Where do you look for E.T.? My paper on just that published in Acta Astronautica

 

Published in Acta Astronautica June 2025, open access till end July

Can there be any answer to that question that makes sense? We’ve been looking since the 1950s but ‘Space is big, really big…’ One answer is to consider from the problem that Schelling posed: “if you have to meet someone in New York City tomorrow but can’t communicate, what is your best option on where to go?” That’s a Schelling Point, one that both you and the person you hope to meet could mutually guess. (The most likely answer back in the ‘50s was the viewing deck of the Empire State building.

But in space? Now you have to consider whether you’re dealing with Apes, Angels or Men. Don’t write off the  Apes; they just need time to – bang the rocks together? – and then they’ll be as good as us and probably behave like us, so time is the only barrier. But we can write off Angels because they’re not here. Something may prevent species like ours ever becoming omnipresent and omnipotent in our own galaxy. So if we limit our search for ‘people like us’ who are limited to power sources we can pretty much scope out – fusion power and fusion drives – then the BIGNESS OF SPACE becomes the limiting factor, and this includes how far a transmitter can signal and be picked up by the sort of tech we can imagine.

It would help, wouldn’t it? to have a unique place that everyone knew about to go look for signals. The only location that has been proposed hitherto is the galactic centre. Unfortunately, it’s a very nasty place! In addition to the super-monstrous black hole SgrA*, there are (by x-ray observation) probably a million stellar-mass black holes flitting around it. Even a space captain of Luke Skywalker’s skill would need all his time and energy dodging problems, let alone set up a beacon. In the very long timescales for a beacon to be of any use, even stars aren’t safe as they can be ejected by the black hole. Need somewhere quieter. In the AMiTe Treffpunkt section of this blog, I proposed the AMiTe point mid-way between the Milky Way and Andromeda galaxies, a great place for chains of starships to thread through and exchange information, but way too far for a beacon to signal with any reasonable chance of refuelling. However, there was another point in that paper also defined by Local Group geometries, the ‘MiM’ (mid-Magellanic) point. At the suggestion of Mike Garrett, academic director of Jodrell Bank, I expanded that idea into a paper. I’m pleased to say that it was accepted for publication by the prestigious Acta Astronautica. Sadly, as I wasn’t funded for the work and ‘Open Access’ is very expensive if not backed up by an institution, it will only be available until end July for free, and then will go behind a pay wall (these guys have to make money too!). For now you can see it at:

https://authors.elsevier.com/a/1lFAPLWHGBKg- 

Picture credit: Elsevier, used with permission

Happy Birthday to Brian Cox: Who I Hope is Wrong

 

The Glories of the Southern Skies

I just have to say Happy Birthday to physicist and musician, fellow Irksider and also 3^rd o’March baby Brian Cox. That’s probably the end of the resemblance but not bad for an intro. Actually, we share that birthday with WW1 poet Edward Thomas who wrote a rather good poem celebrating the day, so a present for all 3/3ers (inc. my mate Eddie).

I’ve just listened to the first of the new series of The Infinite Monkey Cage Southern Skies recorded in Sydney – the lucky lot. And lots of rubbing-it-in about the ‘Majesty of the Southern Sky’ versus our “arse-end-of-the-galaxy” view from points Northern (Robin Ince on poetic form, there).

Charles Darwin clearly agreed: “Amongst the other most remarkable spectacles, which we have beheld, may be ranked, — the stars of the Southern hemisphere…” (BeagleDiaries). Here’s an image from my setting of those words for chorus/orchestra. I’ll post a clip of the music at a later date.

 

"We Beheld the Stars"

The main reason Brain (typo, but why correct it?), Robin & astrophysicist guests gave for the superiority of the Southern Skies was the view of the Galactic Centre, the star lanes and darker dust lanes between them. And lurking in the middle… “Almost every galaxy has a Super-Massive Black Hole” said Devika Kamath. “I recommend looking at it from a far distance” was sensible advice from Kirsten Banks. A terrible place, by the way, for a galactic meeting place for technologically advanced civilisations. @AstroKirsten gave some nice stories from Australian First Nation star-lore. At one point, she interjected, “You’re right, Brian, but not all the time”.

Fair Enough. One thing where I hope Brian is wrong (or, scientifically speaking, a test could be proposed which may show his conjecture to be wrong) is the following. In another, epoch-defining IMC, episode ‘UFO Special’, broadcast 17/2/20, Dr. Maggie Aderin-Pocock set up the question with, “If civilisations don’t overlap, we will never meet the aliens.” Brian replied, “The question is how close the nearest civilisation (is at present); I think the answer may be outside the Milky Way and therefore forever inaccessible.”

Thereby giving me a good steer in the right direction for my lock-down project, ‘how an engineer would find the Aliens.’ Rule 1 in engineering is ‘relax the constraints to make the challenge easier’. If you want to find a needle in a haystack, and you have the chance to remove the haystack, you might find the job easier (other things being equal). I’ve written about a better place to look in this blog and in the referenced paper. If you have the time (about 20MY).

