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Flat Earth Community / Re: Anyone for a public discussion?

« on: November 15, 2017, 03:48:00 PM »

I will try once more, and then sign off. If a flat-earth theorist wants to accept our invitation, please send me a private message. Transportation costs are out of the question; our Board of Directors won't allow it.

Here's why lunar (or asteroid) occultations are important to the question of the earth's shape.

In the flat earth model, to account for the ~5 degree shift in the positions of the sun, moon, planets, and stars as one moves ~350 miles north or south, you must argue that those celestial objects are no more than about 4000 miles away, from simple trigonometry. Never mind that radar measurements of the moon contradict that argument; let's go with your conspiracy theory for the moment.

The stars must be somewhat farther away than the moon, or else occultations would not occur at all, but can't be much farther because the shifts (as one moves north or south) observed for stars would be much less than for the moon (in the flat earth model), contrary to observations.

Therefore in the flat-earth model, an occultation of Aldebaran either occurs or doesn't occur depending on whether the moon crosses in front of Aldebaran. So any place where both moon and Aldebaran are visible at the right time should observe the occultation, and there would be no difference in the circumstances of the occultation (i.e. where on the face of the moon the star disappears and subsequently reappears) whether you move south or north as long as the event is above the horizon. 

What is in fact observed is that some locations on earth see a grazing occultation on the northern limb of the moon, some see a grazing occultation on the southern limb, and locations in between see the star disappear at various points around the moon. This is the effect of the moon's parallax - it is much closer to us than the star is. To demonstrate parallax: close one eye, hold your finger at arm's length so that it occults something you see out the window (a tree, chimney, mountain, whatever). Open that eye, close the other one, and the object is no longer occulted. This is one way we measure distances in astronomy.

The moon's parallax with respect to Aldebaran (or any other star it occults) implies that the star must be very much farther away than the moon. Again trigonometry can give you a (very crude) lower limit to the star's distance based on the precision with which you can measure small angles. But this would further imply that the shift in the positions of those stars as you move ~350 miles north or south on a flat earth would be much less than the ~5 degrees observed - a contradiction that can only be resolved by considering the true figure of the earth.

This coming December 31st offers a nice occultation of Aldebaran by the moon. Try it for yourselves: get an army of flat-earthers to observe the occultation from various (widely-spaced) locations, and bring them together to discuss the results. Sketches or photographs, please. Then let me know by private message whether you wish to engage in a public face-to-face discussion next April Fools' Day.

Farewell, folks, and thanks for the amusing interchange.

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Flat Earth Community / Re: Anyone for a public discussion?

« on: November 13, 2017, 05:36:25 AM »

Hmm, interesting storm of responses.

I'll reply here to Tom Bishop's assertion that modern astronomy predicts occultations by using patterns derived from previous observations. This goes to the heart of how science works.

Indeed, science always starts from observed patterns; then people produce models to understand those patterns, and eventually laws to systematize them. The relevant example here is Kepler's Laws of Planetary Motion, which then led to Newton's Theory of Universal Gravitation. Modern astronomy uses gravitational theory (Newtonian or Einsteinian, depending on the accuracy needed) to calculate the motion of the moon in its orbit about the earth and the planets in their orbits about the sun. Patterns tell us that occultations of Aldebaran by the moon occur regularly, but theory predicts that a particular occultation can be observed at a particular site at a time specified to within a tenth of a second. Observations feed back into the theory, giving us ever better predictive capability.

This is what I ask from a flat-earth theorist. Not patterns, but precise predictions.

That modern astronomy no longer relies on mere patterns to predict occultations is shown by the fact that we can predict occultations of stars by newly discovered asteroids. The popular astronomy magazine Sky and Telescope regularly publishes such predictions to encourage backyard astronomers to look for them.

And since the theme of the three-body problem has crept into this discussion, I should remark that ephemeris calculations of newly discovered asteroids (or of any other solar system object) are routinely done by numerical integration of the equations of motion of that body in the gravitational field produced by the sun, all the planets, and the several largest asteroids. This is not an impossible problem; it is solved thousands of times daily.

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Flat Earth Community / Re: Anyone for a public discussion?

« on: November 12, 2017, 08:40:12 PM »

Thirdly: you repeatedly said that you would want to vet potential "candidates" on their scientific literacy. You have made no attempt at making a similar offer back, and judging by what you've described so far, your understanding of the Flat Earth Theory is rather poor. Once again, you make it clear that you're interested in a very one-sided joke, and not a discussion.

