Christopher M. Graney

About Christopher M. Graney

Christopher M. Graney is professor of physics and astronomy at Jefferson Community & Technical College in Louisville, Kentucky (USA), where he helps keep the college’s observatory running. For some years now his research focus has been the history of astronomy, especially the late 16th and early 17th centuries. He is the author of the 2015 book Setting Aside All Authority: Giovanni Battista Riccioli and the Science Against Copernicus in the Age of Galileo, and the forthcoming book Mathematical Disquisitions: The Booklet of Theses Immortalized by Galileo, both published by the University of Notre Dame Press.

The Great KENTUCKY Eclipse of August 21, 2017: Will the Weather Hold?
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For the past week you have been seeing lots of posts about tomorrow’s eclipse and about Hopkinsville, Kentucky, the town at the point of greatest eclipse (or, to be precise, near that point): Click here for Monday’s post on the eclipse. Click here for Wednesday’s. Click here for Friday’s. Click here for Saturday’s. Hopkinsville is also the place that Vatican Observatory Director Br. Guy Consolmagno is visiting for the eclipse. Of course, not everyone can make it to south-western Kentucky to see this eclipse. If you are unable to make it into the path of totality, you might be able to see totality “virtually”, because Hopkinsville has a live camera mounted up high to give a continuous view of the area. Check it out below: Of course, there will not be much to see of this eclipse if the weather is not good. As can be seen from the Monday-Saturday posts, the forecast for the eclipse has gone this way and … Continue reading

The Great KENTUCKY Eclipse of August 21, 2017: Reading the Signs
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Two days from the eclipse and I am in Hopkinsville. Anyone passing through, even if they did not know that there was an eclipse here, would know that a Big Event is taking place. The signs are everywhere. Some of those signs are the busy-ness of landowners along Kentucky State Highway 91 into town. The path traced by the moon’s shadow will move toward the South-East into Hopkinsville, roughly following KY-91. While driving KY-91 into town earlier today, my wife and I saw lots of farms preparing for the influx of people—some setting up to welcome visitors (“Eclipse parking $50” near the point of greatest eclipse), some seeking to keep visitors from tromping all over their crops (“POSTED: No Trespassing. Private Property.”) Another clear sign of a Big Event are all the streets that are closed off, and the many tents and vendors set up, right in central Hopkinsville. There are also a lot of actual signs pertaining to the … Continue reading

The Great KENTUCKY Eclipse of August 21, 2017: Hopkinsville as the Perfect Point
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The Catholic Astronomer’s Blogger-in-Chief, Br. Guy Consolmagno, Director of the Vatican Observatory, is in Hopkinsville, Kentucky for the big 2017 eclipse.  That, and the fact that I am from Kentucky, is why I am calling this the great KENTUCKY eclipse (check out Monday’s eclipse post, and Wednesday’s, too).  So what is the big deal about Hopkinsville? An eclipse occurs when the moon’s shadow sweeps across the surface of the Earth.  The general path of the shadow in this eclipse is as shown by the arrow in the figure below. But, “it’s complicated,” because the Earth is rotating while the shadow is moving, and because the Earth is a sphere.  Points on Earth’s surface are moving from West to East, as is the shadow, but the axis of Earth’s rotation is not quite perpendicular to the direction of motion of the shadow, and furthermore, the Earth is a sphere.  The result is much more complex than just a round shadow moving … Continue reading

The Great KENTUCKY Eclipse of August 21, 2017: Measuring the Moon’s Distance
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With the eclipse coming on Monday, and with Vatican Observatory Director and boss blogger for The Catholic Astronomer Br. Guy being in Hopkinsville, Kentucky for the eclipse, you can bet you will see a lot of eclipse posts from The Catholic Astronomer’s Kentucky blogger!  (Click here for Monday’s post.) Here’s something you probably don’t think of when you think of eclipses: measuring the distance to the moon.  But you can use an eclipse to measure the distance to the moon.  You just need observers in two different places. Imagine one observer located in Louisville, where the maximum coverage during the eclipse will look like the image at below left, and a second observer located on the edge of the zone of totality, where the moon just covers the sun.  One such place in Kentucky is Morgantown.  Why is the position of the moon against the sun shifted slightly between the two locations?  Because of the difference in viewing position between … Continue reading

The Great KENTUCKY Eclipse of August 21, 2017: One Week Out
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The Vatican Observatory will have a presence in Kentucky during the upcoming August 21 eclipse of the sun.  Brother Guy Consolmagno, who is Director of the Vatican Observatory and of course a blogger here on The Catholic Astronomer, will be in Hopkinsville, Kentucky, to observe the eclipse and to share his insights into astronomy and the eclipse via a public talk and interviews with local media. This is Br. Guy’s second visit to Kentucky in as many years.  He was in the state in December of 2015, right here in my home town of Louisville.  At that time he spoke to a very large group of people at the public library (click here to see that entire talk on YouTube).  Now he is back in Kentucky to see the eclipse from Sts. Peter & Paul Church in Hopkinsville, the place where the eclipse will pretty much have the longest duration of anywhere in country. Br. Guy was invited to Hopkinsville … Continue reading

Benjamin Bannaker and Planet George
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Here is another fun tidbit about the almanac of early US astronomer Benjamin Bannaker (see last week’s post): it features ‘Planet George’. Yes, right under an illustration of how the human body is governed by the constellations of the zodiac, Bannaker has a list of the planets. Take a look in the figure below and you will see it: Mercury, Venus, Earth, Mars, Jupiter, Saturn, George. Why George? Well, among the leading astronomers of the late 1700’s (the time when Bannaker was producing his almanac) were the English astronomer William Herschel and his sister Caroline. While examining stars one evening in 1781 William happened across an object that caught his eye—an object whose position relative to the other stars changed from night to night. Herschel had discovered a planet—the first new planet ever to be discovered. Herschel became famous because of this, and was given a large monetary reward by King George III of England. (This was the same King … Continue reading

