The new ‘Thunderbirds’ – fab or fail? I know what I think…

There’s no getting around it. Just about every bloke of A Certain Age in Britain and its former Empire was brought up with Gerry Anderson’s TV sci-fi classic Thunderbirds. It was at once charming, cheesy, funny, serious and melodramatic, but also hip and very, very cool.

A photo I took of the Corgi Thunderbird 2 model I've had since forever... And it's not tilt-shift. This is what happens on a focal length of 190mm at f 5.6, natural light with exposure time of 1/100.

The Corgi Thunderbird 2 model I’ve had since forever… and yes, I KNOW Thunderbird 4 is a submarine.

Thunderbirds captured the imagination of virtually every kid who saw it when it came out in 1965 – whatever their age, for it also turned Anderson into a pop-culture sensation in Swinging Sixties London. The show’s iconic radio call-back line, ‘FAB’ – not an acronym but a reference to the pop-culture word – summed it up. For me the show was inspiring. Among my books are several on engineering. Guess what got me on to it.

One of my earliest memories of TV – snowy black-and-white, miraculous to a 4-year old me – is watching the ‘Mole’ wobble out of Thunderbird 2’s pod and burrow to the rescue with the help of its rear-mounted rockets. I mean, how cool (if impractical) is that? Not to mention the Thunderbird machines themselves, invented by the stuttering genius engineer ‘Brains’ (aka Hiram J Hackenbacker). In true 1960s style these were atomic powered super-planes.

My favourite was always Thunderbird 2, a forward-swept wing frog capable of 8000 kph. Then there were the marionettes with their big heads, because the solenoid moving their lips couldn’t be made smaller. Their bounce-walk got so embedded in pop-culture that, even a generation later, advertisers were able to subvert the clunkiness without fear of people not ‘getting’ the joke:

Into this flowed Airfix and Revell kit-bashing  curious hybrids of B-58 Hustlers, F-104 Starfighters, Saab Drakkens and so forth. The Mole was made up of bits of Atlas booster, B-58 Hustler and the Airfix railway truss bridge, all poised, like many Thunderbirds vehicles, atop a 1/16 Vickers Vigor tractor chassis. Just for the hell of it, here’s the real Vigor with its Christie-style suspension:

Atlas booster with Mercury MA-9 atop. NASA, public domain.

The Thunderbirds Mole. No – the Atlas booster for real. NASA, public domain.

One of the big appeals of Thunderbirds was its effects complexity. Vehicle suspension really worked – this in small scale, no less. The Tracy brothers entered their craft via complex sliding couches, couch-trolleys, extensible platforms and so on. Thunderbird 1 didn’t just take off. It ran down a conveyor belt for no apparent reason and only then blasted off from a hangar with a real-world lemon-squeezer glued to the wall, hurtling skywards via a sliding swimming pool (well, how else do you launch a VTOL swing-wing hypersonic aircraft?). And then there was Thunderbird 2 with its pivoting palm-tree runway.

The man behind it was Derek Meddings, whose SFX work was leading-edge for the day – so good that when Stanley Kubrick was looking for effects experts for 2001: A Space Odyssey, he called Anderson.

Then there was the ‘2065’ setting with its secrecy schtik – this last a feature in most of Anderson’s work, never explained logically, but very cool nonetheless. And that’s without Lady Penelope Creighton-Ward and her faithful butler, Aloysus Parker – the comedy turn, but what a character.

My favourite model. I've had this Dinky toy of it since I was a kid. For some reason, I've never tossed it out...

My favourite model…

There was always talk of a remake, but the problem was re-creating the charm of the original. When the first effort happened in 2004 – live-action – it was panned. Rightly, too. And now we have another remake. Made in my own city of Wellington by Pukeko Pictures, owned by Sir Richard Taylor. I was at a book launch late last year and spotted him in the group, but I didn’t manage to talk to him. A pity, I’d have liked to have had a chat.

So how’s he done? I guess everybody’ll have their opinion. As for me? Well, the double-length pilot reprised the main disaster of Lord Parker’s ‘Oliday, which was pretty cool. But it all ran at breakneck pace – there was no time to savour the settings or enjoy the story, as there had been in the more leisurely original. Inertia seemed to have disappeared, too – epitomised by Thunderbird 2, all 400 tonnes of it (or whatever an 80-metre long freighter aircraft is meant to weigh) flipping about as if it was a Dinky toy. The original – for all its cheesiness by today’s standards – conveyed a proper sense of momentum and inertia.

