by Rex Parker, PhD director@princetonastronomy.org
Meeting Nov 10 at Sherrerd Hall 101, Princeton University. At our meeting Nov 13 we’ll dive back into the discussion of dark matter in the universe. If you are interested in the fundamental theories in physics then we have a presentation teed up for you. There has always been some tension and dissatisfaction about the absence of a clear physical model for gravity, light, electricity, and magnetism, which remain mysterious for most people outside those highly trained in the mathematics. Quantum physics is indescribably strange and defies conventional human intuition, even for a genius like Nobel laureate Richard Feynman. There is a prevailing notion that at the deepest level the universe is inaccessible to average minds. As Neil De Grasse Tyson says, “the Universe is under no obligation to make sense to you.”
But as amateur astronomers, the natural philosophy of physics is our domain, and as we turn our smart telescopes upwards and outwards in our backyards we find ourselves staring again at the profound questions of cosmology. What makes a giant spiral galaxy spin so beautifully yet hold together in space? How are stars born within nebulae glowing with vibrant colors across vast regions of space, and how did those nebulae arise in the first place?
Dark Matter Illuminated, part 3. The key to cosmology is gravity… but can we understand gravity beyond Newton’s famous equation, or Einstein’s intangible curvature of spacetime? The standard model in astrophysics holds that over 80% of all the matter in the universe consists of invisible “dark matter” that does not interact with light but has gravity. Can we make sense of this as amateur astronomers? That’s the core question we will debate on Nov 10.
Our quest to understand cosmology brings us to an important alternative theory known as Modified Newtonian Dynamics (MOND). This approach to the galaxy rotation/gravity problem is getting more attention now, even as particle physics mounts its strongest campaign of instrumental experiments to detect candidate dark matter particles, the so-called Weakly Interactive Massive Particles (WIMPS). I laid out a simplified summary of the MOND vs. dark matter debate in last month’s Sidereal Times (https://princetonastronomy.com/2026/10/04/from-the-director-164/). One way to say it is, dark matter keeps the laws of gravity intact and adjusts the mass, while MOND keeps the mass as observed and adjusts the laws. On Nov 10 our guest speaker will be the renowned astrophysicist Dr Stacy McGaugh of Case Western Reserve University. He will describe from first-hand experience the emergence of these theories, and update us on how MOND and dark matter are currently seen by the astrophysics community.
Dr. McGaugh will be in Cleveland and join us via Zoom, but we want to get together as a club on campus for this meeting. So, we’ll stream the session live by Zoom and You Tube from Sherrerd Hall 101, where we have met the past several meetings and car parking is easy (see last month’s Sidereal Times for directions at the same link as above). For more on the guest speaker’s background and other future presentations being planned, see program chair Victor’s section below. After the main talk is over Nov 10, we will continue our discussions into current topics in astronomy and club and observatory activities.
Hot Topics for Our Meetings. You are probably the go-to person in your family and circle of friends when it comes to emerging astronomy themes. The popular press and media have been providing abundant PR for supermoons, planet alignments, and meteor showers, but they don’t usually go into the physics. We need your participation each month to help identify in advance the upcoming astro topics soon to emerge in the popular press and media. Please send your thoughts and themes for hot topics for our meetings by email to me at director@princeonastronomy.org.
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