Geo-xcentricities; you too can be Galileo with just a pair of binoculars (and gaffer tape)

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geocentrism_flyerThere’s been a lot of blank disbelief on the blogosphere of late, due to the announcement of a conference on Geocentrism (Galileo was Wrong). Geocentrism is the belief that Earth is the centre of the Universe and everything revolves around it. You would think that, 400+ years after Galileo, people would have cottoned on the the idea that the Earth orbits the sun, the sun orbits the galactic centre and the Milky Way galaxy does … well …complicated stuff with other galaxies, but basically we worked out long ago that the Earth is not the centre of the solar system, let alone the Universe.

Other people, especially Ethan at Starts with a Bang and the Bad Astronomer, have dealt with the technical details (and I have an earlier discussion here and here). My goal is to get you, the ordinary person on the Clapham omnibus (or in my case, the Outer Harbour train, where I am writing this), to try and demonstrate the Earth is heliocentric for yourself and to do so with common household materials. After all, science is at heart a practical endeavour, and non-professionals should be able to find the evidence for themselves.

So for this journey into the starry spheres, we will need a pair of binoculars, a camera tripod, some cardboard and alfoil, and lots of gaffer tape. We also have some luck, as the sky is currently cooperating in the Geocentrism debunking stakes.

First we have to ask ourselves, which “geocentric” theory are we disproving. The classic geocentric theory is that of Ptolemy, in which the planets, Moon and the Sun all orbit the Earth. The most famous variant of this is Tycho Brahe’s helio-geocentric system, where the Sun and Moon orbits the earth and everything else orbits the Sun. There are important differences in the systems which we will explore later.

First off, let’s look at the phases of Venus. For this you will need binoculars and the camera tripod. You will also need a way of attaching the binoculars to the tripod. These days I use a special attachment (but this requires modern binoculars that have a screw thread on the body), but in the past I have used gaffer tape to good effect. Why attach the binoculars to the tripod? Because otherwise there will be too much shaking for you to see the image properly.

The image to the left is the setup I use for observing Sunspots (we come to that later), showing the binoculars gaffer taped to the tripod.

At the moment, Venus is prominent above the western horizon. Point your binocular lash-up at Venus, in my 10x50 binoculars Venus is very small but is a disk which has a distinct “half -Moon” shape. If your binoculars don’t have decent anti-glare coatings, you may have to observe in the early twilight in order to see Venus’s shape without internal reflections from the binocular lenses getting in the way.

As you watch over the coming weeks, you will see Venus expand in size and become more crescent- shaped. Sketch the shape so you can follow its progress. This is so fast you should see a visible change in just one week. By mid-October Venus will be a thin crescent almost 2/3rds bigger than when you started observing. By late October Venus has nearly doubled in size and is a thin, glistening wire. Then Venus vanishes into the Suns glare and reappears in the morning. Over the next few months you can watch Venus shrink and become a tiny disk.

And now you have demolished the Ptolemaic geocentric system. Venus does have phases in this system, but quite unlike what you see here (I leave it too the reader to work out what a Ptolemaic systems Venus phases would look like, you can see a model of Ptolemaic Mercury here, which will give you a good idea). And you have only taken almost 6 months to do it (what, you thought it would be easy). As a reward, here’s an animation of the Phases of Venus.

Left image Jupiter above the eastern horizon, Right Image, Venus above the western horizon, both at the same time in the evening (around 8pm ish in mid September 2010).

But wait! You say What if it is just an illusion, a trick of the optics? Well, you have a control. Having observed Venus, swing your binocular lash-up to the east, to the brightest object there (and second brightest non-lunar object in the night sky after Venus), Jupiter. Jupiter is a distinct oval in my binoculars, and the four bright Medicean Stars glitter around it. Over the nights you watch Venus swell and thin, keep an eye on Jupiter as it does…well…nothing.

Jupiter and three of its moons imaged with a mobile phone.