Thanks for this, Pete. I agree with you, that the vetting that takes place prior to the discussion should be two-sided. I have indeed been looking for more of a "Theory" on the Flat-Earth side, and haven't found your wiki of much help, unfortunately.

Perhaps you could start me off by showing me how the occultations of the bright star Aldebaran (Alpha Tau) during 2017 (9 Jan, observed from Asia; 5 Feb, from north Africa and southern Europe; 5 Mar, from USA, Mexico, and Central America; 1 Apr, observed from Japan and Korea; 28 Apr, Europe; 19 Jul, southwest Asia; etc.) are explained to have occurred and been visible only from the locations indicated. Because Aldebaran has a magnitude of 1.35, these occultations are visible even with good binoculars. Such observations, done with modest telescopes, have helped us to pin down the sizes of this and other stars that are regularly occulted by the moon. Once you've explained the 2017 occultations, you might go farther and predict those that will occur in 2018. Then we can make a head-to-head comparison of your predictions and ours. (Don't cheat, and don't waffle; be precise and take all the time you need, but let me know that you're working on it.)

If you doubt that these occultations occur and are observed, you can simply type "occultation Aldebaran" into Google Scholar and get some 2000 results spanning hundreds of years. A recent one, from the Devasthal Observatory in India, is abstracted at http://www.sciencedirect.com/science/article/pii/S1384107617302610 with the full article to come out next February. You can find lots more, of course.

Thanks for your help.

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Flat Earth Community / Re: Anyone for a public discussion?

« on: November 10, 2017, 11:51:12 PM »

[/quote]

This is a rather interesting proposal. Can you provide some sources or references to verify your role and a confirmation this will take place. Holding it on April 1 seems a bit suspicious.
[/quote]

The idea of holding such a discussion was suggested to me by a colleague at the Planetarium. I was reluctant to do this; holding a public discussion on bad science is a disservice to good science. When the idea of holding it on April Fools Day was mooted, I assented, and volunteered to make inquiries. Because the Flat Earth Model and essentially all of modern science are mutually exclusive, one of us will turn out to be a Fool. Nevertheless, we will reward ourselves with good beer afterwards.

As to a confirmation that this will take place, I cannot yet offer one. We plan our programs at the Planetarium quarter-by-quarter, and will meet to discuss the April - June quarter some time in January. As I said, I don't think we can do a good job with the discussion unless we have someone prepared to defend the Flat Earth Model against some rather difficult questions. If one of you sincerely wants to do this, we should probably have an offline discussion to make sure you have studied the issues carefully. Astronomy, we feel, is your weakest point. The "waffle" about stars in your Cosmos page on the Wiki simply won't cut it. If we don't find someone to skillfully defend the Flat Earth Model, the event won't take place. It's as simple as that.

You can find the website for our planetarium at peecnature.org/events/planetarium. I am one of the presenters mentioned on that page. I won't tell you my name at this moment, but will give you some hints. PhD University of Cambridge 1976 astrophysics. Postdocs at the University of Leiden and Kitt Peak National Observatory. Staff scientist at the National Radio Astronomy Observatory. The bulk of my career was at Los Alamos National Laboratory, and subsequently at the University of Oslo.

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Flat Earth Community / Anyone for a public discussion?

« on: November 10, 2017, 08:15:15 PM »

Hi folks - As my moniker suggests, I'm a retired astrophysicist, well-traveled and with many observations "with my own eyes" over my career. Together with several other retired astrophysicists and other scientists, we present programs for the public at the Planetarium belonging to the Los Alamos Nature Center, in Los Alamos, New Mexico (home to the Los Alamos National Laboratory). Of course we all regard the Flat Earth Model as a joke. Nevertheless, it has been brought to our attention that a growing number of people adhere to this fallacy, and we would therefore like to hold a discussion on the topic.

We think the most appropriate time for such a discussion will be Sunday 1 April 2018. Since none of us could present the arguments for a Flat Earth Model with a straight face, we were wondering if any member of the society would be willing to join us to present your case. Because Los Alamos is a highly scientifically literate community, you might expect to field questions of a fairly complex nature, for example regarding Foucault's Pendulum, occultations of stars by the moon (also eclipse prediction, of course), and trans-oceanic tsunami propagation. The latter case is similar to the long-distance flight problem that I've seen discussed in these pages, but doesn't involve recruiting airline companies and pilots into a fictitious conspiracy.

Our Planetarium is run by a nonprofit organization, and we can therefore not afford to pay transportation costs, but we would be glad to offer a meal beforehand and a beer afterwards from our local brewery. Treat this in good fun; we do not intend to hurl insults or indulge in name-calling. Our mission is public education, pure and simple.

Thanks for your attention.