# We finally receive a message from space indicating intelligence. Do we respond? S. Hawking says no. **URL:** \ **Category:** In My Humble Opinion\ **Created:** [April 26, 2010, 2:17am UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364 "2010-04-26T02:17:10Z")\ **Posts on this page:** 20\ **Page:** 6
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [April 27, 2010, 12:33pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/101 "2010-04-27T12:33:57Z")
I agree with **levdrakon** - and I think it’s not necessarily a failure of imagination when we talk about similarities we might well share with extraterrestrial beings. Assuming the laws of physics and chemistry are the same in other parts of the universe, there are a whole bunch of sweet spots and goldilocks zones that overlap in such a way to make it less than completely impossible for aliens _very broadly similar_ to us to exist. I’m not talking about ST humanoids with bumpy foreheads, just aliens on the same general scale as us, that eat, shit and reproduce, that use tools, sense their environment, and so on. Consider: Carbon/hydrogen/oxygen chemistry offers a very wide range of possibilities - maybe it’s not the only way to do it, but it’s a friendly toolset, and a common one. Liquid water (as well as being part of the above chemistry) has some interesting properties that tend to stabilise an ecosystem (if ice sank - as most solids do when immersed in their own liquid - the Earth’s ecosystem could easily freeze solid), as well as being a good solvent for a wide range of useful substances. Material properties start to set upper limits on the size of motile organisms (if they’re not motile, or organisms, they won’t be visiting) - somewhat mitigated by variation in environment, maybe, but there’s still a gradient of difficulty there. Brownian motion, surface tension, fluid viscosity, the scalability of fire and metallurgy etc start to set lower limits on the size of organisms that could reasonably make and use tools (we could still end up interacting with hive-style biological spaceships, I guess) Evolution by natural selection would tend to favour organisms that ‘want’ over those that don’t care (as well as a whole bunch of other stuff) And so on. None of these things are absolute, but in superposition, they create favourable niches. We can’t expect aliens to be bumpy humanoids, but we should be surprised if they’re too small to be visible, big enough to blot out the sun or not interested in anything. We may still be surprised, of course. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [April 27, 2010, 12:35pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/102 "2010-04-27T12:35:00Z")
> [@Koxinga](#): > > Acknowledged: but aren’t you still projecting some implicit limitations on the aliens? What with power sources, machines, recycling, you seem to be picturing beings that are perhaps a few centuries ahead of us at most, in terms of technology and their own evolution. (Like somebody upthread pointed out: Star Trek!) > > But what if they’re much more advanced, millenia ahead of us or more, in the same relationship to us as we are to chimpanzees (if not further down the evolutionary scale)? What’s the daily concerns of a chimpanzee, and what has chimp society gained from _us_ in figuring those problems out? > > And as for motivation: the chimpanzees can’t very well grasp the rubber trade, or colonialism, or whatever other motivations the Europeans had for being in Africa. But once the men in pith helmets were there, it was bang-bang time nonetheless. > > You might say that they communicated with us (in the OP’s scenario), therefore they’re more on our level and have an interest in communicating with us. But what if we overheard something that wasn’t meant for us? We’d be like chimps screaming at the side of a riverbank in response to the tooting of a riverboat on the River Congo. Again, you’re happy to speculate in a negative sense, but nothing else. Why? ---
**Author:** ![control-z](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@control-z](https://boards.straightdope.com/u/control-z)\ **Post date:** [April 27, 2010, 2:23pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/103 "2010-04-27T14:23:44Z")
> [@ivan\_astikov](#): > > Weigh them against what? If some data variable is unknown, your scales are going to be a bit wobbly anyway. We would have to make our decision based on available information and go from there. Do the aliens materialize out of thin air? Do they glide down on organic parachutes? Do they use liquid-fueled rockets? Can they breathe our air? ---
**Author:** ![Koxinga](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@Koxinga](https://boards.straightdope.com/u/Koxinga)\ **Post date:** [April 27, 2010, 3:32pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/104 "2010-04-27T15:32:09Z")
> [@Mangetout](#): > > Again, you’re happy to speculate in a negative sense, but nothing else. Why? 'Cause I’m interested to see if you have an answer, I suppose. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [April 27, 2010, 3:38pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/105 "2010-04-27T15:38:17Z")
