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Here's One Reason The Moon's Gravity Is So Important To The Military
Business insider ^ | 3/16/2012 | Eloise Lee

Posted on 03/17/2012 8:30:25 PM PDT by U-238

When you're building one of the world's most advanced jet fighters, there's no room for error.

Engineering technology used by BAE Systems, a partner in the F-35 joint strike fighter program and the manufacturer of Typhoons, even takes the moon's gravitational pull into account.

The moon causes the ground to shift by one to two millimeters every time it pulls the oceans' tides in and out. And this tiny movement can throw off the precise alignment of an aircraft's frame as pieces are put together.

"That might not sound a lot, but given the tolerances we are working to on Typhoon, two millimeters is two millimetres too much,” said Martin Topping, head of the aircraft's maintenance at BAE.

Tolerances in mechanical engineering means the space between two materials, such as between a bolt and a nut.

BAE explained that the tolerances used to build the Typhoon, most notably used by the British RAF, are so fine now that even the movements of the tide can throw the jet fighter's tolerances out.

Its frame is 15 metres long, so there's plenty of room for tiny misalignments here and there. Taking the moon's pull into account as the frame is pieced together helps the finished aircraft's computer control system function more accurately in flight. And it saves 16 gallons of fuel per average flight.

(Excerpt) Read more at businessinsider.com ...


TOPICS: Astronomy; Science
KEYWORDS: astronomy; astrophysics; moongravity

1 posted on 03/17/2012 8:30:36 PM PDT by U-238
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To: U-238

That’s amazing.


2 posted on 03/17/2012 8:42:45 PM PDT by unkus (Silence Is Consent)
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To: U-238

Tolerances in mechanical engineering means the space between two materials, such as between a bolt and a nut.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Pure hilarity! Or is it nauseatingly pitiful? Whatever.


3 posted on 03/17/2012 8:47:27 PM PDT by loungitude (The truth hurts.)
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Thanks U-238. The writer erred:
The moon causes the ground to shift by one to two millimeters every time it pulls the oceans' tides in and out.
No, the moon causes the ground to shift for the exact same reason it causes the oceans to shift.


4 posted on 03/17/2012 8:50:06 PM PDT by SunkenCiv (I come to bury Caesar, not to praise him)
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To: U-238

Utter nonsense. The temperature in the room makes more of a difference than the moon does. The heat transfer from your hands make a bigger difference.


5 posted on 03/17/2012 8:56:22 PM PDT by irishtenor (Everything in moderation, however, too much whiskey is just enough... Mark Twain)
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To: U-238

huh

Huh?????

Ok, so the ground shifts say 2mm at the nose of the plane, and 2mm at each wingtip, and 2mm at the tail of the plane.

So isn’t the plane in the same alignment as all of it is 2mm different???


6 posted on 03/17/2012 8:58:04 PM PDT by Noob1999 (Loose Lips, Sink Ships)
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To: U-238

And another thing...”Tolerances in mechanical engineering means the space between two materials, such as between a bolt and a nut. “ If the nut and bolt are put together properly, there is no space in between at all. They should be completely touching.


7 posted on 03/17/2012 8:58:58 PM PDT by irishtenor (Everything in moderation, however, too much whiskey is just enough... Mark Twain)
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To: irishtenor

I find it kind of worrying.
The Germans had designs in WW2 that were technical marvels, and besieged by teething and reliability problems as consequence.
To what degree are we making the same mistake.
Fighters so expensive you can only afford a handful means they have to be spread thinner, and losses become even more dear.


8 posted on 03/17/2012 9:01:47 PM PDT by Gunslingr3
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To: U-238

Frankly, I’d be more worried about this kind of thing:
http://defensetech.org/2007/02/27/that-deaf-dumb-and-blind-jet/


9 posted on 03/17/2012 9:08:09 PM PDT by Psycho_Bunny (Burning the Quran is a waste of perfectly good fire.)
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To: irishtenor; SunkenCiv

Actually, there has to be a tiny, tiny space between the two. If not for that space, it would not be possible to put the bolt into the nut.

