googlef87758e9b6df9bec.html A Sure Word: Exotic Theories Part 2: The Oort Cloud

Friday, August 8, 2014

Exotic Theories Part 2: The Oort Cloud

What do you know about comets? When I was young, I used to think that comets hurtling through space were similar to meteors entering earth's atmosphere; I pictured it as a fiery ball with a long tail of flames. Comets were cool! I know now that comets are made of ice and the long tail we see is actually ice particles being blasted away from the body of the comet as it passes near the sun. Eh, maybe not as cool as a fireball.

The fact that comets lose some of their mass each time they pass near the sun has a bearing on the age-of-the-earth debate. Obviously, if a comet becomes smaller with each orbit of the sun, eventually it must disappear all together. Also, each time a comet comes near the sun, it also risks collision with a planet or the sun itself which would end its life immediately. Simple reason, then, forces us to acknowledge that comets can only exist so long. Their long tails are a visual testimony of their short livedness. Eventually, they will either exhaust all of their matter or crash into a planet. If our solar system were really billions of years old, they should all be gone by now. End of story.

One very famous comet is Halley's comet which passes by our sun once every 75 years. It is consider a “short period,” one who's orbit takes less than 200 years. Since Halley's orbit is only 75 years, in just one million years it would have passed by the sun more than 13K times! No one believes that is possible and I'm not suggesting that's what secular scientists believe. Actually, secular scientists believe the maximum life span of Halley is about 40,000 years. If the universe is less than 10,000 years old, this isn't a problem at all. However, it doesn't comport well with the idea that the solar system is millions or billions of years old. If the solar system is really billions of years old, why are there still so many short period comets left? In order to rescue their theory, secular science must find a source that can replenish comets as they are exhausted. After all, since there still are comets, and we know that most of them can't have been circling the sun for billions of years, these comets had to come from somewhere more recently.

One possible source that had been suggested is the Kuiper belt, a region of space beyond the planets known to have several, small, icy bodies orbiting about 4½ billion miles from our sun. It has been suggested that on occasion, these objects would collide with each other and get knocked out of orbit, fall toward the sun, and become comets. However, the Kuiper belt has a very round and stable orbit. Most people consider its orbit to be too stable to be a source for short period comets.

Overlapping the Kuiper belt is another group of icy bodies known as the “scattered disk.” The objects in this disk have a much more elliptical orbit which could be described as “dynamic.” They consider this to be a far more likely source for short period comets.

Whether or not the Kuiper belt or the scattered disk are viable sources for short period comets could be debated. I will grant this, though: we can observe these regions of space. We've never seen an object ejected from these regions and become a comet but at least we know these regions are there.

The point is moot though because even the secular scientists themselves are not proposing that Halley's comet, or similar comets known as “Halley-family comets” came from either of these sources. They are claiming there is still another source. They've dubbed this 3rd source, “the Oort cloud.”

According to Wikipedia, “The Oort cloud,... named after Dutch astronomer Jan Oort, is a spherical cloud of predominantly icy planetesimals believed to surround the Sun at up to 50,000 AU” [bold added]. Note the use of the word, “believed.” As we read through the entire Wiki article, we see a lot of other conditional descriptions; words like “conjecture,” “thought to be,” and “hypothesized” abound. The Wiki article is brimming with “facts” about the Oort cloud – things like it's composition, size, origin, location, etc. It's amazing that we can know so much about something that we've never seen and really aren't sure even exists!

From the second paragraph of the article, we read, “Although no confirmed direct observations of the Oort cloud are made, it may be the source of all long-period and Halley-type comets entering the inner Solar System, and many of the centaurs and Jupiter-family comets as well.” Interesting, huh? It sounds to me like an admission that the existence of the Oort cloud was born solely out of the need for a source of comets. I take that back. They're not implying any such thing. They are admitting it outright. Also from the article, under the heading, “Hypothesis,” we read the following:

In 1932, the Estonian astronomer Ernst Öpik postulated that long-period comets originated in an orbiting cloud at the outermost edge of the Solar System. In 1950, the idea was independently revived by Oort as a means to resolve a paradox: over the course of the Solar System's existence, the orbits of comets are unstable; eventually, dynamics dictate that a comet must either collide with the Sun or a planet, or else be ejected from the Solar System by planetary perturbations. Moreover, their volatile composition means that as they repeatedly approach the Sun, radiation gradually boils the volatiles off until the comet splits or develops an insulating crust that prevents further outgassing. Thus, Oort reasoned, a comet could not have formed while in its current orbit, and must have been held in an outer reservoir for almost all of its existence.

You can read it for yourselves. The Oort cloud was hypothesized seemingly for no reason other than the need for a source of comets! It about as scientific as saying comets are made by unicorns. We might not see unicorns making comets but since there are comets they had to come from somewhere, right? So the comets themselves are scientific proof of the existence of unicorns!!

Most people agree that science is founded upon observations. Here, we are talking about a hypothetical source of comets that cannot be observed so their belief is the Oort cloud is no more scientific than my belief in God. The existence of the Oort cloud is simply necessitated by a belief in an old universe. It's akin to a faith belief except they see it as more plausible because it's a “natural” explanation rather than a supernatural one.

There's nothing within the understanding that God created the universe that disqualifies the possibility of an enormous cloud of icy bodies orbiting so far away that we can't see them. But it's precisely because we can't see it that makes the entire thing seem suspect. I'm withholding judgment until we have real evidence. Until we actually find such a thing, the entire Oort cloud seems like nothing more than an exotic theory.


