Most educated people in modern society have no difficulty accepting the idea that the earth is roughly spherical, or that the sun is the center of the solar system and the earth moves around it. Nearly everyone laughs, or shakes their head in disbelief whenever you tell them about people who seriously believe in a flat earth or groups of people who still don’t accept the discoveries of Galileo and Copernicus after 500 years. Yet both of these long-rejected ideas have strong adherents, mostly creationists who use literal interpretation of the Bible to deny any scientific reality that contradicts scripture. For these people to continue clinging to these long-discredited ideas, they must ignore the hundreds of photos from earth and space that show its true shape (the flat-earthers claim they are NASA hoaxes, although the other international space programs produce similar images). In addition, we now have space probes visiting all the planets on paths predicted by the heliocentric solar system, and some have looked back and taken shots that show the layout of the solar system, and the earth where it really is. But in this age of the internet, silly ideas like geocentrism can reach an audience of millions in seconds, without any fact checking or scientific peer review, which most mainstream media still practice. Any fool with a hot idea, a computer and possibly some decent graphics or animation can cook up a wild theory and instantly generate thousands of hits, and hundreds of favorable comments from those who can’t tell science from garbage.
Just one step less crazy that flat-earthism and geocentrism is another internet fad: the expanding earth model. Currently, it’s got huge popularity due to a viral (over 1.4 million views so far) internet video by a cartoon artist, Neal Adams. Using modern computer graphics, he put together a gee-whiz animation that appears to show all the continents fitting together in the past on a much smaller globe. The video even plays the trite, overused opening chords of Richard Strauss’ “Also Sprach Zarathustra” (famous from its use in Stanley Kubrick’s film “2001: A Space Odyssey”) to create the appropriate sense of awe and wonder. If you read further, Adams then takes the classic “fringe scientist” view of the world: all other scientists are wrong; they are in a great conspiracy to cover up the problems with their view of the world, and are under social pressure not to give his ideas a fair hearing. I’ve examined most of what he’s presented, and he clearly has no training or experience in geology or geophysics whatsoever, and no idea of the basic science of the earth he’s trying to rearrange.
Back in the 1950s and 1960s, the expanding earth notion was still not considered a truly crackpot notion. A prominent Australian geologist, S. Warren Carey, was the last legitimate scientist to be taken seriously on the idea of the expanding earth (his final book on the topic was published in 1975), since he pointed to the obvious fit between South America and Africa, and how other continental fit together as well. But Carey’s idea was soon overshadowed by the immense amount of data that led to the modern theory of plate tectonics in the 1960s and 1970s, and explained not only Carey’s fit of continents pulling apart, but also showed that other continents were colliding as tectonic plates converged and subducted beneath one another. When I was in graduate school in the 1970s, Carey’s ideas were already an object lesson in the history of our science, a case history about how some good observations can go badly wrong in the interpretation, especially when new data debunk an old notion.
Yet just as a notions debunked 500 years ago (flat-earthers and geocentrism) or 150 years ago (creationism) keep rising among those who know too little science, so too with expanding earth. Over 50 years after S. Warren Carey, it has new life thanks to the internet and cartoonist Neal Adams. And just like geocentrism and creationism, anyone with a few college courses in geology can easily debunk it, since Adams’ cartoon completely ignores geology (which he has no experience in), just as creationist “flood geologists” ignore 99% of geology just to explain the Grand Canyon in terms of Noah’s flood (see Prothero, 2007, Chapter 3).
If you mistake Adams’ slick cartoon for reality, it looks very convincing (although this video shows that there are lots of mismatches that you don’t notice since the animation goes by very quickly and is very fluid). But let’s consider some actual geology, rather than quibble over deceptive animations:
1. The fit of South America and Africa is of course, real. It was first noticed by cartographers when the first good maps of the South Atlantic were published around 1500, and was used as evidence by the early advocates of continental drift, including Alfred Wegener and Alexander DuToit, as well as S. Warren Carey. But the reason the fit is taken seriously is that there are geologic trends (such as glacial striations) and identical rock types in the bedrock on each side of the Atlantic that match up when you close the Atlantic to its configuration about 200 m.y. ago. There are also matches in the bedrock between the rest of the Gondwana continents (India, Africa, Australia, and Anarctica), and bedrock similarities found in eastern North American and North Africa that formed before the North Atlantic opened up. But no such matches in bedrock geology exist between the other continents that Adams’ animation squeezes together, especially those around the Pacific Rim, which geologic evidence shows has never been closed like the Atlantic.
