#OddPuzzlePieces 1

28th May, 2017

We all go around our day, going through our business. Seemingly on autopilot, our brains are doing an awful lot whilst we’re running errands, paying bills, or screaming at traffic. How much of that mental activity is really noticed? How much of what we learn over the course of our lives really sticks?

Have you noticed the way sometimes some simply random knowledge lodges itself in your brain, never to see the light of day? Just like “earworms”; those snatches of tunes that leap into your head from the radio and assail your sanity all day, so to do odd facts. I call them odd puzzle pieces, and random factoids.

To this end, I’m starting a new series of blog posts, taking a look at random factoids and odd puzzle pieces. On Twitter I’ve set some hashtags loose:

#RandomFactoids

#OddPuzzlePieces

Hopefully once in awhile the Twitterverse has something for me! There are a lot of science folks out there, and a lot of people with heads full of plain weirdness.

If anyone has some wierdness for me, it can be anything. It doesn’t have to be technical, or obscure. All it has to do is be stuck in your head!

Anyway, here is the inaugural list of Odd Puzzle Pieces, provided by a couple of super smart gals. The images link to Brianna and Christine’s Twitter profiles. See what they’re up to and say hello!

Facts 1,3,4 and 9 were provided by:

Facts 2,5 and 7 were provided by: 

1: The bumpy texture of a pineapple exterior is actually clusters of individual fruiting flowers! Who knew?

2: Leeches, upon fixing to the skin of their hosts, inject both anaesthetic and anticoagulant into the host bloodstream. Makes for a real feast!

3: No single graph is possible for the statistical test known as a 3 Way ANOVA (Analysis of Variance). This is a widely used statistical test applied in many clinical and laboratory situations. The only way to graph it would be in 3D. That sounds tricky, at best!

Disclosure: I was terrible at statistics in university. 

4: The only characteristic that links the tropical scorpionfish to its close relative the rockfish is a tiny little bone under their eyes!

The scorpion fish Scorpaena scrofa. A face only a mother could love.

5: Snakes “smell” by sticking their tongues out to taste the air. They transfer odorants from the tongue to the vomeronasal organ on the roof of their mouth.

Image: Wikimedia Commons

6: Camels possess a “refridgeration” system in their head, a bulbous system of veins call the Sinus cavernosus. This structure aids in quick heat loss and transfer, protecting the camels brain.

Image: Pixabay

7: Downfield, Deshield, Left! This is a mnemonic device used to interpret NMR spectra.

8: Metameric segmentation is a shortcut that has evolved in arthropods and annelids, whereby repetitive segmentation is used to save the “work” of genetically coding for an entire body.

9: Food chain is an outmoded term used to describe trophic relationships in ecologies. The term Food Web is now seen as more appropriate. The food web for Little Rock, Minnesota is the largest published 3D food web, and shows just connected things in nature are:

A dataset seems almost alive sometimes, as patterns emerge..Image: Twitter.

That’s it for this post. Send in your odd little puzzle pieces; little scraps that just won’t quit. Thank you to Brianna Bibel and Christine, both followers on Twitter for some of these first few pieces.

Until next time, keep thinking.

 

Ben

 

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#SignalDegradation

Soundtrack: the opening theme of “The Big Bang Theory”

 

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When I was in university I majored in Earth Sciences and Biology, thinking this was some sort of suitable compromise with my then academic ambitions. You see, I’d really wanted to study palaeontology. It had been one of those vague childhood longings that had not quite managed to be squeezed into a torpor by life. Having these two majors seemed to make sense. For part of the day I was studying geology, geophysics and sedimentary processes.  For the remainder I was buried in lower eukaryotes,  molecular and microbiology and animal physiology. Dinosaurs are somewhere in the midst of all that, right?

Kind of. Well the dinosaurs fell by the wayside (became extinct?) and I found myself really liking pretty much everything else I was studying. Learning is a joy in itself. Whilst in university I was privileged to attend lectures given by Dr Leigh Burgoyne. For those unfamiliar with molecular biology Dr Burgoyne is half of a pair of scientists who elucidated the structure of chromatin.

What tha’ heck is chromatin? Chromatin is a complex of structural proteins that enable Deoxyribose nucleic acid (DNA) to play the ultimate game of Tetris. DNA is a very wily molecule, which I’ve touched on in a previous post. It has insane data storage potential, and a single strand of DNA is three metres long! Now you understand why it needs some mad packaging skills to squeeze into something the size of one of your cells. That’s basically what chromatin does.

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Life wouldn’t work if it didn’t have an epic case of OCD.

 

I remember a single lecture given by Dr Burgoyne. To be honest, I remember very little of about nine-tenths of it (it’s still stashed in my head somewhere), but then it seemed like he really began speaking.