> [@Mangetout](#): > > Again, you’re happy to speculate in a negative sense, but nothing else. Why? Well, I think history has shown us that when you put two creatures, people or civilizations together, generally the stronger, more agressive, more advanced one gets what it wants. > [@levdrakon](#): > > Any aliens who have concepts like technology and space travel and communication are going to be similar enough for us to come to some sort of mutual understanding. Sort of like the Aztecs and the Spanish conqusitadors? Or the Native Americans and the Europeans? Or the aboriginal Austrialians and the Brittish? I don’t know if being similar to us sweatens the deal. ---
**Author:** ![This\_Just\_In\_2](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@This\_Just\_In\_2](https://boards.straightdope.com/u/This_Just_In_2)\ **Post date:** [April 27, 2010, 3:39pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/106 "2010-04-27T15:39:07Z")
> [@Mijin](#): > > The idea of scooping up H to initiate a star formation does not contravene any physical laws, neither does terraforming. They seem like plausible progressions for such an advanced species. > > OTOH travelling astronomical distances to get to a tiny ball of rock is just a waste of time and resources, for this hypothetical species. This makes no sense. You think advanced aliens or humans would find it easier to create a sun than to fly to one? At .1% the speed of light we could reach Proxima Centauri in 40 years. There are theoritical methods already devised that have not been built yet, of course, but physically could be. We don’t quite have the technology to do it now - [but probably within in a few hundred years we’d be able to do it if we wanted to.](http://en.wikipedia.org/wiki/Interstellar_travel) Now, to create a star you need mass, or H as you say. Incredible amounts of it. I have no idea how your advanced civilization could possible put it together without some serious industrial accidents - but even more to the point where, pray tell, are they going to get it. You can’t just wave a pooper scooper around your star system and get usable quantities of H to create a star. For example, our own sun accounts for about [99.86%](http://en.wikipedia.org/wiki/Sun) of the total mass of the Solar System. Even if you could collect that remaining 0.14% and threw it together you would not have a star. So no matter how advanced an alien is they will not be able to create a star without the material - which is not easy to come by to say the least. Real star formation happens over billions of years of gravitational attraction pulling molecules together - some of it from very far away. In comparison to star creation, interstellar travel is a walk in the park. ---
**Author:** ![This\_Just\_In\_2](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@This\_Just\_In\_2](https://boards.straightdope.com/u/This_Just_In_2)\ **Post date:** [April 27, 2010, 3:55pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/107 "2010-04-27T15:55:08Z")
I agree with Hawking. Aliens are likely to be far more different from us than we are to dolphins. Do we understand dolphins, arguable the 2nd most intelligent species on Earth? They obviously communicate - and despite our intelligence we cannot talk or even understand what they say. And do we go out of our way to protect dolphins - save their ‘home’ in the oceans and make sure we don’t interfere with them? If some advanced alien takes the trouble and expense of going to earth it will be to live here and they will probably decide we’re just pests in the way. They will probably be so different from us that they will be unable to communicate well with us (if at all). Their logical course of action would be to kill any possible threats including humans. After all - we kill or at least remove all potential threats. Or do you often see bears and wolves prowling the streets near your home? And they will kill us, in only because, if they don’t kill us, we might ‘grow up’ technologically and come out to kill them in x number of years. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [April 27, 2010, 4:28pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/108 "2010-04-27T16:28:21Z")
> [@This\_Just\_In\_2](#): > > You think advanced aliens or humans would find it easier to create a sun than to fly to one? I wasn’t talking about “advanced aliens”. I was talking specifically about _your_ hypothetical species that was “millions or billions” of years advanced. > [@](#): > > At .1% the speed of light we could reach Proxima Centauri in 40 years. There are theoritical methods already devised that have not been built yet, of course, but physically could be. We don’t quite have the technology to do it now - [but probably within in a few hundred years we’d be able to do it if we wanted to.](http://en.wikipedia.org/wiki/Interstellar_travel) OK, so we’re talking centuries now, not the M/B species. Fine. Again though, let’s think through the motives in this hypothetical. The resources to accelerate tens of thousands of tonnes of material (and you’d certainly need at least tens of thousands, for an army + settlement + journey) to .1c…already you’re talking incredible amounts of energy, maybe more energy than the whole human race has harnessed to date. Similarly incredible amounts of resources… And probably techs like nanotechnology, genetic engineering, artificial