2. The fit of continents in Adams’ animation is illusory, since he is matching the shape of the modern shorelines of the landmasses that are currently above water. The true edge of each continental plate, however, is the edge of the continental shelf and the shelf-slope break, which is typically 1500-2000 m below modern sea level. If you use this for the shape of the continent, the fit between South America and Africa improves (as geophysicist Sir Edward Bullard showed in the 1960s), but there is no fit for most of the other continents that Adams smashes together.
3. The expanding earth model ignores a gigantic amount of paleomagnetic data collected from rocks of every age on every continent in the past 50 years. These data clearly show that the earth has not expanded more 0.8% in the past 400 million years (McElhinny et al., 1978; Schmidt and Clark, 1980). I’ve collected, analyzed, and published some of these data, and you can tell from the inclination angle of the specimens the paleolatitude of any given sample. If you look at all the samples of the same age over a range of latitudes (say, 250 m.y. ago in the mid-Permian when Pangaea formed), there is no possibility of a significantly smaller earth radius at that time, or any other. Not only this, but the paleomagnetic data give precise positions and orientations of each continent through the past 600 m.y., and these data do not support the fanciful motions suggested in Adams’ cartoon.
4. Plate tectonics has successfully explained a huge amount of data from biogeography and the ancient distributions of fossils as well (such as the distribution of Cambrian trilobites across the Atlantic, which would only work if the proto-Atlantic had closed in the late Paleozoic before reopening in the early Mesozoic). The strange motions of the continents in Adams’ video do not explain these data in any sense.
5. Plate tectonic models of the past motions of continents has successfully predicted where the climatically sensitive deposits of the world should be found in the past: glacial deposits on the poles, swamp deposits in the equatorial low-pressure belts, and desert deposits in the subtropical high-pressure belts. The cartoons of Adams and others fail to explain any of this.
6. We can actually measure the diameter of the earth from hundreds of satellites with great precision now, and these measurements show no evidence of the earth getting larger. The satellite data are sensitive enough to see individual mountain ranges rising, and local subsidence of basins, so we can detect uplift rates in the order of meters or less—and the same data clearly show the earth is not expanding within the decades that such data were collected (Wu et al., 2011). At the rates of expansion suggested by the current expanding earth models, we should be able to detect such expansion even in a few decades.
7. Using growth rings in corals and many other types of fossils that record the number of days in a year, we can easily calculate the gradual slowing of the earth’s rotation due to the tidal friction from the moon’s gravity. From this we can estimate any changes in the earth’s moment of inertia over the past 500 million years, and there is no evidence that the earth has gotten any larger in that time (Williams, 2000).
8. Models of accretion or expansion on a scale required to significantly increase the radius of the earth do not match the known rates of accretion through geologic time. In addition, such expansion by accretion would release a lot of energy that would warm the earth’s interior much more than it actually is.
9. Models based on thermal expansion contradict the most basic principles of the rheology of the earth’s interior, and violate all sorts of constraints about the known mechanisms of melting and phase transitions within the mantle (Beck, 1961).
10. Even a beginning geology student can tell you that there are two kinds of fault systems: extensional faulting (found when the earth’s crust pulls apart) and compressional faulting and folding (formed when the earth’s crustal blocks collide to form mountain belts). Most of the world’s great mountain belts (especially the Himalayas and the Alps, and in earlier times the Rockies and Appalachians) show clear evidence of having been formed by continental collisions and show tremendous amounts of contractional folding, shortening, and faulting due to compression. If you look at any of the expanding earth models, the continents move apart but do not collide, and thus they fail to explain most of the world’s mountains.
