The terms of the Drake Equation seem to be changing

The chances of finding alien organisms have been boosted by the discovery of hundreds of “water worlds” capable of supporting life.

New analysis by Harvard University estimates that one in three “exoplanets” outside our solar system that are larger than Earth are likely to contain an abundance of water.

The scientists say the planets that are two to four times bigger than Earth that have the best chance of supporting life.

Not that this changes the basic problem with alien – or indeed time travelling – life. If such exists, then where in buggery are they?

56 comments on “The terms of the Drake Equation seem to be changing

  1. Short of developing wormhole-technology or warp drive, we aren’t ever going to find out are we ?

    Also 2-4 times the size of Earth ? I think it was Michael Bentine who came up with “Ovoids” creatures where the gravity is so strong, that they developed flat.

  2. Perhaps the evolution of an “intelligent” species, able to manipulate its environment, form political parties, invent nuclear weapons, screen Celebrity Big Brother, etc., etc., is always terminated by total collapse before it reaches the stage when it can identify and communicate with other civilisations, still less solve the problems of interstellar travel.

    I think we are fast approaching that point. If the human Ken Doll isn’t a sign of the End Times I don’t know what is.

  3. After billions have been spent over many years, scientists finally find evidence of remote alien life. They look at each other and say, “Huh, how about that . . . now what?”

  4. “Not that this changes the basic problem with alien – or indeed time travelling – life. If such exists, then where in buggery are they?”

    Have you tried thinking about it in economic terms? What’s the business case?

    Most alien life is probably non-intelligent. We’ve had life on this planet for 3.5 billion years, and life capable of getting off it for about 200 thousand years. If that’s representative, maybe one in 20,000 life-sustaining worlds are capable.

    Then besides the first half dozen neighbours, when a species is exploring, what are you going for? There are no mineral resources there you can’t find at home. There’s plenty of room in space. After your own technological singularity you can build robot workers to do/make anything you want. Interstellar wars would be tedious. Any interesting biology would be available on worlds with no intelligent life.

    About the only thing I can think of that would be worth making contact with intelligent life for would be to trade knowledge. And if you’re a lot more advanced than them, they’ve probably not got much that’s worthwhile, and you can in any case steal it without paying by sneaking in undetectable surveillance devices. Trade only makes sense between species at near parity, and that’s going to be even rarer than finding intelligent species at all.

    Fundamentally, it’s the same reason we’ve not been back to the moon. Once you’ve got the capability, there’s nothing up there worth the effort involved.

  5. The question supposes that the speed of light can be circumvented. If it can’t then the question is meaningless. Our galaxy is 100,000 light years across. A thousand intelligent species evenly distributed would still mean the nearest would be thousands of light years away. How do you propose to communicate with them?

  6. NiV

    You perhaps answered it yourself. Because we can. OK, we can’t, but your last paragraph was the key. We went up there all the same, knowing that economically it wasn’t likely to be worth the effort?

    We’re curious as a species – and actually that’s more than enough.

    There’s amother sound resaon “if we can”: insurance. If we could explore / spread out, we could protect our species from a future ELE possibility on earth.

    RlJ

    “The question supposes that the speed of light can be circumvented.”

    If I was a betting man, then – provided we don’t destroy ourselves first – I’d take it as a given?

  7. “Our galaxy is 100,000 light years across. A thousand intelligent species evenly distributed would still mean the nearest would be thousands of light years away. How do you propose to communicate with them?”

    By moving very fast.

    From the point of view of the traveller, accelerating at a constant 1g would enable you to get to the other end of the galaxy in about 20 years, (although it would appear to take 70,000 years from the point of view of a stationary observer). The same applies if you run around in circles. So you build your interstellar civilisation on a set of fast ships all on them moving at similar speeds. When you meet up, or send one another messages, you have all experienced the same degree of time dilation, and so there are no long pauses in the conversation.

    Or if you can upload brains to computers, you can run your interstellar civililisation on very slow processors – or pause them and restart them when the reply comes in. In subjective time the conversation seems continuous.

    Or from the point of view of an immortal species where individuals can live for millions of years, a thousand years is maybe not so long to wait.

    But it’s not going to be like Star Trek, that’s for sure!

