Cosmic Reflections

What do light, radio waves, and x-rays have in common?

Our Current Human Population is Unsustainable All attempts to address the effects of human-induced climate change, the loss of biodiversity, and environmental pollution will utterly fail without a substantial reduction in human population.

This is one of a series of postings of important classical music dates, from the 17th century to the present.

Did you know that both Venus and Neptune have orbits around the Sun that are more circular than the orbit of the Earth?

I watch very little television—almost entirely documentaries and news—but I must admit that every once in a while I like to dip into happier times through my living-room Atavachron to watch episodes from two 1960s television series1 starring the much-belo…

As of this writing, three objects have been discovered that have passed through our solar system coming from interstellar space. 1I/’Oumuamua Discovery Date: 2017-10-19 Perihelion Date: 2017-09-09 (40 days after perihelion) Perihelion Distance: 0.26 AU In…

Here is how you can easily generate some common international characters on your computer keyboard.

Credit:ESA/ESO/M.

Since moving to Tucson almost four years ago, my biggest complaint has to do with the terrible drivers and lack of enforcement of traffic laws.

There are three stable (non-radioactive) isotopes of the element oxygen: 16O has 8 protons and 8 neutrons 17O has 8 protons and 9 neutrons 18O has 8 protons and 10 neutrons All the oxygen in our solar system was forged in stars that existed before the bir…

If you haven’t yet read Making Democracy Count: How Mathematics Improves Voting, Electoral Maps, and Representation by Ismar Volić (Princeton University Press, 2024) I strongly recommend that you do, especially if you live in the United States.