I’d have to say that screaming in at 6 km/s (13400 mph), while glowing a red-hot 2400 K (3800 F), followed by a Mach 2 parachute deployment and then, the piece de resistance being lowered down from a rocket-powered hovercraft is quite possibly the coolest entrance anyone could make to a party.

Not only that, the Mars Science Lab (aka Curiosity rover) landed with pinpoint accuracy, well within its 20 km x 7 km target landing ellipse in the Gale Crater.  To put this in perspective, considering that the journey took 570 million km, an imperfect analogy would be playing a game of darts and trying to hit the bulls eye target in New York… except you’re standing on the Moon.

And, this was all done autonomously using sensors, feedback and control loops and some pretty fancy decisioning logic.  Sounds like the folks at NASA and all the contractors who supported this effort deserve an enormous pat on the back!

My favorite picture, by far, shows Curiosity with its parachute gently floating down about 6 minutes into the 7 minute entry, descent and landing sequence.

Not only is it a cool picture, but think about it… who took the picture? And how?  Think about the complexity in perfectly timing the orbiting spacecraft Mars Reconnaissance Orbiter (MRO) (which was launched in 2005 and has being orbiting Mars since 2006) to be passing by overhead just as Curiosity is entering Mars, having the MRO spacecraft automatically detect Curiosity in its landing sequence and take a picture.  Their margin of error was 1 second.  That’s right – they had to time this to within 1 second to get the picture.  And once again, all done autonomously.  Unbelievable.

And this is just the beginning.  The mission is baselined for 1 Martian year (about 687 Earth days) and its primary mission is to analyze the local rocks and soil looking for organic carbon compounds that could potentially be biologically generated.  Not to mention the amazing pictures!  Pretty exciting!  I can’t wait to hear more as we get scientific results over the next 2 years.

My colleagues across the research center wanted to congratulate NASA on a killer landing. See below for some photos and thoughts from scientists and engineers across GE Global Research!

Adam

Brilliant landing, from the Global Research Cleanroom!

Great Job NASA, from the Materials Characterization Lab!

Congrats to NASA, from the Airspace Efficiency Team!

This is the first of a series of blogs examining the “science of summer” as we explore the underlying science behind summer-based themes. We’ll be answering deep questions like how does sunscreen work, what are the economics of a lemonade stand, and for today, why beaches have different colored sand.

It turns out that, well, it isn’t really rocket science (like my normal job), but more a matter of geology! The sand, as you would guess, is really just tiny bits of rock that have eroded from the local geology. So the color is pretty much determined by the mineral content of the local sediment and rock. In honor of the 4th of July, I figured we’d look at red, white and yes, blue sand!

Let’s begin with red sand. Red sand is pretty easy to understand. It’s found in areas which are rich in iron (iron-oxide, commonly known as rust, is red-colored). Kaihalulu Beach in Maui is a famous example with the iron coming from the continual erosion of the volcanic cinder cone located behind the beach. Prince Edward Island in Canada is also a pretty unique place as the entire island is composed of iron-rich red- sandstone sediment resulting in very deep-red soil and red sand beaches!

As for the white sand. Well, I am sure everyone is picturing a beautiful tropical paradise with turquoise water and long stretches of white beach. It turns out that white sand is composed of finely ground quartz crystals. Crescent Beach on Siesta Key in Sarasota, FL won the 1987 Great International White Sand Beach Challenge for the whitest sand in the world. The quartz actually originates from the igneous rock in the Appalachian mountains and the eroded material is carried into the Gulf by the major rivers.

And finally, blue sand! This is, by far, the coolest type of sand and can be found on Redang Island off the coast of Malaysia. Unlike the other sands, which are dominated by geological processes, blue-sand is biologically-inspired. It turns out that tiny creatures from the class of ostracods (related to crustaceans, like crabs, lobsters, etc.) can be bioluminescent, giving off a blue-glow. Try imagining the marine equivalent of fireflies. These little guys are tiny (less than 1 mm in size) and are mixed in with the sand. As night approaches, they light up making it seem like the sand is glowing a nice blue color.

I hope you learned a bit about our world’s patriotic sand! If you’d like to see more colorful beaches, check out this site showcasing the world’s most unusual colored sand! Stay-tuned for more on our summer series. If you’ve got a burning summer science question, please post a comment below and I’ll try our my best to answer! I hope you have a great fourth of July and if you are on the beach, be sure to teach your family and friends a thing or two… or three about sand!

I was recently enlightened by Kunter Akbay about TED.  Now, I had heard of TED, before, but never really paid attention until Kunter gave a short talk at one of our lab meetings – and have been addicted ever since.  For those of you who don’t know, TED is an acronym for Technology, Entertainment, Design and their motto is “Ideas Worth Spreading”.  There is an entire community and on-line presence formed around this motto.  In addition, they have two formal conferences each year where the invited speakers are given a very short time (less than 20 min) to get their idea across.  It’s meant to be quick, engaging, and to the point – many talks are less than 6 minutes!  Topics vary widely from technical inventions, to life-lessons learned, to various artists performing.   A great thing is that TED posts all the talks on their web-site – so everybody can enjoy from the comforts of their home.

