill. You seem to indicate he has chosen Mars because he likes the limits, I think he sees no better way. Now, he could be pure evil, but I have a hard time placing myself in Musk’s position: to not yet understand O’Neill. Must be terrifying! Ideally without being too repetitious, Bezos/O’Neill is superior to Earth, thus obviously easier than Mars. Better for both short and timeless goals, not just a matter of well informed preference. Musk does not see this, which is quite common given how hard it is just to learn that the Sun does not *go around* the Earth. Now we are to live *up* there? But he does all sorts of other things that seem motivated not by escape, Tesla, tunnels. Surely someone is talking to him about O’Neill.

9. That’s ham and eggs

10. Right you are… but going to α-Cen is that you’d not be walking.  

    Using reasonable assumptions about energy, if juicy nucleotides such as ³He, ²H, ⁶Li and enriched ²³⁵U / ²³⁸U, and hoping for high efficiency acceleration, well … attaining 2% of ‘c’ seems barely possible.  2%, with the ability to decelerate at the target system.  

    ΔV = G₀ • ISP • ln( M₀ / M₁ )

    Where 

    G₀ = 9.81 N/kg or m/s², Earth’s sea-level gravitation constant
    ISP = specific impulse

    M₀ = starting ship + fuel + reaction stuff mass
    M₁ = midpoint ship + remaining fueld and RE-stuff
    ln() = natural logarithm, on almost all calculators. 

    This is called the Tsiolkovsky’s Rocket Equation.  

    So… usefully predictive features: it tells how much fuel-reaction mass must be aboard at launch, and how much at midpoint. And at the very end, if actual loitering at the target system. 

    Using

    Ek = ½mv² … m = kg, v = m/s, Ek = kinetic energy, in joules…

    one can use that with the foregoing to see

    Ek = ½ (M₀ – M₁) • (G₀ • ISP)² 

    is the total energy of the exhaust plume. Divide by the accel time, and the POWER comes out. Which with generation-and-conversion-and-capture inefficiencies, determines the energy-need at launch.  

    Anyway.
    Math.

    Just Saying,
    -= GoatGuy ✓ =-

11. Actually, the distance between Île-de-France and the Japanese Imperial Palace in Chiyoda is (according to Google Maps) 9,715.36 km. 1000 times that is just shy of 6.5% of an AU. Proxima Centauri is ~4.3 light-years, or 4,2 billion (very near 2^32) times the distance from Paris to Tokyo. And then another 25 times to get to our local interstellar ‘hood (~100 ly).

12. I think the key point in all Musk said on the subject of his Mars city is expressed in his choice of word: “self-sustaining”. One city is not enough to save a human race, as a rough estimate for that goal points at 200 million people to sustain modern civilisation. So it is either a life boat, or a runaway car. Life is not in danger, and all the talk of an asteroid ending it is just talk. What is left is a runaway plan, an escape: from a big war? from dark ages? from 10 billion desperate people? any one, or any combination of them, is reason enough to want self-sustaining city elsewere. As for Mars vs space, it must be a sentimental preference of endless dunes vs endless starry night. Perhaps Mars city is easier and faster to build at this time. Which, again, points at the motivation: an escape. Bezos is different; his vision is space stations. Their difference is personal, meaning Musk is driven by escape from endangered Terra (time-critical goal), while Bezos is driven by expansion around cleaned up Terra (timeless goal).

13. Thanks. At least I know what he was talking about.

14. You have made many interesting points! In the 70s, there were thoughts that the only way to *make* money would be to entertain, as all reasonable needs would be free or very cheap, as you state.
    As a detail, I don’t read Musk’s intentions as you do. I give him much more credit, truly concerned about survival of conscious beings. I strongly disagree with his planet centric plan, but fully with his goal. His rockets are an unexpected 20 year leap, seems to me. This does not preclude his wanting to escape, as you state, also being true.
    The big idea you understand and present:
    “For the entire history humans were prisoners of their own kin and their biological hierarchy” and “richness . . . is purely control over other humans via intimidation or manipulation.”. Chimps have this, but it can be explained by *normal* evolutionary process, in their situation. Bonobo totally different, merely by the absence of gorilla.
    Humans are special, predated by our reproducing *System* of Pain inflicting ritual, particularly at birth. The ritual that causes the most Pain thus out competes the rituals that cause less, as the Pain drives the ritual. This is my gloss of Janov, and it has been going on for ~7 million years. This *System* will kill us if we don’t stop it.