  8. We used to live on the only earth, centre of the universe, specially created for us. Then in the only solar system with planets, at the ideal distance from the sun. Still kinda special. Various of us were part of the chosen race too. Then there were planets and asteroids and galaxies and all the rest. Are we still special? The Drake equation is a vanity. We have found life everywhere on Earth. Why would it not be everywhere else too? And some of it will be intelligent but even then will be so unlike anything we ever knew or imagined (queerer than we CAN imagine, Haldane?)

  9. “You perhaps answered it yourself. Because we can. OK, we can’t, but your last paragraph was the key. We went up there all the same, knowing that economically it wasn’t likely to be worth the effort?”

    We went there because of politics – we stopped going when the political significance faded and economics took over.

    But yes, “because we can” might be a good enough reason if the cost drops to near zero. I’d guess the biggest cost would be being out of touch. There’s no decent mobile phone signal out in deep space…

  10. NiV’s twaddle to the side the Moon could be a useful asset.

    As for lots of water meaning life–well the gas giant planets have enough water in each of them to probably make several Earth-sized water droplets. It is however not free and not too available in its present form. A large part of the matter in the Kuiper belts and Oort clouds will be chunks of –likely–dirty water ice. So what?

    Hey–NiV =Gas Giant –I like it. The Jove of mental junk.

  11. NiV

    We’ve had life on this planet for 3.5 billion years, and life capable of getting off it for about 200 thousand years.

    Ok… I’m pissed up again but what the fuck?

  12. NiV

    We’ve had life on this planet for 3.5 billion years, and life capable of getting off it for about 200 thousand years.

    Ok… I’m pissed up again but what the fuck?

  13. Any rocky planet more than 2X earth size is likely to be very round, due to gravity. and to have attracted lots of water. So no land above sea level. And no point in being even an amphibian.

  14. “Ok… I’m pissed up again but what the fuck?”

    What’s your problem?

    “Any rocky planet more than 2X earth size is likely to be very round, due to gravity.”

    Depends whether they’re talking about 2x radius or 2x mass. Usually, I think it’s mass, so surface gravity is only going to be about 26% greater.

  15. NiV

    My borderline alcoholism or your claim that we’ve been space traveling for 200k years?

    The alcohol might be.,, but the idea Stone Age people were visiting uncharted systems might be a more serious mental illness

  16. Where are they? Are you kidding? The last time one visited he got nailed to a cross. Now wonder they shun us.

  17. I think NiV’s point is that H sap, the only species on Earth with the potential (perhaps) to reach the stars, has only been around for 200,000 of the probably 4 billion or so years that there has been life here.

    If we assume reasonable progress in our development of computers and associated technology for another 100 years, we ought to be advanced enough to construct self-replicating machines that can travel to other stellar systems and mine the resources there to produce further copies of themselves. Without assuming any faster-than-light magic, such entities could spread throughout the galaxy in just a few tens of millions of years – a cosmic eyeblink.

    So the fact that we don’t see them here tells us one of two things: either there’s some reason why building such machines is impossible; or we’re the only advanced technological civilisation to have developed in the galaxy. There are plenty of other galaxies, of course …

  18. “NiV My borderline alcoholism or your claim that we’ve been space traveling for 200k years?”

    “Capable of”. I was talking about intelligent versus unintelligent species. Homo Sapiens has been around for about 200,000 years, and for that time there has been a species intelligent enough to get off it. We could have figured out how any time (give or take a few thousand years).

  19. I was listening to that rare thing a month or two back:a BBC science programme that didnt obsess about global warming. Anyway, the speed of light is a physical barrier. Light only travels at that speed because photons have no mass.
    Therefore any spaceship across the galaxy will have to be piloted by Kate Moss.

  20. “Anyway, the speed of light is a physical barrier.”

    Kinda. As you approach the speed of light, time dilation/length contraction means that from from the point of view of the traveller the time elapsed and the distance travelled both approach zero. At the speed of light, the distance is zero and you get there instantaneously. Any faster, and you’d get there before you set off!

    Faster-than-light implies backwards-in-time travel.

    “Therefore any spaceship across the galaxy will have to be piloted by Kate Moss.”

    🙂

    Oh, yes. And as the speed of light is approached, relativistic mass increases to infinity…

  21. Can’t see many implications for the Drake Equation in what’s being reported.The “water worlds” they’re talking about have a significant proportion of their mass as water. Up to 50% As opposed to Earth’s 0.02%. So life – possibly. Technological civilization – not a chance. At much greater percentage of water than Earth’s, you’re talking about a world spanning ocean. No dry land at all. So, apart from very small amounts dissolved in the ocean, all the minerals would make that possible are in the rocky core. Maybe several hundred miles below the sea. At that sort of pressure, water starts doing strange things Being a solid, for a start. So elements like metals are probably permanently locked away from the surface.

