Monday, November 1, 2010

Jason Lisle and Distant Starlight

The Skeptical Lutheran, or qpsk (I suspect that's not what his parents named him, but I'm not sure) has suggested that I examine and comment on a paper by Jason Lisle published in the Answers Research Journal of Answers in Genesis.  The paper is an attempt to solve one of the most vexing problems in young Earth creationism, the "distant starlight problem:" why, if light travels at one light year per year, and the universe is only about 6000 years old, can we see the Andromeda Galaxy, which is two million light years away, and even far more distant galaxies?

Lisle opens by noting that the distant starlight problem is, after all, very similar to the "horizon problem" in mainstream Big Bang theory: just as YECs don't quite have an explanation for why we can see distant galaxies, mainstream cosmologists don't quite have an explanation for why the cosmic microwave background is so uniform, when the universe is supposed to have been expanding faster than light so that distant regions could never have been in contact with each other.  He doesn't mention inflationary theory, though he does note elsewhere in his paper that "secular scientists" have auxiliary hypotheses that they can use to patch up the problems with their old-universe models.  More importantly, he doesn't note that the Big Bang theory isn't just some fad that caught on like bellbottoms; it explains the distribution of galactic redshifts, and predicts the cosmic microwave background whose uniformity is so puzzling.  I don't think you could really say that the "creation model" predicts the existence of galaxies most of which can't even be seen with the naked eye.

Lisle, like most modern YECs, dismisses without comment the possibility that the entire visible universe is within 6000 light years of us.  Since he gives no explanation, I can only speculate, but I suspect that he doesn't really want to argue that all those apparent galaxies (with their apparent Cepheid variables, supernovae, etc.) are really something else much closer (and if they're really what they appear to be, of course, they won't all fit within a few thousand light years of Earth).   There is one other point: if the stars were created "for times and seasons, days and years" (Genesis 1:14), it would seem fitting for those stars to be visible by the end of the creation week, when Adam and Eve first got to look at them.

He likewise dismisses the classic omphalist suggestion that light was created, already in transit, from those distant stars.  While Lisle agrees with other AiG writers that the term "appearance of age" is meaningless, and has no problem with the idea that various things from galaxies to Adam himself were created "mature," he is bothered by suggesting that God has created a false appearance of history, by, e.g. creating light from supernovae that never occurred.

At the same time, he rejects the possibility that the Earth and universe are really billions of years old and that this light has had time to reach us at 300,000 kilometers/second.  He does mention and courteously allows the possibility of Humphreys' hypothesis that time proceeds faster the  further one is from Earth (so that distant galaxies really are billions of years old), but notes that in that case, we'd expect distant starlight to be strongly blueshifted, not redshifted (unless the expansion of space were very fast indeed).  He also argues that distant galaxies are probably not very old anyway: he disputes mainstream cosmologists' suggestions for forming new stars (and hot, blue stars don't last billions of years) and for keeping the spiral pattern of galactic arms from winding up tight.

Rather, Lisle finds a possible solution in an odd fact of modern physics: it's apparently impossible to measure the speed of light going only one way: all methods for measuring it depend (explicitly or implicitly) on measuring the time it takes for light to make a round trip.  The usual assumption, of course, is that light travels at the same velocity in each direction, but it's conceivable that it travels faster in one direction and slower in another.  His suggestion is that lightspeed is near-infinite travelling to Earth from distant stars, and only about 150,000 km/sec. travelling away from Earth.   Thus, he argues, galaxies billions of light-years away were in fact created only about 6000 years ago, on day four of the creation week, and their light reached Earth only seconds or minutes later.

Technically, this is an "anisotropic synchrony convention" (ASC) for dealing with measurements of the speed of light, and is allowed under relativity theory (which traditionally has used Einstein's synchronization convention: that light has the same speed no matter which direction it's going); he's careful to note that he's not trying to come up with a radically new theory in physics.  Some of the weirder passages in Lisle's paper come from his attempts to argue that the ASC is used in the Bible and even in modern astronomy (e.g. supernovae are labeled by the year they're observed, not the year they're thought to have occurred in ... but then, this is a date for the observation, not a date for the actual explosion of the star).  The Bible, he notes, always treats light as though it moves instantly from source to observer.  Of course, over terrestrial distances, this is virtually  true.  It is not obvious at all that the Bible uses ASC rather than simply assuming that in  fact light just has infinite velocity and/or the universe is actually pretty small (e.g. those stars are fixed to the solid dome of the sky a few dozen miles over  toour heads).  Like Johnson and Humpreys, Lisle finds himself arguing that the Biblical text is really asserting something that its original readers (and indeed any reader prior to the 20th century) would never have suspected lay in the text.