Steven J. said...

Nitpick: with respect to Kuiper Belt and scattered disk objects (and Oort Cloud objects, for that matter) you should speak of "orbits," plural (the orbit of one scattered disk object is not identical to or linked to the orbit of any other object) not "orbit."

Also, unicorns have not been reliably observed even on Earth, much less in space, whereas icy bodies have been observed in, e.g. the Kuiper Belt, and spectroscopic studies of distant dust clouds imply that ice is common in space at vast distances from Earth. In that respect, the Oort cloud is a far more reasonable inference from evidence than comet-manufacturing unicorns.

Note that the Oort Cloud is inferred, also, because the existence of such objects is implied by current models of solar system formation from interstellar dust clouds. Stars and clouds in what appear to be various stages of star formation have been observed, and the various physical principles on which stellar formation models are built are well-supported by empirical evidence.

You treat the conclusion that the Earth and solar system is billions of years old as basically arbitrary, rather than a reasonable inference from a great deal of evidence, ranging from angular unconformities in geological strata, to radiometric dates, to the mere fact that we can observe supernovae in distant galaxies (and calculate from their brightness that we're witnessing stars billions of light-years away, that presumably traveled at light-speed to get here). The inferred Oort Cloud is a very small price to pay, epicyclically speaking, to make observations consistent with one another.

By the way, it seems to me that radiometric dating falsifies young-earth creationism even if we don't assume that such dating is reliable: since an omnipotent Creator could easily arrange for radiometric dating to be entirely reliable and to yield a young age for the Earth (okay, uranium-238 dating isn't going to be able to distinguish between a million-year-old planet and one created yesterday afternoon, but it won't automatically yield an age of billions of years), the fact that radiometric dating doesn't do this argues against a young Earth created to look the age it is -- and we would expect a trustworthy Creator to do this. Therefore, God doesn't want the Earth to look only six thousand years old; therefore, you should assume that it isn't.

RKBentley said...

Steven J,

I'm not sure how to reply except that to say that you have merely echoed many of the same arguments I've already heard for the existence of the Oort cloud. The points you've raised might be used to support the idea of an old earth/universe but they in no way are evidence for the Oort cloud. Basically, you're once again saying something like it must exist because the universe is old. That's the same attitude I discussed in my post.

I will remind you that the presence of comets argues against an old universe so it seems to me the Oort cloud is a case of manufacturing evidence to suit your theory rather than going wherever the evidence leads.

Btw the way, you said, “Stars and clouds in what appear to be various stages of star formation have been observed.” When you said, “clouds” did you mean something like the Oort cloud has been observed around other stars? It would be truly incredible if we could observe such things around other stars yet still can't see one around our own. Too incredible, I think.

I might go back after this series and reply to some of the specific arguments you've raised for an old earth/universe but for now, I'll stick to the point of post. There is no evidence for the Oort cloud beyond a need for it.

Thanks for your comments. God bless!!


Steven J. said...

Why does the existence of comets argue against an old universe? Oh, right, because combining observations of comets with other observations of nature and modeling their behavior indicates that their material boils away over repeated approaches towards the sun. If we disregard the scientific evidence that comets are perishable, their existence is compatible with an infinitely old solar system. Or, conversely, if we pay attention to that scientific evidence but disregard the evidence that the solar system is really, really old, then we can regard them as evidence against the great age of the solar system. Otherwise, it is vastly more reasonable to regard them as evidence for the Oort Cloud than as evidence for a six thousand year old solar system.

RKBentley said...

Steven J,

Comets are only evidence for the Oort cloud in the same way people are evidence for abiogenesis. We're here so it had to happen. It's more than a little circular.

I discussed in my post why comets argue against an old universe. The same problems were also expressed by Oort himself as indicated in the Wiki quote I cited.

You keep point out to me other evidence which you believe suggests an old universe. As has been discussed on this blog many times, a good theory must explain all the evidence. So your theory of the age of the solar system should also explain the existence of comets. It doesn't. I again repeat that - so far - the only evidence for the Oort cloud is the need for it. It is invented in order for a vast age of the solar system to remain viable.

The "age" of the universe is not evidence for the Oort cloud. The Oort cloud is a rescue device for your theorized age.

God bless!!


Lu MontyZ said...

The discussion in these comments reminds me of arguments between current Big Bang cosmology and models under Carmeli's Special Cosmological Relativity. The Big Bang needs factors that have yet to be discovered, much like the Oort cloud, yet the model persists. Carmelian physics not only explain the fudge factors of the big bang (dark energy and matter), but also allows a young earth, yet a view that the universe is old (hence, relativity).

Just as dark matter and energy are inferred, the Oort cloud is inferred because Big Bang cosmology requires it. For an ancient universe, all three are necessary. Without the Oort cloud, comets become an anomaly for such models.

Of course, a common counter is "more comets are being formed." This neither confirms nor denies an old or young age of the universe, if it's even true. Comets could then be replenishing and/or forming. No logical deduction could be made of the universe's age by the observed age of a comet, even if we saw one form. At best, for an ancient universe, it's a non-issue. But it needs proof, or it is simply question begging.

Carvin said...

The model continues because other aspects of the model that predicted things came to pass. But that's because the 'Big Bang Theory' (the name is rather poor for what it describes) predicts phenomenon in our world. A solid model will predict the areas of the model not yet observed. This happens over and over again in actual science.