15. My goal is fairly simple, to bend the conversation from planets to Space as the “right place for an expanding technological civilization.”. This involves changing thoughts and dialog from the far out and hard, interstellar and Mars for example, to the close, easy and soon, as O’Neill proposes. This is gradually happening, but I have been doing it for over 40 years, and there is still an overwhelming unstated mass assumption of planets, not O’Neill Space. I cite Musk and the late Hawking as examples. I also cite the 40 years delay in lunar ISRU as an example of why this topic is vital to our future.

16. The “there” is just the neighboring star system as a whole. I made no mention of planets.

    A generation ship is pretty much a small O’Neill colony anyway, with the main difference that the availability of nearby resources varies depending on its location and velocity, so it may have to be a lot more self-sufficient.

    The slower the ship is going and the longer the trip is, the closer it is to “just living” wherever you happen to be, and just gradually expanding outward from the source star.

    The larger the ship, the slower it will have to move, due to energy constraints. Beyond a certain size, the icicles along the way aren’t enough anymore, so then you have no choice but either go as fast as you can in a single jump, or just stay where you are.

17. I believe Dan is referring to Arthur Janov, developer of Primal Therapy.

    Search for Arthur Janov Primal Therapy and you’ll get loads of web pages and articles.

18. This is certainly pure speculation, but I speculate that space in the context of this discussion breaks the template of “rich vs poor”, along with other templates and thought patterns. If robots can build colossal space stations, same level of robotics easily covers the needs of any man, summarised as “making a living”: food, shelter, all that. If such a man does not depend much on others in “making a living”, why would he work for them? for the rich? all his life?! He would say “thanks, **** you” and do other things, which may be as diverse as staring into endless sky or inventing those robots. For the entire history humans were prisoners of their own kin and their biological hierarchy, locked in and to a land space that was a wee bit tight even 5000 years ago. That puts Musk in perspective, as he is rich, but he wants some cosmic distance between himself and the billions of his kin, including the rich. That does not happen when people want company. He wants cosmic independence. If Musk has that problem, a common man doing his job for the only reason of paying his bills will simply stop, and the richness of the rich will cease to exist at that moment, as it is purely control over other humans via intimidation or manipulation. Actually, empowered men can make it a point of forcing that issue. So, I personally do not believe into “space Elisium for the rich”. Like any top predator, they cannot survive such a change.

19. Well, other than…

    [1] required power
    [2] range
    [3] collimation
    [4] input power source
    [5] megaconstruction
    [6] weapon potential
    [7] cost/kg (or if you prefer, kg/kg)
    [8] received power vectoring
    [9] collector heating, materials, fail
    [10] area-mass ratio, outbound ‘ship’
    [11] drift-without-power most of trip
    [12] chicken-egg braking problem
    [13] minuscule science/comm payload

    Shall I go on? This, while not even being particularly exhaustive in fleshing out the issues. Choose any of them and ask, “Well, Goat, why № 10, 12 and 3, for instance?”, and I could go on. But as of 2020, I’m resolved to no longer write treatises on the off-chance that someone is interested in more info. 

    Happy New Year, all.

    Just Saying,
    -= GoatGuy ✓ =-

20. Yes, growth is the wrong word. I certainly do not predict smooth continuity, nor even smooth expansion. Stuff happens.
    But O’Neill argues that Space is (inherently) easier than earth, so most everyone would move there. The rich would stay on or visit Earth more than the poor. Gentrification.

21. In that scenario, growth is a wrong word, as it implies continuity. Expansion is better: build a new station (Bezos dream), populate it; repeat the process as it deemed appropriate, not at some percentage rate of growth. Assuming lunar mines feed space factories that supply orbital “shipyards”, all of them unmanned, such process is possible and limited by capital costs. How many people, really, does one want to take up there? I would say most decision makers would run out of candidates soon after the first million. It is essentially a Dubai-style real estate project in space. It must not turn into an African-style megaslum (hello, Belters, that would be you). I have no doubt there would be investors for “Elisium”, or it would be sold out in pieces to anonymous private buyers quickly, once it is proven real.