Plus side is that it’s embraced modern effects tech, blending it – subtly – with carefully chosen model-work. The sensibilities have moved on too. There was a lot about the original, including its 1930s-style “Oriental villain”, smoking, implicit sexism, and other period touches that are either unacceptable today, or meaningless to a modern audience. We’ll see where Tintin Kyrano’s reinvention as Tanusha ‘Kaya’ Kyrano, with her own special Thunderbird, goes as the series unfolds.

So yeah, it’s different, but they’ve nailed today’s entertainment needs the way Anderson nailed those of the 1960s. Anderson always was up-to-the-minute; so I suspect that, if Anderson was doing it today, and had access to today’s CGI, this is how he’d have done it too.

And did anybody notice – apart from quick-fire references to Hackenbacker and Meddings – the really specific Space 1999 Eagle command module in the first episode?

Copyright © Matthew Wright 2015

Why does everything taste of chicken, except chicken?

I’ve always had an interest in discovering the secrets of the universe – you know, does dark matter exist, why we can’t have antigravity – and why every weird steak from crocodile to ocelot always has to taste of chicken.

Gallus gallus domesticus on Rarotonga, looking very much like the Red Jungle Fowl (Gallus gallus).

Gallus gallus domesticus on Rarotonga, looking very much like the original Red Jungle Fowl (Gallus gallus).

This last has been puzzling me a lot. Not least because even chicken doesn’t taste of chicken. I found that out in 2012 when I spent a few days in Rarotonga. Over there, chickens run wild – as in, not just free range. Wild. We had one perching on our breakfast table several days in a row, hoping to be fed. They don’t get soaked in antibiotics. They don’t get imprisoned in horrible conditions before being lightly killed, dropped through a macerator, and re-constituted into Chicken Niblets. They are entirely natural. And when anybody wants chicken – let’s say to add to the khorma I bought in an Indian restaurant in Awarua – they go out and catch one.

That natural living means that Rarotongan chickens don’t taste like battery chickens. Actually, they don’t even look like battery chickens. They look more like what they actually were before humans got at them, Red Jungle Fowls, which – like every other bird – are actually a variety of flying dinosaur. Recently a geneticist even found out how to switch on the gene that makes chickens grow dino-jaws instead of a beak, a discovery welcomed by other geneticists with loud cries of ‘nooooooo!’ and similar endorsements.

Here's the diorama - Velicoraptor mongoliensis, Dilong paradoxus, and, off to the right - yup, their close relative, Gallus Gallus. A chicken.

Think birds aren’t dinosaurs? Here’s Velicoraptor mongoliensis, Dilong paradoxus, and, off to the right – yup, their close relative, our friend Gallus Gallus domesticus.

I conclude from all of this that (a) what we call ‘chicken’ doesn’t actually taste of chicken; and (b) if I’m to define ‘tastes of chicken’, I should be thinking of Rarotongan chickens. And I have to say that of all the unusual stuff I’ve eaten over the years, few of them taste of it. For instance:

1. Snail (restaurant in Paris, Rue de Lafayette). These don’t taste of chicken. They taste of garlic flavoured rubber bands.
2. Ostrich (dinner to mark release of one of my books). Definitely not chicken, but could have been confused for filet steak.
3. Something unidentifiable in rice (riverside in Kanchanburi) I know it was meat. It didn’t taste of chicken or, in fact, anything else. I ate it anyway.
4. Goat (my house). Absolutely not chicken. More like a sort of super-strong mutton.
5. Venison (my house). Reminiscent of liver.
6. Duck (my house). Bingo! Yes, this actually did taste of Rarotongan chicken. And duck.

I can only conclude, on this highly – er – scientific analysis, that very little actually tastes of chicken, including chicken. But I may be wrong. Have you ever eaten anything that was meant to taste of chicken – but didn’t?