One of the talks that caught my attention was from William Kamkwamba, a young man from Malawi who garnered fame for his perseverance, ingenuity and dedication in building a windmill to generate electricity for his family.  It is inspiring to hear his story of how he decided to continue to learn on his own by reading books in the library after he dropped-out of school because his family couldn’t afford the tuition… and then ingeniously applied his self-education to improve the lives of those around him.  This young man demonstrated many of the values that I admire:  passion for learning, determination, inventiveness, hands-on solving of real problems, helping the community, making the best use of available limited resources and focusing on renewable resources.

The world needs more people like Mr. Kamkwamba.

One of the requests was to see a match lighting. We didn’t happen to have any matches around that day, so we ended up lighting a candle (hopefully this is close enough). We used a torch that was held about a foot away from the candle, and well, watch here…

Another of the requests was to capture someone sneezing. This turned out to be somewhat difficult – it’s a real trick to get the lighting just right so that it reflects off all the slime and spit for it to show up on the camera. So instead, we figured we would try to simulate it with a spray bottle.

The last two movies we did for fun just out of our own curiosity. The first is a close-up view of flipping a quarter. Here we can see Justin’s thumb as he flips a quarter.

Last, but not least is probably most interesting to engineers. We were really curious to see what happens when you drill a hole. This movie is amazing because you can see the chip growing with each turn of the drill-bit, and then eventually it breaks off and a new chip starts to form.

Well – that’s it for now. We did try almost all the ideas that everyone posted, but sometimes it was just too hard to capture. We tried the Mentos thing, but we used Sprite instead (since it’s clear) – but the reaction was a completely uninteresting fizzle. Maybe next time we’ll do it again with Diet Coke since that’s what seems to result in the volcano-like eruptions. I know Justin was really curious on seeing how his dog drinks water – but we’re not allowed to bring pets into the lab — other than the one day we had a wayward deer coming running through – but that’s another story…

Well.. that’s it for now… I hope you guys enjoyed the series. If you have any more ideas, please let us know and we’ll see if we can accommodate.

Okay… here’s another movie as part of our “In the blink of an eye”  series of blogs (you can view all of them by visiting the “Blink of an Eye” tag. As a reminder, all the movies are taken at the same speed as Doug’s eye blinking.

One of the requests was to capture a twirling maple seed falling – so we figured we’d give it a shot. This was actually one of those rare “hole-in-one” shots where Chris dropped the maple seed from about 8 ft up, and not only did the maple seed twirl its way into the camera’s field of view (dumb luck) – it also found its way straight into the hole on the table! I guess this is just my perspective, but in real-life, the twirling of the maple seed seems pretty normal, however, in slow-motion, it just seems kind of unnatural to me.

In any case, the twirling motion of the maple seed is known as autorotation. As the seed falls, it experiences a “wind” that blows past it. This wind blows over the flat-face of the maple seed, which essentially acts as an airfoil, generating a lift and drag vector that causes it to rotate and “glide”. This is exactly the same phenomenon that’s used by helicopters to “glide” to a safe-landing in the event of an engine failure.

Under normal operation, the helicopter engine is connected to the rotor via a clutch mechanism. Each individual blade in the helicopter rotor is an airfoil (eg. like an airplane wing) that generates lift to keep the helicopter flying. By tilting the plane of rotation of the entire rotor, the lift vector is also tilted to provide a thrust component to move the helicopter in the desired direction. So, for example, to fly forward, the rotor disk is tilted forward, to move to the right, the rotor disk is tilted to the right, and yes, if you can tilt the rotor backwards in order to fly backwards (but not particularly well).

In an engine failure situation, the pilot disengages the rotor from the engine (to minimize the load on the rotor) and the helicopter begins falling to the ground (just like the maple seed). Now, in my books, falling out of the sky is generally a bad thing, but luckily, just like the maple seed, the rotor experiences a “wind” that blows past each blade, generating lift (and drag). Now, the lift is not enough to keep the helicopter flying, but it is enough to make a controlled descent. It’s kind of the equivalent of a “dead-stick” (eg. engine out) landing of an airplane or sort of how the space shuttle lands. You basically get one chance – since you don’t have the option of a “go-around”. Accomplishing a safe “autorotation” landing is not trivial, but it is a skill that helicopter pilots keep up-to-date.

Imagine… all that from a maple seed! Isn’t it amazing how nature is so smart? Well… I hope you enjoyed this… we’ve still got more movies, but I’ll have to save them for the next entry.

Thanks for all the great ideas. Doug had to travel, but luckily Justin Brumberg and Chris Falcone volunteered and we got some amazing videos in super slow motion. We took all kinds of movies that we’ll be sharing over a series of blog entries in the next few weeks.  As a reminder, all the movies are filmed at the same speed as Doug’s eye blinking in our previous blog entry.

For today, we’ll focus on popcorn which was a request from Missa B, who posted a comment on the previous blog.

We used a small bit of oil to pop the kernels and used a torch to heat it from below. The first movie shows what happens when you get a failed popcorn.

The second movie shows a successful pop. One of the main problems we had with this part is that Justin kept on eating the popcorn!

