Lunchtime Ennui

The sun shines through a gap in the maple
After days of cloud and intermittent rain,
Arenberg Castle, her tiled roofs and high gable
Appears, as if in a dream,
Reflected in the limpid waters of a stream.

Ochre brick and black slate,
Onion-domed turrets surmount
The North and South tower.
A golden eagle, the family coat of arms
Is all that remains of
The local seat of power.

These days it’s Kasteelpark Arenberg,
Home to Science and Engineering, KU Leuven.
Look closely, and you might find
Tweed coat, elbow patch,
Frizzled hair untamed,
An academic
Deep in thought and lost in time
In the mullioned windows framed.

Stepped-gables and gothic balconies
Look out over the manicured lawns
Squawking wildly, amongst bushes of rose
There’s a waddling goose-train
Out for their post-prandial stroll.

Lovers lie on the green,
Bodies entwined, hands in folds private,
Each the other’s world entire.
Equally oblivious, magpies hop about,
They dig out tufts of grass
As they hunt for their little worms.

A path through the hedgerows,
Care-worn flagstones,
Centuries of thoroughfare.
It once saw horse and stage-coach
Palace intrigue, a duel or two.
Witness today to traffic mundane,
Harried students, rickety bikes
And the occasional Great Dane.

A one-legged crane stands statuesque by a pond,
Her pointed beak drooping slightly,
While water-fowl chug about ungainly,
Heads in robotic to-and-fro,
Their ripples distort
A riot of reflected rhododendron
Like some 19th Century impressionist masterpiece.

The castle sits in a forest of birch
50 feet tall, green below, red on top
Streamers of ivy along their sides,
They cast soothing shadows dappled
Over the long, straight bike route,
A family of ducks in the Djile alongside,
Mum, dad, hatchlings nine.

A solitary lark calls out
From her high-altitude nest
Her trilling notes
Rising higher and higher,
She brings to mind
The Lark Ascending,
Ralph Vaughan Williams'
Symphony pastoral.

The carillon chimes,
Shakes me out of my ennui
It’s half-past three,
And "Back to research!"
Her melodious notes decree.

Siren Call

Weekend at the lab, poring over code

Ink-stained fingerprints 

Mark research papers new and old.

Deep Neural networks, CNNs, LSTMs, SVMs,

Acronyms - galore,

I'm trying to

Teach a computer how to 

Make sense of this world.

Pictures labelled, videos supervised,

Gigabytes of data at my disposal, 

That for loop needs a new function, 

Abstract that logic out, the phone chimes for attention,

An email from my professor - the intro

Needs a new beginning, we have to emphasize 

Our contributions, market our research, 

Tell our story just right.

Fountain pen across printed page,

Key-strokes describe an algorithm in the night.

Royal blue against inky black,

That anachronism comforts, takes me back

To the 5th standard, when after years 

Of pencil work, we were allowed the ink pen.

I knew back then,

What I wanted to do with my life.

A lifetime later, 15 years in Australia,

And a year and something in Leuven,

5 years in industry

Means my H-index is

Not quite what it needs to be.

I'm struggling for ideas,

For papers, for inter-disciplinary research,

I need to make my mark 

In a sea of competitive sharks

I have to build relationships,

I have to reach critical mass.

And all this while my personal life

Takes a back-stage, 

The girl I'm interested in

Will have to wait.

Science is my mistress,

Her siren-call rings out

Over the rocks, and 

I'm prepared to swim out

Into the blackness of the night.

Fading Light

The setting sun marks in sharp relief

Pink-hued clouds low on the horizon.

They move in slow-motion,

Animated brush-strokes

Across a rapidly darkening canvas.

The soaring, plaintive vocals  

Of London Grammar

"We're Wasting Our Young Years"

Resonates through the apartment -

It feels a bit like that tonight.

10 storeys up, panoramic floor-to-ceiling windows

Reveal a procession of twin headlights making their tired way

Along the long road back to Brussels.

IMEC, the lone skyscraper 

Towers over the freeway, a handful of lights ablaze

Where researchers work late.

