Sunday, July 11, 2010

Problems in Young Earth Creationism Part 2: Star light travel time.

In part 1 of this series I introduced the Star light travel time problem; that is, how can the YEC community maintain the Earth to be only 6000 years old given that light from the stars appears to have traversed distances of millions and even billions of light years? In this post I will be looking at the ideas of YEC theorist Ross Humphreys who attempts to solve this problem.

In my last post on this subject I mentioned the book “The Genesis Flood” published in 1961 by Whitcomb and Morris, a book which seriously put forward the suggestion that photons were created in mid flight. This is the “mature creation” theory; the view that God creates “as seen” even if it means building in the appearance of some kind of bogus history; for example, in the case of star light the Creator has to contrive pulses of light from supernovae that never happened, amongst other shows of faux history. What YECs euphemistically call “mature creation” is an adhoc philosophical bodge that quickly turns into an intellectual quagmire. As many critics have pointed out, “mature creation” so easily succumbs to a reduction to the absurd: It conjures up a picture of a deity who creates in such an arbitrary fashion that science and knowledge are undermined. It introduces the concept of artifice into creation and ultimately subverts even the assumptions needed to interpret the Bible.

Not surprisingly, then, in order to restore the concept of a Creator who creates with integrity thus restoring the concomitant integrity of science some YECs have tried to move away from the highly concocted and contrived notions of mature creation. Some YECs at least want to be seen attempting to do some real science; after all if they want to convince us that evidence of a young 6000 year old Earth is all around us, they will have to concede that the Earth really does provide signs of its true history and not merely a faux facade of its age. Likewise, if they want to be taken seriously on the star light problem YECs have to advance a scientifically tractable solution that does justice to such phenomenon as super novae.

A reviewer of Humphries at Answers in Genesis admits the problems YECs have:

Creationists who believe in short timescales of Earth history have had a few problems with cosmology. Criticisms of the standard Big Bang model have often been made, often drawing on voices of dissent coming from the academic community. However, the positive statements of a creationist cosmology have yet to emerge. ...Light from distant galaxies...... The distances are immense, with some of the estimated times of light travel measured in billions of years.

It's news to hear a YEC admitting that they have “a few problems with cosmology”, but it’s hardly news to hear that a positive YEC cosmology has yet to emerge; as many have remarked YEC “science” tends to be a science of negation – that is, no propounding of theories that join the dots of observation, but rather a seeking to undermine established theories; theirs is the strategy of tearing down rather than of building up. This negative approach is, in fact, very much in keeping the fidiest anti-science strain one often finds in “fundagelical” Christianity. This fideism is apt to label science as “man’s wisdom”, a wisdom which must be scorned and eschewed in favour of the divine gnosis that comes with a gnostic conversion that transcends reason. That is, up until now!

OK, so Humphreys has at last provided a positive statement of YEC cosmology - so what is it?

Let me start by emphasizing how basic and elementary this problem is. It involves one of the first formula I learnt in science and maths: Velocity = Distance/Time! Or in this particular connection we can express it as:

Speed of light = Distance to galaxy/ Light travel time.

This simple formula involves no appeal to some highfalutin and complex big bang theory involving multiple speculative hypotheses, but an elementary mathematical relationship between fairly well established quantities such as the speed of light and the distances to galaxies. When these values are plugged into this equation they return light travel times running into millions if not billions of years. Unlike some other YEC attempts to deal with this problem Humphreys appears to want to preserve the speed of light. (and for good reason since it is such a fundamental constant in the equations of physics). So, given that Humphreys also accepts that the distances to the galaxies may be measured in billions of light years how does he accomplish the impossible of returning a light travel time of around 6000 years? Well, the short answer is that he doesn’t….

And now for the long answer….

In this web article Humphreys says the following about his theory (A theory he published in his book “Starlight and Time”):

In contrast to the big bang story, the Scriptural record appears to imply that the universe is in fact, an island universe. Appendix B of Starlight and Time shows Biblical evidence that (a) the cosmos has a unique center and a boundary for its matter, beyond which there is at least some empty space; and (b) on a cosmic scale of distances, the earth is near the center.