For the last movie, we decided to put 3 kernals together to see what would happen.

So.. after watching these movies – I became curious… why does popcorn pop? A quick search around the web revealed the secrets. A popcorn kernel consists of the pericarp which is the thick, hermetically sealed outer shell and the endosperm which is the internal guts consisting mostly of starch and small amounts of other stuff, including water. Basically, heating the kernel to about 400 F allows the small amount of water inside the kernel to turn into steam.

In doing so, it drives up the pressure inside the kernel to almost 10 atmospheres. This pressure is so high that it ruptures the shell and literally flips the kernel inside-out allowing the endosperm to expand into the white crunchy popcorn that we eat.

Apparently, the ideal kernel contains approximately 13-14% moisture (by weight). Too little, and the steam pressure won’t build-up enough to pop, too much and you’ll end up with smaller popcorns that are kind of chewy. I never realized it was so complicated… I just figured you put it in the microwave, hit the “popcorn” setting and… voila.. a nice tasty treat!  Well… that’s probably more than you ever wanted to know about popcorn! We’ve got more movies, as per your requests… but I guess those will have to wait until next time…

So… we’ve got a bunch of movies to show you. To put things in perspective, the first one is a close-up view of Doug’s eye as he blinks, with the whole blink lasting approximately 430 ms (just under half a second). All the other movies were recorded at exactly the same rate – and helps give a perspective of how fast the event occurs.

The first movie we have is of a mousetrap catching a quarter. It’s really remarkable!

The second one is a close-up view of a drop of milk landing in a glass of milk. This is one of my favourites for two reasons. The first, is that I really like milk – in fact, we were using some of the milk that I usually bring in to have with my lunch. Second, it’s just plain amazing. The milk drop makes a huge crater that sends waves along the surface, and then at the very end there is a strong jet that shoots up from the middle of the crater.

Finally, the grand finale is, by far, the coolest. We used a pin to burst a water balloon – and the result is spectacular. Now, I am not sure how many people actually get paid to go to work and play with water-balloons – but, you know, this is real serious business here. Take a look!

I hope you enjoyed the movies! Okay… so here’s the offer… post a comment below asking for your favorite thing that you would like to see in slow-motion. I can’t make any promises, but we’ll try our best to capture it – and we’ll post it in a few weeks.

I still remember when Justin first returned from his deployment. I didn’t really know him at the time, but the lab threw him a welcome home party – and I remember being somewhat formal and shaking this young man’s hand (I doubt he remembers). I’ve since gotten to know him better as we’ve worked closely over the past few years, pushing back the frontiers of PDE technology together. In addition to being a very capable researcher, he’s one of the most helpful guys around – always willing to lend a hand to a fellow colleague. He really understands the meaning of “team”, and he is also an exceptional leader. Above all, he’s a good friend. We’re very proud of Justin for all he has accomplished – and truly honoured that he is part of the PDE team.

I happened to join them on a trip to GE Healthcare, which for an aerospace guy, is liking visiting a different world. I learned so much about MRIs, CT scanners, X-rays and then a whole bunch about healthcare in general – with a really fascinating look at future technologies. I was really impressed that GE is at the forefront of trying to come-up with solutions for the healthcare system – and not just for specific medical equipment. Ben and Noah have had a chance to visit Global Research, GE Healthcare in Milwaukee, Maternal Infant Care in Maryland, the GE Healthymagination launch in D.C., and even the top of a wind turbine in Massachusetts. After these experiences, I had an opportunity to catch-up with Ben and get his thoughts.

From the perspective of innovation, I learned quite a bit. I am still trying to sort through it in my head, but there are a few things that really stood out. One thing is that a lot of the folks I met are involved in something based off the internet, and their medium is information. This is pretty fascinating environment. Because the “barrier to entry” is so low, it’s relatively easy to very quickly try many different things on the web – and just see which one sticks. And that appears to be one of the keys to coming up with ideas… many cheap and quick iterations to maximize your ability to learn. I am trying to figure out how to apply this to my world, where it simply isn’t practical to build 10 different designs for a jet engine (at billions of dollars and many years of development) – and then take the best one – we’d go out of business! But it is something we can do on a smaller scale in the lab. Also, the other thing that caught my eye was the world of social media. Noah and Ben taught me a lot about this new world (for me). I’ve always used the web as a source of information and entertainment, but Noah taught me that there’s much more. The web is a fascinating place to try all kinds of experiments about human behaviour, as well as a place to gather data about humans. As more and more of the world comes on-line, the web offers the opportunity of one of the greatest social experiments of all time. One of the neatest things is the ability to infer “megatrends” and datamine aggregate trends based on “grass-roots” data from individuals around the world. To me, this brings to mind my earlier blog from SU where Paul Saffo talked about the new economy where individuals behave like consumers and workers at the same time. Somehow, this all ties together – I am still trying to figure out what it all means.

After a bunch of thinking, I decided to “Explore Innovation” – specifically, I was curious to see how other organizations innovate – specially in industries different from GE. I managed to hook-up with Singularity University and the Barbarian Group, spending 1 week at each place. In this blog, I’ll talk a little bit about my experience at SU, and I’ll write a follow-on blog about the Barbarian Group.

