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NASA Sticking To Imperial Units For Shuttle Replacement
JerryQ sends in a story at New Scientist about the criticism NASA is taking for deciding to use Imperial units in the development of the Constellation program, their project to replace the space shuttle. "The sticking point is that Ares is a shuttle-derived design — it uses solid rocket boosters whose dimensions and technology are based on those currently strapped to either side of the shuttle's giant liquid fuel tank. And the shuttle's 30-year-old specifications, design drawings and software are rooted in pounds and feet rather than newtons and meters. ... NASA recently calculated that converting the relevant drawings, software and documentation to the 'International System' of units (SI) would cost a total of $370 million — almost half the cost of a 2009 shuttle launch, which costs a total of $759 million. 'We found the cost of converting to SI would exceed what we can afford,' says [NASA spokesman Grey Hautaluoma]."
How many cwts of Mars Orbiters must be lost before we learn?!
My work here is dung.
You know, a lot of Europeans probably think that U.S. reluctance to embrace the metric system is just another example of our arrogance. But a lot of Americans (like me) are genuinely interested in adopting this system. We even passed a law in 1975 trying to mandate it.
The real problem is that it is surprisingly hard to embrace a new system of measurement when you've spent your entire life thinking in different terms. Try as I might, I still can't picture a kilometer without converting it to a mile first, and still can't picture a centimeter without converting it to inches. The meter is a lot easier because it's pretty analogous to the yard. I think maybe your brain gets locked into a certain measurement pattern pretty early in life and it's very difficult to get out of it, even though many of us would happily embrace it. I'm still trying to think more in metric, but it requires a surprising amount mental effort to do so.
It's not that Americans are really all that arrogant or stubborn about the imperial system. We've actually been trying to embrace the metric system for some time.
SJW: Someone who has run out of real oppression, and has to fake it.
1 foot = 0.3048 meters
There you go, NASA. That one's for free.
It must be some astronomic and powerful calculator they need for those conversions. I'm assuming that it's so expensive because it can calculate the highest prime number and last digit of pi in under a second.
But that still doesn't account for the costs they're making up.
I'd buy them a pint.
The sticking point is that Ares is a shuttle-derived design â" it uses solid rocket boosters whose dimensions and technology are based on those currently strapped to either side of the shuttle's giant liquid fuel tank. And the shuttle's 30-year-old specifications, design drawings and software are rooted in pounds and feet rather than newtons and meters.
And in 20 years, that'll be the same excuse given for building Ares's replacement with imperial units.
Dewey, what part of this looks like authorities should be involved?
Rhapsody in Numbers
What the hell are they spending this money on? If they paid their engineers $150,000/year, they could hire almost 2500 engineers for a year-long project. It's not like they're building anything new or buying raw materials; they just need someone to re-draw plans with new measurements in a different system. The fitting/testing for the Ares should already be budgeted for so it shouldn't fit in with this cost. No wonder we're in debt...
-SaNo
Abe Simpson: The metric system is the tool of the devil! My car gets forty rods to the hogshead and that's the way I likes it.
I work for an engineering company, and unit conversions are not a trivial operation. All of our drawings are created in autocad, and after several years it becomes difficult if not impossible to find the original file. As such, converting achieved documents requires recreating the document entirely from scratch. We also use a fairly vigorous quality control system that requires 3 engineers to check every document change, verify the calculation, and repeat the calculation using a different method to ensure that no mistakes were made.
We recently acquired an older project where we needed to simply change the title block on each page, and this process took roughly 5000 hours. For something on the scale of the space shuttle, 370 million isn't unheard of.
"the shuttle's 30-year-old specifications, design drawings and software are rooted in pounds and feet rather than newtons and meters. ... NASA recently calculated that converting the relevant drawings, software and documentation to the "International System" of units (SI) would cost a total of $370 million" Nearly half a billion dollars to convert into SI units (I've added the required cost overruns)?! Wouldn't all the relevant drawings, software and documentation have to be converted into machine readable formats that are more appropiate for use with today's sofware and document management systems? Is the estimated cost for the SI conversion, or more likely as I suspect the cost of bringing the design information into more appropiate formats.
Research is what I doing when I don't know what I am doing - Werner von Braun
Maybe they should be re-thinking their plan to use 30-year-old technology on their flagship 21st Century project. Really: what does it say about the technical competence of NASA that they admit to being unable to use SI units, even though they would like to?
