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TEDx Talks
Published: 2016-04-25
Source: https://www.youtube.com/watch?v=GyF9LLDL6-k
which I would also solve interesting question I think she's world the aliens %HESITATION which might I am a scientist hi I'm not crazy but I have to think maybe there so convince you that this is a worthwhile scientific question %HESITATION to ask I'm Bob think first of all we need to appreciate how big space is I think the best concert I ever heard was in the
hitchhiker's guide to the galaxy Douglas Adams that space was was big of thirty pick %HESITATION extremely bay we really don't know don't know how big it is but let's give it's could get a little a chance to understand that this is the song %HESITATION even occasionally spotted from here in Manchester %HESITATION both serve the song is about a hundred and fifty billion kilometers away %HESITATION which
is a bit hard to imagine it did the US is about twelve thousand kilometers across so hundred fifty million kilometers is a separate one of the things we tend to do you think about %HESITATION how long would it take to get some words we traveled certain spate %HESITATION so in this case the fastest we can probably the speed of light so that's about a at three
hundred thousand kilometers every second I know that speed of you get to the soul in about eight minutes so far when you look at the sold %HESITATION dot lights is taken night minutes to reach you which is you know hug the sorts of length of time you're in here listening to pop out of these talks are not too long %HESITATION was space is awfully big but
not if you go into our Milky Way galaxy of Milky Way galaxy has many songs many stop hundreds of billions of so you know if we should all the styles are inadequate between all the people on the earth we don't get about fifty H. basically sort of number of stars in Iowa Milky Way galaxy on the nearest of the stall %HESITATION to the sold out like
that's okay minutes to reach us from the sun it's on its way now when I started talking some like settle from the sun and it it'll get their behalf with get here that hopefully through this talk I'm if not like her puspa idea %HESITATION we waited for the light to get to the nearest told the star I would be sitting here listening to my talk of
for about four years %HESITATION so probably not the best thing to to be doing so for huge vast distances between the stalls across the whole of our Milky Way galaxy %HESITATION dot dot dot dot like we take a hundred thousand years to cross that with with those hundreds of millions of stars within a hot you don't picture there is is the galaxies now I will galaxies
the nearest big spiral galaxy to our own it's called the Andromeda galaxy %HESITATION six the nearest to the big lodge galaxy like the Milky Way %HESITATION on the light from the all stars that you see in the picture you can't you see this if you know what to look %HESITATION we can look into see the center of this galaxy just with a donated on you don't
need a little the blob don't like that you can see from the center of that galaxy %HESITATION takes two and a half million years to reach us the backing two and a half million years would you a galaxy like that so so so space is big and this is just the nearest to the galaxy I'm what about if it's all my life we're asking the question
at work where the aliens %HESITATION we need to probably ask a word of the planets %HESITATION weep we know we only know of one example of like so far like here on this want it so we know there are many stars we can see them shot and the night sky %HESITATION but it's very hard to see the planets so do the stars do these hundreds of
millions of startup plummet soul with him I do I'm a living in a very in a special time at the moment actually were %HESITATION twenty is the sole goal we found the first plan that opens in a new style like the song %HESITATION and I looked up what the number was a yesterday are on the new but now you is one thousand six hundred forty two
confirmed planets orbiting over styles %HESITATION so not just the ones we found by extrapolating not tools because now Milky Way we know there are billions and billions of planets in our Milky Way virtually every style you see in the night sky midnight sky will be altered by by planets because you got the question to both parties have life on the %HESITATION one of the key things
there is whether %HESITATION that they're too close to the star would be to halt so for example liquid Waltari something we think K. to life here here on earth the only example of like we have %HESITATION soul if you're too close to you so may be too hot not walls who would %HESITATION would put you would evaporate if you'd see far from you'll stop from your
soul and then %HESITATION then you would actually find that that water would freeze and so you wouldn't have the liquid waltz which we think would be essential for all the salt by chemistry to go on that keeps those are the ally was was to be a life to live lowest of life and death again looking at what we find in our Milky Way alone with these
you know %HESITATION one off I wasn't confirmed planet so far hope we know all the most be billions of so called habitable planets Justin I will Milky Way galaxy not in the I'm dramedy galaxy the one I just showed you this other callous and not in the %HESITATION no in the hundred billion all the galaxies that we can see in the observable universe just in our
own the most be billions of habitual pundits ten Chile habitable planets in other words ones though not to close the star not too hot not too far away not too cold so they got liquid will talk now how many Indians visited us who thinks aliens have visited the F. nobody's Turing's put the hounds help okay this Nabisco quite a lot people around the plot who do
believe Bailey the us and visit the us all the time indeed %HESITATION claimed to have met them but I don't think that's such a much good evidence for the we sort of an interesting question you might have done we've only you know we've only been around for a while you know modern humans have not been around for that long it's all in terms of the history
the plot that have just a few hundred thousand years %HESITATION so my aliens a visit to the us at some point well he's an interesting sort of a thing to think about and it's something we might we might do in the future which is to send out a fleet of wall called for Neuman probes the space probes and the you send off and they go out
to search all around all the stars to see what they can find around to the south we just discussed the fight and the stars are very far away even like takes of four years to reach chips that nearest over star %HESITATION I'm we count make things travel the speed of light the frosty spacecraft trouble at something like him a sixty thousand kilometers in that world outside
of Tulsa speed a small fraction of the speed of light so munching sending that one of the space probes his traveling up that's a fraction of the speed of light of dusk to solve speed we can we can send things out the moment it would take it you know maybe fifty thousand a hundred thousand years to reach the nearest of the star when he gets into
what it does is it self replicates so he gets the I'm maybe along the way it got this material adult material from the stuff between the stars maybe when he gets to the applauding around one of the stars of god has more material and it builds a copy of itself %HESITATION and then actually so spacecraft set off again and they head off in different directions and