22. If you drop the *there* (planets) we’ll get to as the primary concern, rather focusing on the trip, as it were, we are just looking to gradually expand as we live in Space no matter where we are.

23. I totally agree with you and Einstein on this issue, as the *math* is clear. You eventually get to a solid sphere of humans expanding faster than light speed at the edges. Not actually gonna happen.
    My concern is avoiding extinction NOW, by getting into space in a way that, like Musk but in a different location(s), serves as a backup to global cataclysm. Soon thereafter, following Bezos and O’Neill, either being able to prevent the cataclysm or *copy* Earth stuff into safe(r) mode.
    The history of life on Earth is more of a froth of growth and collapse, but not generally total extinction, tho that happens too. (edit: “or die out, all of them.” ??) The change is that we have the opportunity to greatly expand the *world*, now no longer just the Earth, so that the extinction is less likely, and more growth is possible.
    Then, the choice is to grow slightly slower than more resources become available, or wait for the limit(s) to slow us. Not profoundly different from the past on Earth, but far more desirable, IMHO. Thanx for the thinking. We seriously need thinking.

24. They are not exclusive!

25. You have a given amount of fuel and a given amount of propellant (they don’t have to be the same stuff). These are limited by the icicle mass, tank sizes, etc. That determines your maximum delta-v, energy, and propellant budgets. So you optimize the acceleration (and deceleration) profile to fit within these budgets.

    Maybe you accelerate faster, cruise, and then decelerate (higher thrust, lower Isp). Or maybe you accelerate as slow as possible, and then reverse (lower thrust, higher Isp). Either way, the scaling laws are the same.

    (And btw, you don’t take the entire icicle with you. Just what you need.)

    The total fuel and propellant mass and energy for the entire trip may indeed be higher with the slow ISRU approach, but it’s divided into much smaller, much more manageable portions.

    To summarize, I do get that slowing down (and then speeding back up) takes extra energy and propellant. But if that lets us divide the total into small manageable amounts, that’s still a win. And furthermore, by going more slowly, you more than compensate for that extra energy cost.

    (And back to my original point – the slow ISRU approach makes the entire trip primarily a technological challenge, without requiring any magical space drives or new physics. Making it much more likely we’ll get there, eventually.)

26. I know. But if the choice is between 300 years with no stops or 3000 years with stops every few years, the latter is technically easier. You basically end up rebuilding the whole ship several times over by the time you reach the next star, one bit at a time, one stop at a time. Otherwise you need tech that can last 300 years, plus ALL the supplies for repairs etc for the entire trip. If anything, the slow ISRU approach may let you go lighter.

    My energy estimates may be too low by an order of magnitude or two. My power estimates may be a complete brain fart – I just saw the energy and time figures, and figured “divide”. But this doesn’t change the fact that the scaling works in favor in going slow:

    A) Delta-v scales linearly with max velocity, inversely with transit time:
    dv = 2*vmax

    B) Propellant mass scales exponentially with dv and vmax, and inverse-exponentially with Isp:
    mp ~ m0/mf = exp[dv/(g0*Isp)]
    (rocket eq).

    C) Naively, energy scales quadratically with vmax and Isp, and linearly with the expelled propellant mass:
    E = 0.5*mp*(g0*Isp)^2 + 0.5*M*vmax^2
    (M is ship mass at vmax)

    But from B+C, energy actually scales exponentially with vmax. Slow = easier.

27. One large or a million smaller boxes to stash away 10 billion “new” people is not the problem. The problem is time (69 years) and resources, on top of every other economic activity of such a world.
    Robots making robots has the same limit of humans making humans, or bacteria making bacteria: all of them would create exponentially increasing resource consumption. Exponent is incompatible with physical reality, or economy in this case.

