Where, precisely, on page 1?

And, what new claim has Jerry made? I must have missed it.

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Do try not to take me too seriously.

Demigrog,
have you seen this post, on page 18.

In particular:
Since Huygens landed, Jerry has been focusing on details of the descent (four and a half minutes instead of three...).
These details have nothing to do with the orbital mechanics, but at most depend on the specific features of Titan's atmosphere where the landing occured, which were not well known before the landing.
By going from the orbital mechanics to the details of the atmosphere, Jerry did shift the goalposts, in an attempt to save his pet theory.

[EDIT to fix page number.]

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papageno


"Why waste time learning, when ignorance is instantaneous?" - Hobbes (Calvin and Hobbes)

"It's all about context!" - Vince Noir (The Mighty Boosh)

"I've never heard of such a brutal and shocking injustice that I cared so little about!" - Zapp Brannigan (Futurama)

To be precise, Jerry stated in the OP that Huygens would "almost certainly crash". That sounds like a bit more than a "good chance".

I read a few things in this thread every now and then.
I can't believe that this is already going over 19 pages! #-o

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"Flying in space is risky business, but just staying on this planet is risky business too." - John Young, astronaut

I missed this while I was posting...

I absolutely agree with Papageno. Jerry has been "tap dancing" so much, I'm surprised that his shoes haven't melted.

Umm, almost every post on page 1 not from Jerry or you? More precisely, Evan, Taibak, kucharek, ... His mistakes, assumptions, mix-ups and so on were pointed out there. It certainly proved to me he was wrong. E.g. The volcano thing, the Global Surveyor, the sign of G thing, the orbits of planets...
The 'new claims' has been answered by Papageno. And Jerry said in his first post that Huygens will almost certainly fail. Can I now conclude that he was almost certainly wrong?

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Apparently, only if you ignore the 'details'

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Feynman
>~~~~<
Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.

Religion is a culture of faith; science is a culture of doubt.

I focus on the 4.5 minutes between entry and mach 1.5 because it is the ONLY HARD CLUE the ESA has given us about the descent phase of the mission. This is the period of GREATEST acceleration, and increasing this period by 50% either increases the gravimetric effect by a factor of TWO, or diminishes the effectiveness of the atmosphere in slowing Huygens down by a factor of two.

Since they readjusted the closest approach of Cassini because they were "runnining into a few more molecules" than they expected, it seems highly improbably that mission planners grossly underestimated the thickness of Titan's atmosphere by a factor of two.

This is not goal post moving, you can cut and paste out of my posts all you want, the prediction still stands and is consistent with the observational evidence the ESA has released, including both the swooshing in the audio mike, and the ground radar indications of a period of descent at a minimal velocity followed by a moment of rapid acceleration just before touchdown, neither of which was in the game plan.

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jwj

If you always believe what you already know, you can't learn anything - Liz

Which "prediction" would that be, Jerry. The one where Huygens would "almost certainly" crash, or the one where we didn't completely understand the nature of Titan's atmosphere before we even went there.

Either way, it doesn't prove your "theory" at all.

Jerry,

What do you consider to be goal post moving then? :roll:

I don’t see a shift here; the details of the landing, particularly deviation from expected acceleration, could be useful. However, I think it is probably a waste of time, because there are too many variables. It’s Jerry’s time to waste, however, so long as he doesn’t hinge his entire argument on ambiguous landing data—that way lies woo. In any case, since the landing data is the bulk of what little is public about Huygens so far, it is hard not to focus on it.

I agree that the orbital mechanics are the important thing, and I’d like to see more data. At first glance, Huygens successfully hitting its targeted landing zone without orbital corrections is compelling evidence against Jerry’s variable G hypothesis. However, a successful Huygens landing does not rule out deviations in G, it merely puts an upper limit on those deviations. Nobody has done the calculations (so far as I know) to see how much difference there should have been under Jerry’s hypothesis. (IMO, that should have been done before posting in General Astronomy.)

The vast majority of posts on this and the other threads are people pointing out how unlikely and ATM Jerry’s ideas are. This is not the same as actually disproving them. Also, the specific mistakes I’ve seen do not directly impact the original hypothesis, so harping on them is basically a Straw Man. And, in the case of the “incorrect” sign, that was not a mistake.

