Cymric wrote:
falemagn wrote:
Whatever you think of Hoagland doesn't explain those pictures.
So we can leave Hoagland completely out of the equation, and just focus on what we observe about Iapetus. Are we in agreement there?
We don't just can, we must leave out of the equation whatever personal opinions you can have about Hoagland.
That doesn't mean we need to leave out of the equation what Hoagland said.
Mind, I am not a planetary geologist, just an ordinary chemical engineer. Can I just ask you what your background is?
Red Herring. I don't feel the need to answer to this question, It's completely irrelevant. Just stick to the discussion.
Well, I can't say anything about your numbers 'cause I haven't seen the calculations behind them, but I can point you to how things are in reality: Saturn's got many other moons, and many of them have a mass inferior to the one of Iapetus, yet they are perfectly spherical. I think you need to recheck your numbers ;-) Also, consider that not just mass counts, but also the diameter.
I was arguing against Hoagland's ridiculous claim that any body larger than a few hundred miles should be perfectly spherical due to gravitational self-attraction. That is not true: it depends on a number of parameters.
It indeed does, but so what? I haven't said you have to take anything Hoagland says as it were divine truth.
[...] All these factors have to be taken into account before one can say whether an object is likely to be spherical or not. Hoagland did not do this, and that was what I was trying to demonstrate.
Strawman attack. It's you that didn't consider all elements, in fact you've tried to counterargument Hoagland's claim by showing that Iapetus cannot possibly be spherical for solely naturaly reasons. But you yourself now admitted that you don't know for sure, that your calculations may be off, and so on and so forth.
What Hoagland said is that any object bigger than a certain size will always be spherical. This is true, you confirmed it in the previous message. and
in fact you even tried to disprove that
the particular Iapetus case isn't one of the cases where the object becomes spherical. And, as you've said yourself, you made up your numbers.
Moreover, Iapetus doesn't appear to be just non spherical, it appeaars to be geodesic, which can't be explained by just saying that gravity wasn't strong enough to melt it.
My response would be 'so what?'. First of all, nowhere on that site is that claim made.
It's now clear you've not read even 1/3 of that report. Look better, the moon2.htm page is totally centered on that argument.
Iapetus is a squashed ellipsoid.
Then, please, explain this picture:
(Hoagland seems to suggest that because Iapetus' day is 79 Earth days long, it has always been that long, because the moon is still so squashed. He needs that line of reasoning to discredit natural phenomena. Out go tidal locking with Saturn, fast cooling and whatever else you can throw at it. Tsktsk.)
Now
that is a claim I can't find anywhere on the site. I may have as well missed it, can you provide a link, please?
Second, any body with materials which cannot cope with high tensile stresses will turn into a geodesic shape under its own gravity---that's what a geodesic means.
Uh?! Geodesic means that since when? Do you know what a geode is, by any chance? you know what a
geodesic dome is? You're building a whole argument on top of fallacious presumptions.
The Earth is not a perfect ellipsoid, it is a geodesic because of its molten interior: angular momentum and gravitational self-attraction balance out at that particular shape. Third, I really wonder how one could measure the geodesic shape of Iapetus given the relatively crude instruments on Cassini. On Earth, the deviation from the ellipsoid is measured in meters.
You have a totally bogus idea of what 'geodesic' means. You might want to look at a dictionary. Sorry, but I can't be more polite than that.
That is in itself not an explanation for Iapetus' unusual shape, since I lack information about the various processes and their relevance. We'd need a geologist for that. What I am saying is that you shouldn't be jumping to conclusions either.
Did I jump to conclusions? I recall having made perfectly clear that I don't know whether it's artificial or not. I've even proposed a
natural explanation that tries to fit all evidence we have.
Notice I'm not saying Iapetus is indeed artificial, I'm just saying that unless you can explain in detail how could Iapetus "naturally" have such singular characteristics, then the artificial hypothesis can't be discarded.
Which is of course a complete and utterly bogus hypothesis, because you can't scientifically falsify that one.
How would you determine it is constructed?
Uh... How else if not by digging and trying to find what's in it? If it's indeed been constructed, it must have a purpose. Hoagland is even suggesting it's a spaceship, how more testifiable than that can it get?!
Tsk tsk..
Okay, I would call the presence of lorries, bulldozers and workers' huts a pretty good indication of artificiality. But other than that we have no idea what non-human constructs look like (other than evolved ones, like trees or birds) so we chose to anthropomorphisize the entire thing. And that is certainly not scientific.
Oh, please... how more silly can it get?
First of all, no one said it's non-human. For what we know it could have been us ourselves that put that thing there, eons ago. This wouldn't be in contraddiction with anything we know about ourselves and our world, and would instead corroborate some of the old myths that pervade our cultures.
Secondly, I'm sure that you'd be able to recognize a manufact produced by intelligent beings if you had the opportunity to look at it with your own eyes and 'play' with it. Unless the manufact were deliberately made to
not look like an artificial object, which is an extreme case we can avoid considering.
Suppose that we see nothing indicating lorries on the new flyby in 2007, provided even that Cassini passes by so close that such devices can be seen with its cameras. If you then still cling to the artificial hypothesis, claiming some unknown way of construction, you chose to remain ignorant and not look at it in further detail. I would much rather prefer to keep on looking, improving my knowledge of geology and large-scale rock formations.
Uh... of course I'd want to look at it in further detail. If it were up to me I'd land on that moon right away and do all examinations that would be required. It's not
me here that isn't prepared to all possible scenarios.