He told us the tale of life….

In order to parse what he told us I need to paraphrase what he said. I need to mix metaphors and go off on tangents.

Now, any students of science out there will have butted heads with statistics and probability whilst studying. I’m not in any way being elitist here. Most sane people know that the universe is a collection of freakish accidents all cycling constantly and spewing out more freakish accidents. Somehow, a stream of such accidents has led to you. As Terry Pratchett said in one of his Discworld novels;

Million to one chances happen nine times out of ten.”

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We are all freak accidents. Every single person- every single thing– alive today is a current iteration of a single freak accident that took place in a warm, shallow pond nearly 4 billion years ago. Or trapped inside ice. Or on the slope of a deep-sea hydrothermal vent. On a sheet of clay even.

Hell, maybe it was on the shifting gravel filled terrain of a passing comet. Who knows? I’m sure not going to be presumptuous. Theories on the origin of life abound. I strongly suggest venturing out into the literature and checking these out for yourself.

Freak accident.

That accident somehow decided it wanted to keep on keeping on. So it went looking for other freak accidents to consume. This in itself required some changes. And so it began.

Life.

Life is not just a thing in itself.  Life is all of the things that life does. Emergence gave us life.

Life got hungry. Life went looking. Life grew. At some point life joined forces with other life, going onto business. These partnerships have lasted till this day. Life became stronger, faster. Like human explorers expanding forever westwards life travelled. It began to see. It began to conquer. The entire planet was a vast new frontier. A planet of accidents and danger. At every single turn life met with struggle, and it was forced to sink or swim.

So it either sank or swam. You’re only here right now, sitting on this train, or hiding in the toilet for a few minutes because every single one of your ancestors swam. If the theory of a multiverse holds any water, then in another universe it’s someone else reading here in this spot. Or I never existed to write this and you’re watching a Minecraft walk through on YouTube instead. Whatever floats your boat.

I remember the lecture. Dr Burgoyne gave his thoughts on the astronomical run of good luck that led to everyone being in that lecture theatre. I swear, you could have heard a pin drop. People were listening. It was an amazing moment.

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NOT the lecture in question, but you get the picture..

What’s more amazing than the fact that we are here at all? The fact that in nearly four billion years of life, the central message of life has only degraded by a few percent! That’s just nuts! Think about it!

DNA (sometimes RNA) is the information storage molecule for all life. RNA stores the genetic information within viruses, which inhabit a shadowy world somewhere between the living and the abiotic world. For the sake of simplicity I will refer only to DNA.  We’re all scientifical enough to not get all Sheldon Cooper when I hold up DNA  as THE information storage molecule.

Moving on Ben.

Think of life as a signal, and DNA is the filter, tuning out cosmic background clutter and refining it into something pretty improbable. Like you. At a point in time the signal was set in motion. Whether it was in a pond, an iceberg or a comet, life got going; using some kind of information storage in order to send copies of itself out into the big bad world.

That signal’s been around for a very long time, replicating and transcribing and reinventing itself in an endless profusion of forms. Some very ancient cellular machinery has been hard at work, replicating DNA with incredible fidelity. What amazes me about all of this is that cellular automata (proteins for the most part) carry out this herculean task. Proteins aren’t alive. They are essential players in the mechanics of life, but they aren’t alive in themselves. Some proteins are capable of replication, but that’s another post in itself (and an interesting one too).

Let’s play the Pepsi taste challenge, but instead of cola drinks let’s compare say…YOU and a bacterium. That seems a bit silly, right? There couldn’t possibly be two more different organisms on the face of the planet. Let’s put aside the fact that your particular body is about ninety percent bacteria in terms of numbers. Let’s focus on the ten percent of you that’s actually YOU. Ok. You have eyes, ears and wear pants. You’re reading this post on a phone, computer or tablet.

Keyword: Reading.

Implication: highly complex brain along with associated neuronal infrastructure, from which emerges this nebulous thing called a consciousness. You can’t point at it, but you know it’s there.

You wear clothes. I wear warm clothes right now, because it’s a cold day. You’re probably drinking or eating something right now. I’m sucking down a coffee. Implications of this: you have a digestive system, along with associated waste disposal mechanisms. You have fingers, and nostrils to stick them up sometimes, leading to lungs. You can drive a car. Other creatures like you have walked on the Moon and made brainless YouTube videos.

Bacteria, by comparison to you, are a little simplistic right?

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E. coli. Doesn’t seem too impressive, right?

Hah!

Time to shatter some illusions. You may have heard that human beings and chimpanzees are 98 percent genetically identical. Only 2 percent of your DNA makes you human, compared to a chimp. Well, brace yourself.