Copyright © Matthew Wright 2015

Quantum physics just might become rainbow gravity

One of the biggest problems with quantum physics – apart from the way it attracts new age woo – is that it doesn’t reconcile with Einstein’s General Theory of Relativity. The two don’t meet when it comes to gravity. And so one of the major thrusts of physics since the 1940s has been to find that elusive ‘theory of everything’.

The COBE satellite map of the CMB. NASA, public domain, via Wikipedia.

The COBE satellite map of the Cosmic Microwave Background. NASA, public domain, via Wikipedia.

We shouldn’t suppose, of course, that it’s ‘Einstein vs the world’. Our friend Albert was also pivotal to the development of quantum physics – he published, for example, the first paper describing quantum entanglement in 1935.

But he didn’t like this ‘spooky action at a distance’. To Einstein, intuitively, there was something missing from what he and fellow physicists Paul Dirac, Werner Heisenberg, Niels Bohr and others were finding. The so-called Copenhagen interpretation of their observations – which remains the basis of quantum physics today – didn’t ring true. The effects were clear enough (in fact, today we’ve built computers that exploit them), but the explanation wasn’t right.

Einstein’s answer was that he and his colleagues hadn’t yet found everything. And for my money, if Einstein figured there was something yet to discover – well, the onus is on to look for it.

The problem is that, since then, we haven’t found that missing element. All kinds of efforts have been made to reconcile quantum physics – which operates on micro-scales, below a Planck length – with the deterministic macro-universe that Einstein’s General Theory of Relativity described.

None have been compelling, not least because while the math works out for some ideas – like string theory – there has been absolutely no proof that these answers really exist. And while it’s tempting to be drawn by the way the language we’re using (maths) works, we do need to know it’s describing something real.

The Horsehead nebula, Barnard 33, as seen by Hubble. Wonderful, wonderful imagery.

The Horsehead nebula, Barnard 33, as seen by Hubble. Wonderful, wonderful imagery.

Of late, though, there have been proposals that Einstein was quite right. There WAS something missing. Not only that, but the Large Hadron Collider has a good chance of finding it soon, as it’s ramped up to max power.

Here’s how it works. We live in a four-dimensional universe (movement up-down, left-right, forward-back and time). It’s possible other dimensions and universes exist – this is a postulate of string theory. Another idea is that gravity ‘leaks’ between these universes. And this is where the LHC comes in. Currently, in its souped-up new form, the LHC can generate enough energy to produce a micro-sized black hole.

Exactly what this would mean, though, is up for debate. The results could point to some very different models of the universe than the one we’ve been wrestling with since the 1940s.

It could mean that string theory is correct – and provide the first proof of it.

Or, if the black hole is formed while the LHC is running at specified energies, it could mean that ‘rainbow gravity’ is correct. This is a controversial hypothesis – built from Einstein’s theory of Special Relativity – in which the curvature of space-time (caused by the presence of mass) is also affected by the act of observing it. This implies that gravity (which is a function of that curvature) affects particles of different energies, differently. Basically, the wavelength of light (red) is affected differently than a higher (blue). We can’t detect the variance in normal Earth environments, but it should be detectable around a black hole. And if it’s true then – by implication – the Big Bang never happened, because the Big Bang is a function of the way gravity behaves in General Relativity. It also makes a lot of the paradoxes and mysteries associated with bleeding-edge physics go away, because according to rainbow gravity, space-time does not exist below a certain (Planck level) scale.

Another possibility is that the ability of the LHC to make black holes could mean that a ‘parallel universe’ theory is right, and the Copenhagen intepretation isn’t the right explanation for the ‘quantum’ effects we’re seeing. This last is yet another explanation for quantum effects. By this argument what we’re seeing is not weirdness at all, but merely ‘jittering’ at very small scales where multiple universes overlap. These are not the ‘multiple universes’ that Hugh Everett theorised to follow quantum wave function collapse. They are normal Einsteinian universes, where particles are behaving in a perfectly ordinary manner. The math, again, can be made to work out – and actually was, last year, at Griffith University in Queensland, Australia.

It also suggests that our friend Albert was right …again.

Copyright © Matthew Wright 2015

My gripe about the misappropriation of quantum physics by new age woo

A  few years ago I ended up consulting someone over a health matter. This guy seemed to be talking sense, until he started up about ‘quantum healing’. Bad move. You see, I ‘do’ physics.