And posts like this are productive? This thread would be half as long without the fluff.

Edited to fix mis-attributed quote

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And why would you be increasing anything by 50%? Please explain where this increase comes from?

I'll give you that, but I wouldn't go as far as "grossly underestimated".
Realize though, that was the second fly-by of Titan when they made the adjustment. They got this information after the release of the Huygens probe. That's the point of launching these things. To gather knowlege. Now we know that Titans atmosphere is thicker then first speculated.

.

The swooshing sound is what alot of us call "wind". That's what a microphone is supposed to do, record sound. Just because Huygens was floating at 4.5m/s, doesn't mean that it can't pick up anything other then the noise caused by it's descent.

As far as the " a moment of rapid acceleration just before touchdown", that's no mystery either. The probe gets closer to the ground, the radar pulse doesn't have to travel as far. This is not rocket science here. It's just plain common sense.

Actually, I posted that. Productive?, no. Descriptive of what Jerry has been doing for the last (almost 20) pages? Oh most certainly!

What about atmospheric drag, which depends on speed?
If the atmosphere is denser than expected, wouldn't expect the descent to take a bit longer?
What happens if there is wind?

They re-adjusted Cassini's trajectory (a contingency already worked out, just in case) and after release Huygens was on a ballistic path for three weeks.
If the orbital mechanics had been wrong, as you claim, Huygens would not have landed within the programmed parameters.

Three weeks without correcting the trajectory and Huygens did not miss Titan, entered the atmosphere as planned and did not crash.
Not bad for an "inherently flawed orbital mechanics"!

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papageno


"Why waste time learning, when ignorance is instantaneous?" - Hobbes (Calvin and Hobbes)

"It's all about context!" - Vince Noir (The Mighty Boosh)

"I've never heard of such a brutal and shocking injustice that I cared so little about!" - Zapp Brannigan (Futurama)

Huygens was on a ballistic path for weeks, without the possibility of adjusting the trajectory.
Yet Jerry focuses on minutes within the atmosphere.

Jerry said that the orbital mechanics was inherently flawed.
But this "flaw" did not seem to affect the ballistic path which took weeks, and Huygens entered atmosphere as planned.
Yet Jerry decides to focus on the descent, which took minutes or hours and depended on the specific details of the atmosphere in that region.
The orbital mechanics has little effect on the descent profile, as opposed to atmospheric effects.

Outside the amtosphere, there are not that many variables.

This is exactly what he is doing.

But Jerry's prediction had little to do with the details of the descent profile.

You mean, entering the atmosphere as planned is not enough?
After three weeks, getting the day right is already a good achievement.

Jerry said that Huygens would almost certainly fail.
If there is a change in G, it would be so small that its effect would be masked by atmospheric effects.

And pointing out errors, misconceptions and misunderstandings about "mainstream" physics.

Is the evidence of Huygens succesful landing not enough.
It disproves Jerry's claim that the orbital mechanics used to calculate the trajectory is flawed.

If Jerry had accepted that his prediction was wrong...

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papageno


"Why waste time learning, when ignorance is instantaneous?" - Hobbes (Calvin and Hobbes)

"It's all about context!" - Vince Noir (The Mighty Boosh)

"I've never heard of such a brutal and shocking injustice that I cared so little about!" - Zapp Brannigan (Futurama)

Whoops, sorry Fram. Copy-paste error.

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No problem!

Question: if there is a difference in G, why would it have no effect on the three weeks Huygens was on its way to Titan, then have a huge effect on the first part of the descent, and again have no effect on the rest of the descent? The size of the parachute was based on G as we know it, a different G would make the lander fall slower (or faster, but in this case apparently slower). What's the logic behind this?

Noone has perhaps really, truly disproven his theory (except his own predictions), because it's so vague. There is a force that works sometimes, in some circumstances, but it's hard to tell when it does and when it doesn't, or how much the effect is. It's a bit hard to say 'you're right' or 'you're wrong' to such a thing, isn't it. But when the predictions fail (along with many of the examples), I consider the thing disproven anyway.
And the sign was not a mistake, it was a joke. Is that what you mean? A bit weak as a defense, no?

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