11. Whenever you hear the expanding earth models explained, the advocates argue vehemently that there is no subduction (the process whereby one tectonic plate slides beneath another and is re-melted in the mantle). If they knew anything about earth science, they would realize that subduction is one of the best-documented processes in geology. Since the 1940s, the seismic Benioff zones have given us images of one plate plunging beneath another. The great Alaska Good Friday earthquake of 1964 first demonstrated one plate violently subducting beneath another, and the seismic evidence clearly showed that the plates were moving the manner predicted by subduction. Since then, every earthquake on a subduction zone (including the big Sendai, Japan, quake of 2011) has shown similar behavior, and the seismic data clearly show the way the plates have moved. We can even use seismic imagery to see the plates sliding beneath one another (Van der Lee and Nolet, 1977). Without subduction, there would be no explanation for not only the seismic evidence of one plate plunging beneath another, but also the gravitational anomalies associated with subduction zones. Finally, there are many instances of ancient subduction zones that have been smashed into mountain belts and uplifted on land (as in the Coast Ranges of California). These ancient subduction zones have a characteristic suite of rocks, especially blueschist metamorphics, which could only be formed in the high-pressure but relatively cool regions of a subducting plate.
These are relatively simple problems with the expanding earth model based on basic geology that any advanced geology student could enumerate. There is a much larger problem that the expanding earth models fail to address: the source of energy to drive the expansion. The video by Adams proposes childish ideas about physics and particle-particle interactions powering the idea of earth expansion (lampooned and debunked in this video). This completely ignores the huge amount of evidence to show that the earth’s interior is not composed of hydrogen fusing into helium (as in the core of the Sun), but a core of both solid and liquid iron and nickel that is incapable of either expanding much, or producing that much heat (Beck, 1961).
In summary, the ideas of the expanding earth advocates strikingly resembles those of the creationist “flood geologists”: propose one simplistic model to explain a small part of the data, and then ignore the other 99% of the data that don’t fit. No one with even a rudimentary education in geology considers these ideas plausible, since they contradict so much of reality. Not surprisingly, many of the “expanding earth” websites are also creationist websites, some of which use the “decreased gravity” of the earth to explain why dinosaurs could be so big! Pushing the expanding earth as an unscientific mechanism to explain myths handed down from illiterate Bronze Age shepherds is certainly no way to enhance your credibility.
More importantly, the expanding earth model fails to explain the “consilience of observations” that has built and supported plate tectonics for the past 70 years. Like evolution or heliocentrism, plate tectonics is not just a single idea with only one line of evidence, but a multi-faceted theory that explains thousands of observations, and makes successful predictions about new observations. After decades of such observations, and the successful predictions that they produced, the burden of proof is on the expanding earth advocates to disprove every bit of evidence supporting plate tectonics. Likewise, after 150 years, the burden of proof is on creationists to explain away the entire edifice of observations and successful predictions that support evolution. And the tired old tactic of calling scientists “close minded” and “conspiring against” the idea is not going to convince anyone who knows the real data and how science (with all its internal criticism, peer review, and willingness to listen to crazy ideas that might be plausible) actually works.
A word of advice to Neal Adams: stick to cartooning. You’re out of your depth in geology.
- Beck, A.E. (1961) Energy requirements for an expanding earth. Journal of Geophysical Research 66 (5): 1485-1490.
- Carey, S.W. (1975) The Expanding Earth. Elsevier, Amsterdam.
- McElhinney, M. W., Taylor, S. R., and Stevenson, D. J. (1978), Limits to the expansion of Earth, Moon, Mars, and Mercury and to changes in the gravitational constant, Nature 271 (5643): 316–321.
- Prothero, D.R. (2007) Evolution: What the Fossils Say and Why it Matters. Columbia University Press, New York.
- Schmidt, P. W. and Clark, D. A. (1980), The response of palaeomagnetic data to Earth expansion, Geophysical Journal of the Royal Astronomical Society, 61: 95–100.
- Van Der Lee, S., and Nolet, G. (1997), Seismic image of the subducted trailing fragments of the Farallon plate, Nature 386 (6622): 266.
- Williams, G.E. (2000). Geological constraints on the Precambrian history of Earth’s rotation and the Moon’s orbit. Reviews of Geophysics 38 (1): 37-59.
- Wu, X., X. Collilieux, Z. Altamimi, B. L. A. Vermeersen, R. S. Gross, and I. Fukumori (2011), Accuracy of the International Terrestrial Reference Frame origin and Earth expansion, Geophysical Research Letters 38, L13304, 1-5.