  22. NiV

    You’re fucking nuts.

    Our species hasn’t been capable of space travel for 200k years. It’s taken generations of passing down information to get to the point where we managed to put a man on our nearest satillite.

    You’re off your head. And it takes a fair bit for me to say that.

  23. “It’s taken generations of passing down information to get to the point where we managed to put a man on our nearest satillite.”

    We got from stone age to man-on-the-moon in 8000 years, about 320 generations. And we got from subsistence farming to there in about 400 years, about 16 generations. If we had started earlier, we’d have got there much earlier. We could have had those 320 generations any time.

    However, I’m trying to estimate the probability of alien planets with life having sufficiently intelligent species here (f_i). The proportion of time for which our planet has been such is a crude underestimate. Ideally, one ought to use the expected lifetime (both past and future) of the human species. But that all gets a bit weird when we take the Doomsday Paradox into account…

    🙂

  24. As already noted, there’s alien life in Ely.

    Fuck the water worlds, that alien seems to carry quite a bit of water with him. Then again, they were talking about intelligent life, weren’t they?

  25. I’d recommend Saturn Run for both the discussion on orbital dynamics and slow steady approach vs big initial acceleration and the intstellar trading element.

  26. I can’t believe any sane person wants to meet alien life…

    What pathogens does it have associated with it?
    What enzymes does it have?
    How does it feed?
    How does it reproduce?

    As a former Organic Chemist some of the possible answers to the above make me very glad of those large distances between objects in space.

  27. Fred Hoyle and Chandra Wickramsinghe, both eminent astronomers, CW in addition being a biologist, suggested that life could be seeded throughout the universe by the transportation of organic molecules, viruses and bacteria on meteors. This was in the late seventies. As a thesis it has not been disproved. We may have aliens for ancestors.

  28. They look at each other and say, “Huh, how about that . . . now what?”
    “I wonder what it tastes like?”

  29. Thing is, the odds are that if there was intelligent life out there, we probably missed it, or haven’t seen it yet and won’t for ages.

    Distances are cruel – we’ve only been broadcasting radio stuff for a bit over a century, so a hundred light-years is the furthest out any other intelligent species that’s doing its version of the Search for Extra-Zygortian Intelligence might start noticing “hey, weird radio stuff from that little blue planet in the unfashionable end of the western spiral arm of the Galaxy… wow, those guys probably still think digital watches are a neat idea!” even before they start trying to reply (which would crawl back at the same pace) or visit.

    Or, they spent years broadcasting stuff, before Subliming / wiping themselves out in a nuclear apocalypse / their sun went supernova… but Tyrannosaurus Rex had his radio telescope tuned to Dinosaur FM and missed it, and it’s all long gone past and not coming back.

    There’s very likely stuff meeting the definition of “life” somewhere out there, just from the sheer size and variety of the universe. Statistically, though, not much of it will be much past the single-cellled organism stage, barely any of it will be advanced civilisations (how much of the history of life on earth is just bacteria and algae, how little of it involved radios and space travel?)

    The odds of there being life out there that (a) has reached enough technology to notice and reply to life outside its star system, (b) happens to have done so at the same time as us and (c) is close enough that “Hi, how are you?” gets a reply of “Fine, thanks” inside one lifetime, though… that’s the really, really bad odds.

    And to pick some sci-fi tropes… we might only notice “that might be a sign of extraterrestrial life” when a distant planet suddenly starts flickering with the local equivalent of plutonium fireworks… so there was someone living there, and they were advanced enough to blow themselves up in fine style, hopefully there’s some survivors we might one day attract the attention of…

  30. NiV

    “As you approach the speed of light, time dilation/length contraction means that from from the point of view of the traveller the time elapsed and the distance travelled both approach zero. At the speed of light, the distance is zero and you get there instantaneously.”

    So if I’ve understood you right, light (moving at the speed of, er, light) from any one source reaches everywhere in the universe instantaneously.

    I’m not sure I understand that.

  31. Elementary particle, my dear Watson. Only from the point of view of the photon does it arrive at its destination (any) instantly. To the rest of the universe, the photon travels at the speed light and its journey time varies with distance.

    It’s relativity. Space and time are variable, the speed of light is constant (in a vacuum).

