- The Science of Speed: Why Driving Fast is Harder than You Think
- From Nanomaterials to NASCAR: Materials at 200 Miles per Hour
- Nanomaterials: Why Small is the Next Big Thing
Is it really all that hard to drive fast? No – if you assume a spherical racecar. If you think about the physics of a non-point particle turning highly banked corners at 3g on tires with coefficients of friction greater than one, you will quickly realize that there is far more to going fast than stepping on the accelerator. While the driver applies Newton's Laws on the track, a behind-the-scenes group of physicists and engineers are running computational fluid dynamics simulations, developing low-friction coatings, researching energy absorbing materials for safety, and even finding ways to use oranges to reduce flexion losses in tires.
Dr. Diandra Leslie-Pelecky, author of The Physics of NASCAR and the motorspots blog Building Speed, shows why you cannot win races without getting the math and science right. Although race car drivers may not use terms like ‘impulse’ or ‘friction’, the best of them develop a strong gut-level understanding of the rules of physics. As one driver told her “If I’d only realized that racing was really just math and science, I would have paid more attention in school.” The talk ends with a brief examination of how to use popular culture to get – and keep – people interested in math and science.
Level: Can be adapted for any audience from general to physics colloquia. No prior knowledge of racing or physics is assumed.
From Nanomaterials to NASCAR: Materials at 200 Miles per Hour
You cannot win a NASCAR race without understanding science. Materials play important roles in improving performance, as well as ensuring safety. On the performance side, NASCAR limits the materials race car scientists and engineers can use to limit ownership costs. 'Exotic metals' are not allowed, so controlling microstructure and nanostructure are important tools. Compacted Graphitic Iron, a cast iron in which magnesium additions produce interlocking microscale graphite reinforcements, makes engine blocks stronger and lighter. NASCAR's new car design employs a composite called Tegris that has 70 percent of the strength of carbon fiber composites at about 10 percent of the cost.
The most important role of materials in racing is safety. Drivers wear firesuits made of polymers that carbonize (providing thermal protection) and expand (reducing oxygen access) when heated. Catalytic materials originally developed for space-based CO2 lasers filter air for drivers during races. Although materials help cars go fast, they also help cars slow down safely—important because the kinetic energy of a race car going 180 mph is nine times greater than that of a passenger car going 60 mph. Energy-absorbing foams in the cars and on the tracks control energy dissipation during accidents.
To say that most NASCAR fans (and there are estimated to be 75 million of them) are passionate about their sport is an understatement. NASCAR fans understand that science and engineering are integral to keeping their drivers safe and helping their teams win. Their passion for racing gives us a great opportunity to share our passion for science with them.
Level: Can be adapted for audiences from the science-interested public to a physics or materials science colloquium.
If you used makeup or sunscreen, pulled something out of your refrigerator, played golf, wore stain-resistant clothing, hugged a stuffed animal, wore an opal, ate a McDonald’s burger, drove a diesel vehicle or painted your house, you probably came into contact with a nanomaterial. The magic of nanomaterials is the surprising discovery that when you make a material very, very small, it doesn’t always act like itself. This knowledge, combined with the ability to make materials with atom-by-atom control, means that we can produce nanomaterials with properties impossible for the same material to have when it is big. Nano creates an amazing new range of possibilities, from surfaces that self-decontaminate in a terrorist chemical attack to nanoparticles that track down and kill individual cancer cells before they can multiply.
In 1986, Eric Drexler sounded ominous warnings about the dangers of nanotechnology run amok. He proposed a hypothetical construct called ‘grey goo’: A population of self-replicating nanobots would grow like a cancer and consume everything. While Drexler’s apocalyptic vision was certainly attention getting, ‘grey goo’ has been replaced by a far more realistic and imminent concern. The unexpected properties of nanomaterials means we can make materials we’ve never been able to make before – but it also means that we can’t always predict how those materials will interact with people, animals and the environment. The specter of grey goo is hyperbole. Concern over whether titanium dioxide nanoparticles in sunscreen can pass through your skin or how antimicrobial nano-silver might be released into waterways are real challenges we face right now. This talk gives a brief history of nanotechnology (which surprisingly starts in the 4th Century CE) and highlights ways in which nanotechnology is already affecting your life, and will be in the future.
Level: For the science-interested public.
American Program Bureau