But there may be an even better place to look, if you’re a bit impatient. And only those lucky ‘beholders of the Southern Stars’ can gaze up there (but I recommend a Space-based observation, for about a hundred years). Can you spot it in the map above? I will write further about the target at another time.

Happy 3/3:

“Here again (she said) is March the third
And twelve hours singing for the bird
'Twixt dawn and dusk, from half past six
To half past six, never unheard.” 

Edward Thomas (d. April 1917, Arras)

Picture credits:

Music: “Remarkable Sights” copyright DFG

Bridge of a Million Starships – for Arthur C. Clarke’s birthday

 

Needs another thousand years development but recent advances in fusion seem promising

I posted on 1^st December on just about the only definable (and safe!) point in space that all our intelligent neighbours - of ~1.4Trillion star systems - could be expected to agree on: the mid-point between the Andromeda and Milky Way galaxies, the ‘AMiTe point’ (see the post for where to find this in the sky).

The inhuman, monstrous-awful distances and timescales to get there recalls Blaise Pascal:

“Nature is an infinite sphere whose centre is everywhere and whose circumference is nowhere…  I feel engulfed in the infinite immensity of spaces whereof I know nothing, and which know nothing of me.”

The great science-fiction authors weren’t daunted by such difficulties. One of them, Olaf Stapledon, even gave us the adjective ‘Stapledonic’ for concepts on the very largest scale (the word is now practically ungoogleable, returning one broken link and one unsafe site). But the greatest of all, and a good engineer to boot, was Arthur C. Clarke, inventor of the geo-synchronous orbit for communication satellites, whose 105^th birthday it would be today. Boy, did he do immensity.

The journey of an intelligent species – all the way “from Apes to Angels” – is the background to 2001: A Space Odyssey, perhaps the grandest of all journeys. I’m not sure we’ll ever get to the Angel stage, but we’ve come such a long way and have further to go. A vast time dimension is the backdrop to The City and the Stars which takes place “two and a half billion years from the present - ten rotations of the Galaxy”. Humanity has, sort of, reached an end-point but could there be a chance for ‘rebirth’? (a cyclic view similar to mine). There’s a good jaunt to the Centre of the Galaxy, needing a faster-than-light space-drive, which adds distance (and emptiness…) to the picture but in the end it’s the renewal of the human race which will be the imperative. But the real immensities of distance and time – for spaceships obeying the unbreakable, unshakeable velocity limit of c – are best conveyed in Rendezvous with Rama (ignoring sequels). The mystery, “that chilling touch of the alien, the not-quite-knowable*,” of the apparently uninhabited ‘worldship’ of Rama passing through the Solar System remains unbroken at the end - but one conclusion that protagonists and readers can make with certainty is that Rama is one of a chain of similar ships, at least three! Another will follow in seventy years’ time.

I like this vision of chains of ships. If you are going the immense distance to the AMiTe point (see post of 1^st Dec and the AMiTe page on this blog), then being part of a chain means you can get the signal back. A million starships, spaced at 4 light-years apart, would give you a very good chance of interacting with a similar chain coming the other way ‘antiparallel’, or parallel - originating from somewhere else in the Milky Way. See the paper for the maths and rationale of 4.19 light year and 59 year launch separation. Is a million a big number? Not when you consider the >200 million SUVs in the world, and especially if you have several 10’s of millions of years – short by Clarke’s timescale in The City and the Stars. Clarke lived a long time (1917-2008) but didn’t expect to see things like a Space Elevator with his own eyes; he wouldn’t mind taking the long view.

But I think he would like to look up to that fuzzy blob of M31, the right-hand edge (edge closest to Sagittarius) and wonder just how many lines-of-a-million-starships, each originating from a different solar system, are threading their way to, and through, that ‘empty’ region of space. Could be quite a buzz there.

Picture credit IMDb under ‘non-commercial’ license.

*John Leonard, New York Times

Observing the AMiTe Point: busiest point in the (Local) Universe?

 

"The Most Exclusive Address in the Local Group", right hand edge of M31 core

At the date of posting, 1^st December 2022, the Northern Sky is a fine sight (no street-lights in our village). The waxing Moon has proceeded along the ecliptic from Saturn, is now passing Jupiter and, via the two bright stars of Aries, is on its way to join Mars for Opposition on 7^th December (‘Opposition’, for planets further away from the Sun than us is, just like the full of the Moon, getting in line with us and the Sun). When the Moon’s light is out of the way, then it’s a good time to look up and locate the point in space with the highest likelihood, selon-moi, of the presence of Alien civilisations in the known universe.

This blog, with its starry header, indulges my twin fascinations for the origin of life, human‘n’all (via the celebration of music related to Charles Darwin and DNA including my own composition, performed at both Oxford/Cambridge Universities), with a possible far future for humans, which is at least an entertaining one.

