Category Archives: Astronomy

Signature Spikes

John F. Lindner July 20, 2022 10:34 PM

Nearly a quarter century in the making, I was tremendously excited and relieved last week by the release of the first images from the James Webb Space Telescope. I remember the trials, tribulations, and triumph of the Hubble Space Telescope and … Continue reading →

Posted in Astronomy | Leave a comment

Alien Suns Reversing in Exoplanet Skies

John F. Lindner May 19, 2022 10:07 AM

Not only can suns stand still in the sky, from some exoplanets their motion can apparently reverse! Wooster physics-math double majors Xinchen (Ariel) Xie ’21 and Hwan (Michelle) Bae ’19 and I just published an article elucidating these apparent solar reversals. Michelle … Continue reading →

Posted in Astronomy, Mathematics, Physics | Leave a comment

Black Hole Above the Fold

John F. Lindner May 14, 2022 10:04 PM

When grocery shopping, I normally just glance at the newspapers in the newsstand. However, this morning, I was excited to see “above the fold” of the Wall Street Journal a large reproduction of the first image of the supermassive black hole … Continue reading →

Posted in Astronomy, Physics | Leave a comment

Slide Rule Examples

John F. Lindner April 14, 2022 11:30 AM

Slide rules were widely used in engineering, science, and mathematics until the early 1970s, including during the Gemini and Apollo space programs. Although rendered largely obsolete by the advent of inexpensive electronic calculators, their descendants continue to have specialized applications, such … Continue reading →

Posted in Astronomy, Mathematics, Physics, Students | Leave a comment

Diffraction Limited

John F. Lindner March 17, 2022 11:41 AM

Yesterday, Webb optical telescope element manager Lee Feinberg said “We made the right telescope” while reporting that its focus has reached the  diffraction limit of 0.7 arcseconds at the infrared wavelength of 2 microns. (For comparison, from Earth, Luna subtends … Continue reading →

Posted in Astronomy, Physics, Space Exploration | Leave a comment

Halo Orbit

John F. Lindner February 7, 2022 5:43 PM

The Webb telescope has fully deployed and arrived at its halo orbit about the second Earth-Sun Lagrange point. But how can it orbit an empty point in space? In the accompanying animated sequence of inertial space diagrams, a star (red) … Continue reading →

Posted in Astronomy, Physics, Space Exploration | Leave a comment

Astronomy Christmas Gift

John F. Lindner December 25, 2021 5:11 PM

I awoke early this Christmas morning to watch the successful launch of the James Webb Space Telescope. I remember the genesis of the telescope a quarter of a century ago when it was called the Next Generation Space Telescope. (The … Continue reading →

Posted in Astronomy, Space Exploration | Leave a comment

Part Science, Part Art, Part Luck

John F. Lindner November 14, 2021 5:50 PM

Launched just last month, Lucy will be the first spacecraft to visit Jupiter’s trojan asteroids, rocky swarms that orbit about 60 degrees ahead and behind Jupiter in its orbit. Hal Levison, Lucy’s Principal Investigator, has described Lucy’s complicated trajectory, which includes an Earth … Continue reading →

Posted in Astronomy, Space Exploration | Leave a comment

Dandelin Spheres

John F. Lindner September 6, 2021 9:11 PM

In 1609, Johannes Kepler first described how planets orbit the sun in ellipses. Kepler understood an ellipse as both the locus of points whose distances from two foci sum to a constant and as the intersection of a cone and a plane. But how … Continue reading →

Posted in Astronomy, Mathematics, Physics | Leave a comment

Free-Fall Spinning Tunnels

John F. Lindner April 28, 2021 9:01 PM

Jump into an evacuated hole drilled straight through a uniform, static Earth-like sphere. Accelerate to 7.9 km/s (or 18 000 m.p.h.) at the center, then decelerate back to zero at the antipodes 42 minutes later! Step out of the hole upside down — … Continue reading →

Posted in Astronomy, Physics | Leave a comment