It's convenient to think of our senses as separate data channels, each delivering information of a different type faithfully to the brain. While that's true on a basic level, the picture of the world we perceive in our minds is actually quite a bit adjusted from what's taken in by the ears, eyes, skin, and organs, and it stands to reason that some of signals get mixed up in the processing. One of the most startling such cases is the McGurk effect, which you can read more about here: McGurk effect
Like the Matrix, though, the McGurk effect needs to be seen to be truly understood:
The world is complicated, and our minds are quite sophisticated as well. It makes sense that some odd quirks in the system emerge when we try to make sense of the universe using senses that are at best fallible and at worst downright kludge-y. Still, the McGurk effect is one of those illusions that pushes the envelope of the ways we're able to misinterpret what's happening.
I don't have much time tonight, so I'll be upfront about why I think The Chemical Brothers's 1997 Grammy-winning single "Block Rockin' Beats" is notable. In short, this video, one of the best that exists on youtube:
When Robert Heinlein famously said that Earth orbit is halfway to anywhere in the solar system, he was speaking more of the difficulty of permanently leaving the surface of the Earth than of the ease of voyaging across interplanetary space. Even the lowest-energy stable geocentric orbits require speed beyond easy comprehension, something Randall Munroe discussed on his indispensable "What if?" blog a few weeks ago. For this reason rocket makers have sought every assistance imaginable in bootstrapping their way toward space, and if at all possible launch eastward to gain a little nudge from the rotation of the Earth. Since launch sites closer to the equator maximize this boost, and also reduce the need for expensive plane change maneuvers in orbit, a consortium of Ukrainian, Russian, Norwegian, and American companies thought "Why not simplify matters by towing the launch site into the middle of the ocean?" You can read more about their joint venture here: Sea Launch
Sea Launch does exactly what you'd expect form it's name. The rocket (a Zenit 3-SL, an amalgam of former Soviet stages perfected by decades of sending reconnaissance spacecraft to spy on America's arsenal of weapons of mass destruction) launches from the sea, more specifically from a patch of remote Pacific Ocean far from shipping lanes and inhabited shorelines so the system can set its own schedule without concern for competition from rival launch services for range time or raids from pirates. Since most of the spacecraft carried by Sea Launch are bound for geostationary orbits, a launch site on the equator allows it to reach a pinpoint-accurate circular orbit with no inclination to the equator more easily and efficiently than rockets can from anywhere else in the world. The tradeoff is the need to operate two large ships and a three-stage launch vehicle far from civilization and a long lonely trip from any resupply, but the trade has proved sufficiently sweet to fetch 35 launches so far. Sometimes complicated ideas make life simpler in rocket science.
Sea Launch is based on rugged Cold War-era technology, but three of its launches have failed so far, two spectacularly. In 2007 one of the turbopumps on the first stage ingested a piece of debris not cleared from the propellant tanks during production, shutting the vehicle's propulsion system down a few seconds after launch. If nothing else, the failure validated Sea Launch's two-ship philosophy that evacuates everyone from the launch platform to an independent command ship just before departure:
Earlier this year, another Sea Launch Zenit failed in first stage flight, this time apparently due to faulty guidance:
Venturing into the cosmic ocean remains a difficult enterprise even today, more than half a century after the first human explorers ventured there, and even with a strong profit motive from the commercial telecom industry. Sea Launch shows that our ability to work here is growing in fits and starts, not monotonically, but at least we're growing. That humans do such baroque things, and actually seem to be reasonably successful at it most of the time, never ceases to amaze me.