Singularity University is a brand new university (just founded in 2009 and has some heritage with the International Space University that I attended a few years ago. Co-founded by Google and NASA Ames, SU is focused on innovation and entrepreneurship using Ray Kurzweil’s theories of accelerating technological change as a basis. Just like ISU, they offer a 9-week summer session, and I was lucky to be able to join them for 1 week. And wow… what a week! I had some pretty awesome lectures on topics ranging from nanotech, biotech to future studies and energy. To top it off, we even had a field trip to the IBM Almaden center where we used their STM to move around iron atoms (no joke!). Back in the early 90s IBM amazed the world by arranging some Xe atoms to spell IBM. I got to see the place where that happened – and on top of it, we did our own atom re-arrangement and spelled SU using Fe atoms!! They had it all setup using a computer with a mouse. Literally, click and drag, and voila… you just moved a single atom to your desired location!

So… what did I get out of this? Well, in particular, two lectures got my attention. One was by Bob Metcalfe, co-inventor of ethernet and founder of 3Com. He presented a fantastic lecture in which he compared the development of the Internet over the past 40 years with the present challenge of developing the “Enernet”, the energy network, over the next 40 years. The analogy was surprising to me, and the many lessons are very relevant. In particular, he was one of the few persons I’ve heard recognize that “solving energy” is going to take decades, just like the internet really took 40 years to develop.

The other lecture was by Paul Saffo in which he talked about how the basis of the economy is in the process of fundamentally changing – this really resonated with Jeff Immelt’s recent thoughts about “living in a reset world”. In particular, he described how from the 1800s to the 1950s, we lived in the Industrial Revolution where the primary actor was the worker and GDP was based on worker output (eg. goods). In the 1950s, the Consumer Economy began where the primary actor was the consumer and GDP became based on consumer purchases of goods and services. I had a fun conversation with Pankaj, one of the students I befriended, who made a really good point. He indicated that if he sold me a banana for a $1, and then I sold it back to him for $1 – we’ve increased GDP! But obviously, we haven’t done anything to increase value of anything. To simple-minded me, this very much sounds like a house-of-cards, and it’s no surprise it all came to a crashing halt in 2008. And now, we appear to be resetting. It’s not clear how things will shape out, but it will take several decades and the hypothesis is that the new economy will blur the lines between consumer and worker. For example, right now, when you click on a link on the web, you’re behaving as a consumer following a link to obtain some particular information, however, at the very same time, you just did some work for some search engine company who just learned something about your preference! At the same time, you were both a consumer and a worker – real value was exchanged via information – and yet no money ever changed hands! If this is the new economy, then a very real question is how does this apply to a company like GE which makes jet engines, advanced medical equipment and large-scale powerplants? Or, is this just another exchange of bananas?

Last but not least, the best part was meeting the other students – they’re really a very unique bunch. As you might imagine, competition to attend this first summer session was very intense with several thousand applicants for only 40 spots. Next year they plan on taking the full complement of about 120 students. Also, starting in the Fall, SU plans on offering 3-day and 10-day executive classes. Overall, it was a unique experience, and certainly worth considering. If you’re interested, please visit the SU website.

Did you know that a coal-fired power plant can produce almost 500 tons of carbon dioxide (CO2) every hour?

The idea of capturing CO2 emissions from power plants and storing it in the ground is both easier and harder than you think.

It is easier because most of the technology needed to do it exists today. In fact, people have been putting CO2 into the ground to help recover oil for many years. However, it’s harder than you think because the technology is both expensive and isn’t widely used at the scale needed to capture and store CO2 from a typical power plant.

That’s where my team and I come in. We’ve been looking at ways of using the things we’ve learned from our Nanotechnology research program to reduce the cost of capturing CO2.

GE is investing heavily in cleaner coal, aka integrated gasification combined cycle (IGCC) technology, which allows precombustion CO2 capture . IGCC involves turning the coal into a synthesis gas and removing undesirable components such as sulfur and CO2 before burning it to produce electricity. The potential for cost savings comes from the fact that the gases are at high pressure and concentration, making them easier to separate.

Membranes are one of the technologies we’ve been working on. For those of you who aren’t familiar the concept, membranes are physical barriers that let some gases penetrate through them much faster than other gases. As you can see in the figure, the membranes we are developing have small holes that approach the size of the molecules. These pores tend to let smaller molecules through more rapidly. With proper nanoengineering of the molecular structure to favor selective adsorption and surface transport along the pore walls, we can also produce membranes that favor larger molecules over smaller ones. We are currently working in the lab on minimizing performance degradation over long periods of time as well as making membrane units large enough to handle CO2 at the scales produced by a power plant.

Check back here for occasional updates from our lab as we make progress on this important work. I’d also recommend our company Ecomagination site for the latest news on GE’s technologies for reducing emissions, utilizing renewable energy, making the electrical grid smarter, and eco-related activities.

