Monday, October 22, 2018

Interstellar Missions a 21st Century Possibility

I was at the 2nd Montreal Space Symposium this past Friday, held this year at Concordia University.  I could only attend one of the days, and was again impressed by the level of professionalism the student-organized two-day conference was run with.  I appreciated the format this year, where more than 50 talks (mostly around 15 minutes with 5 minutes of questions) were run, usually two concurrently.

The one talk I took in at the conference that I will never forget was given by Professor Andrew Higgins (Mechanical Engineering Department of McGill University).  He and I have not crossed paths much since the last time I was a student in one of his courses (Fluids II in 2003, I believe).  The talk, entitled, "Bringing Interstellar Down to Earth," was delivered with his usual sense of humour and flair for the dramatic.

Higgins began the talk by explaining the typical reservations he holds for very futuristic project proposals (personally, having spent most of my adult life exploring the dynamics of space elevators, I hold few such reservations).  But, current breakthroughs in some key technological areas have him believing that he may live to see a fraction of light-speed transit to an exoplanet.

Today, we can detect the presence of exoplanets (planets orbiting stars other than the Sun) and even get a sense for their habitability (temperature, and whether it may have an atmosphere).  There is, however, no reason to believe that telescopes near Earth will enable us to learn any more than this about such planets, which are located at minimum around five light years away.  The only way we can hope to learn if life did or currently does exist on such a planet would be to go to it and take a picture, and send the image back to Earth.

While such a mission was laughable even five years ago, it is conceivable that we are now as little as two or three decades away from sending such probes to far off lands.  The challenge is to get a tiny satellite (a few inch diameter thin disk on the order of grams) to move at some fraction of the speed of light.  The number envisaged in the talk was 0.3c.

The 'TinySat' would be propelled to such a mind-boggling speed by a concentrated collection of coherent photons striking its surface... Basically, we would focus sunlight in a fancy way up to the satellite, where it would strike it (each photon carries a tiny amount of momentum, which it can transfer upon colliding with a surface).  The idea is to focus these streaming photons onto the satellite for a matter of minutes, accelerating the disk to, perhaps 0.3c.  If this were accomplished, TinySat would reach an exoplanet that is, say, 6 light years away, in about 20 years.  Then, it could snap some pictures, and send the images back to Earth, where it would arrive exactly 6 years later.  So, in total, in this scenario, pictures of the exoplanet arrive 26 years after the mission launches.  "Launches" ... This mission gives new meaning to the term launch.

What makes this plan reasonable to even discuss is threefold: (1) the emergence of the field of photonics, (2) advances in reflective materials (the surface of the satellite disk could reflect 99.9995% of the photons, and avoid melting during the photonic barrage), and of course, (3) the miniaturization of electronics, which means a useful satellite could be on the order of grams.

The project is known as "Breakthrough Starshot".  Some of the major challenges were outlined by Higgins.  He seemed most interested in how space dust might collide with a TinySat moving at 0.3c.  Would it destroy it?  In my mind, the most exciting challenge is those few minutes of acceleration.  At such high speeds, even the smallest non-zero torque would cause a rotation and a TinySat that moves very fast, but not in the direction that was intended.  Keeping the satellite pointed correctly during this acceleration is a monumental control challenge.  But, while we are on the subject of 'minutes', why not add a few more minutes of acceleration and get to 0.5c?  I mean, it would save us years of waiting for the probe to reach its destination.

Here is another challenge: can we even take a useful picture while moving at some fraction of the speed of light?  Maybe yes, if we account for the Doppler shift - I honestly do not know.  But that is what made the talk so exhilarating.  The numerous challenges posed by this mission are new, and many of them solvable and even testable in a lab here on Earth.  If I were looking for graduate work in engineering or physics, I would surely consider tackling some aspect of this project.

At the end of his 15 minute talk, Higgins was surrounded by eager young students with questions and novel ideas.  The enthusiasm in the room was palpable.  What I can say with confidence is that although the Breakthrough Starshot is a long shot (in every sense of the word), a lot of kids are going to have a lot of fun trying to make it. 

Thursday, October 18, 2018

You Are a Miracle

Truth be told, I cry in public sometimes.  I estimate that 95% of this crying comes from uncontrollable laughter, which, for me, is one of life's greatest gifts, like mango and avocado, and also tortilla chips dipped in guacamole consisting of mango mixed with avocado.

The other 5%, well, that is another kind of tears, sometimes out of sadness, but not always.  This variety of tears can be rendered uncontrollable with well-timed music (or poorly-timed, depending on one's desire to cry).  Films like E.T., the Extra-Terrestrial - I just get so triggered by the music at the end.  If I watch Elliott hug E.T. good-bye on mute, I'm just like "Bye E.T.," but turn up the volume, and I'm a mess.  Don't even get me started on the ending of Coco (the combination of my wife's tears and my own required more tissues than were available).

There is yet another variety of tears, which show up during public speaking (Yay!  I mean, public speaking is just so easy otherwise).  Giving a eulogy at a funeral (or trying to) can bring tears to even the most hardened individual.  As a 'soft' individual, I am batting a perfect 1.000 for crying during eulogies at this time of writing, and I see no chance of that success rate changing.

The weird thing is that I probably cried most trying to deliver a speech at my own wedding (insert marriage joke here).  Honestly, it was such a joyful occasion, and yet, I simply fell apart in the moment.  I have come to realize that I cry not really due to sadness, but actually, due to truth.

I find that truth has the power to overcome me.  If I am standing at a podium, speaking about stuff I do not truly believe in, it will not be touching to anyone listening, and it will not make me feel any kind of emotion other than, perhaps, boredom.  Words that are true to me, and deeply meaningful to me, are hard for me to speak out loud.  That is why I will not record an audio-book for this or anything else I ever write.

This brings me to this short piece, which I will never attempt to read aloud again, because there is just no point.  It reduces me to a sobbing mess, even in the absence of background music.  I remember feeling pride as I wrote it, and then nearly cried trying to read it to my class.  Then I really cried when I tried to read it at a community 'spoken-word' event.  So, I am done.

Feel free to read these words aloud to someone you love...

You Are a Miracle 

"Consider all of the extremely improbable events that led to your being here today...

After the Big Bang, matter needed to become complex enough to form stars.  These stars burned for billions of years, and it was necessary that many of them ended their life cycle in supernova events, which led to the formation of new stars, more complex matter, and planets that orbit these stars.  Of these planets, some were in habitable zones - not too hot, not too cold.  For life to evolve, a conducive chemical soup was necessary, and then, perhaps the most unlikely event of all: one that synthesized a single-celled organism.  Then came evolution, whereby more and more complex organisms evolved - each necessary species along the line managed to avoid extinction before its critical mutation that led to the next branch in the tree.  Finally, the human race emerges (perhaps the most fragile form of all life thus far), and manages to survive millennia of hardship.  And if that were not enough, of all of the billions of humans to have come and gone, your parents met, and pro-created you.

How can you not feel at least a little bit special?  How can you see your existence as anything less than a miracle?

I think this is what is most beautiful about life: a seemingly endless set of possibilities out of which one actual outcome emerges.  I cannot help but have a certain affinity for each and every one of these improbable outcomes.

In this frame of mind, everything is worthy of attention, every topic deserves to be studied.  It seems to me that this is the place where science should begin."