But Ah! The Medicean Stars, now known as the Galilean Moons, they will shuttle backwards and forwards during the nights as you watch. The realisation that these “stars” were Moons of Jupiter were not a blow to any form of geocentrism per se, although they were the second of a series of powerful blows against the Aristotelian physics that underpinned Ptolemy’s system, which aided its demise. Determining that these specs actually orbited Jupiter, and were not just accidentally there, took a lot of effort.

Try keeping track of these sparks, and without reference to an almanac, try and determine their orbits (heck, try and keep track of which near identical points of light are which). It may take a while, you will need to keep careful sketches, and track the Moons and Jupiter with respect to the stars as Jupiter moves through the heavens, but a) You are sketching Venus anyway and b) it will be well worth it (hey, you proving things for yourself!).

The next bit is more demanding. The Phases of Venus demolished the Ptolemaic Geocentric system, but the Tychonian- Geo-heliocentric system had Venus phases just like a pure heliocentric system (which is not surprising, as Tycho’s system is an inverted Copernican system). To eliminate the Tychonian system, we need to observe sunspots.

Luckily the Sun is coming out of its quiet phase, so you will have some to record. For this you will need to set up a safe binocular projection system (as shown above), where the image of the Sun is projected onto a surface so you can record the Sunspots. NEVER LOOK DIRECTLY AT THE SUN WITH BINOCULARS AS SEVERE EYE DAMAGE WILL RESULT.

Anyway, while you are recording the Phases of Venus and the orbits of Jupiters’ Moons, record the passage of Sunspots over the Suns face, over the 5-6 months you are recording the Sunspots, you will notice the path taken by the sunspots moves up and down. This is due to the Earths orbit not being exactly in the plane of the Suns rotation. In a geocentric system, with the Sun orbiting the earth once a day, this variation would show up on a daily basis, but what you observe can only be seen in a heliocentric system.

So, congratulations, you have just demonstrated that geocentric models don’t describe the solar system we see using very simple tools. It took a while, and was hard work, but you have demonstrated it yourself, and all the blovation of geocentricists won’t take that away (yes, Stellar parallax gets all the glory, but annual Sunspot variation was a powerful blow to Tychonian geocentric models). If you want to, you can take this further by making your own Foucault’s Pendulum.

211 Comments

I once got into an e-mail argument with a geocentrist. I used Hipparcos measured parallax of nearby stars as evidence against geocentrism. He assured me that Hipparcos data was unreliable because communication channels weren’t secure.

Hipparcos

Sungenis has been ranting about relativy for years. I would love to put him in a room with some of the DI folks and see how that would go.…

All this proves nothing. When Galileo invited the church fathers to look through his telescope, they refused, knowing full well that anything seen through an infernal instrument could only be and illusion created by Satan.

The pillars of our faith are much stronger than the flimsy legs of your tripod.

Geez, you scientists, first you kill Tinkerbelle and now this.

“I don’t have to match your pathetic level of detail!!111!!!eleven!!!!”

All this proves nothing. When Galileo invited the church fathers to look through his telescope, they refused, knowing full well that anything seen through an infernal instrument could only be and illusion created by Satan.

The pillars of our faith are much stronger than the flimsy legs of your tripod.

Exactly! Without a mind enlightened by faith (the faith that I get to define, btw) you are subject to Satan’s deception!

RIY: Refute It Yourself! I would support this being a semi-regular feature!

First of all, for really eccentric (to put it nicely) ideas, take a look at the Wikipedia article on “Hollow Earth” under the heading “Concave hollow Earths”:

http://en.wikipedia.org/wiki/Hollow[…]ollow_Earths

The idea being that we, and the whole of the skies above us, are all inside the hollow earth.

Now, I am not a scientist of any kind, but I think that this provides a cautionary tale for those of us who would like to have a handy rebuttal to geocentrism.

What is interesting about this is that one can make a mathematical transformation between the inside of a sphere and the outside of a sphere, so that the two are indistinguishable. There is no way that one can “demonstrate” that we are on the outside of the spherical earth. Even though the idea is crazy - it says that when we go “up”, we (and all of our measuring devices) shrink by just the right amount so that we can’t tell that it is happening to us.

