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Goddard Space Flight Center, Greenbelt, Maryland 20771

ENGINEERING COLLOQUIUM

Monday, September 29, 2014 / 3:30 PM, Building 3 Auditorium

John Ashmead

"Invisibility,  the Theory & Practice,  or A Sufficiently Advanced Science Can Be Even Better Than Magic!"

ABSTRACT -- We'll look at the history, theory, & practice of invisibility.  We'll start with Wells's The Invisible Man (which has some surprisingly accurate physics); look at the uses of invisibility in war & peace, for stealth aircraft, traffic safety, & entertainment; then review the extraordinary progress of the last few decades.

In 1964 Vesalago showed Maxwell's equations allow for negative indexes of refraction. With these he showed we could achieve extraordinary effects, wrap light around objects, even make it bend backwards.  But it has only been since 2000 that we've had the technology -- with nano-fabrication & 3-D printing -- to build materials with the necessary properties.  But if we can build it, can we design it?  In 2006 Leonhardt & others found ways to use general relativity & complex analysis to do the math.  And it was only just last year that we saw the first engineering applications of this.

What next?  Because practical invisibility has applications everywhere we need to focus & control light, in war & in peace, for camouflage, for telescopes & optics, for entertainment, optical computing & switching...

SPEAKER -- John Ashmead says of himself that

I have a BA in physics from Harvard, summa cum laude and a masters in physics from Princeton. My physics dissertation, Time and Quantum Mechanics, is scheduled for completion this year. It asks what happens if we quantize time using the same rules as we use for space. Curiously enough, this line of attack doesn't appear to have been tried before. It predicts that -- if we take Einstein's theory of relativity seriously --  the usual quantum wave functions in space must also jut a few attoseconds into the future and the past.  This concept doesn't seem to "break" any other concepts & is testable.

I presented a poster on the dissertation at the Third International Conference on the Nature and Ontology of Spacetime and did a short talk on the dissertation at the 4th Feynman Festival in Olomouc. The experimentalists I've met said if I can give them numbers, they can put the numbers to the test.

I'm currently building software at Nistica, a firm that makes some of the optical switches that route the internet.  Fierce competitive pressure means we work at the bleeding edge between engineering & physics, pushing the optics & electronics sometimes harder than they really want to go!


Engineering Colloquium home page: https://ecolloq.gsfc.nasa.gov