Riding on a light beam

Some of you probably have read about a project called Breakthrough Starshot that began perhaps eight years ago (and which was championed by none other than Stephen Hawking), which proposed sending small remote-controlled cameras to nearby star systems, powered by lasers that could propel them up to twenty percent of the speed of light.

If something like this were launched today, it would mean we could be getting photographs back from Proxima Centauri in twenty years.

[Image licensed under the Creative Commons ESO/M. Kornmesser, Artist's impression of the planet orbiting Proxima Centauri, CC BY 4.0]

It's an ambitious project, and faces significant hurdles.  Even if propelled by lasers -- which, being light, travel at the speed thereof -- navigation becomes increasingly difficult the farther away it gets.  Just at the distance of Pluto, our intrepid little spacecraft would be 4.5 light-hours from Earth, meaning if we tried to beam it instructions to dodge around an incoming meteor, it would be 4.5 hours until the command arrived, at which point all that would be left is intrepid scrap metal.  And Proxima Centauri is 4.3 light years away.

You see the problem.  The Starshot spacecraft would have to be able, on some level, to think for itself, because there simply wouldn't be time for Mission Control to steer it to avoid danger.

There are other obstacles, though.  Besides the obvious difficulties of being in the cold vacuum of interstellar space, contending with cosmic rays and the like, there's the problem engendered by its speed.  Assuming the estimate of a maximum velocity of twenty percent of light speed is correct, even tiny particles of dust would become formidable projectiles, so Starshot is going to require some heavy-duty shielding, increasing its mass (and thus the amount of energy needed to make it go).

Three years ago we got an encouraging proof of concept, when the group working on the mission -- Russian entrepreneur Yuri Milner's Breakthrough Foundation -- launched a test of the Starshot craft.  It was a tiny little thing, small enough to fit in your hand and weighing about the same as a stick of gum, designed and built by engineers at the University of California - Santa Barbara.  In the test flight it achieved an altitude of nineteen miles, all the while functioning flawlessly, returning four thousand images of the Earth taken from aloft.

And just last week, a paper in Nature Photonics describes further research on how to overcome the weight/propulsion issue, with the creation of a fifty-nanometer-thick membrane of silicon nitride that was tested to measure the actual thrust a laser could create on something that lightweight -- a feat that has never been done before.  The miniature sail passed with flying colors.

"There are numerous challenges involved in developing a membrane that could ultimately be used as lightsail," said Harry Atwater of Caltech, who led the study.  "It needs to withstand heat, hold its shape under pressure, and ride stably along the axis of a laser beam.  But before we can begin building such a sail, we need to understand how the materials respond to radiation pressure from lasers.  We wanted to know if we could determine the force being exerted on a membrane just by measuring its movements.  It turns out we can."

The most significant remaining hurdle is to design the laser system to make Starshot move -- lasers that are extremely powerful yet so finely collimated that they can still strike a ten-centimeter craft square-on from several light years away.  The engineering director for Breakthrough, Peter Klupar, is designing a 100,000 gigawatt laser -- to be located, he says, in Chile -- that could be the answer.  Of course, such a powerful device is not without its dangers.  Reflected off a mirror in space, Klupar says, such a laser could "ignite an entire city in minutes."

Not that there's a mirror out there.  So you shouldn't worry at all about that.

"You would think that this is all impossible, but we have folks at Caltech and the University of Southampton and Exeter University working on about fifty contracts on making all [of] this happen," Klupar said.  "No one has come up with a deal-breaker that we can find yet.  It all seems real."

All of which may seem like science fiction, but it's phenomenal how fast things go from the realm of Star Trek to reality.  Klupar compares his light sails to CubeSats, tiny (ten by ten centimeters, weighing a little over a kilogram) orbiting telemetry devices that are now common.  "It feels a lot like the way CubeSats felt twenty years ago," he said.  "People were saying, 'Those are toys, they're never going to develop into anything, there's no way I can see that ever working.'  And today and look them: hundreds of millions of dollars is being spent on them."