    But for the sake of experiment, Let’s say a habitat requires 1 ton per human. Let’s consider a notional “resource” planet with mass between Mars and Terra, at 1e21 tons. This time no FTL, no ZPE, no nucleosynthesis, just that mass inside one star system. That mass is enough for 1e11 times 10 billion, so how long until it is used up in 1% growth scenario? 2545 years. After that, just 69 years later, those 1e21 people will have to do it again, and spend another planet while at it, or die out, all of them.

    But hey, let’s go nuts and spend the Sun using 100% efficient nucleosynthesis. Start with 10b people and 1.989e27 tons of mass, and in 6317 years you get to the same place where extinction awaits. That time seems long, but it is about the same as recorded human history. To end this madness, let’s spend the whole universe (1.5e50 tons) on 100kg human bodies. In short, it would buy 11’842 years of 1% growth. Game over.

    No matter how you turn it, exponent will destroy your plan. The cosmic choice is either zero growth, or extinction.

28. As beliefs go, I would rather believe in cosmic scale industrial nucleosynthesis. But I do not. 🙂

29. One detail: I’m almost certain there have already been possible ways proposed that would make stable, very light *metal* from H. Can’t imagine what else the story would have been about. Certainly not yet!

30. Thanx! I agree with the out of control nature of exponential growth.
    However, I certainly disagree with this one statement:
    “Needless to say, building a synthetic planet for 10 billion people in 69 years is pure magic far beyond sci-fi.”
    10 B scattered around, not one planet, in rotating habs by 2100 would be sorely disappointing to O’Neill, using his *standard* ~1970’s tech. Think of exponential growth in an environment where energy, material, space and robots making robots have no practical limit! The rotating habs make the planets a rounding error. Now, we would need the people, of course.

31. Sigh… perhaps you “will get” this: in a car you burn fuel to get ‘up to speed’, and over a longer period, a lot just to keep that speed.  When you come to a stop, technically you need little (ideally none, and for an electric car, ‘regenerative’ or recharge energy).  

    This is HUGELY different from space travel.  

    As an example, to go from San Francisco to LA by car requires:

    GAS → gas → gas → gas → gas → gas → GAS (grapevine) → gas → gas → braking, stop.

    From a trip from Sol to α-Centauri requires

    REACTION-MASS + ENERGY … max-speed achieved → drift → drift 
    → drift → drift → drift → drift → drift → drift 
    → drift → drift → drift → drift → drift → drift 
    → drift → drift → drift → drift → drift → drift 
    → REACTION-MASS + ENERGY → stop.

    Which is worse for picking up and ‘loitering at’ various Oört and Interstellar lumps of resources …

    RM+E … to same speed → drift → drift → drift → drift RM+E → stop → loiter, load more RM+E, → 
    RM+E … to same speed → drift → drift → drift → drift RM+E → stop → loiter, load more RM+E, → 
    … 100 times …
    RM+E … to same speed → drift → drift → drift → drift RM+E → stop → loiter, load more RM+E, → 
    RM+E … to same speed → drift → drift → drift → drift RM+E → stop → loiter, load more RM+E, → 

    Just Saying,
    -= GoatGuy ✓ =-

32. Whups… gotta admit that for me the line between exoplanets and sci-fi gets a bit blurred

33. I used only planets in my calculation. Synthetic worlds like O’Neil are indeed an extra space, but it would not make a difference of more than a hundred years, or a few. At 1% population grows, it doubles in 69 years: if you have 10 billion on a planet, and in 69 years you build synthetic spaces for 10 billions, you are back when you started in all constraints, but with twice the population. Needless to say, building a synthetic planet for 10 billion people in 69 years is pure magic far beyond sci-fi. And in another 69 years you will have to do it twice in the same time, to just keep up with modest population growth of 1%. Exponent is a monster you do not want to fight, as it will win, and you will lose.
    Star Forge, yes. Problem with that is element abundance. Stars are almost entirely hydrogen and helium plasma. You cannot make hard things from hydrogen, and you cannot make any things from helium. Unless astroengineering-level transmutation (nucleosynthesis) is achieved, which is an even higher level of pure magic, star matter is not a source of construction material.
    Petri dish is the demonstration of killing everything: killing by growing to find a hard physical limit, then dying. Nature is the opposite: regulated population and species immortality.