Giant cranes, construction done for the day

Stand like sentinels, their red eyes 

Twinkle in staggered succession,

As they acknowledge their mechanical brethren

Plying a modern day migration route,

Stratospheric contrails in their wake,

To Heathrow and further west.

A gentle breeze blows in,

A candle flame flickers.

Summer laughter drifts in from a garden below,

A spread, family, friends.

There's that atmospheric bass and reverb again,

"We're Wasting Our Young Years",

And it feels a bit like that tonight.

Post

Post

From Australia!

From a continent, once that was home.

60 cents and jagged edges

Transmit images from a faraway land.

The MCG,  that modern day gladiatorial arena

Reflected in the Aviators of a cricket fan. 

A kangaroo, in repose, on a sun-drenched beach,

Meditating to the sounds of an antipodal sea.

A man and his retriever

Gaze out to the horizon

As waves break out

On an azure shore.

Body paint on a Wurundjeri adolescent

Marks his entry into adulthood

And the stars of the Southern Cross 

Adorn the cheeks

Of children celebrating the arrival of the First Fleet.

Postage stamps,

A relic from the 20th Century.

Anachronistic

In an era of electronic mail,

Adorn the front of an envelope.

They bring back memories from a faraway time,

Scenes from an Imaginary Homeland.

A welcome respite,

From the cares of a European life.

Interstellar - Inspirational Science

"We're still pioneers, we've barely begun. Our greatest accomplishments cannot be behind us, because destiny lies above us." - astronaut Cooper, Interstellar.

I was excited to go and see Interstellar, but coming out of the theatre after watching the film, I was walking on air. It had begun to snow for the first time this winter in Leuven, and as the snow flakes floated gently down on me, I experienced, to borrow Milan Kundera's words, an unbearable lightness of being. I felt the joy of science and space exploration washing over me - I've always been excited about this stuff, but this film has influenced and inspired me as no other film has, and re-kindled within me, my childhood love for physics.

Without giving too much away about the film, the basic plot is as follows: In the near-future, planet Earth has become uninhabitable for mankind, and the protagonist, astronaut Cooper (played by Matthew McConaughey), supported by a surviving, skeleton staff from NASA, blasts off in the direction of a black hole to explore 3 planets in its vicinity that have been deemed suitable as candidates for supporting future human life. The trouble is, these planets are many million light years away, with no known technology to get there. So Cooper and his fellow astronauts journey through a worm-hole, a short-cut through the fabric of space-time to get to Gargantua, the black hole around which their candidate planets orbit.

Caltech physicist Kip Thorne was the consulting scientist in the film, and for once, Hollywood has taken great care to get the physics right. I'm going to be taking this opportunity (and the inspiration - while it lasts) to write about some of the physics in the film. 

One of the most visually stunning effects in the film is the view of the black hole Gargantua, as Cooper and his crew approach it. A black hole is a collapsed star of such high density and gravitational pull that nothing, not even light can escape from it, and consequently, it itself is invisible. However, stars and other inter-galactic matter in its vicinity are constantly being sucked into it, and as their hot gases spiral down the vortex into the centre of the black hole, they leave behind a tell-tale, brightly glowing disk, called an accretion disk. It is this disk that is seen as an indicator of the presence of a black hole, and has actually been visually confirmed by the Hubble Space Telescope.

Now, what would this accretion disk look like, as you approach a black hole?

Artist's impression of an accretion disk around a super-massive black hole [source]

Artists' impressions of black holes show the accretion disk orbiting the black hole's shadow, flattened along its equatorial plane. 

Light no longer travels in straight lines around a black hole - its intense gravitational pull bends light towards it - this phenomenon is called gravitational lensing [source]

Interstellar's Visual Effects team Double Negative (they won a special effects oscar for their efforts), instead of relying on previous artistic impressions, took Kip Thorne's advice and used Einstein's equations of General Relativity to simulate what a black hole would look like, from up close.

Einstein's General Relativity equations define the curvature of space-time around a black hole - the more massive a black hole, the more this curvature and the more the gravitational lensing, or bending of light due to the black hole's gravity. 