Well… I guess it’s been a while since I’ve last blogged – and as you might imagine we’ve made some terrific progress. In my first blog entry (back in Jan ’06), I alluded to some testing we were doing with an eight-combustor version of a PDE integrated with a turbine. But you know what… I never told you what we found out! Needless to say, it turned out well… which is why we’re still investing in PDEs as a potential disruptive technology. How well did it turn out? Well, that set of experiments resulted in more than 8 conference papers and technical reports. And how about the rest of the PDE world? Well, you may have heard the exciting news that AFRL actually flew a PDE-powered small airplane at the end of January 2008. That’s right! Very exciting! So, it’s not exactly the futuristic “methane-misted PDE-powered airplane” that Dan Brown describes in his book “Deception Point”, but it is a huge leap forward for the PDE world.

Now, the PDE Turbine Interaction Program (PDE TIP) was a collaborative effort between GE and NASA that tested the first multi-tube PDC-turbine hybrid system. It consisted of eight unvalved tubes arranged in a can-annular configuration integrated with a single-stage axial turbine nominally rated for 10 lbm/s, 25000 RPM and 1000 hp. The system accumulated 145 minutes of operation including many runs of 5+ minutes for the rig to achieve thermal steady-state and for the turbine to attain constant speed. The rig was operated at frequencies up to 30 Hz (per tube) in different firing patterns using stoichiometric C2H4-air mixtures at conditions up to 8 lbm/s, 22000 RPM and 750 hp. Pretty impressive, eh?

By no means have we solved the major challenges. In fact, if anything, we raised a whole bunch of new questions!!! But that’s the whole point of research!! If it were easy, well, we wouldn’t be doing it. Aside from actually working in the first place (without falling apart), one of the key results showed significant attenuation of the pressure wave across the turbine. This strongly suggests that overall PDE-turbine hybrid engine noise would not be much louder than existing commercial engines. That’s a big deal since most people’s first reaction to hearing a PDE is “Wow… that’s loud”… well, so is driving your car without a muffler… and nobody really does that. Turns out that having components downstream of the PDE tubes acts a lot like a muffler – without really even trying to tune or optimize the design in any way. We also did more than just make sure it held together, but rather we instrumented the rig with strain gauges and we also quantified the rotordynamics to get a sense of the overall mechanical responses. We were happy to report that, although the mechanical response levels were higher than existing commercial engines, they were within the material strength limits. Of course, there’s still a lot of work to do in this area because we weren’t operating at the really high temperatures and pressures of true engine conditions. The rig also raised a lot of questions… so, we made our life a little bit easier by using a gaseous fuel as a surrogate for liquid Jet fuel… so how do you go about detonating liquid fuels? And what about the turbine design? Could we do a better job of it? Our experiments showed no change in turbine efficiency when fired under PDE mode as compared to its normal steady state mode (mind you, we had a fairly large uncertainty). This was quite a pleasant surprise since we had made no attempt to optimize the turbine – and the next time we do it, we’ll have to improve our measurement uncertainty.

So… we’re not exactly going to be flying on one of these in the immediate future… but, hey, the PDE TIP rig did give us great confidence in the future of the technology. It tackled a whole range of issues from operability to turbine performance to mechanical response and identified no insurmountable barriers. In that sense, the PDE TIP’s true value was in demonstrating the feasibility of the PDE-turbine hybrid concept. It’s what we call a “jugular experiment” the tough first experiment that says… “Yeah, this thing could work”, but with a lot of details that still need to be ironed out in future experiments!

Well… I’d better get going… we have some more “ironing” to do!

This past summer, I had one of the most exciting experiences of my career when I attended the 9-week International Space University Summer Session Program (ISU SSP) from June 20 – August 25, 2007 in Beijing, China. The ISU is an accredited Masters degree university based in Strasbourg, France that also organizes an intense summer session hosted by a different country each year. This year, it was hosted by the Chinese Aerospace Science and Technology Corporation (CASC) and Beihang University, one of the top aerospace universities in China. For me, this incredible opportunity was enabled by a fellowship from the Canadian Foundation for the ISU (CFISU). From the work perspective, I took advantage of an educational leave of absence that GE researchers can take for professional development.

The SSP brought together 117 international young professionals from all walks of life. Founded on the principles of the ’3 I’s': International, Intercultural, Interdiscipinary, the ISU has the goal of building personal international relationships across all disciplines relating to aerospace and space exploration. Students came from 27 countries with a variety of backgrounds ranging from engineering to life sciences to policy and law. I guess I should give the obvious description of the curriculum, but the experience is much more than just workshops and lectures. It’s about interacting with a unique and phenomenal group of individuals, experiencing new cultures and really broadening your outlook in life. I think the best way to share some of these experiences is through pictures.

The ISU curriculum begins with 4-weeks of lectures and workshops. The first picture on the left shows Dr. Jeff Hoffman, one of the astronauts who fixed Hubble in 1993 and is now a professor at MIT, who taught large sections of the space sciences and engineering sections. During the evenings, we had panel sessions with invited guests – the second picture shows me with Colonel Yang Liwei, the first Chinese astronaut (taikonaut) to orbit the Earth in 2003. We were also honoured by several field trips to see a variety of the Chinese space program facilities that are normally not accessible to the public. The picture on the right shows me with Shenzhou 6, the second manned-space capsule launched in 2005.