You and that bacterium you look down upon so loftily differ genetically by 10 percent. TEN percent! In nearly four billion years, bacteria, one of the oldest lineages of life to exist, have barely changed. All of those changes have been tiny and incremental, giving rise to the kaleidoscopic variety of life that runs, flies and swims across this planet now. That’s pretty amazing. Just knowing something like that feels like being privy to some cosmic secret. Hell, I think it is.

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Ha! Thought you were hot stuff, didn’t you?

Let’s keep going with this biological Pepsi taste challenge.

Can you keep gossip to yourself? We live in an age where information and reality are becoming blurred. The very existence of Alt-news, Alt-facts, false news, filter bubbles and a host of other ills plaguing the last few bastions of enlightenment are nothing new. Have you ever played the game of Chinese whispers? I’m Australian, so it may be called something different where you come from. A story is spoken, or whispered into the ear of a player, who whispers it into the ear of the next, and so on. It’s fun to see how the story spontaneously mutates, changing as it goes. Sometimes it reaches the final person in the line a completely new beast. This string of mutations happens quickly, completely changing the original story, and all in a few moments.

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Social media. It has a weapons grade case of Chinese whispers….

Think of your genetic information, or genome, as a book. Blindly and efficiently this book is replicated. The two entwined threads in it’s double helix are unwound by DNA helicase. Then DNA polymerase attaches to the strands, and attaches complementary nucleotides to their respective exposed base pairs along the strand. This is an extremely cut down version of what happens, but all you really need to know in the context of this post is this: it all happens extremely quickly. In the bacterium Eschericia coli, replication can speed along at the rate of around 1,000 nucleotides per second. DNA polymerase in your cells works much more slowly, at a snail-like 50 nucleotides per second. Such speeds are achieved by many polymerases attaching to unfettered DNA strands. Many hands make light work after all. How much can you achieve in one second? All of this goes to show that parallel processing is one of Nature’s oldest tricks.

You’d be completely reasonable to assume that such a process would be fraught with errors. It is. But unlike the game of Chinese whispers, or the rant on Facebook, errors of interpretation and transcription happen much more infrequently. After all, if DNA replication was untidy and prone to errors life would have eventually never taken off. Early in the piece evolution made sure that efficient replication of information was critical. Some mutation is good, but too much is bad. A few mutations here and there over the eons have given rise to you. Too much mutation and life breaks down. So what constitutes a few mutations here and there?

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Without organisation and proofreading, life would maybe have made it this far….

For every 10 billion base pairs that are replicated, approximately 1 error gets through. DNA polymerase on its own is pretty good at what it does. Being completely automatic it doesn’t have a pesky brain doing bothersome things like over thinking or day-dreaming. It isn’t perfect, however. Left to itself, DNA polymerase will stuff things up to the order of 1 bad base pair in every 100 million replicated. A suite of repair enzymes are at its disposal, tidying up these mistakes and getting replication fidelity up to the 1 in 10 billion mark.

Boy, talk about an amateur. Me, that is. I’m a chef by profession. After 22 years of sweating it out in kitchens, I still manage to burn at least one piece of bread a day (don’t tell anyone). If pieces of toast were living things, then at my hands not only would they never evolve, they would become extinct long before they ever had a chance. Maybe they should have enzymes working in kitchens.

Maybe not.

So, I hope you see what I mean. Every single living thing on earth (and who knows where else) exists purely because extremely high fidelity of replication has evolved to ensure against excessive mutation. Another way of putting it is; even after four billion years of nearby supernovae, disasters, extinctions, geochemical catastrophes and endless strife, life has been able to hold on, and all because of extremely faithful data storage and propagation. If we ourselves can evolve past our own tendency to conflate every thing we hear and describe, maybe we could stick around for a while longer too.

Life is a signal, a signal that can’t be broken. Let’s learn from it.

 

Ben.

Welcome and thanks for hopping on

Just a very short post. A big thank you to newcomers to this blog. I’m in the midst of transplanting myself from YouTube to the world of blogging..I already know I’m going to enjoy this far more. I’ve always liked writing, and can say the things I want to say in this format. 

Like a bacteriophage I’m digging into the juice entrails of some new story..and loving it.

Having said that, live streaming, particularly on Periscope and Periscope Producer is definitely a direction I want to move in as well. Both formats are quite fluid and lack the restrictions that a schedule of making videos (or trying to) imposes on you.  

Follow me on Periscope and tag along. Feel absolutely free to jump into a discussion.  It’s what I love! 

https://www.pscp.tv/Bens_Lab/follow
I have a few ideas for the Periscope stuff, including a way to integrate blog posts with live video. Perhaps reading a post- with video and pictures/effects added of course! 