Artwork by Plognark Creative Commons license

Artwork by Plognark Creative Commons license

One of his associates had a machine that used low voltage DC electricity to ‘heal’ by ‘quantum’ effects. This was gibberish, of course, and a brief discussion made clear that (a) the meaning of ‘quantum’ didn’t correlate with anything I knew from the work of Paul Dirac, Niels Bohr, Werner Heisenberg and the rest; and (b) invoking the word, alone, sufficed as a full explanation of how this ‘treatment’ worked.

It was, in short, total snake oil. The science is clear: quantum effects – the real ones – don’t work at macro-level. The end.

That’s why ‘quantum jumping’, ‘quantum healing’ and the rest is rubbish. I don’t doubt that ‘quantum healers’ occasionally get results. The placebo effect is well understood. And maybe sometimes they hit on something that does work. But it won’t be for the reasons they state.

Niels Bohr in 1922. Public domain, from Wikipedia.

Niels Bohr in 1922. Public domain, from Wikipedia.

The way quantum physics has been co-opted by new age woo is, I suppose, predictable. The real thing is completely alien to the deterministic world we live in. To help explain indeterminate ‘quantum’ principles, the original physicists offered deterministic metaphors (‘Schroedinger’s cat’) that have since been taken up as if they represented the actual workings of quantum physics.

From this emerged the misconception that the human mind is integral with the outcomes of quantum events, such as the collapse of wave functions. That’s a terribly egocentric view. Physics is more dispassionate; wave-functions resolve without human observation. Bohr pointed that out early on – the experimental outcome is NOT due to the presence of the observer.

What, then, is ‘quantum physics’? Basically, it is an attempt to explain the fact that, when we observe at extremely small scales, the universe appears ‘fuzzy’. The ‘quantum’ explanation for this fuzziness emerged in the first decades of the twentieth century from the work of Max Planck; and from a New Zealander, Ernest Rutherford, whose pioneering experiments with particle physics helped trigger a cascade of analysis. Experiments showed very odd things happening, such as pairs of particles appearing ‘entangled’, meaning they shared the same measurable properties despite being physically separated.This was described in 1935 by Einstein, Podolsky and Rosen – here’s their original paper.

Part of this boiled down to the fact that you can’t measure when the measuring tool is the same size as what you’re measuring. Despite attempts to re-describe measurement conceptually, then and since (e.g. Howard, 1994), this doesn’t seem to be possible at ‘quantum level’. That makes particles (aka ‘waves’) appear indeterminate.

Albert Einstein lecturing in 1921 - after he'd published both the Special and General Theories of Relativity. Public domain, via Wikimedia Commons.

Albert Einstein lecturing in 1921. Public domain, via Wikimedia Commons.

All this is lab stuff, and a long way from new age woo, but it’s what got people such as Einstein, Dirac, Heisenberg, Bohr and others thinking during the early twentieth century. From that emerged quantum physics – specifically, the Copenhagen interpretation, the accepted version of how it’s meant to work. And it does produce results – we’ve built computers that operate via the superposition-of-particle principle. They generate ‘qbits’, for instance, by holding ions in a Paul trap, which operates using radio-frequency AC current – not DC.

The thing is, quantum theory is incompatible with the macro-universe, which Albert Einstein explained in 1917. Yet his General Theory of Relativity has been proven right. Repeatedly. Every time, every test. He was even right about stuff that wasn’t discovered when he developed the theory. Most of us experience how right he was every day – you realise General Relativity makes GPS work properly? Orbiting GPS satellites have to account for relativistic frame-dragging or GPS couldn’t nail your phone’s location to a metre or so.

So far nobody has been able to resolve the dissonance between deterministic macro- and indeterminate-micro scales.  A ‘theory of everything’ has been elusive. Explanations have flowed into the abstract – for instance, deciding that reality consists of vibrating ‘strings’. But no observed proof has ever been found.

Lately, some physicists have been wondering. ‘Quantum’ effects work in the sense described – they’ve been tested. But is the ‘quantum’ explanation for those observations right? Right now there are several other potential explanations – some resurrected from old ideas – that will be tested when Large Hadron Collider starts running at full power. All these hypotheses suggest that Einstein was right to be sceptical about the Copenhagen interpretation, which he believed was incomplete.