People who lived in the last century witnessed the most rapid increase in human technological capability in history. The slope of the curve of progress will clearly be positive for some time, but its curvature remains an open question. Some who speculate on the future, Ray Kurzweil most prominent among them, insist that technology will not only improve, but the rate of its improvement will improve long into the future, until the machines we create are able to improve themselves faster than we can design them, and all ability to foresee the direction of technology will vanish like light across a black hole's event horizon. Such an event is known as a technological singularity, and you can read more about it here: Technological singularity
The arguments in favor of a technological singularity happening in this century go something like this. Computers are much better now than they were a few decades ago, and if you plot a number of figures of merit (including processor speed, storage space, internet connectivity, and so on) against time, an exponential curve fits the data pretty well. Intel co-founder Gordon Moore first noticed this in 1965. The people who build computers obviously want this trend to continue into the future, so what happens if it does? In a few more decades, then, computers become almost unimaginably powerful and cheap. By the end of the 2020s, Kurzweil claims, a $1,000 computer will have the thinking capacity of a thousand humans, and human brains will compose only 1% of the total intelligence on Earth. What then? Clearly there would be a lot more computational muscle around than we're used to having, and it's conceivable that problems seemingly intractable now will be solved after a simple bit of computer concentration.
The idea of a technological singularity reminds me of those cartoon scenes where a character does the math and figure out that given his wimpy allowance, it'll take hundreds of years afford the sweet new video game or bike or whatever. Trends, especially exponential ones, are impressive when they have staying power, but whether that endurance exists depends on details well hidden from a simple log-log plot. The increase in computational power over the last half-century, for example, is mainly dirven by improvements in integrated circuit technology, allowing more and more processing horsepower to fit into a machine with the same size and price tag. Matter isn't continuous though, it comes in integer amounts of atoms, and we're close to the point where integrated circuits can't be made any smaller because the quantum noise of individual atoms will start to drown out the processing signal. A fundamental breakthrough is required, perhaps through spintronics or quantum computing for Moore's "Law" (really a trend) to continue. Whether and when this will happen is virtually impossible to say with any kind of certainty, unless you're trying to see tickets to your next lecture.
It's possible that the greatest slope in the curve of technological progress for the time being lies in our past. As sci-fi author Rick Robinson put it, "I also suspect that the Singularity, to the extent there is one, already happened, centered around 1870-1930, though it will take at least a couple more centuries for its consequences to become clear." Regardless of what the future holds, we have a lot to wrap our heads around right now.
20 years ago yesterday the first rocket-propelled, vertical-takeoff, vertical-landing (VTVL) flying machine designed for Earth took off for the first time from the White Sands Missile Range in southeast New Mexico. It was an experimental proof-of-concept craft called the Delta Clipper or DC-X, it was built by McDonnell Douglas (now part of Boeing) for about the price of one single-aisle airliner, and you can read more about it here: McDonnell Douglas DC-X
VTVL is a launch vehicle configuration that has many fans in the aerospace industry. Some even go so far as to claim that a vertical launch followed by a descent and landing under rocket power is "The way God and Robert Heinlein intended" rockets to work. Hyperbole aside, I'm skeptical that God has any particular opinions when it comes to aerospace vehicle design, and with all due respect to the dean of science fiction, what works matters much more than the preferences of speculative authors. There are appealing attributes to the VTVL concept. The weight and drag penalties of aerodynamic control surfaces are kept to a minimum, compact launch and landing sites are possible, and it's possible that vertical landing results in the lowest recovery weight of any viable reusable launch vehicle technology. The unappealing aspect of VTVL rockets is the obvious insanity of betting the lives of the ship, crew, and passengers on the ability of rocket engines to ignite with rock-solid reliability and guide the vehicle's way to a precision stop with mere seconds of margin. Any more margin than that and the weight advantage over wings disappears.
Landing engine reliability and maneuverability are daunting challenges for VTVL launch vehicles, but the advocates think these dragons can be slain by adequate testing. In the late-1980s this coalition was able to convince the Strategic Defense Initiative Organization (SDIO, better known as Reagan's Star Wars program) that propulsive landing was the easiest way to achieve low-cost reusable launch. SDIO in turn was more than happy to put down $60 million to retire some of the risks that might one day enable a way to launch the dizzying number of spacecraft required to enable the Brilliant Pebbles space-based kinetic kill vehicle concept it was toying with at the time. In the event SDIO was repurposed and disbanded by the time the DC-X flew, and the clipper flew less than a dozen times before it was bought by NASA and almost immediately crashed and burned. In her short life, though, the DC-X demonstrated the principles of reusable, lean operations with a rocket-powered vehicle taking off and landing under its own power.