My Periscope topics can be random, but hopefully interesting.

Facebook Live seems to be getting a lot of love these days, but for the life of me I can’t seem to make the damn thing gain traction. Zero viewers,  zero engagement. Pity really.  

My Ben’s Lab Facebook page has several thousand page likes. If I could produce videos for that audience it’d be awesome. Again,  practically zero engagement. 

It all leaves me scratching my head. 

But not to worry. Enjoy this blog, hunt me down on Periscope,  and let’s start a conversation. 

Ben.

#Yggdrassil: The World Within a Tree

“We live in a Universe that seems to be unsure of its rules sometimes. Is everything preordained, folded and tucked into the very tiny recesses of whatever quantum realm underpins our own world? Is everything an emergent property, constantly cycled and coded in real-time? Writers and thinkers have pondered this question and its countless variations since thought began. I’m not arrogant to declare I have the answers, and honestly, at this point in time could anyone? 

Whatever viewpoint you have on the universe and how it all stacks up, there are some things no body can deny. Everything works the way it works, no matter what explanation you put forward for it.”

Staring at traffic gets me in a pensive mood sometimes. It makes me wonder (as an aside) how much thinking is done at windows, watching the world rush by? Right now I’m thinking about several hours just spent at some local wetlands. Just near my home, they have been virtually rebuilt by local councils over the last fifteen years or so, in a bid to clean up the environment a little bit. It isn’t really a token gesture. The wetlands have been a beacon of success amid the constant flood of tales of environmental woe. I visit them all the time when I get time off work, and love nothing more than wandering for hours at a time, taking photos of insects and whatever else takes my fancy.

You see, I really like science. I even studied it, slogging through five years of university, so I could get a nice big certificate to put on my wall. It was fun, but I’ve realised that for me science is all about wandering around in lonely places and just paying attention to things that others sometimes don’t see. It’s all about where you feel at home, and I’ve always felt at home in my imagination.

Today’s walk took me through the Paddocks Wetlands. They’re an area set aside by local government for environmental remediation. They constitute a fairly large chunk of land, set behind factories and commercial precincts.

The open space didn’t interest me today. I was armed with a bunch of cameras and a cheap little macro lens for my smart phone. Today, I went bug hunting. I went yesterday as well, just a boy and his smartphone.

Today’s trek through the wilderness was initially not panning out. With some pretty miserable weather, insects seemed to be sleeping in that day. I was getting a little bored. I was streaming my walk on Periscope, and getting a little distracted, clowning around for the viewers.

Then, a tree happened.

Trees hold a powerful place in world mythology. The mighty Ents of J.R.R. Tolkien’s Middle Earth are derived from ancient European myth. Trees are sacred in many cultures. This probably found its greatest expression in Norse mythology, with the World Tree Yggdrasil.

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Rooted in Eurasian mythology, Yggdrasil continues its hold on modern imaginations.

According to Norse legend, Yggdrasil was a mighty Ash (sometimes Oak) tree, whose branches extended beyond the heavens into the nine realms of existence. It’s roots extended far below, into the homes of Gods and demons. I personally have always loved this tale. It’s always given trees a certain mystique. When I was younger I used to believe they could think and feel just as we do, and wondered what secrets they kept to themselves…

In a way this assumption wasn’t far off. At the paddocks wetlands today I was able to focus on a single tree, finding a host of life and drama within.

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This quiet unassuming tree became my main focus for the day.

This wasn’t just some boring old gum tree. On walking past it, I immediately noticed something I don’t see very often:

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This praying mantis, about 4 cm long was lurking quietly among some drooping Eucalyptus branches.

I was truly excited to find this little beastie. It was in the midst of eating the still twitching halves of a European wasp. It’s not every day we get to see nature at its violent best, and my camera was at the ready. The mantis was on to me, I’ll give it that. About the only important thing to heed when trying to photograph or film insects is that they are 1: extremely alert, and 2: extremely timid as a rule. They’ve been around for a very long time, and they’ve been on everyone’s menu for a long time. They’ve become very good at evading big clumsy beasts like myself. If you are, however, very quiet and move really slowly, you can get decent shots.

Or at least Twitter worthy shots.

The tree was home to so many. Dramas were unfolding before my eyes, and that was what was so great! From blood thirsty evisceration amid large gum leaves hanging like drapes to the aftermath of pitched battles:

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Sometimes, no one wins.