  32. Photons have mass. It’s very tiny, but it is there. Feel free to Google why. Too late for me to even try to explain (and I’d probably get it wrong). Can be experimentally shown by suspending a small blob of glass in a high power laser.
    If anyone is interested, I’ll get out my textbooks tomorrow and see if I can find the reasoning.

    I’d like to think we will spread throughout the solar system at the very least. It makes sense as an insurance against extinction as previously stated. And if we aren’t all squashed up together on one rock, maybe we’ll not feel the need to kill each other all the time…

  33. “So if I’ve understood you right, light (moving at the speed of, er, light) from any one source reaches everywhere in the universe instantaneously.”

    As PJF says, only from the point of view of the photon, but yes.

    “Photons have mass. It’s very tiny, but it is there. Feel free to Google why. Too late for me to even try to explain (and I’d probably get it wrong).”

    Photons have zero rest mass, but non-zero relativistic mass.

    Every particle has a universal, fixed and constant rest mass, which is the same in every reference frame. The relationship between energy E and momentum p for particles with mass is:

    E^2 = (pc)^2 + (m0 c^2)^2

    but corresponding the formula for light is:

    E^2 = (pc)^2

    which is what you would get if you set the rest mass m0 to 0 in the formula for massive particles.

    However, the other way of thinking of mass is as the force divided by the acceleration in Newton’s law. Newton said F = ma, so m is F/a, describing how forces change the speed of objects. However, because of the speed of light limit, as you accelerate a particle closer and closer to the speed of light, the acceleration that results drops to zero. So F/a tends towards infinity.

    This form of mass is called relativistic mass, and is in fact identical to the energy of the particle. You can use E = mc^2 to work it out, but since c is a constant this is really just changing units of measurement. It’s actually just saying E = m, once we measure them in the same units. Relativistic mass is the one that obeys the conservation law, (rest mass isn’t conserved – it can appear and disappear during collisions), but since it’s really just equivalent to energy, a lot of physicists prefer to drop it as a redundant concept and use energy instead. Tastes vary.

    So because any photon carries energy, it therefore has a non-zero relativistic mass. The further towards the blue end of the spectrum, the heavier it is. (E = Planck’s constant times the frequency. The higher the frequency, the more mass it has.) It takes photons up in the gamma ray region to have even as much mass as light particles like electrons, so most photons we experience are very light indeed.

    “Do those other planets have beer?”

    http://mentalfloss.com/article/51271/there-are-giant-clouds-alcohol-floating-space

    (For those of you who don’t like my links, it’s safe to follow *this* link – you’ll like it! 🙂 )

  34. Mojave Greenie

    Is that Kim Kardeshev ? Gosh didn’t know she did physics too. What a woman.

  35. @MG thanks for that link (I like it because it agrees with what I posted previously, but extends it to intergalactic expansion).

    One way to think about time dilation is that all matter ‘moves’ at the (constant) speed of light through space-time. An object at rest within an inertial frame will move through time ‘at the speed of light’, i.e. one second per second. An object travelling at the speed of light won’t ‘move through time’ at all. For an object at intermediate speeds the ‘sum’ of its speed through space and its speed through time is always unity (with appropriate choice of units, i.e. the speed of light = 1).

    HTH (but perhaps not) 🙂

  36. The distances are indeed forbidding. The chance of alien life being anything like us is infinitesimal. They will not be bipedal pasty-headed humanoids who speak English. There will be no babelfish. Chances are their intelligence will be orthogonal to ours. Likewise their interests and motivations. We just might not be able to communicate or have anything we want to say. But the main point of the discussion of predicting alien contact is just how unpredictable it is. It’s pointless too, but don’t let that stop us.

  37. ‘The chance of alien life being anything like us is infinitesimal.’

    I disagree. Like Carl Sagan, I don’t believe we are all that special. We are the end product of normal processes.

    As a biologist, I’d say the key difference we would encounter – though there will be no encounter: the distances are prohibitive – will be due to gravity differences. Our legs are sized to deal with our gravity. Larger/smaller planets will result in different body shapes to deal with their gravity.

  38. I agree that we are the result of normal processes, but I regard it as a massive leap to suggest that the particular combination of normal processes that brought us about might occur commonly.

    We see a lot of what we call “organic precursors” in space, but it could be that it is an extraordinarily unlikely event that these come together to form even dumb self-replicating nucleic acids, let alone single cellular life.