In a similar way, we can mathematically transform anything that happens in a Galilean universe to something happening in a geocentric universe. The laws of physics and the geometry become horrendously complicated, to be sure, but there is, in principle, no way to “demonstrate” that the earth is moving, given the existence of this transformation.

I don’t know whether the geocentrists take this approach. My experience with eccentrics (if not geocentrics) is that they don’t have the necessary dedication to consistency to do it. If they trusted rationality, after all, they wouldn’t be geocentrists. But the point that I am trying to make is that it isn’t all that easy to demonstrate the failings of geocentrism against a persistent supporter.

Some of the geocentrists do make an appeal to the General Theory of Relativity, in which just about any framework, including a framework which rotates and revolves with the earth (that is, moving in Galilean astronomy, but fixed in geocentric astronomy), is physically equivalent to any other such framework. It may be true that there are some unwanted complications in GR for geocentrism, but I suspect that it would take a specialist in GR to understand them. Possibly changes in the rotation of the earth (or, from the geocentric point of view, the rotation of the heavens) due to things that happen on earth (seasonal changes, earthquakes, or even tides) would be problematic for geocentrism (why should something that happens on earth today affect the motion of stars that are lightyears away, immediately?), but I’m not sure that that has been worked out. Can they just respond with a “you can’t explain the changes in the so-called rotation of the earth any better than I can explain the changes to the rotation of the heavens”? (Is there an expert on chronology who can help?)

As I said at the start, I’m not a scientist, so there may be something obvious that I am missing here, and I would be very glad to be corrected.

Tom S.,

You may want to visit the Bad Astronomy post on the same subject.* He talks in somewhat more detail about just the subjects you’re interested in (mathematical transformation between the two, and use of relativity by geocentrists).

IMO your points bring up a teachable lesson about science: unlike religion, it isn’t just about truth. Sometimes science is about useful approximations. If we were to discover tomorrow that the universe was geocentric, we’d still use heliocentric models to launch space probes. Why? Because the heliocentric math is easier. All reference frames may be metaphysically equal, but scientifically some are more useful than others.

*I’m not affiliated with Phil Plait or BA. But I do recommend his book. And I did stay at a holiday inn last night. :)

I think “modern” geocentrists argue that the earth is at the center of the universe rather than at the center of our planetary system.

They seem unmoved by the argument that all points in the universe appear to themselves to be the center.

TomS said:

The idea being that we, and the whole of the skies above us, are all inside the hollow earth.

Inside a “hollow Earth” there would be no net force of gravity.

Pick a point somewhere inside the hollow sphere. From that point draw a solid angle that intersects the spherical shell. The mass of the spherical shell contained within that solid angle is proportional to the square of the distance of the shell from the chosen point. Its gravitational attraction drops off as the square of the distance from the chosen point.

Now extend that solid angle from the chosen point in the opposite direction. The mass of the spherical shell contained within that opposite solid angle is also proportional to the square of the distance from the chosen point. And as before, the gravitational attraction of this opposite mass drops off as the square of the distance.

Thus the inverse square law of gravity is exactly compensated by the square-of-the-distance increase in mass. The gravitational attraction due to the two spherical mass “caps” on opposite sides of the chosen point exactly cancels.

The same goes for all opposite pairs of spherical caps contained within opposite spherical angles surrounding the chosen point.

Thus all the forces due to the surrounding shell cancel.

I suspect that our standard trolls are avoiding this thread. They may be nuts but they’re not THAT nuts. We might get a posting from near-blatant jokers like “Higabu”.

Here’s my favorite crank anti-science site:

http://www.fixedearth.com/

-

Here’s my favorite crank pseudo-science site:

http://www.holoscience.com/synopsis.php

I think “modern” geocentrists argue that the earth is at the center of the universe rather than at the center of our planetary system.

They seem unmoved by the argument that all points in the universe appear to themselves to be the center.