The old British Prime Minister Sir Winston Churchill once said: "You can depend on the Americans to do the right thing once all other options have been exhausted!"
No offense, Sir Winston, but after over a decade of living and working in the US, I have to change it to: "You can NOT depend on the Americans to do the right thing once all other options have been exhausted!"
Get on with the program and get rid of the antiquated foot, inches lbs and what not and move into the 21st century!
If you mod me down, I *will* introduce you to my sister!
Most systems engineers in the space industry know that it's difficult to completely use metric for space missions. There are usually many components and subsystems that are designed by different vendors that have their own paradigms set up. These paradigms are usually kept do a legacy of proven use, and engineers will agree with me that if a product works well on-orbit, why on earth would you want to change a product simply due to unit conversions. You simply take note of the units and move on. I never thought I'd have to deal with microinches, to be honest, but it's no big deal since everyone knows 1 uin = 0.0254 microns.
the issue isn't just one of redoing the drawings along with the various checks and cross checks to make certain the units were converted properly. I'm sure they could that, but the resulting set of new drawings would be extremely prone to encouraging mistakes. As a minor example. Let's assume that on one piece they currently have a dimension of 12 inches +/- 0.01 inches. So they convert this dimension to metric giving a new value of 30.48 cm +/- 0.025 cm. Excuse me?!?!? That's a rather odd and strange dimensional target to hand off to the machinest. And you'll be getting these rather strange dimensions for everything on the original design. Frankly using the metric measurements would make that rocket utterly hell to construct. So the "proper" solution would be to use the original design and then stretch/shrink various dimensions in order to make the dimensions "rounder" and easier to manufacture. But upon doing that, they have effectively come up with a new design that has to be recertified.
I prefer imperial units for lots of everyday tasks like cooking. Imperial units are much closer to a binary-based system, which is very convenient for human beings. Two cups in a pint. Two pints in a quart. An ounce of water weighs about an ounce. A pint of water weighs about a pound. Human beings are very good at halving or doubling things by eyeball, but we're lousy at dividing into tenths.
But if you're building a fucking spaceship, use SI units for Christ's sake.
Yes...stored in electronic form. That's right. Wait, remind me again, what file format did Autocad use in the 1960s? 1970s? 1980s? Was it DWG back then?
Plus we're not building another shuttle. We're going back to the days of Apollo, with a capsule^Wspacecraft on top of a rocket. Apparently, though, they found that they can utilize the SRB design for part of the new project. (The big white rockets that get reused after launches.) The SRBs date from the start of the Shuttle era which...erm, yeah. 1970s.
So here we have a rocket booster already designed that works like a champion. The blueprints are all done. They work. They're reusable. They've been fieldtested over 100 times.
And you want to redesign them essentially from scratch? As many coders here want to say to their bosses when upper eschelon wants to recode an application in the new flavor of the month language: if it is not broken, do not fix it.
after several years it becomes difficult if not impossible to find the original file...We also use a fairly vigorous quality control system
How do you keep quality on your products, but not even keep your original documentation files? What happens if there is a change?
our drawings are created in autocad... unit conversions are not a trivial operation
The engineering team where I work uses Solidworks, and there are macros to do the conversions. Of course, those macros only work on the original files, not the printed documents... :-) So that brings us back to having lost the files...
Not sure if you are joking or not, but 1 foot is exactly .3048 meters, because 1inch is exactly 2.54 centimeters.
$370 million to do undergrad-level (at most) grunt work? Isn't that what unpaid interns are for?
I'll do the job for only $170 Million, and I'll get it done on time and within budget, something that NASA is not used to.
For an extra $30 Million, I'll even make sure it's accurate!
Never underestimate the potential of Human stupidity. -Heinlein
The only units I would like to stick with in the U.S. are all automotive-Horsepower, Torque (foot pounds), PSI, Quarter Mile and 0-60mph. Yes 0-100kmph=0-62mph, but that's still not accurate. Some cars are designed to redline in second gear at 60mph so they only need one shift to do 0-60mph, while they may need to hit third for 100kmph. Otherwise, metric is fine for distances, weights, volume, etc. It makes doing technical business with international companies difficult, and although the U.S. doesn't want to change I believe it would be a good use of the stimulus money.