So keep your eye on this project.  If there's a chance at a remote visit to another star system, I think this is our best bet.  The Breakthrough Foundation estimates an actual, honest-to-goodness launch toward a nearby star as early as 2030.  Meaning perhaps we could get our first photographs of planets around another star by 2050.

I'll be ninety years old at that point, but if that's what I'm waiting for, I can make it till then.

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Starshot update

Two years ago I wrote about a project called Breakthrough Starshot, which proposed sending small remote-controlled cameras to nearby star systems, powered by lasers that could propel them up to twenty percent of the speed of light.

Which means we could be getting photographs back from Proxima Centauri in twenty years.

[Image licensed under the Creative Commons ESO/M. Kornmesser, Artist's impression of the planet orbiting Proxima Centauri, CC BY 4.0]

It's an ambitious project, and faces significant hurdles.  Even if propelled by lasers -- which, being light, travel at the speed thereof -- navigation becomes increasingly difficult the farther away it gets.  Even at the distance of Pluto, our intrepid little spacecraft would be 4.5 light-hours from Earth, meaning if we tried to beam it instructions to dodge around an incoming meteor, it would be 4.5 hours until the command arrived, at which point all that would be left is intrepid scrap metal.  And Proxima Centauri is 4.3 light years away.

You see the problem.  The Starshot spacecraft would have to be able, on some level, to think for itself, because there simply wouldn't be time for Mission Control to steer it to avoid danger.

There are other obstacles, though.  Besides the obvious difficulties of being in the cold vacuum of interstellar space, contending with cosmic rays and the like, there's the problem engendered by its speed   Assuming the estimate of a maximum velocity of twenty percent of light speed is correct, even tiny particles of dust would be formidable projectiles, so Starshot is going to require some heavy-duty shielding, increasing its mass (and thus the amount of energy needed to make it go).

But last month we got an encouraging proof of concept, when the group working on the mission -- Russian entrepreneur Yuri Milner's Breakthrough Foundation -- launched a test of the Starshot craft.  It was a tiny little thing, small enough to fit in your hand and weighing about the same as a stick of gum, designed and built by engineers at the University of California - Santa Barbara, and in the test flight achieved an altitude of nineteen miles, all the while functioning flawlessly, returning four thousand images of the Earth taken from aloft.

The Breakthrough Foundation is planning a suborbital test next year, and perhaps a full orbit the year after that.  So things are moving along.  But the most significant hurdle is to design the laser system to make Starshot move -- lasers that are so finely collimated that they can still strike a ten-centimeter craft square-on from several light years away.  The engineering director for Breakthrough, Peter Klupar, is designing a 100,000 gigawatt laser -- to be located, he says, in Chile -- that could be the answer.  Of course, such a powerful device is not without its dangers.  Reflected off a mirror in space, Klupar says, such a laser could "ignite an entire city in minutes."

Not that there's a mirror out there.  So you shouldn't worry at all about that.

"You would think that this is all impossible, but we have folks at Caltech and the University of Southampton and Exeter University working on about 50 contracts on making all [of] this happen," Klupar said.  "No one has come up with a deal-breaker that we can find yet. It all seems real."

One possible way to increase the thrust generated by the laser is to increase the surface area that the beam strikes, and Klupar thinks he knows how to do that -- using a "light sail."  He's already built a prototype.  "The sail is very thin. It's about 400 atoms thick, it weighs about a half a gram, and it's four meters in diameter," he said.  "I think of it as 'reflective smoke.'"

All of which may seem like science fiction, but it's phenomenal how fast things go from the realm of Star Trek to reality.  Klupar compares his light sails to CubeSats, tiny (ten by ten centimeters, weighing a little over a kilogram) orbiting telemetry devices that are now common.  "It feels a lot like the way CubeSats felt twenty years ago," he said.  "People were saying, 'Those are toys, they're never going to develop into anything, there's no way I can see that ever working.'  And today and look them: Hundreds of millions of dollars is being spent on them."