Gravitational lensing bends light from behind the black hole over 
and under the black hole [source]

                             

Using these equations for their computer generated renderings of the black hole, the team from Double Negative found that if you're near and just above or below the equatorial plane of the black hole, you will see light from the accretion disk behind it curve up and around its bottom and top. This will mean that in addition to the ring of the accretion disk along the black hole's equatorial orbit, you will see a ring along its polar orbit. 

The secondary, tertiary and higher order images of 

gravitationally-lensed stars behind a black hole​ [source]

Some of these light rays will spin around the black hole a few times before they escape and reach your eyes, which will lead to secondary and and higher order images of the gravitationally-lensed stars behind the black hole, with the black disk at the centre (whose edges coincide with the Event Horizon, from where light cannot escape). 

               

A spinning black hole like Gargantua drags space around it into 
whirls and eddies [source]

                      

A spinning black hole like Gargantua would also drag the space around it into a whirl, and this produces eddies of light and a much more complicated pattern of gravitationally lensed stars behind it. Along the accretion disk itself, as light approaches and then recedes away from an observer, it would appear bluer, and then redder along the approaching and receding sides, due to an effect called the Doppler Shift. The Doppler Effect is a physical phenomenon that changes the apparent frequency of a wave (light in this case) as it approaches an observer - the crests of the waves approaching you appear bunched together (higher frequency - blue) compared to the crests of the waves moving away from you (lower frequency - red). The same effect was observed by Edwin Hubble (after whom the space telescope is named) with galaxies - they seem to be more red-shifted (moving faster) the further away they are from us, indicating that the universe is expanding. In fact, Einstein had predicted this using his equations of General Relativity, but was so shocked at what his equations were telling him, that he decided to put in a "fudge factor" to account for this perceived anomaly. His theoretical predictions of an expanding universe were later confirmed by the astronomical observations of Hubble.

 Blue and red Doppler shifts seen along the approaching and receding 
sides of the accretion disk [source]

Back at Double Negative, the blue and red, Doppler-tinged accretion disk and some of the more complicated star patterns were deemed too complicated for a movie audience (already overwhelmed by a booster-dose of physics) to digest, and so they decided to slow down the spinning of the black hole a little bit (to tone down the Doppler shifts) and give it a slightly more anaemic accretion disk. If you were to strictly follow the laws of physics, Gargantua needed to be spinning faster to have a planet - Miller's planet (the first planet that the crew explores) so close to it and not break the speed of light barrier. The whirl of space (dragged along by a rapidly spinning Gargantua) means that the speed of Miller's planet, relative to the speed of whirling space around the black hole is still under the speed of light. 

And why does Miller's planet need to be so close to Gargantua?

Just as the immense gravity of a black hole curves space around it, it also slows down time, a phenomenon called time dilation, again a consequence of Einstein's General Relativity. 

Space and time are connected - scientists use the hyphenated space-time to describe this. The more "bendy" space is, slower the clock ticks and this effect is really pronounced in the vicinity of a gravitational heavy-weight like a black hole. 

Cooper's crew loses 7 years of Earth-time for every hour spent on Miller's planet, an important story element, and this would only be possible if the planet was very close to the gravitational tipping point of no return, the Event Horizon of Gargantua. 

The final result from the Double Negative effects team is the rainbow of fire effect that you see in the film, a spectacular visualization of what a black hole (or more accurately the space around it) would really look like. 

Gargantua and Miller's planet, as seen in the film [source]

​                              

You'll find more details about the visual effects of the film in this video. And for those who want to dive into the equations, here are the links to the published journal and book:

Gravitational Lensing by Spinning Black Holes in Astrophysics, and in the Movie Interstellar Oliver James, et. al., 2015.

The Science of Interstellar, Kip S. Thorne, 2014.