There's a VERY good reason to re-use the SRB's, they are a well tested design with the flaws worked out and the real operating parameters known. There is an existing assembly and refueling pipeline (figurative) with skilled workers who know exactly how to produce the parts. They are also reusing the main fuel tank (stretched in some configurations I believe) and the SME's which are a feat of engineering (especially now that we have the Russian designed turbopumps). Redesigning all of those components from scratch would cost probably hundreds of billions and probably another billion or two in lost test vehicles.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
We're just talking about units of measure. If it is easier to use imperial units because previous design and drawings were done in imperial, then that's the smart choice. I would be upset if NASA was wasting taxpayer money just so that the design could be done in metric. I actually applaud NASA for making a smart, cost/benefit engineering decision.
The only real valid arguments I've ever heard for using metric are that (a) it's easy to learn the conversions, and (b) everyone else uses it for all science and egineering.
(b) is the reason that NASA should just use metric... And anyone else in the world doing any kind of science or engineering.
But for everyday life, imperial or American units turn out to have a lot of utility that most people aren't aware of, because most of us of the younger generation have just relied on calculators doing decimal calculations for us most of the time. If instead you picture fractions in your head, imerial or American units are quite handy. They also often match real world objects a bit closer. If you're dividing meters into centimeters, you can really only talk about tenths, hundreds, etc. If you're dividing yards into feet and inches, or pounds into ounces, etc. you have thirds, 16ths, 12ths, and all kinds of other useful fractions to use to think about the divisions. Find a carpenter who is good at this to see what I mean. Same with volume and weight; if you do a lot of cooking and modifying quantities in recipes you can get good at those conversions.
The fact of what it's based off of is irrelevant, everything comes down to the metric system being consistent in staying in base 10, and the imperial system is not.
Next time you should replace 4999 of those hours with a simple BASH script.
The original files were not available. What shell do you use that compiles to paper?
Write your representatives! Repeal the 2nd Law of Thermodynamics!
both SI and Imperial units are pegged to arbitrary things. In the case of Imperial units it was some king's foot. In the case of SI it is the distance light travels in some amount of time. whatever.
That's beside the pont. Yes the SI units are pegged to arbitrary things but they are not arbitrarily pegged to *eachother*.
Converting from centimeters to kilometers requires dividing by 100,000. I can do that in my head.
Converting from miles to inches requires dividing by 63,360. I can't do that in my head.
You don't seem to understand, even a little. These numbers are on a piece of paper that no longer exists on a computer. Not even the most advanced computer script in the world can adjust paper. So okay, I understand part of your point, put it into the computer first, and then run the script. These documents are crawling with numbers. Line numbers, electrical classifications, instrument identifiers. Even if I had a script to manage the process, you then have the problem of units. I'm not doing 5000 ft to meter conversions. We have lengths (using both ft, in, ',and "), weights, volumes, temperatures, powers (hp, MMBtu/hr, kW, MW) and so forth. Even if you could have a script smart enough to check for units, how would it tell the difference between a temperature and a temperature change? If I have a heat exchanger with a temperature change of 50ÂF, the correct metric temperature change is 27.8ÂC. If you got 10ÂC, you used the wrong method. The sheer amount of back checking I would have to do to make sure a rogue script didn't destroy my drawings would be insane.
This is not a simple database you're playing with.
Exactly. And that's a flaw that's been fixed.
How many flaws will be introduced if they have to be redesigned from scratch?
The problem with imperial is not what it is based upon (actually, these days the US units are all defined by reference to the SI units anyway - since 1959 an inch is defined as 2.54 cm - see http://en.wikipedia.org/wiki/Inch ) the problem with the imperial system is the arbitrariness and inconsistency of the relationships between the units. The SI system has a consistent relationship between all of the units, and a consistent naming system and a consistent abbreviation system. In the imperial system, the relationships between units are not only arbitrary, but they are also inconsistent, there are multiple uses of the same word (ounces for example) used to describe different measurements (weight as well as volume) or dry vs liquid volumes.
Except unit conversions are not the norm. When a grocery store manager orders potatoes, it doesn't really matter if he orders 200 10 pound bags (which is really tough to convert to 2,000 pounds) or if he orders 200 5 kilogram bags (which is really tough to convert to 1,000 kilograms).