These new (old) hypotheses make the need to reconcile Copenhagen-style quantum physics with Einstein’s relativistic macro-scale world go away. They also have the side effect of rendering new age ‘quantum’ invocations even more ridiculous. More soon.

Copyright © Matthew Wright 2015

A chat with Elvis about Nibiru and other woo

Every other Tuesday, Elvis* – who’s living on Mars disguised as a walrus – drops in for a burger from the slider joint just down the road, because nobody on Mars knows how to make a good one. This week, as we chowed down on Chicken Anchovy Supreme, I mentioned that somebody’d posted a comment on my blog about Scholz’s Star – the red dwarf that skidded past the solar system around 70,000 years ago.

Conceptual picture I made of a red dwarf with large companion using my trusty Celestia installation.

Conceptual picture I made of a red dwarf with large companion using my trusty Celestia installation.

By this guy’s proposal the star – sorry, ‘Nibiru’ – hosted a planet with intelligent life who’d come to Earth and coded secrets into our genes, and he pointed me to a website that – er – proved it.

Actually, when I looked at the site, it was filled with stuff about aliens – aka Sumerian gods – wanting to steal Earth’s gold in order to warm their planet. A prelude, I suppose, to the way aliens always wanted to steal women and water in the 1950s.

Elvis wasn’t worried. Between mouthfuls, he told me this sort of argument is common enough among the woo brigade. There’s no point trying to counter-argue using science because the people who peddle this stuff believe what they say as an act of their own faith in it and merely get angry if you question it.

I still thought science might offer something and pointed out that red dwarfs are the smallest and most innocuous looking stars ever, but they have an unfortunate habit of suddenly exploding into a wild fury. Their brightness can increase 400 times or more on the back of a major flare. They make our local solar flares, even the biggest, look feeble. And if you’re in the way of that licking – well, there you are, an innocent little cell just starting out on the evolutionary tree, and suddenly you get the world’s worst dose of radiation poisoning and die. Oops.  And before life can re-develop, the broken bits get radiated. And again…and again…and again…

Solar flare of 16 April 2012, captured by NASA's Solar Dynamics Observatory. Image is red because it wa captured at 304 Angstroms. (NASA/SDO, public domain).

Solar flare of 16 April 2012, captured by NASA’s Solar Dynamics Observatory. Image is red because it was captured at 304 Angstroms. (NASA/SDO, public domain).

That happened on early Earth, too, when our Sun was young and boisterous. Life didn’t start developing until after the Sun had stopped lashing us. Turns out that life needs a stable environment. Red dwarfs don’t offer one – ever. And that, I explained to Elvis, was quite apart from the fact that alien life is – well, alien. The chances of an alien planet producing a biota identical to ours is pretty low.

Not to mention that Scholz’s Star is orbited by a brown dwarf companion at the distance of Venus – a companion that has three-quarters the mass of the star, meaning they’re actually orbiting a mutual point in space where their gravitation balances, the barycentre. Planets could stably orbit the barycentre, providing they were further out again – but that would put them too far away to have human-type life on them.

And the other problem is the travel. Sure, Scholz’s Star came close by astronomical standards. But that’s the point. Astronomical. It never came closer than 0.82 light years. Yup, light – the fastest thing you can get – still took eight-tenths of a year to reach it. In everyday terms, that’s 7,800,000,000,000 kilometres. Woah! As I told Elvis, our fastest space probe, New Horizons, would take 16,000 years to cross that distance.

He nodded throughout. Obviously he didn’t dispute it. But I hadn’t addressed his basic point.

‘The problem,’ Elvis suddenly said, ‘is that as a species we humans suffer terrible delusions about self-importance.’

‘Don’t say that too loudly,’ I said ‘you’ll upset people.’

‘What do I care? I live on Mars.’ He crumpled his burger wrapper.

‘Tuesday week?’


Copyright © Matthew Wright 2015

*Well, he says he’s Elvis, anyway. But even if he’s AN Elvis (as I actually suspect) rather than THE Elvis, who cares? He talks sense, which isn’t bad for someone who lives on Mars most of the time and has to hide inside a walrus costume to avoid being mobbed by Elvis impersonator fans.