34. The search for exoplanets is the most exciting field of research today. I`ll never see a trip into interstellar space but it holds the promise of the first discovery of life beyond earth. Not necessarily intelligent life but even the discovery of plant life would be amazing.

35. > The faster you go, the harder to capture (paraphrased)

    Under the worst case scenario, the point isn’t to get there as fast as possible, but rather to get there at all. So this line of reasoning is irrelevant.
    If you have no better choice, you stop to refuel when you have to. And if the trip takes a few thousand years because of it – so be it.

    As I explained in my other reply, you go slow, and you stop as often and for as long as necessary. Dock or orbit, not capture.

36. (part 2)

    Of those 1 million tons of ices, ~20-50 tons should be deuterium. Around 2e18 J per hop. This would cap propulsion to the years range for a reasonable-sized ship. But a bigger icicle would have more fuel, and if we can fuse regular hydrogen, the fuel supply is 5000 times bigger.
    The problem is finding the next icicle.

    It may take a few thousand years to reach the nearest stellar neighbor, but that’s barely a tiny moment on cosmological time scales. And this is the worst case scenario we’re talking about. If new physics and technology allow faster options – all the better.

37. > expect to not have to accelerate total for more than 6 days per hop

    See, that’s not a necessary assumption. The hopping worst case implies generational ships anyway. So a hop may as well take 6 months, or 6 years. Or even 60 years, if the life-support and maintenance systems are good enough. Again, that’s primarily a technological challenge.

    Ek = 0.5mv^2, so a low speed and low acceleration win big energy savings.
    ~600 AU = ~1e14 m
    6 days transit = ~2e8 m/s avg, Ek/m = 2e16 J/kg, avg specific power P/m = ~4e10 W/kg
    6 mo = ~6e6 m/s, Ek/m = ~2e13 J/kg, P/m = ~1e6 W/kg
    6 yr = ~5e5 m/s, Ek/m = ~1e11 J/kg, P/m = ~5e2 W/kg

    Even with 6 year hops, propulsion dominates the energy requirements.
    As it happens, a lower acceleration also allows higher Isp for the same power. So less fuel needed.

    A single 100 m class icicle would contain on the order of 1 million tons of CHON ices. That should be enough for repairs and resupplies. If the hops are short, the next stop isn’t too far away. If the hops are long, the tech has to be good enough that there won’t be a need for many repairs and resupplies, other than fuel. Over 99% recycling etc (probably more than 99.9% – full nanotech level).

    (continued in reply)

38. Making it all MUCH simpler…

    Its like if you placed power packs (every kilometer) down a track, each filled with a bit of power to make you go faster by 1 m/s.  

    After picking up 20, you’d be going 20 m/s or 45 mph. This is fast enough that ‘capturing them’ gets mechanically more difficult.  

    After 100, you’re up to 200 miles an hour, and ‘capturing them’ is near-impossible. Not precisely, but close!

    After 500, you’d doing 1,000 miles an hour. Forget capturing any more.  

    And so on. 

    Slowing down to capture the next, and next-next defeats the purpose of deriving energy from the successive ones.  

    And that’s the problem in a nutshell.

    -= GoatGuy ✓ =-

39. Nice, but largely BS, physics wise.

40. OK… you need a short lesson in Reality Physics.  
    The opposite of space-opera physics.  

    There are trillions (10¹²) to quadrillions (10¹⁵) of Oört objects. The probability of finding ‘a good one’ (250 m diameter, right stuff) in any direction is about ¹⁄₆₀₀ AU. I just did hours of math to prove it 3 different ways. 

    Let’s say we have an almost unimaginably powerful thrusting technology that just loves reaction mass and fuel. Which we get from ‘right stuff’ Oört objects. And we expect to not have to accelerate total for more than 6 days per hop.

    But d = ½at²; to attain v = 1% of c in 3 days:

    v = 0.01 × 299792458;
    v = 3,000,000 m/s;

    t = 3 × 60 × 60 × 24;
    t = 260,000 sec

    a = Δv/Δt
    a = 3,000,000 m/s ÷ 260,000 s;
    a = 11.6 m/s² (÷ 9.81 m/s² = 1.2 G’s!)