Sure, sometimes someone has to get a calculator to figure out how many inches are in 200 feet (but hopefully not most people) before they figure out how many 1.65 inch pieces they can cut that 200 feet into, but the other guy is going to need a calculator (or some scratch paper, whatever) to figure out how many 4.191 cm pieces they can get from 60 meters anyway.
Nerd rage is the funniest rage.
Yes the SI units are pegged to arbitrary things but they are not arbitrarily pegged to *eachother*.
Actually "imperial" units are pegged to SI units. Since July 1, 1959, the the inch, foot, yard, and mile have been defined on the basis of 1 yard = 0.9144 meters. The pound is defined as exactly 453.59237 grams.
When our name is on the back of your car, we're behind you all the way!
And a liter of water weight exactly a kg. There are exactly 1,000 meters in a kilometer. And there's exactly a year in a light year.
Wait ... one of those is wrong.
Damn right.
Consistently and accurately labeling numbers with their units is a lot more important than making sure that it is easy to convert between units and occasionally be able to quickly do math.
SI is certainly easier to work with, but the constant implication that this makes it hard to work in Imperial units is ridiculous. If someone has trouble with inches and feet, I'm not going to pay them to do any work on my rocket.
Nerd rage is the funniest rage.
There's a VERY good reason to re-use the SRB's, they are a well tested design with the flaws worked out and the real operating parameters known.
We would be remiss if we did not note that the engineering kinks of the SRBs have been ironed out, by that they killed seven people in the process.
Don't blame me, I voted for Baltar.
It never ceases to amaze me the resistance to going to metric here in the states for measurements but no one bats an eyelash at the fact our money is basically metric (base 10).
It is in fact soo damn easy that we can instinctively give somone a $5 and a penny for something that costs $4.01 so we can get back a dollar rather then 3 quarters 2 dimes and 4 pennies....
Boo metric it's too damn easy to use! Forget cutting a board 1.46 meters in half. it's too damn hard to cut it .73 meters! Better yet that 3 5/8th inch board needs to be cut in half so we need umm... err... need some scratch paper here....
-=[ Who Is John Galt? ]=-
Yeah, that's very helpful.
Patents Drive Free Software as Hurricanes Drive Construction Industry
I know exactly what you are talking about. We had 2000 logic diagrams to change once, and we used a script to do it in AutoCAD. Took the farm 3 hours to do, but it took us 4 weeks to check over. It's even worse when the drawings didn't come from your department, or (god help us) an outside source. We got drawings from a sister company once that were not to scale, and the title blocks were scaled by hand to 'look' right. Half of them don't even use the same blocks either, so when you write the script it only works on half of them and you are left saying 'WTF?'. Then you add in a layer filter, for example, to help the script find the right block. Guess what? Some trade school graduate from drinkachusetts screwed up the layers on every individual drawing. So you add a filter for linetype. Turns out the linetypes are all different to, and in order to make each drawing look consistent they changed the linetype scale so the .5 linetypes look ok. ARGHH we should have just redrawn them.
Speaking of databases, have you ever designed in AutoCAD using Bently AutoPlant? It links the drawings to a database. We use it where I work to design for power plants. It sucks, but we have tried many other solutions over the years and it works the best. Trying to link Pro-E or Microstation or Solidworks to a database we can use to generate Process Flow Diagrams, Piping and Instrumentation Diagrams, and Logic Diagrams is nigh impossible. Sure they are perfect for modeling, but taking the model data and converting it to schematic line drawings is a technological boundary for sure. Oh well.
You scan the entire document in, OCR for text, and try to perform an automatic conversion. Then people go through where they see a graphic of the original scanned text and the OCR'd text. For each one the person selects it is correct, or adds the correction. I've known people that do this for a living, and this was cutting edge methodology 15 years ago. Now it is pretty standard.
The alternative method is to detect the text, but not OCR it. Force the user to enter the text themselves. In either case, you show the graphic to multiple users and check for consistent answers between them. The best part about this is that reading text can be done by minimum wage workers, and can be done extremely fast after a while.
The resulting electronic file has an image containing all lines from the original drawing, with text replacing scanned in text. This can be printed out and should look identical to the original, but with converted units.