So keep your eye on this project.  If there's a chance at a remote visit to another star system, I think this is our best bet.  The Breakthrough Foundation estimates an actual, honest-to-goodness launch toward a nearby star as early as 2030.  Meaning perhaps we could get our first photographs of planets around another star by 2050.

I'll be ninety years old at that point, but if that's what I'm waiting for, I can make it till then.

**************************

When the brilliant British neurologist and author Oliver Sacks died in August of 2015, he was working on a collection of essays that delved into some of the deepest issues scientists consider: evolution, creativity, memory, time, and experience.  A year and a half ago, that collection was published under the title The River of Consciousness, and in it he explores those weighty topics with his characteristic humor, insight, and self-deprecating humility.

Those of us who were captivated by earlier works such as The Man Who Mistook His Wife for a Hat, Musicophilia, Awakenings, and Everything in its Place will be thrilled by this book -- the last thoughts of one of the best thinkers of our time.

[Note:  If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Speculation, extraterrestrial life, and Kepler 452b

Dear readers,

This will be my last post for a bit, as I'm going on a short hiatus for a (hopefully) well-deserved vacation.  I'll be away for three weeks, so my next new post will be on Monday, August 17.

This is a chance for you to check out some other great blogs and webpages, so here are a few of my favorites:

The Reason Stick
James Randi Educational Foundation

Potato Chip Math

Reddit: Skeptic

Doubtful News
SkepChick
The Skeptic's Dictionary
The Call of Troythulu
The Richard Dawkins Foundation for Science and Reason
Friendly Atheist
Quackwatch
Bad Archaeology
Bad Astronomy

That should be enough to keep you occupied while I'm gone, don't you think?

So until my return, keep reading, keep thinking, and keep hoisting the banner of logic and reason... and I'll see you on the 17th!

************************************************

It is one of my dearest hopes that unequivocal proof of extraterrestrial life is discovered during my lifetime.

I'm buoyed by the discovery of extrasolar planets, with new ones being identified virtually every other day.  As astronomers develop better and more sensitive techniques for detection, more and more of the planets they find are turning out to be small, rocky worlds like our own, and some are in the "Goldilocks Zone" -- that region surrounding a star where the temperature would allow liquid water to exist.  Not too hot, not too cold... just right.

The effort to prove that we're not alone in the universe has just received a nice shot in the arm in the form of a project called Breakthrough, funded by Silicon Valley entrepreneur Yuri Milner and announced this week by none other than eminent physicist Stephen Hawking:

We believe that life arose spontaneously on Earth, so in an infinite universe, there must be other occurrences of life.  Somewhere in the cosmos, perhaps intelligent life might be watching these lights of ours, aware of what they mean.  Or do our lights wander a lifeless cosmos, unseen beacons announcing that, here on one rock, the universe discovered its existence?  Either way, there is no better question.  It's time to commit to finding the answer, to search for life beyond Earth.  The Breakthrough initiatives are making that commitment.  We are alive.  We are intelligent.  We must know.

The project will survey over a million of the closest stars for any signs of extraterrestrial intelligence. The technology required for this is staggering; Breakthrough will be covering ten times the number of stars of any previous SETI project, and do so a hundred times faster.

"We will be examining something like 10 billion radio channels simultaneously," said University of California, Berkeley astronomer Geoffrey Marcy, who has been involved in previous efforts to locate extrasolar planets. "We're listening to a cosmic piano, and every time we listen with the telescopes, we'll be listening not to 88 keys, but 10 billion keys."

Couple that with this week's announcement of the discovery of the "most Earth-like extrasolar planet ever found," Kepler 452b, and it's been a pretty good week for people who, like me, think that Contact is one of the best movies ever.

Which is thrilling.  But of course, given the human tendency to take what we know and run right off the cliff with it, this week's announcement was accompanied by a couple of rather ridiculous articles from media sources that should really know better.