Also, about the tides, one of the reasons for the movement of the ground is the direct pull of the Moon’s gravity. The other is due to the shifting of the weight of the water mass on the land bearing it, due to the tides.


10 posted on 03/17/2012 9:10:17 PM PDT by James C. Bennett (An Australian.)
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To: U-238

Amazing! I would have never thought about that.


11 posted on 03/17/2012 9:12:25 PM PDT by Vendome (Don't take life so seriously, you won't live through it anyway)
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To: James C. Bennett

My bad... Whatever the nut and bolt are holding together should have no gap. If they are installed properly.


12 posted on 03/17/2012 9:14:09 PM PDT by irishtenor (Everything in moderation, however, too much whiskey is just enough... Mark Twain)
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To: irishtenor
They should be completely touching.

not true at all...if the fit was with no space at all, you wouldn't be able to put them together. In a common nut and bolt combination, with acceptable normal tolerances, you can actually move the nut up and down on the bolt just a tiny bit.....you can also put them together manually...no tools required!!!!

13 posted on 03/17/2012 9:19:04 PM PDT by terycarl (lurking, but well informed)
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To: SunkenCiv; KevinDavis

Ping


14 posted on 03/17/2012 9:21:45 PM PDT by U-238
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To: U-238

It sounds rather silly that a combat aircraft will be more sensitive to tidal gravity than, say, a fragile edifice like the Crystal Cathedral.


15 posted on 03/17/2012 9:22:46 PM PDT by raccoonnookkeeper (I keep raccoons in a nook!)
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To: irishtenor
Utter nonsense I'm inclined to agree with you. I would reckon the tidal effects over the length of the airframe to be about on part in 10^15.
16 posted on 03/17/2012 9:33:54 PM PDT by Lonesome in Massachussets ("Jihad" is Arabic for "Helter-Skelter", "bin Laden" is Arabic for "Manson".)
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To: terycarl

Read my post 12.


17 posted on 03/17/2012 9:35:42 PM PDT by irishtenor (Everything in moderation, however, too much whiskey is just enough... Mark Twain)
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To: Gunslingr3
I find it kind of worrying.
The Germans had designs in WW2 that were technical marvels, and besieged by teething and reliability problems as consequence.
To what degree are we making the same mistake. Fighters so expensive you can only afford a handful means they have to be spread thinner, and losses become even more dear.


True, the Germans made remarkable stuff ahead of its time but there was no time to work out the teething problems to say the least plus the complexity and cost was so bad, they could only make so many. We and the Soviets on the other hand decided to "Zerg Rush" the Germans where you had 4 or 5 Shermans/T-34's to each King Tiger. As Stalin said, there is a certain quality in quantity."
18 posted on 03/17/2012 9:41:10 PM PDT by Nowhere Man (Send Obama back to the ghetto, November 6th.)
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To: Gunslingr3
The same lesson we should take away from the AK-47 reliability in the field. It was a 5 MOA rifle. Not exceptionally accurate, but very rugged. Operating reliably in spite of loose tolerances.Our M16/M4 actions have pretty close tolerances. They require frequenct cleaning and the correct lubrication for the environment. The CLP that was OK at home was a disaster in the powder fine sand of Kuwait/Iraq. A dry lubricant was required to avoid a gummy mix of the oily CLP and powdery sand.
19 posted on 03/17/2012 9:46:57 PM PDT by Myrddin
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To: U-238

The writer must be scientifically illiterate. The vertical amplitude of earth tides can be as much as 15 inches. And yes, ocean tides do load the edges of the land masses to a very small but measurable degree.


20 posted on 03/17/2012 9:53:34 PM PDT by Poincare (Reality is not a fool.)
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To: Psycho_Bunny

Thank you for the link. Interesting article

:)


21 posted on 03/17/2012 9:58:12 PM PDT by U-238
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If only we had a candidate with such a ‘far fetched’ engineering vision...


22 posted on 03/17/2012 10:00:19 PM PDT by Gene Eric (Newt/Sarah 2012)
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To: U-238

Hmm, how does this fetish with tight tolerances affect field and depot level maintenance? Can you realistically expect to maintain scientific lab level tolerances with 20 year old maintenance techs in an open hanger 500 miles from nowhere?