    If this is the only place in the universe where life has happened, it will still seem mundane to us because it is all we know. Just saying we’re nothing special does not make it so.

  39. What NiV said…

    Though for all practical purposes, it isn’t possible to stop a photon yet. I remember reading that someone got close a couple of years back for a fraction of a second.

    Been too long out of that field though, so only dip the odd toe in for nostalgic curiosity.

  40. It’s not that the “terms of the Drake Equation” are changing. It’s that we are slowly beginning to work out what the actual numbers are to put in each variable. But this process will take a very long time to complete and in the meantime the Drake Equation is little more than a wish list of things that we’d quite like to know multiplied by other things that we’d quite like to know.

  41. “I regard it as a massive leap to suggest that the particular combination of normal processes that brought us about might occur commonly.”

    It can be extremely uncommon. Uncommon to the tiniest fraction. BUT, and this is HUGE, with BILLIONS of galaxies with BILLIONS* of stars, most with some number of planets, it will happen many times.

    *”Billions and billions” was Sagan talk. Belief today is that there are trillions of billions of stars.

  42. The uncertainties in the Drake equation are of a magnitude sufficient to make a plausible choice of the number of civilisations in the observable universe anywhere between one (i.e. us) and a number with lots of zeros after it. It’s hand-waving rubbish. Our being alone isn’t even particularly unlikely; one meta-analysis of the equation put it at around 40%.

    I don’t really like the term relativistic mass as it suggests things get heavier the closer they get to the speed of light. They don’t, it’s just that their momentum isn’t linear with velocity and their kinetic energy isn’t quadratic, as they are in the Newtonian case. I prefer relativistic energy such that E = γm₀c² = m₀c²/√(1 – v²/c²), and thus momentum = γm₀v and kinetic energy = (γ – 1)m₀c² (you get the familiar p = mv and K.E. = m₀v²/2 by doing a binomial expansion of these and truncating after one term; the first relativistic K.E. correction is 3m₀v⁴/(8c²)).

    Sagan said “billions of billions”.

  43. If the tiniest fraction of likelihood is equivalently mindboggling to the total number of sites of opportunity, then our single known example could easily be the only one.

    Indeed, we cannot assess the number of sites of opportunity without knowledge of the conditions needed for the origin of life. And as we don’t even know how life came about, we cannot describe those conditions.

    All we know is that it happened once. It is fashionable to assume we are not special, but applying that assumption to science is pure Underpants Gnome reasoning.

    life once –> ? –> lots of life

  44. Lovely to see all of the physicists here.
    Serious question – what is c in e=mc**?
    Don’t mean speed of light. Mean measurement.
    Kilometers per second?
    Miles per hour?
    Furlongs per fortnight?

    Anybody?

    Thanks.

  45. “Serious question – what is c in e=mc**?”

    Do you mean numerically? It’s defined to be 299,792,458 metres per second.

    Or conceptually? It’s really just the units conversion constant between the units we historically use for space dimensions and those we use for time. Space and time are just different directions in 4-dimensional spacetime. Tilt your coordinates, and they get mixed up. It’s as if, for historical reasons, we measured an aircraft’s horizontal position using miles, and its vertical position using feet. If you tried to describe aircraft motion in such a coordinate system, you’d get this mysterious constant of ‘5280 feet per mile’ popping up in the equations all the time.

    Light in a vacuum happens to go at that speed as a consequence, but really it has nothing to do with light as such – it’s purely a property of how we measure space and time; the units with which we choose to do so.

  46. Thanks, NiV.
    Very much appreciate the answer.

    So the universe wide conversion from mass to energy just happened to involve a conversion constant that is the square of a distance calculated by 18th century french scientists based on the circumference of the earth multiplied by a time value calculated by Sumerian scientists based on the length of an earth day.
    Quite a coincidence.

  47. “So the universe wide conversion from mass to energy just happened to involve a conversion constant that is the square of a distance calculated by 18th century french scientists based on the circumference of the earth multiplied by a time value calculated by Sumerian scientists based on the length of an earth day.”

    No, that would be 1 metre per second.

  48. Oh, yes, and so far as I know the Sumerians didn’t use seconds as a unit of time. I think the nearest they got was 1/360 of a siderial day, a fraction under 4 minutes.

    Of course, the history of metrology is all a bit tangled, and the definitions have changed several times. There are numerous different versions of “the metre” and “the second”. The current definition of the metre is itself based on the speed of light, as I expect you already know.

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