How Stephen Hawking reconciled the irreconcilable

I finally caught up with The Theory of Everything the other week – an awesome biopic about Stephen Hawking, the British physicist whose life’s goal is to find a theory – a single equation – that explains – well, everything. And what they didn’t mention in the movie is that he’s already made the first big discovery along that path.

The Horsehead nebula, Barnard 33, as seen by Hubble. Wonderful, wonderful imagery.

The Horsehead nebula, Barnard 33, as seen by Hubble. Wonderful, wonderful imagery.

Let me explain. There are two main theories of the universe. Albert Einstein’s ‘General Theory of Relativity’ of 1917 totally explains space-time – the macro-scale universe. Quantum physics, which emerged a little later at the hands of Paul Dirac, Max Planck, Neils Bohr and others, works brilliantly in the micro-world – specifically, scales around a Planck length (1.61619926 × 10-35  metres). But the two don’t play nicely together. Not at all.

So far, nobody’s been able to reconcile them – despite the profusion of hypotheses such as string theory, where the maths work out fine, but where nobody has been able to find any evidence to prove it. (I can’t help thinking this is why Sheldon is a string theorist…)

Finding a ‘theory of everything’ has long been Hawking’s goal; and with Jacob Bekenstein he was the first to discover a way in which both Einstein’s General Relativity and the Copenhagen interpretation of quantum physics could work together. They found that way in 1975, at the extreme edge of the possible – inside a black hole. Here’s Hawking’s original paper, ‘Particle Creation By Black Holes’ Commun. math. Phys. 43, 199—220 (1975).

A bit of explanation first. A ‘black hole’ is actually a ‘singularity’, a mathematical point where the curvature of space-time becomes infinite. The normal laws of space-time – the ones our friend Albert Einstein described – totally fail at that point. Even causality doesn’t apply. As Hawking once pointed out in a lecture, we can’t even imagine what might happen inside a singularity (he suggested a singularity could emit Cthulthu – it wouldn’t violate the laws of physics. I disagree. I can’t even pronounce Cthulthu. I think it would emit Sauron instead.)

Artists impression of a GRB. Zhang Whoosley, NASA, public domain, via Wikipedia.

Artists impression of a GRB. Zhang Whoosley, NASA, public domain, via Wikipedia.

Luckily for us, the everyday universe is shielded from singularities by the event horizon – the point where the escape velocity of the singularity exceeds light-speed. Stuff can fall in. But nothing gets out. Hence the term ‘black hole’. Hawking disputed that. Quantum theory states that particle pairs – positive and negative – are always appearing out of nowhere, then annihilating each other. It doesn’t violate thermodynamics because the net energy outcome is still zero. The effect is known as ‘quantum vacuum fluctuation’.

What I’m about to describe is the heuristic overview – the physics of it is complex and involves some mind-exploding mathematics (‘Bogoliubov transformations’). Basically, Hawking reasoned that if a quantum vacuum fluctuation occurred on the event horizon, there was a chance that one particle, the negative, would be drawn in while the other escaped. They couldn’t annihilate each other, because nothing can escape the horizon. Being negative, the falling particle would reduce the mass of the black hole. Meanwhile the positive particle would escape – effectively as heat – from the black hole.

The result was that ‘black holes’ weren’t actually the black dead ends previously imagined. They were glowing. And they’d eventually evaporate. And THAT is Hawking Radiation.

This also meant that black holes had life limits, and while larger-mass holes had lifespans measured in billions of years, small ones would disappear quickly – which, incidentally, is why nobody’s worried about forming one with a few tens of particles in the Large Hadron Collider at CERN, which is about to be deployed at full power for the first time this year. It’d evaporate in way less than a microsecond. And so Hawking showed that, yes – at least in this extreme case – quantum physics and Einsteinian determinism could play nicely together.

The next question was whether the two could be reconciled in more everyday terms. And that’s been the stalling point. But if anybody can solve it – well, I figure it’ll be Hawking.

Copyright © Matthew Wright 2015

Getting winked at by a mystery star! Really

The latest wow-find from astronomers has snuck up on us by stealth. A small red dwarf star discovered in November 2013 by German astronomer Ralf-Dieter Scholz looked, first off, to be pretty ordinary.