23 posted on 03/17/2012 10:07:49 PM PDT by ThunderSleeps (Stop obama now! Stop the hussein - insane agenda!)
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To: ThunderSleeps

I would assume that BAE would hire the best techs.


24 posted on 03/17/2012 10:10:06 PM PDT by U-238
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To: ThunderSleeps

If BAE did not hire the best, BAE would be out of business and planes would be dropping from the sky.


25 posted on 03/17/2012 10:11:57 PM PDT by U-238
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To: SunkenCiv

>> “No, the moon causes the ground to shift for the exact same reason it causes the oceans to shift.” <<

.
And it makes everything attached to said ground move right along with it.


26 posted on 03/17/2012 10:23:50 PM PDT by editor-surveyor (No Federal Sales Tax - No Way!)
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To: editor-surveyor

It’s easier than going on a diet.


27 posted on 03/17/2012 10:28:41 PM PDT by SunkenCiv (I come to bury Caesar, not to praise him)
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To: Psycho_Bunny
Frankly, I’d be more worried about this kind of thing: http://defensetech.org/2007/02/27/that-deaf-dumb-and-blind-jet/

Good Lord!

28 posted on 03/17/2012 10:40:43 PM PDT by Talisker (He who commands, must obey.)
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To: irishtenor

You are correct the ingorance of the aircraft people knows no bounds. The damn thing cost 60,000 +++ dollars an hour to fly and they talk about 16 gallons of fuel. Dang!


29 posted on 03/18/2012 12:28:47 AM PDT by org.whodat
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To: U-238

Oh.....this is why the towel bar I put up in the bathroom keeps falling off.


30 posted on 03/18/2012 2:47:46 AM PDT by blueunicorn6 ("A crack shot and a good dancer")
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To: unkus

So the old axiom ‘Don’t plant a fence post on a Full Moon’(or whatever it was) actually had a scientific basis! :^)


31 posted on 03/18/2012 3:11:29 AM PDT by Vinnie
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To: unkus

Back in the 60s, a friends Father worked as an engineer and gave us a tour of the equimpment for making huge shafts and other items. A lathe had an operators car by the tool bit and was a few hundred feet long. The said they had to level it with lasers, because the curvature of the earth made minute, but problematic differences if they leveled it normally. When it was true, a level in the center showed level - put it at either end and it showed the end slightly high.


32 posted on 03/18/2012 4:02:14 AM PDT by trebb ("If a man will not work, he should not eat" From 2 Thes 3)
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To: trebb

A level showing the ends high? I guess it would if the shaft was geometrically straight and then you used a level at the end. The level would show the end tilting ever-so-slightly down in the direction of the center of the shaft length.

I have performed the following gedanken experiment:

Imagine that you were to build a very large, smooth, pefectly flat platform that was absolutely level in its center. Let’s say that the platform was 1000 feet in diameter. Put a ball bearing on the platform at its edge.

Q: What, if anything, would the ball bearing do?

A: It would roll toward the center, just as if the (perfectly flag) platform were slightly dished toward the center.

(True, I don’t get out much.)


33 posted on 03/18/2012 4:29:12 AM PDT by Erasmus (BHO: New supreme leader of the homey rollin' empire.)
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To: Erasmus

I can picture the ball bearing rolling toward the center of gravity due to the center being gravitationaly “lower”. Used to do a lot of thinking/playing like that but the need to earn a living has tarnished the glow - keep up the active mindset.


34 posted on 03/18/2012 4:53:25 AM PDT by trebb ("If a man will not work, he should not eat" From 2 Thes 3)
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To: trebb

Thanks for sharing that. That’s neat. You reminded me of something. In the 1960’s there was a USAF tunneling project near Dulce, NM. I remember one of the engineers who was an acquaintance of my Dad saying basically the same thing about the lazers.


35 posted on 03/18/2012 8:58:24 AM PDT by unkus (Silence Is Consent)
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To: Noob1999

How does the moon pull the land but not the computer guided machine?


36 posted on 03/18/2012 10:54:57 AM PDT by willyd (your credibility deficit is screwing up my bs meter...)
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