Though the DC-X died young, a small fleet of similar vehicles now carry the torch of VTVL toward, the faithful hope, one day making space travel as routine as air mail was in Lindbergh's days. John Carmack's Armadillo and Dave Masten's company have matched much of what McDonnell Douglas did in the DC-X days by rapidly iterating the development of small vehicles, though they've both run into serious challenges integrating aerodynamics into their vehicle designs as they've rapidly ascended in altitude and speed. Climbing the scale of financial investment, Blue Origin has flown several rockets closer in size to the DC-X in the last few years. For reasons that are obvious if you've ever seen my resume, I'm fond of Blue, and I helped in a very small way to put together the vehicle shown below (I once spent an afternoon helping to place propellant lines and fasteners around the fuel tank):
Finally, there's the 800-pound gorilla in the room for any discussion of the future of spaceflight, SpaceX. While all the launch vehicles SpaceX has flown so far have been expendable rockets much like those made by their arch-rival from old space, United Launch Alliance, Elon Musk has made it clear that SpaceX intends to transition to fully reusable launchers within the next decade. This makes sense when you consider that propellant cost is insignificant compared to vehicle cost, but seems less economical when you consider how insanely difficult it will be to shoehorn reusability into a throw-away rocket. Still, SpaceX is nothing if not tenacious, and they've already made considerable progress in understanding the flight of rocket-levitated craft at their test site in central Texas:
Personally, the idea of trusting my life to a cluster of braking rocket engines terrifies the nonrational part of my brain and seems nuts to the rational part of my brain. As they say, takeoffs are optional, but landings are mandatory, so the VL part of VTVL carries much more pucker factor for me. Personally, I think air launching and winged recovery are more promising ways to attack the problem of the cost of orbital transport, at least initially, though VTVL vehicles are probably better suited to the transport of oversize payloads like space station and starship components. As my high school theory of knowledge teacher was fond of saying, though, my opinions don't matter. What matters is results, and Carmack, Masten, Bezos, and Musk are all producing impressive results in spades. May the daughters of the Delta Clipper fly on, high, fast, and long into the future:
For most of the history of cancer treatment, patients and doctors had three options. Surgery aimed to completely excise local cancers from the body, while radiation and cytotoxic drugs were used to attack cells in the act of dividing. All three avenues are rather blunt in scope, carry frequently horrific side effects, and rarely resulted in true cures. Once the root causes of cancer became clear through genetic research in the 1980s, researchers first in America, then around the world, sought more precise weapons to bring to bear against the ghostly target of cancer. The first such drug to pass clinical trials is imatinib, marketed as Gleevec in the United States, and hit the market in 2001. You can read more about it here: Gleevec
Much of the development work on Gleevec was performed at the old Sandoz lab in the rugged alpine meadows and mountains of Switzerland. This is the same place where Albert Hofmann discovered LSD a half century earlier, and just as LSD would revolutionize psychotherapy in the 1950s, so Gleevec revolutionized cancer therapy in the 2000s. Unlike Hofmann's psychedelic potion, though, Gleevec was found through a carefully planned research and test program, rather than through serendipity and happenstance. For decades oncologists groped for better drugs empirically, dosing patients with nearly anything that looked like it had at least a slightly better chance of killing cancer cells than a healthy human body. The difference, unfortunately, was often very slight, and researchers remained ignorant of the mechanisms that lay the foundation for cancer, tightly constraining their ideas for exploration.
When geneticists began to identify the hereditary instructions that govern cell division, it wasn't long until mutations were found that jammed the works and caused cells to divide endlessly. Working with researchers in Oregon, Italy, and the UK, Novartis eventually found a large molecule that fit like a key into the lock of a specific mutated cancer gene that causes chronic myelogenous leukemia. The side effects are mild, since it aims to inhibit cell division only of the effected, mutated cancer cells. Gleevec is a surgical strike where only carpet bombing had been tried before, and is certainly the shape of things to come in oncology.