Yggdrasil continued to unfold before me. Fire ants were foraging in the tree branches, coming down to investigate the praying mantis. The mantis actually tossed the wasp away, on realising I wasn’t going to leave it alone! That, and the inquisitive ants coming down to assess the situation and the mantis went into lock down, assuming it’s well-known posture of supplication. As I’ve said, insects are incredible survivors. On turning away for a few moments to further explore the tree the mantis was gone forever, melting into the greens and browns of the branches drooping down to the ground.

Note: My identification of these ants may be completely wrong. Feel free to correct me. 

The ants only numbered in the dozens.  They were like a scouting party, sent from their command centre to gauge the lay of the land before invasion day. One explorer to another, I watched them go about their business.

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When going on these kinds of walks,  I have found that you can’t go out intending to find something. Most times the only times I find things worth capturing on film is when some random glance leads me to a new discovery. Even knowing where to look is not enough sometimes. Insects are extremely elusive. Their size and alertness has kept them alive for hundreds of millions of years. Like Tolkien’s Hobbits, it seems that insects and their arthropod cousins will only be seen by us big folk when they want to. This is when we go out using only our eyes to look.

One tree was full of dramas and epic struggle. A fight for survival, a loser vanquished by a stronger foe and rent asunder like a bloody trophy. The first tendrils of conquest, seeking new worlds, coming into contact with the natives. These first contacts not going so well for some; even for combatants from both sides. Perhaps there’s a lesson in that for those who care to see it.

For these tiny creatures, this eucalyptus tree was their world. Like the Norse stories, the tree was their Yggdrasil, their entire cosmology. Branches swept up out of sight into the heavens, where only the foolhardy would ever travel, risking swooping birds. The tree’s roots grasped deep, clenching around the foundations of their universe. Some branches were reaching out, entwined with those from other universes, where brave travellers would cross over, meeting inhabitants of the neighbouring universes. Unknown to them all, they were all being watched by higher powers, hovering over them.

Or, were they unaware?

#GalacticAnatomy: Dissect the Milky Way

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As readers of a blog like this (and many others), it’s pretty safe to say that you’ve probably bumped into a book or two in your time.  No surprises there! Who read fantasy novels?

Yeah, me too.

Hands up those who used to love examining those little maps that seemed to be a standard part of many fantasy and science fiction novels? I’ve always loved maps; the hours lost in imaginary places. To be able to see the roads travelled by a band of adventurers, or the grim fortress overlooking some craggy windswept peak where the reluctant hero made their last stand was an important part of the story. It gave the events within the narrative a sense of place.

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A randomly generated fantasy map. I’ll bet your imagination is already populating it with peoples and events… Image: Mark Frauenfelder, Boingboing.net

Well, the ultimate map is all around us. It’s the Universe. A couple of posts ago I explained the joy of the unexplored vista; of finding out what lies out in the unknown. This has always been my fascination with science and studying the Universe in all it’s infinite facets. Many moons ago I purchased a copy of an Australian science news magazine; Australasian Science. I couldn’t resist the picture on the cover, showing a generic artists impression of a galaxy, and a headline promising the secrets of the Milky Way.

This was a map, a road map to the greatest fantasy kingdom in the history of creation.

The article was a good one (so believed much younger Ben), and I actually still have that very magazine lying around somewhere. To be completely honest much older Ben still thinks it’s a cool article.

I will find that magazine and show it to you. It’s one of a few science publications that changed my life. That is actually a good topic for a future blog post right there.

Moving on. This magazine article introduced me to galactic anatomy. It dove into something called the GHZ, which stands for Galactic Habitable Zone. In addition the article taught me a little about the structure of our very own Milky Way. Obviously this was not a scholarly journal piece, although it was careful to include solid references where it could.  I learnt of things like metallicity, and a mysterious ring of this mysterious  stuff called the Galactic Halo, encircling our little ol’ Milky Way. Most likely a great many other galaxies possess such a band as well. Apparently the Halo is is a band of dark matter: that mysterious cosmic MacGuffin, which plays an as yet unknown role in galactic metabolism: akin to the way junk dna plays a role in the comings and goings of genetic information.

The Milky Way is a pretty standard galaxy, one of about 2 trillion in the observable universe!

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“My God, it’s full of stars….” A tiny slice of the sky, courtesy of Hubble. Image: Wikimedia Commons

Of course, standard can mean so many things (especially in this day and age), so I’ll put up another post when the fancy takes me regarding the galactic bestiary. For now, we’re going to focus closer to home. That’s not to say that the Milky Way is at all insignificant. It’s a vast armed spiral of stars and countless other stellar objects, self contained and packaged by collective self gravitation. It’s a cosmic gated community, encircled by a moat of dark matter, warding off the extragalactic night. Containing over 100 billion stars (and several billion planets) this behemoth is approximately 100,000 light years across- not counting our dark matter moat.