    Nice space drive. 1 G for 3 days, then flip around and another 1 G for another 3 days.  

    d = ½at²
    d = ½ 11.6 × 260,000²
    d = 392×10⁹ m … conversion
    d = 2.5 AU … times 2
    d = 5 AU per inter-rock in accelerations

    Nice, huh.
    BUT NOT.
    NOT because we HAVE TO ‘stop’ BETWEEN EACH BLOB.

    d = 600 AU – 5 AU/hop for accel (6 days);
    595 AU at 1.75 AU/day = 343 days between intercepts. 

    63,000 AU/LY ÷ 600 = 100 hops … Solside … ≈ 350 years. 
    180,000 AU in between, = 250 years to drive toward α-Cen;
    Then 350 more years to capture more rocks.  

    It begs … why capture the rocks at all, IF one has to slow down for every one, just to catch it?

    Just Saying,
    -= GoatGuy ✓ =-

41. Right at the end of his *Cosmos* re-make, Dr. Neil deGrasse Tyson pointed out that once we make the interstellar ships, we can just forget the propulsion and live in them in this star system, in Sol orbit, much as O’Neill proposed. Very much like.

42. Are you limiting, as it were, to planets, or considering the much much larger pops possible in O’Neill Space? I know the result is the same eventually, but consider David Criswell’s method for pumping material from stars, for example.
    Also, prosperity, inherent in O’Neill plans, seems to lead to negative growth, altho that may be from the false belief that the world is small. The Earth is small, the world as we create is much larger, if we can get started before killing *everything*.

43. Isaac Arthur’s concept isn’t new as it was experimented by NASA in the early to mid 1960’s and with working prototypes they discovered that the problem with any photon or plasma propulsion systems is the astronomical amount of fuel required to push each kilogram of craft and payload in space for any significant distance.

    Even if super efficient solar panels could be built that not only captured light to feed the lasers, but were also propelled by the impinging photons, you would still have a net loss between the energy captured by the solar array and that thrusted out by the lasers.

    Also keep in mind that even if you create an enormous solar array to power lasers the dark catchment area of the array would create a negative attraction towards the light source thus cancelling out the photo-thrust
    of the laser.

    The future may likely be in moon based hobby sized space crafts, and smart phone sized payloads; but even then, you have the fuel issue which at some point may be mined on the moon itself.

44. Yup… and when they point those high resolution telescopes back at California’s most developed utopian cities, they’ll discover intelligent life living in the turd-world.

45. Sounds interesting, but the last name of the author isn’t all that helpful.
    A link, or full name of author & title of book or article would be nice

46. All growth is physically limited. It is much less bad for “we” to physically limit themselves, than wait to be physically limited.
    The point can be formulated as follows. Pick a limit number and do not exceed it, for any reason, ever. That applies not to everything, but to eliminate exponential material growth drivers: population growth (one child per fertile adult as an unconditional right, which needs clarification, but statistically it has to be “1 begets 1”), and resource depletion growth (as reserve/consumption ratio measured in remaining years of consumption). On the point of growth limit, it is a wondeful experience to take USGS dataset and compute reserve/consumption ratio for metals. On avarage, it is several decades, definitely less than a notional lifetime.
    Without such limits, “we grow” will end the same way as for bacteria in Petri dish, when nutrient is depleted. In nature, limits are imposed on growth, and species are essentially immortal. Coelacanth is my witness. 🙂

47. Nobody is suggesting that we’ll be crossing interstellar distances anytime soon. Not even Jean Baptiste, as evidenced by:

    this long term outcome is a near certainty, as long as we survive and reach that stage of our civilization’s development.

    Even in the worst case of having to hop from icicle to icicle, some estimates place the outer edge of the Oort cloud at well over half the way to Alpha Centauri… where it likely overlaps Alpha Centauri’s Oort cloud. Those icicles are likely to hold decent amounts of all four CHON elements (and some other stuff), which is all we really need to make the crossing. Sure, it would be a multi-generational effort, but it seems likely we can eventually go interstellar in at least some directions. The challenges are mostly technological.

