Thursday, July 19, 2012

Falling apples

I’m going to comment on some statements by John Byl:

Let me note first that the above diagram is more a reflection of the ignorance of modern scholars than of ancient civilization. Ancient man was a much keener observer of the night sky than modern desk-bound scholars. They were well aware that the stellar sky rotates daily. Hence it cannot be a solid hemisphere held up by pillars fixed on the earth. Further, they were well aware of months and seasons. Hence the sun and moon were not fixed in a stellar shell. They were also well aware that the sun and moon were much more distant than flying birds.

Here Dr. Byl is taking issue with the cosmography which liberals like Peter Enns and Paul Seely impute to Scripture. However, let’s compare this criticism with something else Byl has written:

Closely related to these geometrical models are some unusual conceptions of the universe. For example, Fritz Braun (1973) asserts, based on his interpretation of biblical texts, that the Earth should be inverted. The Earth's surface is the inside of a hollow sphere enclosing the Sun, Moon, and stars. Heaven is at the center of the inverted universe, thus making this model literally theocentric (see Figure 4).

However, this model is not that easily dispensed with. It can be devised so that disproof is impossible.      The above tests take for granted that the normal laws of physics hold. In particular, light is expected to travel in roughly straight lines and rockets, in the absence of forces, are expected to move at a constant velocity. But what if this is no longer the case?

The hollow Earth model can be derived from the more usual picture of the universe via a simple mathematical transformation called a "geometric inversion". The procedure is very simple. For each point in the universe, measure its distance r from the center of the Earth and move the point
along the center-to-point line to a new distance 1/r. The result of this operation is that all objects originally outside the Earth (e.g., mountains, houses, clouds and stars) are now inside, and vice versa (see Figure 5). Inversion is a conformal transformation, which means that local shapes are preserved.

The laws of physics are also inverted, with consequences that may seem strange for those accustomed to thinking in terms of the more conventional universe. For example, light now travels in circular arcs. Also, a rocket launched from the Earth to outer - or, rather, now "inner" - space will shrink and slow down as it approaches the central heaven, never quite reaching it (see Figure 5).

Consequently, Braun's inverted universe is observationally indistinguishable from more conventional models of the universe. Yet, although the two models are empirically identical, they involve quite different ways of viewing reality. Braun's model reflects his theological beliefs. Again, the mathematical model functions here to connect a particular worldview with observations, thus making that worldview more viable.

Note that, if we were to take a point on the Earths’ surface as the center of inversion then we would get a flat Earth (i.e., this is the stereographic projection of geography). As you travel to the edge you become infinitely large at the edge, so that you re-appear at the right (see Figure 6). Again, this model is observationally undisprovable.

So, in principle, the apparent sphericity of the earth could be an optical illusion. A flat earth and a spherical earth are empirically equivalent.

But if it’s possible to save appearances in reference to a flat earth, then to say the ancients were “well aware that the sun and moon were much more distant than flying birds” could also be an optical illusion.

Another interesting line of thought is pursued by Peter Leithart (A House for My Name 2000), who sees many similarities between Genesis 1 and the building of the temple. God's universe is described as His three-storied house. Also G.K. Beale (The Erosion of Inerrancy in Evangelicalism 2008) contends that Genesis is expressing its theological conceptions of the universe, understood to be a huge temple for God (p.163). Hence the architectural depictions of the temple-house are to be understood figuratively. He argues that Israel's temple is a small model of the cosmos, which is a huge temple. (for more on this see the post Cosmology and Heaven). Beale specifically (pp.196-201) rebuts Seely's notion of a solid raqia.

i) Yet the hermeneutical approach taken by Beale isn’t confined to a flat-earth/triple-decker universe. Isn’t that equally applicable to geocentrism? Both could be architectural metaphors which foreshadow the temple and the tabernacle. Yet Byl defends geocentrism. Can he deploy Beale against Enns without having the same approach undercut his commitment to geocentrism?

ii) Apropos (i), assuming (ex hypothesis) that there’s prima facie Biblical evidence for geocentrism, isn’t there, by the same token, prima facie Biblical evidence for a flat earth or triple-decker universe? Does Byl subscribe to a flat earth? If not, where does he draw the line, hermeneutically speaking?

This denies the perspicuity of Scripture and exaggerates the difficulty of reading Gen.1-11. Contrast this with Sproul's own earlier (2006) words ("What is RC Sproul's Position on Creation"):

For most of my teaching career, I considered the framework hypothesis to be a possibility. But I have now changed my mind. I now hold to a literal six-day creation, the fourth alternative and the traditional one. Genesis says that God created the universe and everything in it in six twenty-four-hour periods. According to the Reformation hermeneutic, the first option is to follow the plain sense of the text. One must do a great deal of hermeneutical gymnastics to escape the plain meaning of Genesis 1-2. The confession makes it a point of faith that God created the world in the space of six days.

Is Dr Sproul now repudiating his Reformation hermeneutic of following "the plain meaning of the text", thereby reverting to his earlier hermeneutical gymnastics?

i) That’s a valid critique of Sproul on his own grounds. Byl has caught him in an inconsistency. So that’s fair as far as it goes.

ii) However, that doesn’t mean the rest of us should define perspicuity in terms of the “plain sense” of the text. Is “the plain sense of the text” equivalent to “Reformed hermeneutics”? Suppose you were a 14C Western European. To you, the “plain sense” of Jn 3:5 is baptismal regeneration. To you, the “plain sense” of Jn 6 is transubstantiation.