Benjamin Bannaker and the Practical Why of Astronomy
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Astronomy is often said to be the oldest of sciences. But why would anyone have cared to study the heavens, way, way, ‘back in the day’? Surely people back then had pressing demands on their time that would have kept them from wasting it star-gazing! Well, one answer to the question of why is that the heavens provide a great method for keeping time. Today we keep time with watches and clocks and cell phones, but for most of human history time-keeping devices either did not exist at all, or were not very accurate. The heavens provide a time-keeping service. Our basic units of time—the day, the month, and the year—are based on the cycles of the heavens. Those cycles were humanity’s first clock and calendar. Time is money, as they say, and because time is money people will care about what the heavens show us. Imagine if there was no way to keep time. Imagine a school or business … Continue reading

This Post is Heretical! (and best read on long flight)
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This past Spring semester a student in my Astronomy 101 class at Jefferson Community & Technical College here in Louisville asked an interesting question: “Are Star Wars and Star Trek science fiction, or are they fantasy?”  Well, if science fiction requires scientific plausibility, then they are probably fantasy.  Why?  Because they rely on faster-than-light travel.  As best we can tell from the laws of physics, faster-than-light travel and communication are highly problematic from a theoretical perspective.  Moreover, even far slower travel has turned out to be problematic from a practical perspective.  Technology is not advancing in these key areas, and in one way we are significantly retreating.  Technology is endlessly hyped and marketed, so to say such things in today’s culture—or pop culture, if we are thinking of Star Wars and Star Trek—is to speak heresy.  But is it not true? Star Wars and Star Trek are built around an imagined advanced technology that allows for rapid travel and communication … Continue reading

How Frs. Riccioli and Dechales Argued that Science Shows the Earth to be at Rest – The Coriolis Effect
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The Coriolis Effect is an apparent deflection of projectiles and falling bodies that is caused by the rotation of the Earth.  It is named for Gaspard-Gustave de Coriolis, a French scientist who described it mathematically in the early 19th century.  It is responsible for the rotation of weather patterns such as hurricanes.  But it turns out that a century and a half before Coriolis did his work, other scientists were discussing the Coriolis Effect.  These scientists were Jesuits—Fr. Giovanni Battista Riccioli, who discussed the effect in his 1651 book Almagestum Novum, and Fr. Claude François Milliet Dechales, who discussed the effect and included some nice simple diagrams of it in his 1674 book Cursus seu Mundus Mathematicae. What is interesting about this is that Riccioli and Dechales were discussing an effect that they did not believe to exist.  Their whole point was that, were Earth rotating like Copernicus says, that rotation would produce observable effects—deflection of projectiles and falling bodies.  … Continue reading

The Sun’s Many Strange Neighbors
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The table at right* shows the distance to and luminosity of the twenty stars closest to our solar system. Distance is measured in light years (meaning that if a star is 10 light years from Earth, then it would require 10 years to reach that star, travelling at the speed of light). Luminosity, or power output, is given in terms of the Sun’s output (so a star with the same power output as our Sun would have a luminosity of 1). The stars in this table are the solar system’s twenty nearest neighbors. Notice what a wimpy lot our neighbors are. Yes, there are some respectable stars among the bunch—obviously Sirius A, with 22 times (22x) the Sun’s power output, is a serious*~ star. Sirius is the “Dog Star” in the constellation Canis Major, and the brightest star in the night sky. It appears bright to us both because it is very close and because it is quite powerful. Procyon, … Continue reading

Nibiru, Kepler, and some basics on orbits
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Let’s take another look at Johannes Kepler and at Nibiru, the supposed planet that supposedly will wreak havoc on Earth in October.  This is my second Nibiru post on this blog, the first being a couple of months ago.  As I mentioned then, some people find this Nibiru business to be a lark, or just an example of the worst sort of internet misinformation.  Others take it seriously—or don’t know how they are supposed to be able to know what to believe.  But here at The Catholic Astronomer, Nibiru is a great opportunity to talk about how the solar system works, and about Johannes Kepler, the first astronomer to really figure out how the solar system works. The Washington Post asked “Will the mysterious shadow planet Nibiru obliterate Earth in October?”  They answered “No”, but no one need take their word for it, or anyone else’s.  A person can reason this out for himself or herself, with a little help … Continue reading

Strange Tales of Galileo and Proving: Telescopic Evidence for Earth’s Immobility through Double Stars
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This is the fourth in a series of posts on the subject of Galileo and proving the Earth’s motion.  This is the year 2017, and 2017 marks the 400th anniversary of the first observation of a double star, made in 1617 by none other than Galileo and his friend the Benedictine Fr. Benedetto Castelli.  Up until our current century, the first observation of a double star had been attributed to the Jesuit Fr. Giovanni Battista Riccioli, but in 2004 Sky & Telescope magazine published an article by Leos Ondra on how Galileo and Castelli were the first to do it (“A New View of Mizar,” July 2004).  Ondra discovered this by going through Galileo’s observing notes.  An extended version of the Sky & Telescope article is available on Ondra’s web page. The double star that Castelli and Galileo observed was Mizar, the star in the bend of the handle of the Big Dipper.  Seen with the naked eye, it appears … Continue reading