Artist's rendition of Kepler 452b and its parent star [image courtesy of NASA]

Starting with the article "Is There Life on Kepler 452b, the Most Earth-like Planet Ever Discovered?" from the site CosmosUp, the text of which should state, in its entirety, "WE DON'T KNOW."  But there's no reason not to spin a nearly complete lack of information into a lengthy article, right?  It's laced with quotes from actual scientists (who also should know better), such as the following baffling assessment from NASA's former chief operating officer, Carlos Gonzáles Pintado:

Mathematically speaking, there’s high possibility that could be intelligent life on Kepler-452b... We move in four dimensions and to get something extraordinary we have to find some ‘new’ dimensions.  Some theorists believe that the universe must have eleven dimensions and we are at the dawn, we ‘discovered’ just four and nothing more.  When we would find the other missing seven, maybe we’ll find something in the middle to break the barrier of speed of light.

Which gives me the impression that however Mr. Pintado may excel at being chief operating officer, he doesn't know a damn thing about physics.  Finding the "missing seven dimensions?"  Then finding something "in the middle of them?"  What the hell does that even mean?

And what is a "high possibility, mathematically speaking?"  2%?  50%?  98%?  The fact is, we know nothing about Kepler 452b except for an estimate of its size and distance from its parent star -- most importantly, we have no information about the composition of its atmosphere.  Even if it's in the Goldilocks Zone, what's to stop it from being like Venus -- a boiling hell of a planet, with an atmosphere made primarily of carbon dioxide and hydrogen sulfide?

The fact is, Pintado is doing what members of scientific institutions shouldn't ever do, which is publicly engaging in idle speculation.  It's hard enough getting laypeople to understand how science works without this sort of thing.

Worse still, we have Jeffrey Schweitzer's piece for Huffington Post entitled "Earth 2.0: Bad News for God."  Schweitzer is a neurophysiologist and former White House Senior Policy Analyst, which didn't stop him from writing the following:

[I]t would be difficult to claim the unique position of universe center if other planets held life that was zipping around in anti-gravity cars traveling at the speed of light.  Clearly, if the ancients knew there was alien life, any form of life at all, the idea that the earth was the center of the universe would be more difficult to sustain.  Again, though, there is no mention of alien worlds or life beyond this little blue dot. 

None of the 66 books of the bible make any reference to life other than that created by god here on earth in that six-day period.  If we discover life elsewhere, one must admit that is an oversight.  So much so in fact that such a discovery must to all but the most closed minds call into question the entire story of creation, and anything that follows from that story.  How could a convincing story of life's creation leave out life?  Even if the story is meant to be allegorical, the omission of life elsewhere makes no sense.

So the implication is that the discovery of extraterrestrial life, or (better) extraterrestrial intelligence, would be a serious blow to religion.  Schweitzer himself calls into question whether his own contention is true, however, in his last paragraph:

Religious leaders will simply declare that such life is fully compatible with, in fact predicted by, the Bible...  They will create contorted justifications to support this view, cite a few passages of the bible that could mean anything, and declare victory.  Don't say I did not warn you.

So if you think that the religious will be able to argue away extraterrestrial intelligence as being consistent with the bible, why is the discovery of Kepler 452b "bad news for god?"  Or were you just trying to come up with an eye-catching, click-baity title?  Because let's face it; if the overwhelming mountains of evidence in favor of evolution hasn't convinced the biblical literalists that their worldview is wrong, then receiving a hearty "NuqneH!" from the Klingon home world won't make a damn bit of difference either.

Religion, after all, has nothing to do with evidence; it's all about revelation and internal experience.  So Schweitzer's suggestion that the discovery of extraterrestrial life will have any effect at all on the devout is probably as accurate as all of the other times people have declared that belief in a higher power was on its way out.

Anyhow, none of this should minimize the fact that we live in an amazing time, when we are taking steps toward solving one of the most fundamental questions we have -- whether life is common in the universe.  It'd be nice, however, if people would keep their eye on the ball, rather than zooming off on tangential speculations that really have nothing to do with the reality.  The reality, honestly, is cool enough in and of itself.