Right, they’ve got it all backwards.

I believe all and any points in the universe are at the periphery of the universe - if you happen to be at ‘that’ point.

My reasoning is that wherever you might be in the universe, the light coming towards you will have left it source sometime in the past. Every point in the universe away from your own (four dimensional) spot is older; your spot is the newest in the expanding universe. That is, it represents the outer boundary of the universe if we consider the time dimension. You are at the present; the outer boundary of the time dimension..

Looking at the sky, we are looking back in time, all the way back to the big bang. The big bang must be at the centre of the universe, not at the outer boundary. It is not speeding away from us; we are speeding away from it. Whichever direction we look, wherever in the universe we might be, we would be looking towards the beginning.

What is wrong with my model?

Fantastic post. Thanks a lot!

Rolf Aalberg mentions the apparently paradoxical fact that when we look outward from earth in any direction, we are actually looking inward toward a smaller and smaller universe. All of the sightlines that originate at this time and place - or at any time and place in our universe - converge at the big bang. I first encountered a layman-friendly exposition of this elegant demonstration of the obvious reality of curved four-dimensional spacetime in Robert Osserman’s fine little book, Poetry of the Universe. This is a great read for anyone who is, like me, awe-philic and math-phobic.

So perhaps the position of the Roman Catholic Church on heliocentrism really is the same as for evolution: Allowed, but not encouraged.

I suspect that our standard trolls are avoiding this thread.

If you mean “Christians are avoiding this thread”, I can only say that a possible reason is that there’s simply not much to say.

Simply put, the Bible does NOT teach geocentrism, and in fact is quite silent about “centrisms” at all.

B’dee b’dee that’s all, folks!

FL

Mike Elzinga said:

TomS said:

The idea being that we, and the whole of the skies above us, are all inside the hollow earth.

Inside a “hollow Earth” there would be no net force of gravity.

Pick a point somewhere inside the hollow sphere. From that point draw a solid angle that intersects the spherical shell. The mass of the spherical shell contained within that solid angle is proportional to the square of the distance of the shell from the chosen point. Its gravitational attraction drops off as the square of the distance from the chosen point.

Now extend that solid angle from the chosen point in the opposite direction. The mass of the spherical shell contained within that opposite solid angle is also proportional to the square of the distance from the chosen point. And as before, the gravitational attraction of this opposite mass drops off as the square of the distance.

Thus the inverse square law of gravity is exactly compensated by the square-of-the-distance increase in mass. The gravitational attraction due to the two spherical mass “caps” on opposite sides of the chosen point exactly cancels.

The same goes for all opposite pairs of spherical caps contained within opposite spherical angles surrounding the chosen point.

Thus all the forces due to the surrounding shell cancel.

Of course the easier way to demonstrate that is by Gauss’s law.

Rolf Aalberg said:

I think “modern” geocentrists argue that the earth is at the center of the universe rather than at the center of our planetary system.

They seem unmoved by the argument that all points in the universe appear to themselves to be the center.

Right, they’ve got it all backwards.

I believe all and any points in the universe are at the periphery of the universe - if you happen to be at ‘that’ point.

My reasoning is that wherever you might be in the universe, the light coming towards you will have left it source sometime in the past. Every point in the universe away from your own (four dimensional) spot is older; your spot is the newest in the expanding universe. That is, it represents the outer boundary of the universe if we consider the time dimension. You are at the present; the outer boundary of the time dimension..

Looking at the sky, we are looking back in time, all the way back to the big bang. The big bang must be at the centre of the universe, not at the outer boundary. It is not speeding away from us; we are speeding away from it. Whichever direction we look, wherever in the universe we might be, we would be looking towards the beginning.

What is wrong with my model?

What is wrong with your model?

Well, everything. Starting (or ending) with the assumption that the big bang happened at a point. It happened everywhere. The big bang is not, as you say, at the center of the universe–there is no such place.

Olorin said:

So perhaps the position of the Roman Catholic Church on heliocentrism really is the same as for evolution: Allowed, but not encouraged.