intelligence etc will have advanced unimaginably. Already this sounds like a society that has little to gain from invading sol’s third tiny ball of rock, let alone how far their goals will be from the Conquistador analogy. > [@](#): > > Now, to create a star you need mass, or H as you say. Incredible amounts of it. I have no idea how your advanced civilization could possible put it together without some serious industrial accidents - but even more to the point where, pray tell, are they going to get it. Remember, this is your M/B y.o. species again. So for where they’ll get the H from, yeah that is a toughie, as it is only the most abundant material in the universe. I mean, it’s not going to take long for them to use all the hydrogen in a nebula millions of times the size of the solar system, and then what? ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [April 27, 2010, 4:31pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/109 "2010-04-27T16:31:13Z")
> [@This\_Just\_In\_2](#): > > They will probably be so different from us that they will be unable to communicate well with us (if at all). Their logical course of action would be to kill any possible threats including humans. So different to us that we won’t be able to communicate, but so like us that we can extrapolate our behaviour (or at least just our negative behaviours) to them. Gotcha. ---
**Author:** ![This\_Just\_In\_2](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@This\_Just\_In\_2](https://boards.straightdope.com/u/This_Just_In_2)\ **Post date:** [April 27, 2010, 4:53pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/110 "2010-04-27T16:53:21Z")
> [@Mijin](#): > > I wasn’t talking about “advanced aliens”. I was talking specifically about _your_ hypothetical species that was “millions or billions” of years advanced. Point of fact - the universe has been around at least 10 billion years or more. If I can take the liberty of assuming an ‘advanced’ species is one that has discovered radio and is able to transmit and communicate off-world, then we can say humans have been advanced for roughly 100 years or so. Now, if we ever meet an alien species the statistical likelihood is that they are not likely to be on the same evolutionary stage that we are. An alien isn’t likely going to say - oh yeah, we discovered radio about a hundred years ago too. The odds that our paths would be so close are really small. No, statistically, an alien that communicates with us is going to have been advanced far longer than earthlings. Probably for millions of years. Possibly billions. > [@Mijin](#): > > Remember, this is your M/B y.o. species again. > So for where they’ll get the H from, yeah that is a toughie, as it is only the most abundant material in the universe. > I mean, it’s not going to take long for them to use all the hydrogen in a nebula millions of times the size of the solar system, and then what? Just because H is ‘abundant’ in the universe doesn’t mean you can collect it easily. The H is scattered everywhere over vast distances - even within a nebula. Do you understand how large a nebula is? Take the Crab Nebula - it is a supernova remnant and it is 11 lights years in diameter. So, your advanced aliens are going to fly around all throughout a nebula and collect all of the H and put it together and create a new star? It is 11 light years just to fly across the thing! And you serioiusly think this is easier, than say, flying to a different star. From Sol, it is 4.2 light years to proxima centauri. So I maintain that it is magnitudes easier to fly to a different star - than collect enough H from nebulas/etc to create a new star. ---
**Author:** ![This\_Just\_In\_2](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@This\_Just\_In\_2](https://boards.straightdope.com/u/This_Just_In_2)\ **Post date:** [April 27, 2010, 5:07pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/111 "2010-04-27T17:07:20Z")
> [@Mijin](#): > > So different to us that we won’t be able to communicate, but so like us that we can extrapolate our behaviour (or at least just our negative behaviours) to them. Gotcha. What you don’t get is that the only concievable purpose for an alien going to the extreme expense of flying to another planet like ours is to establish another colony. Another ‘egg’ in the basket so that they can hedge against the likelihood that their species would die off through an extinction event. Once they are here - we are just in their way. ---
**Author:** ![levdrakon](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@levdrakon](https://boards.straightdope.com/u/levdrakon)\ **Post date:** [April 27, 2010, 5:10pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/112 "2010-04-27T17:10:20Z")
> [@msmith537](#): > > Sort of like the Aztecs and the Spanish conqusitadors? Or the Native Americans and the Europeans? Or the aboriginal Austrialians and the Brittish? I don’t know if being similar to us sweatens the deal. Not sure what that’s got to do with it, but if you’re starving for a contemporary analogy, whatever happened to that US-Russia-China global nuclear war? Oh yeah, didn’t happen. Instead, Russians and Americans give each other rides on spaceships and hang out on the ISS telling jokes and making videos for the kiddies and even China is publicly looking forward to an age of multinational space cooperation. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [April 27, 2010, 5:13pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/113 "2010-04-27T17:13:24Z")