The second part of the curriculum is a 2-week focused set of workshops and a project. I selected the life sciences department because it is the subject area with which I am least familiar. The first picture shows my colleague, Jon Liberda, participating in a demonstration by Dr. Gilles Clement, Director of Research at CNRS who was our department chair at ISU. Jon’s eyeball is being projected on the screen using hardware that was flown on the Mir space station to perform similar experiments in space. The second picture shows Meritxell Vinas and Erin Tegnerud being launched into the sky on a “reverse-bungee” Beijing amusement park ride which had a launch acceleration of 6g followed by severe tumbling motions. For our project, my colleague, Steve Ulrich and I, used the ride to study vestibulo-ocular reflex in highly disorienting environments which could be important for pilots in emergency situations. We’re hoping to present our results at an upcoming aerospace medicine conference. In the last picture, Dr. Jeff Jones, a NASA flight surgeon, is discussing the challenges of extra-vehicular activities (EVAs).

The last part is a team project. I chose to work on the “Earthquake” project which examined the role of space-based assets to predict earthquakes and assist with disaster-relief efforts post-earthquake. The most interesting aspect was organizing individuals from different cultures, disciplines and language abilities to produce a 100-page report and final presentation – with absolutely no project management structure. Our project is being presented at the International Astronautical Congress in Hyderabad (Sept 2007) and was presented to NASA headquarters in October 2007. It will also be presented at the American Geophysical Union in December 2007. We’re also planning on presenting it to the United Nations Committee on the Peaceful Use of Outer Space (COPUOS).

Living in China for 2 months was, of course, an incredible experience… Chinese foot massages, deep-fried scorpions, the Hutongs, the Olympic facilities, playing basketball with the Chinese students from Beihang University, and of course the food!

Next year, the Summer Session Program has been renamed to the Space Studies Program (in recognition of the southern hemisphere nations whose summer is in December) and will be held in Naples, Italy. If you’re interested, please visit the ISU SSP website.

With a start I realized I was late for work, jumped out of bed, ran through the waterless shower and quickly dressed.

Looking outside, I noticed that my wind turbine had stopped, but luckily my solar panels and geothermal sinks were making up for the power deficit. My neighbours thought I was crazy getting rid of our Fusion-o-matic generator – relying purely on renewable energy was considered only for the environmentalist EcoCrazies. To me it just made economic sense, the fusion generator was expensive to maintain – and hey, if the Sun and Earth want to give me free energy – I’ll take it! The sun was shining and it was going to be a beautiful day – but it was getting late!

David, my personal electronic assistant (PEA), was one step ahead of me.

“Adam, I’ve already contacted Piet to let him know you’ll be late,’ David droned. I couldn’t afford the expensive PEA, which came complete with a 3D hologram, so I just had this disembodied voice that piped through my handheld BlueBerry.

By the time I made my way downstairs, David had already adjusted the room heating and had interfaced with the Fooderator to have my breakfast ready. As I gulped down my milk, David read out my daily biostats. “Heart rate 55 beats per minute, Blood Pressure 120/80, cholesterol… Adam… it’s a little high – you really need to watch what you eat!”

“Awww… lay off David. Do me a favour and warm up the IntraCity Teleporter”, I asked. I was running late, so I had no choice. I hated using the thing – the thought of all my molecules being torn apart, only to be reconstructed at the receiving station unnerved me – what if it put my head on backwards? It was only a machine, afterall – what did it care? I was still old-school. I much prefered my cold-fusion powered personal transport – but I have to admit that the price of water was getting pretty high. There’s some talk of a water shortage, but personally I think its just profiteering by the “Big Water” companies.

Alright… so maybe this isn’t exactly how I started my morning, but you know, this might just be a glimpse into the future!

If you want a glimpse into perhaps a more realistic future, check out Wired NextFest, a 4-day technology festival showcasing some of the newest and most innovative products and technologies. This year, it’ll be in NYC and GE will have a bunch of stuff on display.

I am pretty excited because several of my colleagues and I will be at the GE Global Research booth giving demos of some of our latest scientific research. Some of these demos have already made their way into actual products, but most of them are still works in progress straight from the lab! Stop on by if you have a chance!

As evidence, the first picture (left) shows an image of Hurricane Katrina on August 28, 2005 as it approached New Orleans. Note the counterclockwise swirl. This second picture (right) shows Cyclone Larry (on March 20, 2006), which was the largest cyclone to hit the northeast coast of Australia since 1931, wiping out 90% of Australia’s banana crop. Note the clockwise swirl.

The Coriolis force is definitely real! As an aside, “tropical cyclone” is the general term for these swirling storms, which have different names in different parts of the world for historical and regional reasons. For example, the storms in the Atlantic (that impact North America) are called hurricanes and in the Northwest Pacific Ocean they are called typhoons. In the Indian Ocean and Southwest Pacific Ocean they’re called cyclones. Apparently, Australians have historically preferred the scientific term “willy-willy” (presumably because they make their heads spin willy-willy), but have adopted the term cyclone in modern times. (But I am told they still use willy-willy to describe “mini-dust devil type” phenomenon that sometimes occurs in the Australian desert).