    So it seems to me that we know pigs and chickens exist, we have some rough idea how to raise them, and we’re at the very early stages of planning the farm. We can’t quite make ham and eggs yet, but we probably will at some point… once we build the farm (and raise some pigs and chickens).

48. Yah… if we had bacon, we could have bacon & eggs. If we had eggs…

    Lasers powerful enough to push a spacecraft to near-relativistic speeds are pretty much built on solid Science Fiction. But OK, if we had bacon. 

    Then there’s powering the things. Tho’ many an effort has been made to use self-realigning laser beams in a regenerative propulsion scheme have actually achieved quite a bit of success, the “beam divergence” problem remains unsolved. Probably unsolvable. 

    So, beams situated on Earth (or some orbit pulling in prodigious amounts of solar-power to power them) cannot realistically get beams out to 1,000 AU … or even 10 AU and maintain a illumination diameter of less than 1 km. At visible wavelengths.  

    The illuminated spacecraft would need … 1 km of reflector to DIVERT beams … for maximum forward thrust … and would need to take in billions or trillions of watts of power. Well… if we had the eggs.

    Just Saying,
    -= GoatGuy ✓ =-

49. OK, what’s your take then?

    Should we grow or not? only up to certain level? how?

50. Yes, in so many ways.

51. I once computed the time until “we” run out of planets in this universe, and need another (that will last only 70 years more, then it is two new universes asap). The assumptions were extremely favourable: 1% population growth, something like 10 billion “us” per planet, instant FTL and unlimited ZPE, no resource restrictions, basically “wish and you are there”. The result was less than 6000 years – less then the recorded history of “us”. So “grow” is a very dangerous word: it can and did destroy (physically, to extinction) entire civilisations. Exponent is not a toy, it is a monster.

52. Wouldn’t a plastic telescope degrade over time anyways? Due to UV exposure…

53. You should note that Janov was rejected for reporting dramatic physiological changes during his experiential therapy, long before epigenetics was dreamed of. Now, reversing epigenetic imprints is a big topic!

54. Whisk Tango Foxtrot Dan, that dude is as defunct as Freud. Crazy is not a useful term. It’s used for two things specific but undefined mental deficiencies and to make fun of people you disagree with… I think you only use it in the later sense. Feel free to stop anytime.

55. I agree, but have a more specific mechanism to offer. Our ‘insanity’ certainly leads to restlessness and destructive ideologies, but is actually a ~7 million year process of coevolution with our mostly predatory *System* of repressed birth and childhood trauma, mostly avoidable now that it is understood. This system is neither good nor evil, just there. As Janov sez, “Once understood, the system must be destroyed.”

56. We only need to solve the problem of jumping the chasms between the stars.

    … if we had bacon, we could have bacon and eggs! … if we had eggs … 

    A slow Hegira of nuclear ships could glide tens of AUs a step, then loiter to look for resources, to settle and repeat, again and again into the deepness of the Oört cloud. This is nearly certain, IF we survive as a civilization long enough.

    Breakthroughs of space-travel science would only speed up the Hegira.

    The biggest risk … is societal or culture collapse that causes us to refuse serious investment in Science, and instead retreat to worry-beads and mummified-head spirit-rattles. 
    ________________________________________

    I really think that “the problem” with the Hegira concept is wrapped up by the ham-and-eggs comment. Excepting for not having LONG-LONG distance space travel expertise, we could jump to any of these new-found earth-like planets. If we could live that long.  

    SPACE IS BIG. Way bigger than most can really comprehend. No math, no numbers, no physics, no unbreakable Laws, too many space operas and warp drives, and drinking brandy out of improbable flasks from Aldeberon. 

    BIG ≡ TIME.

    It is like (but still 1,000’s of times long than) contemplating crossing from Paris to Tokyo … by foot. Now, multiply by 1,000 … for our nearest starry neighbor. And 100 times that, for just our local interstellar ‘hood. 

    Just Saying,
    -= GoatGuy ✓ =-

57. That ‘insanity’ or human restlessness is what got the first human ancestors out of the Savannah and out of Africa, allowing them to survive extinction from localized climate and ecological changes.