> [@Mangetout](#): > > The fact that c represents an absolute limit in our universe is not a gulf in our knowledge, it’s the sumnation of it. If we’re wrong about that, we have to be wrong about a whole load of other things too. _c_ is not “an absolute limit in our universe,”; it is merely the fastest speed that light can propagate in a “ground state” vacuum, and thus, represents a limit on the causal connectiveness of two points in spacetime via a geodesic curve (a straight line mapped onto a Schwarzschild metric). It is, within the framework of special and general relativity, entirely possible for information or objects to go from Point A to Point B at a rate greater than _c_, either by changing the vacuum state of the underlying plenum of spacetime (stretching it out as in the Casimir effect and the Alcubierre metric), dragging the information or object along with spacetime (Hubble expansion, relativistic frame dragging), or creating a manifold connection that goes around normal spacetime (wormholes). All of these are possible within the framework of general relativity, and it is possible that a unified theory of everything may provide a means by which connectivity between distant points seen in quantum phenomena is realizable on a macro scale. Whether any of these phenomena can be actualized into a practical system of transportation is far beyond our current state of the art and would almost certainly take energy levels that are literally astronomical, but it is inaccurate to say that _c_ is the “fastest speed” anyone can ever possibly go. As for the aliens, I find it unlikely that they’ll come for our women, desire to serve us up for dinner, enslave us to work in their mines, feast upon our material resources like locusts, or any of the other standard sci-fi scenarios. No do I think that it is particularly likely that they would intentionally wage war upon us, or if they did, that there is any effective way that we could repel a species capable of interstellar transit. I find it much more likely that we would barely have a basis for communication, and it is entirely possible that they wouldn’t even regard us as being more intelligent than we consider cockroaches. It is almost certain that they would have no appreciation for our cultural values and arts, and even in more rigorous areas like mathematics and logic their approach is likely to be so different that there may be no basis for communicating basic concepts. In short, we’d have better luck trying to figure out what the dolphins are trying to tell us with their complex sequence of squeaks, chirps, and acrobatic tricks. Stranger ---
**Author:** ![ivan\_astikov](https://avatars.discourse-cdn.com/v4/letter/i/58f4c7/32.png) [@ivan\_astikov](https://boards.straightdope.com/u/ivan_astikov)\ **Post date:** [April 27, 2010, 6:51pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/114 "2010-04-27T18:51:06Z")
Humans don’t seem to have had a great deal of trouble communicating their intentions or needs to several animal species, and we haven’t even had to threaten some of them. Why shouldn’t an advanced alien species be able to teach us a few basic “commands” and tricks? ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [April 27, 2010, 7:10pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/115 "2010-04-27T19:10:37Z")
> [@levdrakon](#): > > Not sure what that’s got to do with it, but if you’re starving for a contemporary analogy, whatever happened to that US-Russia-China global nuclear war? Oh yeah, didn’t happen. Instead, Russians and Americans give each other rides on spaceships and hang out on the ISS telling jokes and making videos for the kiddies and even China is publicly looking forward to an age of multinational space cooperation. Really? You aren’t sure what that has to do with it?😕 What it “has to do with” is two civilizations of disperate technological levels coming into contact with each other. Here on Earth, what has historically happened is that when push comes to shove, the stronger and more advanced civilization gets to impose their agenda over the other. The reason that didn’t happen with the Cold War is that for all intents and purposes, Russia and the US are at the same level of technology. And as both civilizations are trapped on the same planet, neither wanted to engage in a war which would ultimately destroy them both. A space-faring civiliation would be under no such restraint. They could simply nuke us from orbit (because it is the only way to be sure), or beam their death rays at our cities and we would be unable to respond in any meaningful way or simply ignore us as they grind up the Earth to build a Dyson Sphere around our sun. Even assuming they don’t feel like causing our extermination intentionally or through indifference, and assuming we can actually communicate with them, it stands to reason that they would be here for their interests and not ours. Interestingly, people always assume that a race of aliens would be more intelligent than ours. I think it would be amusing if they were a race of fat dumbasses like out of Idiocracy or Wall-E. Flying in mostly automated, self maintaining ships they no longer know how to build or repair where basically a child can point to Earth and press a giant red button that says “go here”. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [April 27, 2010, 8:12pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/116 "2010-04-27T20:12:48Z")
