Rick Nelson

Gravity waves and newborn babies
June 21, 2008

ATLANTA, GA. I had always wanted to study theoretical physics in college, but my parents thought that a more practical filed, such as accounting, would provide a better return on their tuition investment. We compromised, and I studied electrical engineering.

Of course, other than for the need to declare a major there needn’t be a sharp divide between pure science—the pursuit of knowledge for its own sake—and applications-oriented engineering. The relationship between the two was addressed by Joseph H. Taylor, the 1993 Nobel Laureate in Physics, in a keynote speech at the IEEE MTT-S International Microwave Symposium June 17.

At the beginning of his talk, titled “Symbiotic Relationships in Technology and Basic Science,” Taylor invited the applications-oriented MTT-S show attendees to step back for a few minutes and think about the relationship between technology and the fundamental laws of nature that make technology possible. Technologists, he said, need to understand how the materials they use interact, and they need mathematical description of nature’s laws to form extrapolations to predict how materials will respond in real-world applications. “It’s a two-way street,” he said. “Science enables technology, and technology enables science to get done.”

He commented that we should remind ourselves that it’s only been for the last couple of hundred years, commencing with Michael Faraday’s experiments and continuing with Joseph Henry’s work on mutual- and self-inductance, that we’ve had any idea of relationship of magnetism and electricity. He said that researchers like Faraday and Henry were not engineers, but rather scientists doing research just to acquire understanding. He cited the probably apocryphal exchange between Faraday and Queen Victoria, who asked of what use are the discoveries related to electricity, to which Faraday replied, “Of what use is a newborn baby?” (A similar conversation regarding the value of flight is said to have occurred between Benjamin Franklin and a skeptic in attendance at the first hot-air balloon flight, in Paris in 1783.)

Indicating the tension that can exist between scientists and engineers, Taylor said that Henry, the first head of the Smithsonian Institution, built the first telegraph, but as a professor, he didn’t get the credit—that went to Samuel F. B. Morse.

Taylor went on to note that James Clerk Maxwell put into a mathematical framework the experimental observations of others. Maxwell’s equations, he said, predict a radiative form of electromagnetic energy, which Heinrich Rudolf Hertz was subsequently able to generate and detect. It wasn’t long, Taylor said, until practical radios came into use, as did electric motors, which also depend on the effects modeled by Maxwell’s equations. In fact, Taylor said, Maxwell’s predictions have lead to the rise of the industries that produce much of the world’s wealth and prosperity.

The road between science and technology is fundamentally a two-way street, Taylor said. Scientific understanding enables technology, and the useful machines developed by technologists can enable new scientific inquiries in a cycle that we all benefit from.

He described his own work with the large radio telescope at Arecibo, Puerto Rico, recounting the 1974 discovery of a binary pulsar—among the remnants of supernova that exploded in 1054. He said that subsequent observations on that pulsar confirm Albert Einstein's prediction that objects accelerated in a strong gravitational field will emit gravitational waves. The pulsar’s relativistic velocities of one tenth the speed of light, he said, afforded an opportunity to test predictions that the pulsar’s orbit should shrink by 1 mm per orbit.

“It was the ultimate in scientific chutzpah,” he said, “to think that we could make that measurement from 25,000 light-years away.” But he added that very high-bandwidth low-noise receiver front ends developed by engineers made the feat possible.

He cited other research projects, including the Laser Interferometer Space Antenna (LISA) spacecraft, which will further study gravitational waves, and the Wilkinson Microwave Anisotropy Probe (WMAP) NASA Explorer mission, which measures cosmic background radiation and helps confirm the presence of dark matter.

Such missions, he concluded, would not be possible without healthy and continual interaction between scientists and engineers.

I would certainly agree with that. My only quibble might be in Taylor’s drawing of such a sharp line between pure science and applied engineering. Samuel F. B. Morse was not, strictly speaking, an engineer; he was a painter who had a serendipitous encounter with experimenter Charles Thomas Jackson that lead to a practical telegraph. And in fact, Taylor did acknowledge that there is crossover in which scientists may turn to engineering, and vice-versa. The important thing, he said, to find a position for which you can’t wait to get up in the morning and get to work.

Posted by Rick Nelson on June 21, 2008 | Comments (0)