The Real Risks of AI

"The development of full artificial intelligence could spell the end of the human race" - Stephen Hawking.
"AI represents an existential threat to mankind" - Elon Musk.
What is it about AI today, that is making leading scientists and engineers sit up and take notice? Does it really pose an existential threat, as Hawking and Musk would have us believe?
The real threat, I discover is one of jobs and livelihoods to hundreds of millions in the developed world. More about the current state of the art in AI, and its possible social impacts in my post: The Real Risks of AI.

[source]

The War to End all Wars Turns 100 This Month

Fog over the trenches

It is late afternoon here and the fog drifts slowly over no-man's land that fades away into a sea of white. The soft patter of rain breaks the eerie silence that had fallen over the trenches since morning. Rain is as much an enemy here as the soldiers positioned inside opposing trenches, less than 200 metres away. It has fallen everyday over the past month and the flooding makes our lives even more miserable than the gas and the artillery barrages. I'm peering through an observation port-hole as I stand in knee-deep water, the cold permeating my every bone. I dread that call from my CO to "go over the top", scale the trench walls in the face of a hail of machine gun fire. Bodies of fallen comrades lie rotting next to me, their faces frozen into grotesque masks.  The threat of gas, which arrives soundlessly, is ever-present.

I'm in farmland outside the city of Ieper or Ypres in west Belgium near the French border and I inhabit the mind of a young officer in the British army fighting in the trenches here, on the Western front in the autumn of 1917, almost a 100 years ago. The Great War had dragged on for more than 3 years and the opposing armies, British (including vast numbers of troops from India and Australia), French and Belgian on one side, and German on the other, had ground themselves into a stalemate along trenches from Italy in the south to the western coast of Belgium here. It was a battle of attrition, characterised by heavily fortified German defensive positions and brief, and largely unsuccessful Allied attempts to break through. One of these, the Third Battle of Ypres or the Battle of Passchendaele, during which only a few kilometres of ground were captured by the Allies between July and November 1917 cost half a million lives and led to the complete destruction of the city of Ypres.

Row after solemn row of white tombstones at the Tyne Cot cemetery (outside the city of Ypres in west Belgium) stand testament to the carnage of WW1

The Tyne Cot cemetery, the final resting place for 12,000 soldiers from the Commonwealth

Wreath of flowers at the Tyne Cot cemetery

Wreath of flowers at the Langemark cemetery for the German war dead

Four mourning figures stand guard over the dead, Langemark German cemetery 

Almost a century later, the physical scars have healed, the trenches have been filled in and homes and farmland have taken their place. This 100th anniversary of the war is being commemorated with solemn ceremonies across the continent. This is the month that Germany invaded neutral Belgium to try and outflank France. 

The city of Leuven, the city I've made home for the past year, is today a bustling Flemish university town, with cobbled-stoned streets, mesmerizing Gothic town halls and churches that have been faithfully restored after the destruction of WW1. In August 1914, this city was razed to the ground and its 10,000 occupants forced to flee or butchered by the advancing forces of the German Reich. 

Flashing lights, sirens and the roar of police bikes greeted Leuven recently, when the modern representatives of the two warring countries, the King and Queen of Belgium and the president of Germany arrived here, at KU Leuven. They visited the university (whose library and its collection of 900,000 books was deliberately destroyed by German forces), and remembered the fallen on both sides. 

Leuven town centre, circa 1914 (image source: Flicker)

Leuven town centre, circa 2014

"Where they burn books, they will ultimately burn human beings" - Heinrich Heine
The ruins of the KU Leuven library, 1914 (image source: wikipedia)

 The university library today

My generation knows little about this war from 100 years ago. The 2nd World War, with its horrors of fascism and Hitler's systematic and clinical efforts at ethnic cleansing is the war that occupies a bigger slice of our psyche, given the number of books and films that have documented that war. 

An accident of birth and a quirk of fate has allowed me to inhabit a relatively peaceful era of world history, where I find it possible to travel to Belgium, and live in a continent at peace. A slightly different roll of the dice could possibly have seen me travelling to Flanders in 1914, as part of the 1.5 million strong contingent from pre-independent India, forced to fight someone else's war. 

Trenches, mutilation, horror and death, instead of study, travel, culture and the leisure to look back and learn from history. A sobering thought.