Author Archives: John F. Lindner

About John F. Lindner

John F. Lindner was born in Sleepy Hollow, New York, and educated at the University of Vermont and Caltech. He is an emeritus professor of physics and astronomy at The College of Wooster and a visiting professor at North Carolina State University. He has enjoyed multiple yearlong sabbaticals at Georgia Tech, University of Portland, University of Hawai'i, and NCSU. His research interests include nonlinear dynamics, celestial mechanics, and neural networks.

Logic with Nonlinear Maps

In 1999, Bryan Prusha ’98 and I wrote an article for Physics Letters A illustrating why logic requires nonlinearity. Recently, with Bill Ditto, I revisited this theme by demonstrating how to encode all 16 binary boolean (true-false) functions in … Continue reading

Posted in ScotBlogs Contributed | Comments Off on Logic with Nonlinear Maps

Barred Warped Wobbly Spiral

Advances in astronomy can rewrite even introductory astronomy textbooks. Although no spacecraft have yet exited our Milky Way galaxy to image it from the outside, the Gaia astrometry space telescope recently completed a dozen years of accurately measur… Continue reading

Posted in ScotBlogs Contributed | Comments Off on Barred Warped Wobbly Spiral

Weak Prime Number Theorem

As a child, I was inspired by Arthur C. Clarke‘s 1956 science fiction novel The City and the Stars to search for patterns in prime numbers. Chapter 6 begins: Jeserac sat motionless within a whirlpool of numbers. The first thousand … Continu… Continue reading

Posted in ScotBlogs Contributed | Comments Off on Weak Prime Number Theorem

Fram2 Over the Poles

Historically, astronauts have launched roughly eastward to exploit Earth’s spin, whose equator moves at nearly 1000 mph with respect to its center. But last week the Fram2 SpaceX Dragon crew became the first humans to orbit Earth over its poles. … Continue reading

Posted in ScotBlogs Contributed | Comments Off on Fram2 Over the Poles

2D Kepler Conjecture

Johannes Kepler asserted in 1611 that no packing of identical balls has density greater than the hexagonal close-packed “cannonball” packing of oranges at a grocery store’s fruit stand. But the gulf between intuition and proof was so … Continue reading

Posted in ScotBlogs Contributed | Comments Off on 2D Kepler Conjecture

Blue Ghost Eclipse

Last night’s lunar eclipse, as seen from Earth, looked like a solar eclipse, as seen from Moon. Firefly Aerospace‘s NASA-funded Blue Ghost lunar lander recently became the first commercial spacecraft to successfully land on Moon. Blue Ghost&#8217… Continue reading

Posted in ScotBlogs Contributed | Comments Off on Blue Ghost Eclipse

Mach Cutoff

Two weeks ago, I watched live via Starlink as the Boom Supersonic XB-1 test aircraft broke the sound barrier in level flight, the first all-civilian aircraft to do so. This success promises the return of commercial supersonic flight, at least … C… Continue reading

Posted in ScotBlogs Contributed | Comments Off on Mach Cutoff

Mount Wilson Trek

Nobody walks in L.A., but as a Caltech grad student in the mid 1980s without a car, I once walked from my dorm room up Mount Wilson and touched the enclosure of the famous 100-inch Hooker telescope where Hubble & … Continue reading → Continue reading

Posted in ScotBlogs Contributed | Comments Off on Mount Wilson Trek

Outer Planet Cloud Colors

From my teens to my twenties, from junior high school to graduate school to young professor, I excitingly followed the first reconnaissance of the outer solar system by the Pioneer and Voyager spacecraft. But the exploration isn’t over. For the &… Continue reading

Posted in ScotBlogs Contributed | Comments Off on Outer Planet Cloud Colors

Sum of Reciprocals

The sum of the reciprocals of the natural numbers diverges, but slowly, like the logarithm of the number of terms. The sum of the reciprocals of the prime numbers also diverges, but even more slowly, like the logarithm of the … Continue reading &… Continue reading

Posted in ScotBlogs Contributed | Comments Off on Sum of Reciprocals