> [@This\_Just\_In\_2](#): > > What you don’t get is that the only concievable purpose for an alien going to the extreme expense of flying to another planet like ours is to establish another colony. Disagree. The only value planet earth has is its unique (we would assume) species and culture. If a hypothetical extraterrestrial race is anything like us, this may be reason to visit. Nuke earth OTOH and you destroy pretty much everything that gives the planet any value. ---
**Author:** ![This\_Just\_In\_2](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@This\_Just\_In\_2](https://boards.straightdope.com/u/This_Just_In_2)\ **Post date:** [April 27, 2010, 8:27pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/117 "2010-04-27T20:27:54Z")
> [@Mijin](#): > > The only value planet earth has is its unique (we would assume) species and culture. Valuable to who? Do we value the dolphins culture? Why would aliens care about ours? > [@Mijin](#): > > If a hypothetical extraterrestrial race is anything like us, this may be reason to visit. Perhaps it is enough reason to send an interstellar probe, but not to visit. > [@Mijin](#): > > Nuke earth OTOH and you destroy pretty much everything that gives the planet any value. Most of what we think of as the ‘Earth’ will recover from a nuclear attack and nuclear winters within years. In fact, after 30 years I’d bet nature would be doing much much better as a whole since us pollution spewing humans will be gone. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [April 27, 2010, 8:30pm UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/118 "2010-04-27T20:30:54Z")
> [@Stranger\_On\_A\_Train](#): > > _c_ is not “an absolute limit in our universe,”; it is merely the fastest speed that light can propagate in a “ground state” vacuum, and thus, represents a limit on the causal connectiveness of two points in spacetime via a geodesic curve (a straight line mapped onto a Schwarzschild metric). It is, within the framework of special and general relativity, entirely possible for information or objects to go from Point A to Point B at a rate greater than _c_, either by changing the vacuum state of the underlying plenum of spacetime (stretching it out as in the Casimir effect and the Alcubierre metric), dragging the information or object along with spacetime (Hubble expansion, relativistic frame dragging), or creating a manifold connection that goes around normal spacetime (wormholes). All of these are possible within the framework of general relativity, and it is possible that a unified theory of everything may provide a means by which connectivity between distant points seen in quantum phenomena is realizable on a macro scale. Whether any of these phenomena can be actualized into a practical system of transportation is far beyond our current state of the art and would almost certainly take energy levels that are literally astronomical, but it is inaccurate to say that _c_ is the “fastest speed” anyone can ever possibly go. I’ll stand corrected by your clearly superior knowledge here - except I think this still means FTL travel will never happen for anyone, so it wouldn’t be reasonable to just assume that aliens have it. ---
**Author:** ![Yumblie](https://avatars.discourse-cdn.com/v4/letter/y/76d3ee/32.png) [@Yumblie](https://boards.straightdope.com/u/Yumblie)\ **Post date:** [April 28, 2010, 3:57am UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/119 "2010-04-28T03:57:52Z")
A lot of scenarios involving aliens killing us and taking over our planet are under the assumption that Earth would be hospitable for them. Earth is in the “habitable zone” but that doesn’t mean _any_ kind of life can survive here. Earth has gone through different climates and biospheres throughout its lifetime, and many species that existed in past climates would die if exposed to today’s climate, and vice versa. So the aliens could terraform Earth to suit their needs, except if they have the capability to do that, they could just do Venus or Mars (or even one of the Jovian moons) instead. ---
**Author:** ![jasg](https://avatars.discourse-cdn.com/v4/letter/j/f0a364/32.png) [@jasg](https://boards.straightdope.com/u/jasg)\ **Post date:** [April 29, 2010, 1:07am UTC](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364/120 "2010-04-29T01:07:51Z")
> [@Mijin](#): > > If we were to find a new continent tomorrow, with it’s own native human population, I doubt we’d handle things the same way today. > So already things are different, just a few hundred years later and without changes to our genetics. I believe that there are some tribes in the Amazon Basin that would disagree. [Previous page](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364.md?page=5) [Next page](https://boards.straightdope.com/t/we-finally-receive-a-message-from-space-indicating-intelligence-do-we-respond-s-hawking-says-no/537364.md?page=7)