Now, given that hurricanes are affected by the Coriolis force, I guess it seems logical that whatever occurs in the atmosphere must occur in my toilet. It reminds me of my favorite Simpson’s episode where Bart visits the American embassy in Australia and flushes the toilet which is equiped with a huge electro-magnetic-mechanical contraption that changes the direction of the water so that it flushes ‘the American way’. The short answer is that the myth is indeed a myth. The Coriolis effect is real, but in your toilet it is several orders of magnitude smaller than the local effects (such as the the exact geometry of the drain, or in particular, any microscopic residual motion in the water). It’s these random local effects that dominate and determine the final overall direction of spin. I have personally verified this in numerous toilets throughout Australia and Ecuador. That’s the short answer. For a more detailed answer… read on!

My friend, Piet Moeleker, and I decided to travel to Ecuador a few years ago to study this phenomenon in detail (okay… we were on vacation). Like every tourist, we visited the Equatorial monument (Mitad del Mundo) just outside Quito. The first thing to know is that the official Equatorial monument is in the wrong spot (GPS indicated 7 seconds North – about 300 ft North) – this fact is generally acknowledged by everyone. A small private museum has sprung up beside the official government tourist attraction with the claim that they have the ‘true’ equator as determined by GPS. They even have ‘science’ experiments to prove it. This experiment involved filling a basin with water, then pulling the drain plug and observing the direction of spin of the water. They had a line painted on the ground, which was the ‘Equator’. The guide moved the basin approximately 1 meter to the ‘south’ and did the experiment and observed the water spin CW. The guide then moved the basin 1 meter to the ‘north’ and watched the water spin CCW. The guide repeated the experiment a third time on the ‘Equator’ and observed it can go in either direction. Sure seemed convincing… except it defied our intuition of fluid mechanics. Even more puzzling was that their “Equatorial line” painted on the ground didn’t seem to be the true Equator (my handheld GPS was reading 3.5 seconds North – about 110 meters North). Hmmm… so what’s the science?

The governing equations for fluid mechanics can be written in a rotating reference frame such that all the important effects (including Coriolis effect) are represented by mathematical terms. Using some simplifying assumptions and rearranging the terms yields the Rossby number, a dimensionless number that represents the ratio of the inertial effects (acceleration) to the coriolis effect:

Where U is the fluid velocity, L is the characteristic length scale of the system, w is the rotation rate (=24 hours/day = 7.27×10^-5 rad/s on Earth) and theta is the latitude.

We can see that if the numerator is large, then inertial (or acceleration) effects dominate, and if the denominator is large, then Coriolis force dominates. A general rule of thumb is Ro < 1 means Coriolis force is important. Lets examine our two cases, but first we need some numbers. Using a highly calibrated tape measure, I measured my toilet bowl to be 12 in (0.3 m). Let’s assume that the water approaches the drain at around 1 m/s (which is really fast… I guess I have a ‘turbo toilet’). Most of the hurricanes that viciously attack the US actually start their life as perturbations in the Easterly trade winds just off the coast of Africa. These low pressure atmospheric systems (tropical depressions that eventually form into hurricanes) have wind speeds of about 10 m/s with length scales of the order of 1000 km. Hurricane formation is a complicated process (subject of another blog?), but it turns out that the rotation of the hurricane is determined at these early stages of formation. We’ll assume a latitude of 20 degrees.

Well… that’s pretty clear. The tropical depression is definitely influenced by the Coriolis force, whereas the toilet is not!! It turns out that the local forces in our toilets are much more powerful than a hurricane!

Seriously, what’s happening is that, on the small length scales and fast rotation rates (compared to the Earth’s rotation) of water draining in the sink, the effect of the Coriolis force is relatively weak. Other effects, in particular, any microscopic residual motion of the water (prior to pulling the drain plug or flushing the toilet) dominates the final direction of spin. In principle, if you did a very carefully controlled experiment and waited long enough (days) such that all residual motion in the sink had ceased, you would then see the effect of Coriolis force and the water would spin in appropriate direction. In practice (ie: everyday use) – this does not happen.

A fascinating discussion arises from Figure below which shows the Rossby number as a function of latitude for both the toilet and tropical depression. Remember, Rossby number less than one means Coriolis force dominates, so we see that the Coriolis force is smallest at the Equator and largest at the poles. This is in agreement with the basic definition of Coriolis force which predicts that it is greatest at the poles and identically zero at the Equator. At all latitudes, the toilet does not feel the effects of the Coriolis force since the Rossby number is huge. Large scale atmospheric phenomenon (like hurricanes), however are affected, provided the latitude is greater than 5 degrees (where it crosses the Rossby = 1 line).