That’s a long way.  As Douglas Adams so succinctly put it:

Space is big.

A light year is the distance in which a photon of light travels in one year. Light travels at 186,000 miles in a single second. As Steve Irwin would have said: crikey!!

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She’s a fair dinkum ripper!

The numbers are unimaginable. The Milky Way is vast beyond comprehension. The crazy part is however, that as far as galaxies and cosmic objects go the Milky Way is fairly modest in size. To quote a favourite line from the (unfairly) maligned movie “The Phantom Menace”:

 

N.B. I will often throw in a cheesy sci-fi reference. That’s just how I roll. Stories are an excellent resource, because they can sometimes help you see how the world works.

Welcome to the Neighbourhood

The Milky Way is one of three larger galaxies, forming part of a greater cosmic community called The Local Group. Andromeda and the Triangulum galaxy make up the other two heavyweights.

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The Local Group. With a diameter of approximately 10 million light years, the Local Group contains 36 galaxies or dwarf galaxies. Image: Wikimedia Commons

Ten million light years is a lot of distance. But it doesn’t stop there. The Local Group is part of a greater group: the Virgo Supercluster. This is in turn part of the Laniakea Supercluster. For, after the mere 100,000 light years of the Milky Way itself, things just got silly. This post doesn’t venture beyond the immediate neighbourhood of the Milky Way. As for the great beyond, to quote “The Neverending Story”; that’s another story, and shall be told another time.

We have nearly 50 smaller galaxies orbiting us! Three are of note. The Large and Small Magellenic Clouds are visible with the naked eye, and have been since before Man came down from the trees. It’s getting harder and harder to see them. Urban sprawl and light pollution from the world’s cities is inexorably removing the sky from the collective memory of the human race. If you ever can get a chance to get away to remote places, where the night sky is still awe inspiring, then do it! It is absolutely worth it.

 

The Milky Way, like all other galaxies has a structure. Over time our view of it has changed. It has progressed in the minds and eyes of observers throughout history. Native Australian mythology believed the band of stars stretching across the night sky to be some kind of river of the night, along which supernatural beings and the spirits of fallen warriors would travel between worlds. I have to admit, mythology really puts a fascinating spin on these things.

Whilst it may not be a river, the reality of it is just as interesting. As mentioned previously we see the galaxy as a band across the night sky. This is because we are looking along the plane of the galaxy. We are, after all, embedded deep within it, some 26,000 light years away from a supermassive black hole, some 4 million times the mass of our own sun. This monster is busily devouring neighbouring stars and clusters in the bulge which comprises the galactic core.

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A hungry black hole prowls our galactic core…

Oh, to live in some science fiction movie, watching the spectacle of stellar destruction. Future tour operators really will have some impressive vistas to explore!

Let’s move on to this “Galactic Habitable Zone”. It sounds like some interstellar demarcation in a cheesy space opera. To my own biased ears it sounds positively mythical; like a really cut down version of the Galactic Empire.

Or, it just sounds cool.

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The blue band represents the GHZ. Image: NASA/Caltech

Readers of previous space based posts will have come across references to something called the “Goldilocks Zone.” Another word for this is the Habitable Zone. We on Earth only exist because we’re smack bang in the middle of it. Venus happens to orbit just within the inner cusp of our Goldilocks Zone, whereas frigid Mars lies at it’s very outer limits. It’s the zone around a star where the temperature is amenable to liquid water existing on the surface of a planet, hence greatly increasing its habitability. Of course life needs a little more than this, but it sure helps. As far as we know, no life can exist without liquid water.

The recently discovered TRAPPIST-1 system comprises a red dwarf sun, with FOUR planets within its habitable zone! In the above video, TRAPPIST-D, E, F, and G all lie within the TRAPPIST-1 Goldilocks zone, and so are all hypothetically capable of at least bearing life.

As these planets (and those within our own solar system) orbit their parent star, so does our solar system move around the galactic centre, with a galactic year lasting some 250 million years! What then, makes our position in the Milky Way so special?

As they say in the real estate business, location location. Consider you’ve just moved into a large city, looking to set yourself up. You start by looking for a home. They all look nice. You’re not overly fussy about the house itself, but it has to be in a good spot. There’s a fantastic place on the outskirts of town. Big, roomy, plenty of space to accidentally lose the kids. There’s also this nice little flat smack bang in the CBD. How do you weigh these two places up? The edge of town is nice, and there are plenty of open spaces, but that’s a drawback. There’s nothing out there. Like, really. No one to talk to but trees and ageing hippies. In the centre of town, there’s an insane buzz. Nothing ever closes. Everywhere you look, there’s plenty of action. But that also worries you. Also, the crush of humanity in the inner city is nuts. There’s no room to swing a cat anywhere. You’ll lose your mind within two weeks of moving in. No thanks.