    We thrive when we surrender to that impulse, go out, settle and create new lands. Otherwise that tendency becomes destructive.

    We start seeing others as sources of problems, we as part of a zero sum game and then we start festering all kind of destructive ideologies and beliefs.

58. So the basic story (not the science story!) is that we can more easily build telescopes in Space than on Earth, to find planets to live on, which are also more difficult to do things on than in Space. Such as living and working. A grave distraction from the need to use Space to benefit Earth.

59. Yes, but your existential context matters. It is different to embark on the risky choice of deciding you no longer want to grow and expand while being part of on a space-faring civilization, either as a lay person or as a petty tyrant of a bunch of them, than to do the same when none of us has ever lived outside our planet (our current situation).

    If people gets really averse to crewed space travel & settlement (outlawing it, due to some misunderstood conservationism ideals), or if we can no longer afford to do it due to some big real threat (war, disease, whatever) then the outcome can be the same: we won’t be going to live in space and the stars will remain forever closed.

    And yes, ‘we’ as a source of intention is just a placeholder for the mass of outcomes the decisions of unrelated people make.

    Except on one thing: either ‘we’ all share and depend on a single biosphere/planet or we don’t.

60. *start look inwards and downwards instead of outwards and upwards.*
    We need both. Our insanity is a tool to escape planet(s), but must be stopped before being a tool of total destruction. We have slowly evolved “love” as a way to survive the insanity, the “System” Janov describes, and it will remain once baby and child abuse is no longer routinely practiced.

61. *little interest in living on planets* then, or now!

62. The future needs Janov. People are as crazy as they can possibly be.

63. Power addiction a a symptom of usually curable repressed childhood powerlessness. See Janov for details.

64. Yeah, I expect that if we don’t go the relativistic approach, we’ll eventually get there by “island hopping” through the Kuiper belt and into interstellar space. (Although once we have self replicating tech, the first mover advantage in colonizing a new star system would be enormous, and might trigger a race.) Mind, people who arrived at a new star system by that route probably would have little interest in living on planets. There’s a good chance they wouldn’t even look particularly human by the time they got there.

    But first we have to colonize the Solar system. Job one!

65. I’ve got my doubts about huge rigidized plastic telescopes in space. Frankly, “huge” and “rigid” don’t go together that well, and maintaining a sub wavelength figure on a plastic bubble seems unlikely. I suppose if some optical approach that didn’t require near geometric perfection was to be used…

    My preferred approach to huge telescopes in space is multiple reasonable sized independently flying mirrors using ultra precision station keeping to form a very large sparse mirror. It has the advantage that you can start small and add mirror segments as you go. With a long enough focal length the individual mirror segments can be optical flats, which are much cheaper to manufacture. The approach is well suited to the economies of mass production.

    With this approach you can also add free flying imaging units, and use the mirror array to look at multiple targets at once.

    With either of these approaches you don’t want to station your telescope too close to Earth. Maybe in the Earth-Moon L3 point, if it isn’t too dusty?

66. Let me summarise.
    The biggest risk for “us” is us, and we will bring it with “us” anywhere we go, no matter how far and how fast. If it so happens that another nice planet is reached, let’s say a veritable paradise, it will end up the same as the last one. Because of “us”. With that said, it is a pleasure to inpire the next generation with unvarnished reality they so love to ignore.
    As a token of solace to those who may need it at this moment, in reality there is no such thing as “us”. “Us” is a great lie. You are welcome.

67. meanwhile down on earth: trump

68. We only need to solve the problem of jumping the chasms between the stars.

    But given even a slow Hegira of nuclear ships would do it, jumping a step of a few tens of AUs at a time, looking for resources, settling and repeating the same process in the deepness of the Oort cloud, I think this long term outcome is a near certainty, as long as we survive and reach that stage of our civilization’s development.

    Any other breakthroughs of science and tech pending to be discovered in space travel would only make this process faster.

    The biggest risk we face is a big societal collapse and/or a cultural regression, either accidental or by choice that makes us refuse the high road and start look inwards and downwards instead of outwards and upwards.

69. Even if human population does grow to 10 Billion that still works out as 1% of a planet each.

    Should do us for a while.

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