On ‘8-Billion Day’ (15^th November 2022), I posted an article suggesting a very unorthodox view of future population first published in my ‘AMiTe Paper') – or see the separate page in this blog. This came out of my lockdown musing of ‘how to meet the Aliens’ and neatly gets the humans out of the picture for a few million years. (Don’t worry: “We Shall Return!”)

The AMiTe paper is all about how, practically, with currently envisaged technology, an engineer from any technical (sorry! no super-dolphins!) civilisation, with our level of vanity - might try to crack the problem. A difficulty, of course, is for everyone in the galaxy to agree to meet at the same place when you can’t talk to them first (the ‘Schelling Point’ problem). The answer, funnily enough, and ‘proving Brian Cox wrong’ (in a way), is almost certainly for robotic ships to meet outside the galaxy (Martin Rees should approve, leaving it to the robots).

Just above Aries (see map) is the long line of bright stars connecting the Square of Pegasus with Perseus and his bright ‘Sword Handle’ double-cluster, the three middle stars being ‘Andromeda’. You may well have observed the farthest-you-can-see-with-the-naked-eye Andromeda galaxy, at 2.54 Million light years distance and 2.54 Million years ago. You go up from the central star Mirach (‘Girdle’), do a little shimmy to the right and the cloudy smudge is it. Or rather, it’s the bright central part of a monster galaxy of a trillion stars. The lovely spiral stuff covers a much bigger extent – about 6 full-moons in breadth – but is just beyond the grasp of eyes which also have to cope with the daylight Sun. It's our Milky Way’s biggg sister (we’re the middle-weight of three). Just in line with the right hand edge of the smudge (to our line of sight) is the most exclusive address in the Local Group – the mid-point of the two galaxies, the AMiTe point, Andromeda/Milky-Way Treffpunkt (‘meeting point’, see the paper for why). The beautiful thing is that every intelligent race in the trillion stars of Andromeda and the four hundred billion of our own spiral knows where it is…

I will write again on 16^th December, Arthur C. Clarke’s birthday, (which I hope he’d have appreciated) of a grand but tenuous ‘intergalactic bridge’…

Eight Billion on 15th November, extinct by 5,400C.E.?

 

"Just your friends making reasonable choices"

The UN has named Tuesday as ‘Eight Billion Day’, see: 8 Billion Day 15 Nov 2022 - Population Matters. Clearly this is the forcing function for all our environmental problems (proportional to ‘N’) and a good many of our wars.

The best response to 8bn is to spread a pointed message: “if you don’t like your first two children, have a third”, and have smart, humane tax and migration policies. But I’ll save practical suggestions for another time (it would include a bollock tax for individuals like Boris Johnson and… *see below!).

Demographers are now seriously considering ‘peak human’ and started to map out various scenarios of decline – but all far enough away not to affect current economics. An exception is Elon Musk* Elon Musk IsTotally Wrong About Population Collapse, who is dead right about the collapse but only worried because it spoils his dream about him being the enabler of humankind’s expansion out of the Solar System (he’s dead wrong about that, see AMiTe page on this blog).

But the collapse, yes. I started thinking about this twenty years ago after many years business in Japan.  With a female friend experiencing professional sexism and ‘expectations’ around marriage, and making some consequent choices, I was interested-but-not-surprised to learn of the very low Total Fertility Rate in Japan and Korea and also noted the low Western Europe rate of 1.6. I did a thought-experiment extrapolation at the time and have been banging on about “the human race dying out in 5,400CE due to lack of interest!” ever since. See the graph above which I published in a scientific paper in Feb 2021 (see AMiTe page for its unusual context and link to the full paper).

TFR = 1.6 might sound impersonal but think of it in the following way. How about where your friendship group of [ten] all pair up, let’s say for life; four couples have 2 kids each (or 3,2,2,1), and one couple just decides not to. Ten parents, eight kids. That’s TFR of 1.6, just by your friends’ choices. Sound familiar? Try your siblings & cousins as a check. Repeat for a few generations. TFR = 1.6 is also the average of OECD countries and 40 countries are at that rate or below.

Those thinking that something will turn to reverse this trend had better sharpen up their arguments; Matt Reynolds deals with it pretty well in the Wired article using France as an example. See also my personal French famille nombreuse discount card below from 1995, another failed government attempt to stimulate breeding. This population collapse is an example of ‘de-Darwinization’ – departure from Natural Selection – a phenomenon implicitly recognised by Charles Darwin and explicitly by Daniel Dennett: see From Bacteriato Bach and Back, eg p148. Darwinian evolution and de-Darwinization neatly link two of the subjects of this blog!

Since bringing a child into the world is now, or is becoming, pretty much a matter of absolute choice, the driving force is individual happiness in a modern (constrained) society rather than Natural Selection.  

But there’s plenty of time before my log graph reaches the ‘last humans’ – over 3,000 more seasons of the Premier League and Strictly Come Dancing. I included the population graph in the AMiTe paper to show that, while there isn’t likely to be time enough for humans to reach the Stars, there’s plenty of time to get the technology right to get the Stars to come to us.

My discount card from 1995 - valid for two children!