So, you look to somewhere in the middle. Out in the suburbs, life is a little boring, but that’s probably for the best. Not much crime or craziness, with just enough to keep your brain from going stale. Oh, and you don’t want to be on a main road either. Little kids and traffic don’t mix. That decides it then.

Our position in the galaxy is something like that. Too close to the galactic centre and life would never have made it. It’s vastly overcrowded with stars and stellar clusters (not to mention Sagittarius A*) and supernovae rates are off the charts. You know what that means for life? Curtains. The Galactic Core is a hellhole of cosmic radiation. Life wouldn’t even start there.

Out on the rim things aren’t much better. When categorising stars, astronomers group and observe stars under two main types: Population 1 and Population 2.  Population 1 stars, like our own sun are deemed metal rich, or have high metallicity.  In the context of stellar populations metals are any elements heavier than hydrogen and helium; the most abundant elements in the universe. Such stars are common in the disc, gradually thinning further out toward the galactic rim. Heavy elements are crucial for the construction of all other material in the universe, ie planets and the organic compounds needed for life.

Out in the rim, Population 2 stars dominate. These stars are older, and are metal poor. Not much new stellar construction goes on out here. Stellar nurseries; the cosmic factory floor are more common in the disk.

So what’s all this about main roads? Revisiting the real estate analogy, roads are bad news, right? Hard core traffic is plain dangerous. Well, if we take another look at the galaxy (any spiral galaxy for that matter) we see that tremendous arms radiate outward from the bulge at the centre:

milky_way
A typical barred spiral galaxy, just like the Milky Way. Image: Wikimedia Commons

These arms are the main roads. Densely populated with throngs of stars and solar systems whizzing around the centre. Lucky for us the Sun is situated between two of these highways, free from too much interference from nasty neighbours. It whiles away it’s time, drifting peacefully through the quiet galactic suburbs. Life, as we’re finding out, is extremely tough but there’s no way on God’s green earth it would have started at all if conditions on earth were too apocalyptic.

I’ve left my favourite part of the galaxy til last. The galactic halo. The very name is evocative, carrying obvious religious connotations. We don’t really know it’s there, due to the fact that it is likely composed of dark matter. That stuff gets around, doesn’t it? It exerts an invisible pull on the large scale universe, drawing space and time into a new dance. It encircles the galaxy, like the diffuse corona of light surrounding the heads of saints in old paintings. To date, no one really knows what dark matter is; only what it does. It’s something like the wind: no one can see it but we can all see what it does. Something this mysterious is like science candy, and it’s the subject of much debate.

After all. Remember those maps I was talking about at the start of this post? My favourite parts were the hazy lands that lay outside the story….

This has been a slightly longer post, but it’s pretty hard to squeeze something 100,000 light years across into a few paragraphs. Please feel free to leave a comment. There’s nothing better than meeting other science buffs.

Have a good one.

Ben.

P.S., The European Space Agency’s Gaia Probe has been hard at work imaging and tracing the position and movements of over 1 billion stars, enabling us to gain a highly detailed picture of the galaxy and it’s development. I’ve provided a link to a YouTube video which visualises the movements of two million stars over the course of five million years.

Wanna keep up with Gaia? Follow them and catch all the galactic fun on Twitter!

 

References and other stuff you may like:

 

https://en.wikipedia.org/wiki/Hubble_Ultra-Deep_Field

https://www.scientificamerican.com/article/sagittarius-satellite-spiral/

https://en.wikipedia.org/wiki/Satellite_galaxies_of_the_Milky_Way

https://www.universetoday.com/22285/facts-about-the-milky-way/

Sons of War: The view from Phobos

The crackling airwaves reverberate with the ethereal radio noise of the universe. You’re sitting cross-legged in fine regolith staring out into the big empty. You reach down and tune the receiver on your space suit, trying to lock in some broadcasts from Mars.

It’s pretty quiet down there today.  Traffic is slow. There sure as hell isn’t too much happening here today. Not even commercial vessels hover over the skyline of this tiny moon.  Phobos is alone with its thoughts on this Martian Sol,  and so are you.

view
Come to Phobos! Spectacular views!

It’s a good place to get away. When you’re after some quiet time, you don’t mess around. Mars is a hub of busy-busy, as a melting pot of factions; corporate, government and private explore and carve it up. Maps are being drawn down there, maps of the future.