(The conversion is not necessary to see along the OCR'd text as proper conversions are trivial to perform automatically. All you really need to see is that the original OCR occurred properly.)
Somehow the idea that U.S. units are called "Imperial" units has taken root. That term only applies to a system used in the British Empire/Commonwealth (hence the name) before they went metric. The U.S system is "English units" (because it's based on units that were widely used in England at the time of American independence) or "U.S. Customary Units." The two systems are very close (length and weight are the same) but not identical (volume units are quite different, even thought the names are the same).
In most other contexts, I'd just say, "OK, sloppy usage eventually becomes the standard, like 'broadband' instead of 'high-bitrate'. Been happening since language was invented, not going to change."
But in this case you have terms that are defined in standards. And miscommunication can cause much wackiness. For example, suppose I need 10 gallons of something. The nearest store is just across the border in Canada, and they're metric, so I use Google to convert units and come up with 45.5 liters. Nice and simple, right?
Wrong. I only needed a little less than 38 liters. The U.S. gallon is 20% smaller!
OK, this particular example is kind of artificial, because most people would just say "gallon" and Google assumes that "gallon" means "U.S. gallon". Still, you need to be careful with this stuff. Like, suppose you're putting fuel in an airplane!
Of course, all this extra confusion is yet another reason for the U.S. to go metric. I work for for a computer manufacturer that not only sells widely in metric countries, our actual production is outsourced to companies that are mostly in metric countries. Does this cause headaches? You bet!
because base 10 is always the best answer? as a nerd i'd expect you to want a base 2 or derivative (base 16) system.
"If still these truths be held to be
Self evident."
-Edna St. Vincent Millay
Next time you should replace 4999 of those hours with a simple BASH script.
The original files were not available. What shell do you use that compiles to paper?
lpr
So your owner there... he wants 200 10 pound bags, good... good...easy enough...
How many ounces is that? Tons?
It's a stupid system which is held onto simply because it's what we're used to. (and yes, it's easy to google the answer, but I could give you the kilogram converstions faster then you could type it)
Beware of he who would deny you access to information, for in his heart, he dreams himself your master.
To paraphrase from a post above you:
"How many 4.19cm pieces of wood can you cut from a length of wood that is 6m long?"
I'll bet you can't do THAT in your head either and it's just as valid of a math example as your own that involves miles to inches.
In the real world both systems can be a real PITA but it's not the fault of the system. It's the fault of the real world where numbers aren't some exact multiple of your base system.
France first adopted the Metric System in 1791 (according to Wikipedia). Let me repeat that... 1791.
The first public, commercial, industrial use of the Metric System in America was Coca-Cola; Coca-Cola bottles have always displayed their volume in metrics, and they have been around since 1886. Let me repeat that... 1886.
First shuttle flight was in 1977.
Now here's the surprise on my part. For as long as I have been alive, all science and math text always focused on the metric system. Aside from off-tasks in grade school of converting Celsius to Farhenheit(sp?) or inches to centimeter... gallons to liters... everything has always been in metrics. Growing up, the total icon of science and math has been primarily NASA. It is very hard to for me to conceive, that given the adoption of the metric system in acadamia and almost exclusive to intellectuals and professionals... that NASA has for so long, and so widespread throughout any of their projects, adopted anything other than the metric system. Had this article not been published, I would have refuted any claim that NASA didn't use the metric system. All I can say in 2009 is "wow".
humans find it much easier to divide into halves than into tenths [...] Give me a gallon of liquid and a set of unmarked jugs and I'll probably have pretty darn close to 1 fl. oz. long before you can cut 1 L down to 1 mL.
a) Wow. Ok. Is that a problem you encounter frequently? This seems a bit artificial. :)
b) Yeah, I'll grant you that dividing something physically in half is easier. But while YOU might be able to pull a fluid ounce from a gallon using unmarked jugs, lets be honest most people would still really struggle with that.
c) Next, people like you and I who could solve this problem are also smart enough to realize that they don't have to physically divide into 10ths, but halves and fifths. So to cut 1L down to 1mL they need to divide by 1000... or 2x2x2x5x5x5. Fifths is harder than halves but not THAT hard.
d) Further its bit of an unfair problem. The SI problem is a 1000th cut, your imperial problem is considerably less. Its only a 128th cut. A closer problem (both in difficulty, and in the actual amounts of liquid involved would be: 4L to 50mL, which 2x2x2x2x5.
e) Further you are cherry picking imperial units. Tablespoon to Teaspoon is 3rds. Feet to inches is 12ths (2x2x3). Yards to feet is 3rds. And from yards to feet is 1760ths... and 1760 factors to 2x2x2x2x2x5x11. Yeah there's an 11 in that one. How many people do you know who are facile at 11ths? I suppose we could dig through rods and chains etc but I'd have to look up what those actually are...
f) decimal is easier for any serious work, where you have paper and calculators and computers instead of sets of unmarked jugs and cherry picked problems.