In other words Humphreys starts by assuming a finite creation with a centre of gravity; in fact according to this reviewer on AiG Humphreys assumes that all we see in the heavens today was initially concentrated in a radius of 1 light year or more. Humphreys proposes that the Earth is somewhere near the centre of this island universe and this is crucial because of what happens next: Some kind of inflation then occurs expanding the island universe and so…

…. it turns out that when the expanding universe was at a critical size (about fifty times smaller than it is now), gravitational time dilation would have been very important. My theory proposes that the cosmos was at that critical size during the fourth day of Creation Week. While one ordinary day was elapsing on earth, billions of years worth of physical processes were taking place in distant parts of the universe. This allows starlight from even the most distant star to arrive during or soon after the fourth day, the same day God created all the stars. During that day, most of the expansion of the cosmos would have taken place.

In short Humphreys is proposing some kind of asymmetrical big bang – yes, he’s actually proposing a big bang – but because the distribution of matter is asymmetrical, (that is, concentrated in a finite volume in this case) this leads to clocks running at different rates in different parts of the universe. In particular, near the centre of the big bang where the high concentration of matter implies that space is highly compressed, clocks will run more slowly than those that those less centrally placed during the inflationary period. This is the trick that allows Humphreys to deduce that time on Earth passes much more slowly than elsewhere in the universe; and it is this trick that allows light to creep at a snail’s pace across the universe for billions of years to reach the Earth where an initially high space compression slows clocks down to the point where only a day or two has elapsed!

The asymmetry or non Copernican nature of Humphreys’ cosmology is very clear from this quote:

But in a creationist cosmos having a center of gravity, if you were to travel outward from the center you would, on the average, go steadily "upward" in a gravitational sense. On a large scale, the heavens would be at a higher gravitational "altitude" than the earth. As Isaiah 55:9 says: "For as the heavens are higher than the earth . . ."

I’m always amused by the way YECs manage pull out of their hats very novel and unexpected literal readings of poetic Biblical metaphors that somehow fulfill their theories! But quite apart from that, when I read about Humphreys’ theory I was gob smacked. My first reaction was: Is that really it? Humphreys has actually made some big concessions to current cosmology. Firstly Humphreys is positing a form of big bang, although with an asymmetrical boundary condition that produces the time dilation differential which leads to a considerable slowing of clocks on Earth. Secondly, he has actually conceded the existence of an old universe – in parts. In fact since the greater part of the universe is well beyond the 6000 light year limit it follows that most of the universe, in terms of its local clocks, is a lot older than 6000 years! However, Humphreys declares that it is the gravitationally slowed clocks on Earth that really matter:

The bottom line is that relativity forces us to say by whose clocks we specify the age of the cosmos or the timing of events within that cosmos. My book points out that the Bible gives us time in terms of the "earth's frame of reference, not some other frame." Scripture says, and my theory agrees, that the universe is young as measured by clocks on Earth.

Relativistically speaking clocks in other parts of the universe are just as valid as clocks on Earth, whatever Humphreys thinks scripture tells us which clocks measure the real age of the universe. In fact in a reply to a critic (which can be found here) Humphries admits to the symmetry of clocks in relativity:

Duff claims in his second-to-last paragraph that even if my theory were true, the cosmos would still be billions of years old. But he is simply expressing a personal preference in clocks, regarding the distant clocks as more important than the ones on earth. How unrelativistic of him!

And conversely, if by personal preference we should find the distant clocks more useful a coordinate system when measuring the age of the universe we could thus equally validly declare the universe to be billions of years old! In fact given that the overwhelming volume of the universe is going to have clocks which run for millions if not billions of years we might prefer this coordinate system when doing cosmology! Moreover, the majority of planets out there in the depths of space would have existed for millions of years and thus have an old planet geology! It does seem a bit of a coincidence that Earth geologists have come to the conclusion that our own planet also displays an old planet geology..…oh, I forgot they are all part of anti-God conspiracy.

In one sense Humphreys is admitting that the cosmos at large is very old; measured in terms of the huge number of events that have actually happened out there – which only becomes apparent if we use local clocks – that cosmos returns great age. But in order to keep the YECs happy he tells us that the cosmos is not old with respect to the time dilated Earth clocks. He resolves the ambiguity in the age of the cosmos by suggesting that the Biblical convention is that of using Earth Clocks to measure time. So perhaps we should rescale our coordinate system and start measuring cosmic light travel times using Earth time – using dilated Earth time means that star light has been travelling for only for a few thousand years as measured from the moving goal posts of Earths changing rate of (with respect to the cosmos) clock ticking.