you go to the next well the stars when they get the each of those self replicates and sends off again this is not sounds a bit like signs for it's possible to a much we would be able to do this in the how to get if you look at how long this takes you calculate how long you could actually explore the whole galaxy in less than
a hundred million years yeah to an astronomer outside is quite quick because of the earth is about five billion years old for a half billion years old phone half I wasn't million years this was less than a hundred million years you can speed up by making multiple copies of making the trouble of it fast so this is what she show all on the lifetime of a
planet like the author in the lifetime of the styles that are in the galaxy so if you imagine that the might be like one of these of the planets that might be doing this home one interesting question is word of the aliens if they had been a civilization before us that we're able to do this might they have done this might we about to be visited
by these fleets serve probably robot spacecraft self replicating and spreading through the galaxy we don't we don't see any evidence of hot button it's an interesting question would not be here for very long in the history the us this is something we should be looking for skull the Fermi paradox if aliens exist what were out there on because really this this is actually not too long
to populate the galaxy so how we gonna look for life and all the planets I'm well I'm one of the ways to look for intelligent life and I'm only gonna talk by intelligent life here %HESITATION not because of him we know all I'm the on the history of life on earth most most of that time life was %HESITATION T. real life is basically microbes the billions
of years before evolved into it's our animals or even intelligent like Lycos so home he may well be the bacterial life is common boy who were interested intelligent life if one of the conversation some of these aliens one of the ways we might do is buy used to read your telescope this is the one that children bank %HESITATION where I work the little telescope and this
is just a recalled in of the soul of signal we pickup without telescope full disclosure of the problem lies with the fall that who midmarket little bit bored just seems like this is just noise at what she read you away not case it was radio waves that can stop it exploded %HESITATION in about the year sixteen seventy has it happened but you know you can't really
hear what you just sounds like no worries if you were expecting to pick up a signal from aliens you probably expect something a bit more complicated than not signal the just talk the just thought noise and he is an example of something that was picked up not long after we stopped to think about using radio telescopes big ones like the the little telescope there in Georgia
was built in nineteen fifty seven so in the nineteen sixties we started to use these telescopes to look out for messages maybe more school type messages but we did not in not noise I'm just a few years off by nineteen sixty seven one of the signals was kept open here again is recalled in maybe that would telescope %HESITATION pointed to a particular direction in the sky
this is a bit of a surprise used to him and knowing that his it's clear the senior regular radio flock because I would be quite surprised not to go first I object to the point just a ballot can be cute seven not first %HESITATION thing was called a little green mountain wall hell GM while the calls it because they thought you know this is this is
possibly an alien signal we ought she now know the remnants of exploded stars the things call pulled saws very exotic objects that we use to test our understanding of physics and Einstein's %HESITATION theories of %HESITATION theories of ballots so no aliens APOP sadly by exciting for physics all that what do we do up with all the telescopes what we use telescopes like this one this is
the Arecibo telescope this is a a massive radio telescope the world's biggest radio telescope are missing a volley in Puerto Rico %HESITATION it's three hundred meters in diameter the mixing four times the size %HESITATION in diameter of the of the little telescope Ajanta bank a huge a telescope that's used up a lot of different things but one of the things it does is a project called
serendipity she might some of you might know a set he'll hold and you can download a screensaver feel computer and it will basically processed data looking for the source of extraterrestrial signals he picks up with the with the radio telescope might not want another radio telescope around the world to spin house done and is doing this sort of work eyes the green bank telescope this is
in West Virginia %HESITATION they so telescope is about a hundred meters in diameter these large telescopes collect lots of radio waves of they say you'll they feel like they hear very faint things %HESITATION coming from the distant universe and so these are the sorts of things we might be interesting using to pick up extraterrestrial signals and this one's been use to such Sharples look in the
direction of those planets that we that we know of a pox Telescopii arm is in Australia again of this telescope on the greenback telescope involved in a new project looking for the extraterrestrial signals called the breakthrough listen pro %HESITATION howling telescopes here in the UK we start a project with these telescopes a network of telescopes spread across the country between here and %HESITATION between children bank
are no waves Cambridge seven radio telescopes all connected by optical fibers link together trucks as one giant telescope when again among so few things were doing was started to look through those signals looking for essential I extraterrestrial signals what's coming in the future has an amazing telescope we design of the ball is called the square kilometre array is going to be built in southern Africa and
Australia it's good we made up of hundreds of dishes connected together until the types of aerials connected together how that will make a giant of the telescope who's who size is equivalent to a two hundred and twenty times the size of a little telescope juggle banking bill seat credibly a faint things in the universe pick up incredibly weak signals and in terms of looking for aliens
are in just one minute not telescope will be able to look for outlook every star in the direction it's pointing out to about three hundred light years away from us so the newest of the star was pull like is it will get three hundred light years away such in every star in just a minute for the salts of a strong signals that come from %HESITATION tools
the radar systems we use in our big telescopes so if there are aliens out there with the sort of technology and if those messages the signals coming our way this telescope is going to be an amazing facility for us to be able to attack those signals so my friend I count why can't do is give you the answer so my question the beginning which is where
all the aliens we we don't know we haven't detected aliens %HESITATION anywhere we do believe we do know there are potentially habitable planets that's a that's a fact that wasn't we didn't know about twenty years ago we know that now we have got the technology we will have the technology that is allowing us to search ever greater bits of Iowa %HESITATION galaxy searching for the source