Indeed!
1 gal = 4 qt = 8 pt = 16 c = 128 fl oz
:D
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
It's easy to pull up a keyboard and get on your high horse.
It's even easier when you're wrong.
SI units were established as an international standard in 1960. That's 139 years after Napoleon died, in case you don't feel like doing the math. Before that, they were just yet another system of units like all the other random systems.
The "fucking excuse" for building the shuttle using any other system is that they sourced parts from thousands of small machine shops throughout the country. Those shops were not tooled with metric equipment.
The Space Shuttle was a new machine, but it was built by old machines. (Plus, it wasn't really a completely new machine. It contained plenty of stock parts from previous aerospace projects)
The Imperial System of measurements is not the same as the customary measurements used in the United States. The legal arbiter of measurements in the United States is the National Institute of Standards and Technology. Apendixes B [PDF] and C [PDF] to their Handbook 44 provide a good overview of the structure of the respective standards and their relationship to SI (the science based International System, which was based on the Metric System).
The word system seems misleading when applied to US customary measures. For example:
Does this make a difference? From one viewpoint, no, when do you ever need to keep something accurate within 2 mm over a mile? From another, yes, repeated iterations of computations based on incorrect conversions can produce just plain gibberish. Another bit of measurement chaos to keep in mind:
We also must remember that NASA has proven itself incapable of managing the different systems of measurement before. Ten years ago NASA crashed a Mars bound probe because of botched conversions from customary to SI units. You would think that having paid $125 million for that lesson, they would want to avoid a recurrence. But, I suppose that they are from the government and they do not have to care.
In the land of the blind, the one-eyed man is king.
Yes, it's an artificial example, but you're more likely to divide things in halves (or even thirds) than into fifths simply because it's easier. If I had to do fifths, I'd probably start with sixths (1/3 * 1/2) and estimate 1/5 to be slightly bigger.
My point was not that any dummy off the street could get 1 fl oz from 1 gal. My point was that any dummy off the street could successfully divide the liquid in half repeatedly if that's what you told him to do.
I'd forgotten just how darn tiny 1 mL is. Give me 10 mL and call it fair enough.
Again, even thirds is a lot easier than fifths. Imagine cutting a cake: cut almost in the middle, but not; cut halves from the small side, and thirds from the larger one. The halves and thirds are going to be easy, but good luck getting the first cut right. Luckily nobody will care, since somebody probably wanted the bigger piece anyway.
1760 is the conversion from yards to miles. I can't say I've ever had to do that, so it really doesn't concern me. Yards actually aren't used that much, and distances long enough to be expressed in miles aren't usually thought of in feet, much less yards.
Decimal is easier? On paper, maybe. On a computer, absolutely not. Binary can't express decimals very well anyway. I see no reason that a base 10 system would be better, on a computer, than a base 12 system.
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
ummm,
I live in Rural Idaho, Cow tipping is a lot like snipe hunting.
We would take gullible kids out to a farm in the middle of the night. They would try to sneak up on a cow and tip it. It would either move or not tip, and then move. We would convince them that their shoes were making too much noise.
After they gave up their shoes, we would hop in the car and leave them in the middle of a pasture, barefoot, in the middle of the night, miles from home.
That is what cow tipping is really about.
Seeing the discussion here, I wonder why nobody has brought this up yet:
http://xkcd.com/526/
I grew up in rural Canada, and can assure you that you can, indeed, tip a cow. Certain breeds are more difficult to sneak up on and others wake up before they hit ground, but it is certainly not difficult once someone has shown you how. If you really are from a farm and have never done it or even seen it done, I suggest you visit us up north and we'll take you out one night and show you the finer points.