All this seems very far removed from the meaning that copper/bronze age arcadians would have invested in the text as they wrote the passages that eventually got incorporated into Genesis 1. Also, I suspect that some of today's "arcadians" - that is, the fundagelical fideist ultras - won’t like this scientific tinkering one little bit as it really introduces an ambiguity in the age of the cosmos which for those who like to be “biblical, accurate and certain” could go down like a feather sandwich.

The big question, however, is whether, Humphreys’ scheme works observationally. Conservapedia, the right wing web encyclopedia which is sympathetic to young earth creationism is not so sure:

However, this theory is not without problems. The evidence contradicts Humphrey's assumption that the earth is in a large gravity well. If the earth were in such a gravity well, light from distant galaxies should be blue-shifted. Instead, it is red-shifted. Also, gravitational time dilation, if it existed on such a large scale, should be easily observable. On the contrary, we observe (from the periods of Cepheid variable stars, from orbital rates of binary stars, from supernova extinction rates, from light frequencies, etc.) that such time dilation is minor. It is thought that here is some time dilation corresponding with Hubble's law (i.e., further objects have greater red shifts), but this is due to the well-understood expansion of the universe, and it is not nearly extreme enough to fit more than ten billion years into less than 10,000.

And yet Conservapedia claims:

This model receives cautious but wide support among creationists.

…well I suppose there is not much else out there on the ideas market to receive YEC support.

I’m not sure whether Conservapedia is right about the blue shifted light; the actual shift is the result of two competing effects – firstly expansion which red shifts light and secondly the gravitational well which blue shifts light – without wading through the calculations it is difficult to determine the net result. However, I would expect some vestige of Humphrey’s asymmetrical universe to be apparent in the distribution of cosmic matter; as Conservapedia points out we might expect to find vestigial differences between the rate at which clocks tick in distant parts of the universe and those on Earth, which as far as I am aware has not been detected as I am sure we would have heard about …oh, I am forgetting again; astronomers are all part of a sinful anti-God conspiracy.

The moral of this story is that it is not enough for YECs to bask in the detailed problems of Big Bang theory when it is clear that they have quite elementary problems of their own - the problem with star light is far more basic than Big Bang theory. Whatever the exact history of creation, the light from those distant galaxies is fairly compelling evidence of one thing; namely that those photons have made a very long and historic journey. In fact the problems for YECs increase for every light year beyond a paltry radius of less than 6000 light years. This is not a question of how the universe got started but just how long those photons have been travelling – and it is here that Humphreys actually concedes the point – yes they did travel for billions of years, whilst the Earth, Rip Van Winkle style, was stuck in a time dilation pocket. What is remarkable is that Humphreys does not deny the plain meaning of the fact that photons reach us from distant parts, implying that the universe, when measured locally, is a very old place. As an aside Humphreys’ theory also begs questions about those YEC theories which claim that galactic dynamics implies young galaxies. So who is right: Is it Humphreys who is claiming the cosmos to be very old in terms of its local clocks or is it those YECs who claim the galaxies are young?

In some ways YECs have the advantage of being able to face both ways; if their foray into positive science fails they can always retreat into mature creation theory with its great flexibility of ad hoc explanation. But in order to implement a scientific creationism they have to some extent work against mature creation theory because they are then forced to maintain that the Earth really does contain at least some evidential pointers to their claims of a 6000 year old history (like for example the concentration of salt in the seas – which they claim is evidence of a young Earth). In other words some evidences they treat as pointers to a genuine “maturity” and some evidences as a faux maturity.

But in all their difficulties YECs seldom, if ever, turn the critical spot light on what is the source of their problems, namely their interpretation of scripture; the writers of scripture were an arcadian people who thought in arcadian ways and this consideration must be factored into Biblical interpretation; God's Word comes through this interface. But modern YECs claim their interpretations of the Bible to be the very words God; God means what they say He is says. But I think it has less to do with “The Word of God” than it has with community inertia, investment and face saving. On the age of the Earth there is no chance of YECs reviewing their views without them (and their multi-million dollar creation museum investment) becoming a laughing stock – no make that, "an even bigger laughing stock". The YEC community has passed the point of no return.

The YECs have a PR problem: Any thing goes in creationism?

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