Some of my best memories from college consist of sitting around a table, beer in hand, talking about about mega-projects with my engineering friends. As the condensation accumulated and dripped down our glasses and the ethanol began to flow across the blood-brain barrier our deferrals to practicality and experience gradually ebbed as talk of travel to the stars, active structures towering above the atmosphere, and bridges across wide ocean passes became more and more giddy. It's great fun, talking about the wonderful things that could be done, even if they're unlikely to come to pass until the next great civilization.
The world is indifferent to such talk from college seniors and grad students, but when a man claims that he'll use his own money to ferry goods to and from low Earth orbit, and to make electric cars cool and practical, then makes good on this talk, people tend to listen. Elon Musk is pretty busy running the show at SpaceX and Tesla, but thinks he can come up with a better way to link the biggest cities of California than a planned $68 billion high-speed rail line. The idea is Hyperloop, and the details are now online here: Hyperloop
Musk claims Hyperloop could link Los Angeles and San Francisco faster than the terminal-to-terminal time of a subsonic airplane and at far less cost than high-speed rail or even the most efficient cars on the road today. If the system could actually be built for his price tag of $6 billion it would be a phenomenal achievement, but I doubt that things would actually turn out that rosy. A two-mile tunnel designed to bypass an unsafe section of freeway in downtown Seattle has an estimated cost of $4.25 billion, and overruns are not out of the question. Is it even remotely feasible to build a twin low-pressure, earthquake safe tunnel across most of the length of California for just $1.75 billion (less than one Curiosity) more? Color me skeptical.
Keeping the tunnel pressure reliably low enough for operation would probably be the biggest challenge, since the design pressure of 100 Pascals is a factor of 1,000 different from ambient sea level air. That's an intense vacuum, and it won't come cheap. Even though no tunnel boring machines would be required to put the tubes in place, someone powerful in California will find something to complain about when it comes to Musk's plans. Perhaps a demo project in a more technology-friendly place is in order. Houston-to-Dallas or Seattle-to-Portland would be good choices, although the latter route is short enough you might as well extend the line to Vancouver, British Columbia. Avoiding the Mount Rainier lahar zones would be nice, too.
As an aside, Musk's claim about supersonic air travel is completely bonkers. Supersonic air transports have inherently lower L/D than their subsonic counterparts since they burn extra fuel pushing against their shock waves. Maybe there's a way to coax high-speed engines to higher per-mile efficiency, but for now the subsonic high bypass turbofans are the kings of the efficiency game, and they're unlikely to be dethroned anytime soon. Let's ignore that part of his treatise.
Since SpaceX and Tesla are busy just staying alive at their tenuous businesses, it'll be up to someone else to make Hyperloop a reality. I hope someone at least gives it a shot, since the technology is challenging but workable, and the benefits would be tremendous to the cities linked. If nothing else, it'll make for some more interesting engineer bar talk while the tubes are going up along I-5.
The ratio of a circle's circumference to its diameter is both an important fundamental constant of the universe (though some would argue that it contains a hidden coefficient that ruins everything) and a transcendental, irrational number. This is inconvenient, since the digits in pi go on forever in a manner that's fundamentally unpredictable, and despite this they matter, all the way down. For practical applications this in't really a problem (since as many digits as matter can be easily memorized with a sufficiently nerdy poem), but that hasn't stopped people from coming up with cleverly stupid workarounds. Ryan North, for example, proposes celebrating Pi Approximation Day on July 22, since 22/7 is reasonably close to the true value of pi for the first few digits. You can read more about that here: Pi Approximation Day
Too be honest, endless chains of random digits don't excite me much, even when they correspond to real things like circularity, exponential growth, or efficient optimization. I'm actually a fan of North's comic more for its maxim at the end, "Failure is just success rounded down." All this aside, pi does seem to have an almost rapturous appeal for some people, witness the transcendental number subplot in the book version of Contact. July seems just as good a time to celebrate nerdiness and mathematically-inclined awe as March, so why not?
Also this was supposed to be posted on July 22. I'm not very good at keeping things on schedule. I'll refrain from apologizing if for no reason other than to avoid winding up like this guy.