If you read up on Sungenis, you’ll find that even the RCC doesn’t want anything to do with him. I went to a catholic school 40+ years ago, and the Nuns didn’t have a problem (as far as I could tell) teaching old earth and evolution back then. In fact, when I transferred to public school, I was way ahead of the other kids in math and science.

TomS said:

In a similar way, we can mathematically transform anything that happens in a Galilean universe to something happening in a geocentric universe. The laws of physics and the geometry become horrendously complicated, to be sure, but there is, in principle, no way to “demonstrate” that the earth is moving, given the existence of this transformation.

Sorry, Tom, but this proposition does not hold true. It would be fine as long as there were no accelerations (i.e. net forces) involved, but is damned easy to spot a net force, if present.

Consider the Foucault pendulum cited in the post.

Given that the pendulum revolves rather erratically around the axis traversing its fulcrum and its foot, either you can come up with a convincing explanation for an external force driving the pendulum itself, or you come to terms with the fact that the ground is moving underneath the pendulum.

If you take into account GR (or even SR, to some extents), things get even more asymmetric and complex to explain if you assume Earth as an inertial system: you should explain seasonal variations in chronometers (was that the reason for you calling in an expert on chronology, which BTW I am not?) but also seasonal variations in the ephemeris for the occultations of the moons of Jupiter, and it gets rather embarrassing having to assume instantaneous action at interplanetary distances just to get rid of tiny weeny variations in the timing of an occultation…

As others have already pointed out, anyhow, Phil Plait’s site is ripe with informations on the subject: definitely a good reading.

Wheels said:

RIY: Refute It Yourself! I would support this being a semi-regular feature!

That’s a good idea! I’ll see what we can do. Has to be with simple accessible material, setting up your own molecular biology lab could be problematical.

FL said:

I suspect that our standard trolls are avoiding this thread.

If you mean “Christians are avoiding this thread”, I can only say that a possible reason is that there’s simply not much to say.

Simply put, the Bible does NOT teach geocentrism, and in fact is quite silent about “centrisms” at all.

B’dee b’dee that’s all, folks!

FL

[SFX:ploite cough] What was the basis of Tycho’s rejection of the Copernican system? Let Tycho tell us in his own (translated) words.

Since all these results [parallax measurements of Mars and Venus] did not all agree with the Ptolemaic hypotheses I was urged afterward to put more and more confidence in the Copernican invention. The exceedingly absurd opinion that the Earth revolves uniformly and perpetually nevertheless made up a very great obstacle, and in addition the irrefutable authority of the Holy Scripture maintained the opposite view. [emphasis added]

The Reception of Copernicus’s Heliocentric Theory 1973 ed Jerzy Dobryzcki, Reidle Chapter 3.

…and in addition the irrefutable authority of the Holy Scripture maintained the opposite view. [emphasis added]

Tycho Brahe was certainly hooked on geocentrism, as demonstrated by your quotation. Seems totally convinced that the Bible taught geocentrism.

The trouble would have started when somebody asked Brahe to **actually support and defend** the highlighted statement, using the Scriptures themselves.

Then he’d be a-scramblin’ hard, and quite unsuccessfully.

FL

Philosophically geocentrism makes sense but it’s relative to whomever is the speaker. Every religion considers itself infallible and the center of wisdom and truth, physical earth/universe centrism follows spiritual tenets.

Ancient cultures, and modern as well, consider/ed themselves geocentric, e.g., the Chinese, the Greeks, and Egyptians, et. al. The U.S. is the only superpower, we are the center of world power, until the Chinese overtake us of course, when their world view will supplant ours.

FL stated, “Simply put, the Bible does NOT teach geocentrism, and in fact is quite silent about “centrisms” at all.”

It is implied if not explicitly stated that the bible is central to the world view, and anything else would imply fallibility, e.g., earth moves, the heavens are not immutable but change/evolve over time.