The very aspect of measuring the speed of light that makes his model possible means that testing it needs to be indirect.  Lisle argues for it by suggesting that distant galaxies look as if in fact they haven't had much history: as noted, he brings up creationist arguments against forming new stars as old ones expand into red giants or go supernova, and against the possibility of natural processes maintaining spiral arms.  Despite his earlier suggestion that his model and and Humpreys' could be combined, his evidence for his model implies the falsity of Humphreys' varied cosmologies.   And of course one objection that "secular" cosmologists will have to his idea -- that it creates a favored frame of reference rather than treating all positions in the universe equally -- is a feature, not a bug, for a model designed to rescue the idea that the Earth and humanity are more or less the whole point of the universe.

One point in favor of old distant galaxies is rather quickly hand-waved away.  Quite a few distant galaxies look "old" in the sense of looking as if they have a past history.  It's one thing to be "mature" in having a panoply of stars and dust clouds and spiral arms (even if they won't last: it sometimes seems to me as if YEC vaguely denigrates the Creator, implying that He's churned out some cheap gimcrack of a universe that falls apart after a few thousand years of normal use); it seems rather another for galaxies to look, for all the world, as though they've just collided with one another (see the photo above) (note that given the size and speed of galaxies, a collision would take millions of years) or as though massive explosions have wracked their cores.  Lisle tries to argue that galaxies with massive flares of gas and dust were simply created "mature," but this is a sort of maturity analogous to trees created with ring patterns showing the effects of nonexistent droughts, fires, and lightning strikes in nonexistent centuries past, or of Adam being created with healed scars from nonexistent past injuries.  Whether or not distant galaxies look old, quite a few of them look very experienced.  It's very, very hard for YECs to avoid invoking, at some point, what looks very much like the omphalos "hypothesis" (except that, of course, by its very nature it's completely untestable).

There is one more point, brought up by Skeptical Lutheran himself and several other people more knowledgeable than myself about physics, who've examined Lisle's thesis: there are physical constants important in electronics that are dependent on light being a wave, and the performance of capicitors and magnets ought to vary as you change their position and orientation unless light waves move at the same speed in all directions.  I presume that Lisle, who seems rather bright, will eventually come up with an auxiliary hypothesis of his own to deal with this problem.  He doesn't, however, seem to have done so yet.

4 comments:

  1. You say

    "it's apparently impossible to measure the speed of light going only one way: all methods for measuring it depend (explicitly or implicitly) on measuring the time it takes for light to make a round trip."

    Are you certain of this? I know that the speed of light was calculated using Maxwell's equations, which predict that light will behave as an electromagnetic wave. Direct measurement may have this round-trip pathology, but waves propagate uniformly and isotropically (in homogeneous media).

    Your observation that eventually he must fall back to an omphalist argument of some flavor is a good one. You mention colliding galaxies. Consider also that so many stars are going supernova within just a few thousand years of being created. I would think this challenges our understanding of stellar fusion.

    Thanks for taking the time to comment on this. You are correct that QPSK is not my given name, but quaternary phase-shift keying is probably the method by which I was able to tell you that.

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  2. QPSK, I am not certain of that, but I have never heard of the speed of light being calculated through Maxwell's equations. This does not mean that it has not been done, but all references to determining lightspeed I've run across involve measuring it more or less directly; it may be that Maxwell's equations imply that at whatever speed it moves, it moves at the same speed in all directions.

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  3. The refutation to Lisle’s ASC comes down to imagining a mirror 5,000 light years from Earth and looking at it. In our universe, you would see a 10,000 year old universe. In Lisle’s universe, you wouldn’t.

    There’s also the issue that the ASC is geocentric; if that mirror were big enough and far away enough, you would see in it a sphere of darkness with Earth in the center contracting.

    I have updated the ASC article at Rational Wiki with this refutation.

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  4. Doesn't supernova 1987A completely debunk Lisle's paper? According to Wikipedia, neutrinos from the explosion were detected on earth at three independent locations 2 hours before the light was. Doesn't that imply a neutrino speed of faster-than-infinite?

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