From the point of view of Coriolis force alone, the strongest ‘cyclonic storms’ are likely to occur at high latitudes (ie: ‘nor’easters in the US) since the Rossby number becomes much smaller than 1. Polar lows are “hurricane-like” storms (with the characteristic swirl) that form near the arctic – but no one really lives there, so we tend to hear less about them. Luckily, neither of these can form into hurricanes because they lack the warm ocean water which is the required energy source for hurricane formation. So… interesting, hurricanes are highly unlikely to form within 5 degrees of the Equator because the Coriolis force is not strong enough so close to the Equator. As it turns out, the warm waters required for hurricanes are typically found at latitudes less than 20 degrees…. hence tropical cyclones are almost always formed between the latitudes of 5 and 20 degrees!

Now… back to our Ecuadorian equatorial paradox. What was going on? Piet and I proceeded to perform our own experiments with the “magic” water basin using small leaves to visualize the flowfield.

We were able to conclusively demonstrate that we could indeed get the water to swirl in any arbitrary direction. The museum guide was apparently a “sham artist” and deliberately left a little bit of ‘spin’ (no pun intended) in the water basin – that’s what set the spin direction of the draining water. What about the location of the Equator? The museum claimed to use GPS to identify the location of the Equator. Well, it turns out they probably did. However, until the late 1990′s the US deliberately degraded the GPS signal for civilian users to approximately 100 meter accuracy – and this “equator” was just about 100 meters off. Piet and I set off to find the true equator using my handheld GPS which had 30 meters accuracy. Sure enough we found it – on some kind of highway with dump trucks and buses passing by at high speed. We proceeded to build our own lasting monument to the TRUE equator using garbage, Sprite bottles and an old bucket to document our historic find. And that, ladies and gentlemen, is the unswirled truth!

In the first frame, the tube had been filled with a hydrogen-air mixture and a regular automobile-style spark ignited the mixture further upstream (ie: to the left). The regularly spaced obstacles (washers) are there to assist the DDT process. In the second and third frames, a regular deflagration has formed and is propagating to the right – the white regions represent luminosity from the combustion. The obstacles help promote flame acceleration (ie: they cause stretching of the flame front so that there is more burning area, which causes the flame to move faster, which causes it to stretch more, which results in even more burning area etc etc). Eventually, the accelerating frame reaches a sonic condition and you have the formation of localized shock waves and hot spots.

In the fourth frame, the luminosity is very intense at the last obstacle – it is just about ready to transition. In the fifth frame, a very planar luminous structure is seeing at the far right – the detonation wave has formed!

This entire DDT process takes a certain length (DDT length) and time (DDT time). A key challenge is to minimize the length (to make a shorter engine – which saves weight) and to minimize the time (to maximize the firing frequency). The movie is also available here.

Since the tube was plastic, the luminosity from the combustion can be seen in Frame 124 while the detonation wave was still in the tube. The detonation wave exits the tube and diffracts in Frames 125 through 128.

In Frame 130, we see that the leading shock wave is starting to decouple from the combustion zone indicating that the detonation is failing. In Frame 134, the leading shock wave is completely decoupled and the detonation has failed. If you look closely in the middle of the combustion zone you can see a Mach disk being formed.

The past few weeks have been a blast… literally!! I am smack in the middle of some exciting, ground-shaking experiments testing a new kind of airplane engine called a Pulsed Detonation Engine (PDE). These aren’t just any experiments, they happen to be the first of their kind in the world. I’ll tell you more about them, but first… let me tell you some more about PDEs.

As the name implies, a PDE uses “detonations” to burn the fuel in a more explosive and more efficient manner compared to your usual steady deflagration flame. A deflagration is the normal way to burn fuel… you see it everywhere… a fireplace, a candle burning, inside an internal combustion engine, and inside today’s aircraft engines. It’s also what powers the world in today’s large megawatt scale gas turbine based powerplants. A detonation, on the other hand, looks nothing like a deflagration. A detonation is a shock wave travelling at Mach 5 (5 times the speed of sound!!) that ignites the fuel-air mixture as it passes. The combustion products are at higher pressure (this is a key difference from a deflagration) and that translates into a more efficient conversion of the chemical energy stored in the fuel into useful work.

The reason why I am so excited about PDE’s is that we can potentially reduce the amount of fuel burned by a whopping 5%!! That might not sound like much, but in the aircraft propulsion world a 1% improvement translates into hundreds of millions of dollars of savings per year!! Considering that present day deflagration-based gas turbine engines have already been highly optimized over the past 50 years (a 0.2% improvement is considered a major breakthrough)… PDE’s represent a possible game-changing technology that could revolutionize aerospace propulsion. Equally important, by reducing the amount of fuel burned, PDE’s also reduce the amount of emissions and greenhouse gases that get put up in the atmosphere… it’s good for the environment too!

So… back to my experiments… what exactly am I doing? Well, we’ve designed and built an eight-combustor version of a PDE and integrated it with a turbine… the first steps to understanding how to integrate a PDE in a real gas turbine engine. I’ve been leading this collaborative effort with NASA for the past two years and we’re in our final phases of the program. Now, this particular laboratory experimental engine will not be flying anytime soon, but we’ve gathered some unique data that has increased our understanding and has moved us one step closer.

Well… I’d better go… time to get back to my experiments… there’s nothing like the sound of the turbine spooling up as the PDE’s fire. I’ll see if I can find some video of an experiment, then you’ll see why this is so much fun!