Sam Harris said in “The End of Faith:”

“Tell a devout Christian his wife is cheating on him or that frozen yogurt can make a man invisible, and he is likely to require as much evidence as anybody else, and to be persuaded only to the extent that you give it. Tell him that the book he keeps by his bed was written by an invisible deity who will punish him with fire for eternity if he fails to accept its every incredible claim, and he seems to require no evidence whatsoever.”

I do not mean to feed the FL troll, but the Hebrew Bible makes at least a dozen references to a flat earth, and Koheleth says

The sun also rises, and the sun goes down, and hastens to the place where it arose [my italics].

If that is not geocentric, I do not know what is.

Matt Young said:

I do not mean to feed the FL troll, but the Hebrew Bible makes at least a dozen references to a flat earth, and Koheleth says

The sun also rises, and the sun goes down, and hastens to the place where it arose [my italics].

If that is not geocentric, I do not know what is.

Oh give me a break. You don’t know what it is? Really? OK I’ll tell you what it is: it’s a friggin’ figure of speech–the same sort of figure of speech you find in modern English. If I find a modern book that says something like: “it was noticeably hotter; the sun had moved directly overhead” does it mean that book teaches geocentrism?

And gee, if people come from all four corners of the earth to attend a scientific conference, does that mean…

heddle said:

Of course the easier way to demonstrate that is by Gauss’s law.

Unfortunately that doesn’t work for the layperson.

But you bring up a good point that I have often had to address in giving talks to the general public.

Those of us in the physics community are far more comfortable with the math. Our instinctive response is to pull a pen out of the nerd pack, grab a napkin and start explaining with equations. But in attempting to explain stuff like this to the general public, one has to find other means.

Math is usually out. No algebra, no probability and statistics, no lovely things like Gauss’s law, Stokes’s theorem, divergence theorem, gradient, divergence, or curl. Nothing.

This is not an insult to the general public; most people have other talents they have developed. Physicists make up a very small percentage of the population.

Then what? Finding colloquial explanations that don’t add confusion with metaphors that ultimately backfire is much more difficult than it first appears. Many well-intentioned popularizations often make things worse.

But given that charlatans like the ID/creationists keep churning out deliberately deceptive crap in order to taunt as well as misinform, there need to be people in the science community who put some serious thought into explaining science in a way that most people can grasp while not talking down to them.

There is little professional reward for doing this except for the clarification it provides to the person who digs deeply into his/her conceptual understanding.

Meanwhile the hucksters put all their effort into misinforming while hauling in the cash and the followers. The science community needs more volunteers to help take out the garbage.

heddle said:

Matt Young said:

I do not mean to feed the FL troll, but the Hebrew Bible makes at least a dozen references to a flat earth, and Koheleth says

The sun also rises, and the sun goes down, and hastens to the place where it arose [my italics].

If that is not geocentric, I do not know what is.

Oh give me a break. You don’t know what it is? Really? OK I’ll tell you what it is: it’s a friggin’ figure of speech–the same sort of figure of speech you find in modern English. If I find a modern book that says something like: “it was noticeably hotter; the sun had moved directly overhead” does it mean that book teaches geocentrism?

And gee, if people come from all four corners of the earth to attend a scientific conference, does that mean…

You say it’s a metaphor, but you insist that other parts of the book are literally true. Please provide an objective means of decide which passages are to be taken literally and which are not. A means that can be applied by anyone…believer or not.

–W. H. Heydt

Old Used Programmer

The real problem, unfortunately, is that with our current understanding of the universe, one of the things that we know is that the universe has no center. So the real problem is the claim that there is a center at all. That said, what you are probably demonstrating is that, in some sense, the sun-centered system is closer to a large-scale inertial system than is the earth-centered one. But all this will be lost on a “geocentrist” because such a person is not actually making claims about the physical world that can be tested in detail. There isn’t that much thought involved in their claims. The simplest, and most accurate answer to the geocentrists is, I think, “there is no center.”

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This page contains a single entry by Ian Musgrave published on September 15, 2010 10:23 AM.

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