Mars rolls slowly beneath you. Phobos’ orbit brings it close to the red planet. With a semi-major axis of 9377 kilometres, Phobos makes a closer approach to its parent body than any other satellite or moon in the Solar System. By contrast, Phobos’ little brother; Deimos has a semi-major axis of 23460 kilometres. IF you were standing on the surface of Mars you might just see Deimos as a point of light, something like the folks back on Earth see Venus in the morning and at dusk.

At The Martian equator Phobos is about 1/3 the size of the full moon as seen on Earth.  Artist’s impression.

So, why “Sons of War?”

Asaph Hall, who inadvertently discovered the pair in 1877 after some pushing from his wife (after which Stickney Crater was named), had a penchant for ancient Greece it seems. Phobos and Deimos were the sons of the Greek god of war; Ares! (Mars to the Romans.) Phobos meant panic and Deimos meant fear.

They sounded like a handful for their old man!

The universe is a gift. What else can it be? Every single day seems to bring something new and completely interesting. Sometimes you need to hunt for it, and sometimes it’s right there, hiding in plain sight.  You’ve been known to have a fascination with the phenomenon. You never thought sitting up here on this nondescript pile of rubble could be so interesting. All alone with this incredible vista you look down at Mars and think about tossing your tickets back home out into space. It wouldn’t take much. Here on Phobos you are your own launch system. Phobos is the ultimate destination for weight loss. Back on earth you weigh in at just over one hundred kilograms. Here on this tiny little rock you weigh just over 60 grams! That’s right! You and your little sister’s black and white kitten weigh the same right now!

How cute.

Ha! You’re a lightweight like me! Puny human!

It makes going for a walk tricky though. In the first few years of the Great Mars Rush Phobos was a hotspot. Stickney Crater, that 6 mile wide basin swallowing up one end of the moon became an overnight spaceport, with Hamer Station becoming a sprawl of impossible architecture in a couple of years. People being what they are, didn’t really look before they leapt: literally. Rescuing floating space tourists who’d become new martian moons became a profitable cottage industry. Magnetic boots won’t work here of course. The terrain is almost entirely regolith: powdered rock formed by millennia of impacts. In fact, gravity is so low that with every step you carefully take a cloud of dust slowly puffs up, taking several minutes to descend back to the ground behind you.

You’re holding onto a handrail, one of several hundred which stretch for collectively dozens of miles around the moon. These handrails were the workaround some bright spark came up with in the early days. Straight out of an OH&S* manual, these rails are pretty much all that keeps you from launching yourself into the Big Empty.

Because gravity is so light, you can’t really “feel” the terrain. Probably if you weighed your actual 100 kilos, you’d sink into the several metres of regolith beneath you. It’d be like dry quicksand. Beneath all that are voids; a handy feature of the moon. Phobos is about one-third empty space. It’s a feature of the moon’s formation. Back when Mars was in its infancy something huge crashed into it, like an interplanetary T-Rex.

Space is rough.

A lot of Mars was kicked up into space, forming a secondary cloud of dust and rock around what was left of it. Some of this matter clumped and glommed together, under gravity’s inexorable pull, and moons formed. Phobos and Deimos are the last survivors of these martian offspring. They are piles of rubble. Imagine you’re an extra in a disaster movie, where a building has collapsed on your head, and you play a survivor, trapped in the rubble. All the bits of the building don’t fall down in an orderly manner. This would be an entirely different universe if they did.

Just imagine physics lessons!

Anyway. Survivors, trapped under fallen rubble. Girders, chunks of concrete and twisted metal have fallen randomly, strewn in a completely chaotic heap of mess, under which our film extras wait for the heroic star to pull them out. Phobos is like this. Chunks of randomly shaped Mars have simply fallen together, resulting in an odd honeycomb of dark empty caverns and spaces; now used by humanity, which is rapidly filling them up with the detritus of colonisation and industry. Even living quarters. Like some bizarre sentient ant colony humans hide underground here. It’s a refuge from some crazy space radiation, the same as that bombarding and frying electronics down on Mars.

Mars is virtually zipping past. Phobos has an extremely fast orbit. Right now you are sailing around the red planet, completing an orbit in just over seven hours. Deimos, all alone out there lags behind, making the journey in just over thirty hours. You’re holding the handrail tight, but part of you wants to let go, to reach out for the Red Planet. It really is moving fast, now that Humanity is here.

To paraphrase Kim Stanley Robinson: “Once Mars was a dream. Now, it was a place.”

Valles Marineris, the longest and deepest canyon in the Solar System. Stretching away into the future, like a new Wild West.

The Japanese Space Agency is currently putting together a mission to not only explore the moons of Mars, but to return samples to Earth. Good luck guys. Follow them on Twitter to keep up with their progress and mission updates:

 

 

*Occupational Health and Safety