That’s because you’d be conditioned by your Catholicism. What’s “plain” to one reader isn’t plain to another. “Plain meaning” is really a disguised form of reader-response theory. What’s plain to the reader. By definition, that’s relative. Person-variable.

That’s in direct contrast to the grammatico-historical method, which is concern with ascertaining original intent. What the text would mean to the author. What it ought to mean to the original audience.

iii) What about perspicuity? Does that mean the Bible is equally clear to everyone? Surely that’s overstated. There are parts of Scripture that would be more intelligible to the original audience. In that respect, Scripture serves a specific purpose for the original audience, and a general purpose for subsequent generations. There are lots of oblique topical references which at this distance we’re not likely to catch. But that’s fine, because God doesn’t intend all Christians to need all that. Parts of the Bible can serve different purposes for different people at different times and places.

We may find certain verses in 1 Corinthians (to take one example) a bit obscure. But they weren’t obscure to the Corinthian Christians. So they served their immediate purpose in reference to the situation of the Corinthian Christians. But in the providence of God, 1 Corinthians retains a long-range purpose in the life of the church. It doesn’t all have to be equally clear to everyone to accomplish the multifaceted purpose God assigned to it.

This can even be true at a purely individual level. In the life of a Christian, as he passes through the lifecycle, some parts of the Bible are more significant to him at some points in life than at others–where his situation parallels something in Scripture.

First, Dr Sproul--like many others-- misunderstands geocentricity. The issue was not whether the Sun was the center of the solar system, as Sproul puts it. Rather, the issue was whether the earth--or the Sun--was in a state of absolute rest. Since science can deal only with relative motion, this issue must be settled via extra-scientific considerations. There can therefore be no valid scientific objections if the Bible takes the earth to be fixed in an absolute sense. Science has not disproven Biblical geocentricity (See my post A Moving Earth?).

Historically, the issue was not whether the sun or earth was the center of the solar system, as many people mistakenly believe. Rather, the question was whether the sun or earth was fixed at the center of the universe. Most geocentrists held also that the fixed earth was non-rotating: the sun and stars rotated about the earth every 24 hours.

At one time, when Newtonian mechanics still reigned, it was widely believed that the earth had been proven to be moving in an absolute sense. Since 1915, with the advent of Einstein's general relativity, scientists know better.

Indeed, how could science possibly show that the earth really moves? Any astronomer will tell you that the earth’s absolute motion cannot be proven. To determine absolute motion we need an absolute reference point. What point should we choose? the sun? distant galaxies? But how do we know that, say, the sun, is at absolute rest? After all, even with a telescope, we can observe only relative motion. We get exactly the same observations whether we assume the sun moves around the earth or vice versa. To determine absolute motion we must go beyond the observations.

Nor do mechanical considerations help. Einstein’s general relativity, too, uses only relative motion. Whether we consider the earth to be fixed or moving, we end up with exactly the same physical consequences. According to Einstein, writing in 1938, the two sentences “the sun is at rest and the earth moves” or “the earth is at rest and the sun moves” simply reflect two different choices for coordinate systems, both equally valid. If Einstein had no scientific objections to a fixed earth, why should we?

Much the same points have recently been made by George Murphy ("Does the Earth Move?", Perspectives in Science and Christian Faith 63 (June, 2011):109-115. Murphy, however, argues that, although the center of the earth could be fixed, the earth itself must be rotating, else objects further than Neptune would be moving at speeds greater than the speed of light, which relativity prohibits. On this point Murphy is mistaken. The relativistic constraint that objects can't move faster than light refers only to motion with respect to the local background space--or aether. The aether itself may move at any speed. Thus, if the entire universe--including the aether-- revolved about the earth, this would not violate relativity.

In this regard, it has been shown that, in general relativity, the universe rotating about a fixed earth produces Coriolis and centrifugal forces, the bulge at the earth's equator, and all other phenomena generally adduced to prove that the earth is rotating (see D. Lynden-Bell, J. Katz and J. Bilak, “Mach’s Principle from the Relativistic Constraint Equations”, Monthly Notices of the Royal Astronomical Society 272 (1995), pp. 150-60). The two reference frames--fixed earth or rotating earth--are thus scientifically equivalent.

In short, Dr. Clark's reasoning reveals an out-dated knowledge of science. Ultimately, one's choice of an absolute standard of rest must be based on extra-scientific considerations, based on philosophical or theological factors. A geocentric biblical frame of reference is thus beyond any scientific disproof.

Two issues:

i) I believe Dr. Byl is an antirealist in his philosophy of science. In particular, an instrumentalist:

In that case, he doesn’t think general relativity is true. So when he invokes general relativity to defend geocentrism, that’s presumably for the sake of argument.

But unless all inertial reference frames are actually equivalent, how does general relativity lend support for geocentrism? If general relativity is just a useful fiction, then where does that leave the reality of the situation?

ii) Moreover, Byl is arguing for an absolute frame of reference–the earth. Wouldn’t that be more Newtonian than Einsteinian?