Conceptual picture I made of a red dwarf with large companion using my trusty Celestia installation.

Conceptual picture I made of a red dwarf with companion using my trusty Celestia installation.

It even had a boring name: WISE J072003.20−084651.2, courtesy of being found lurking in data collected by the WISE Satellite. It is estimated to be 19.6 light years distant – in our neighbourhood, as stars go, but not exceptionally close. It has around 86 times the mass of Jupiter, making it a M9.5 class red dwarf, one of the smallest possible.

It is orbited – at the equivalent distance of Venus – by a ‘brown dwarf’ companion, a body with 65 times the mass of Jupiter. This world is warmed to near-luminescence by gravitational compression and – potentially – deuterium fusion, but isn’t massive enough to trigger hydrogen-1 fusion and light up like its star.

Yawn. Red dwarfs are the most common stars around. Proxima Centauri, the closest star to the Sun, is a prime example. In fact, of the 60 stars known within 16.3 light years, 46 are red dwarfs. We’re finding lots in our neighbourhood lately because many are so cool and dim – by stellar standards – they’re invisible even to high-powered telescopes. It takes satellites with sensitive infra-red detectors to pick them up. Brown dwarfs are also appearing to these instruments – singly, or orbiting stars that (wait for it) are often red dwarfs.

Since 2013, though, Scholz’s Star has rung alarm bells. First was its proper motion – the way it tracked tangentially across the sky, relative to other stars. Eric Mamajek of the University of Rochester in New York led a team looking into that, using data collected by the South African Large Telescope and the Las Campanas Observatory’s Magellan telescope in South America. They discovered the proper motion was very slow. But the star itself had very high radial velocity – its actual speed. Around 83 kilometres a second, in fact – four times the usual velocity of stars in this part of the galaxy.

This added up to a star that was travelling fast – but which from our viewpoint didn’t appear to be moving. That’s no paradox – imagine you’re looking up a straight road at a car disappearing into the distance. It’s moving fast, but from where you’re standing, it isn’t moving left or right (‘proper motion’). That’s because it’s moving directly away – and that’s true of Scholz’s Star.

Comparison between stars and brown dwarfs. Not strictly to scale. Public domain, NASA/JPL/Caltech.

Comparison between stars and brown dwarfs. Not strictly to scale. Public domain, NASA/JPL/Caltech.

Mamajek and his team ran 10,000 mathematical simulations to find out how close it had been. And – just announced this month – they discovered that, some 70,000 years ago, Scholz’s Star skimmed past our solar system. With a closest approach of just 0.82 light years – some 52,000 times the distance of Earth from the Sun – it banged through the outer fringes of the Oort cloud, the icy cloud of debris left over from the formation of our solar system, which extends out to a light year or so.

The star was far too small and far too distant to affect the orbits of the Sun’s planets. Here on Earth, the Moon has 2,000,000,000,000,000 times the tidal effect exerted by Scholz’s Star at closest approach. But it will have perturbed some of the the ice-and-dirt clusters of the Oort cloud.  Passing stars are thought to do this every so often, and it’s thought that Scholz’s Star was far from the most serious. Some material will probably have been lobbed sunwards, and will still be on their way in – meaning there will be a small scattering of comets arriving in about 2,000,000 years. Yah, we’re talking about astronomy here – which means having a barrel full of zeroes by your desk.

Did ancient humans see the star? If we draw a circle around the Sun at 100,000 times Earth’s distance and plot Scholz’s Star’s path through it, we find the star took around 10,000 years to traverse that line. Back then it had huge ‘proper motion’ by stellar standards – enough to move across the sky by the angular width of the full Moon in 26 years.

But even at closest approach Scholz’s Star would have been around 11.8 magnitude and thus utterly invisible to the naked eye. But the thing about red dwarfs is that they’re often magnetically unstable – and emit huge flares. In some cases that can increase the brightness of the star, briefly, about 400 times. That would have been enough to make it visible as it tracked through our skies – intermittently. The jury’s out on Scholz’s Star, but Mamajek has speculated that it probably did flare regularly.

Yup, Scholz’s Star was probably winking at us. Which is kind of cool. And begs a question – what would happen if a star came even closer? More soon.

Copyright © Matthew Wright 2015