NASA's Juno, Armored Tank Heading For Jupiter 185
coondoggie writes "When it comes to ensuring that its upcoming Juno spacecraft can survive its mission, NASA is surrounding the spacecraft's electronic innards with titanium to ward off mission-threatening radiation. Juno's so-called radiation vault weighs about 200 kilograms (500 pounds), has walls that measure about a square meter (nearly 9 square feet) in area, about 1 centimeter (a third of an inch) in thickness, and 18 kilograms (40 pounds) in mass. About the size of an SUV's trunk — encloses Juno's command and data handling box, power and data distribution unit and about 20 other electronic assemblies, according to NASA."
Let the fat jokes commence (Score:4, Funny)
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Your satellite's so fat, they had to launch the earth off of it.
shiny (Score:2, Funny)
But if you hold it the wrong way it blocks the antenna
Couldn't get past the headline... (Score:2, Funny)
it is just screaming for a pewpewpew tag!
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Made me lol, but my carrier is already slow...
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I didn't say I have plates, was just commenting that armor tanking makes you slow. I have 3x Amarr Navy EANM 2x Repper and a CPR on my Archon if I remember correctly.
1.8 g/cm^3? What material is that? (Score:2)
Per the measurements given (18kg/(1m^2 * 1cm)) the vault's density is 1.8 grams per cubic centimeter. This is much less dense than aluminum (or steel or lead obviously) - anyone know what the vault is made from?
-Isaac
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Per the measurements given (18kg/(1m^2 * 1cm)) the vault's density is 1.8 grams per cubic centimeter. This is much less dense than aluminum (or steel or lead obviously) - anyone know what the vault is made from?
The density of extra glossy thick marketing material is about one and a half g/cc, I kid you not. (I'm talking about "junk mail" type paper thats almost but not quite cardboard slathered with glossy ink).
Obviously the device is made out of printed out power point presentations. I've heard NASA is pretty good at making power point presentations, if nothing else...
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Presumably it also has more than one wall.
The summary is horribly written, but it does mention that the vault masses 200 kg (is that including contents?) then later that one wall (?) is 18 kg, which doesn't add up either.
Supposing the 200 kg is correct and we're talking about a cube, then each 1 m^2 wall masses 200 / 6 = 33 1/3 kg, or 3.33 g/cm^3. That's close enough to the density of titanium that I suspect the 200 kg figure is correct and the box just isn't a cube.
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Hopefully it'll bring back some great science and help us better understand Jupiter and our solar system.
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It's made from the journalist's incompetence.
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...anyone know what the vault is made from?
Metal.
Read the summary to find out which metal...it's in there.
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Titanium is over twice as dense - about 4.5g/cm^3 - so either the material spec is wrong or the dimensions are wrong.
Probably the latter, I guess.
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No, it's... in space! With no gravity, so it weighs less! Yeah!
That, and they were probably holding the tape measure wrong.
Is there an engineer or scientist in the house? (Score:5, Insightful)
"about 200 kilograms (500 pounds), has walls that measure about a square meter (nearly 9 square feet) in area, about 1 centimeter (a third of an inch) in thickness, and 18 kilograms (40 pounds) in mass. About the size of an SUV's trunk "
I notice a few issues in this description, which also appears in the article. Some fact-checking might be in order.
How can a single thing be 200 kg, and also be 18 kg? You would think that a single thing would have only one mass.
Then, of course, a square meter is slightly more than 10 square feet.
How can a single square meter of material be made into all six sides of a box the size of a SUV trunk, without slicing it into thinner sheets. A square meter might make one side of such a box, but not all six. If all six sides of a cube total 1 square meter, each side would be about 40.8 cm square. Of course, the box doesn't have to be a cube, but the sum of the areas of the six sides still cannot exceed the total of the material.
Titanium has density of 4.5 g/cm^3. So a 100x100x1 cm piece of it would be 45 kg, not 18 kg.
Re:Is there an engineer or scientist in the house? (Score:4, Informative)
Maybe they are estimating badly. Encasing a command module in square plates of titanium, however, would require 6 of those plates (envision a six-sided die). 6*18kg = 108kg. Using your math, 6*45kg = 270kg. The summary estimates 200kg which falls somewhere in between the two back of the envelope calculations.
So my guess is that 200kg refers to the total enclosure that's being created from 6 different components that are estimated in the summary to each weigh 18kg.
It'd be nice if people who submit articles "measured twice and cut once" for the maths they include in their submissions, since this is that place where discussion of the incorrect math will dominate an otherwise interesting conversation about Jupiter exploration.
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Also the comments about Juniper having moons. I would like to think that it was a typo, but it is too conveniently a Google keyword that would raise the page rank.
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I suspect you are essentially correct about the mass of the assembly, as compared to the mass of one side or component. I also thought that, perhaps, the sides might not all be of equal shape, size, or thickness. The shape may have more or fewer than six faces, or even some curves. Even if it is a polygon, it still doesn't have to be regular. Also, if one side will be toward the sun most of the time, that side might be thicker than the others. Similarly, if another side is to be oriented away from the
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well, that whole article smacks with errors.
funny enough, he is apparently editing and updating the article live. That and censoring most of the comments that are critical of the writing and suggesting corrections.
Victory Unintentional (Score:2)
Asimov's ZZ-1, ZZ-2, and ZZ-3 now have a companion! Can we call it ZZ-4?
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I say we call it ZZ Top. :-P
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Damn. beat me to it while I was typing.
Now I'm going to get Redundant mods that's hurt my karma.
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Let's call it ZZ-Top.
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Internet undo button (Score:2)
Something new? (Score:2)
Ordinarily, we don't hear about shielding, certainly not about a titanium tank to shield those electrtonics. Crap, they should have welded some A-10 cockpit tubs together...
Is this because NASA is using some COTS electronics on this mission? In the 'old days', we saw hardened electronics being used. Or is it a unique mission requirement, beyond what the old probes did?
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From TFA ..
It's going to see hella radiation, so it needs some pretty beefy shielding. They're also using hardened components developed for Mars missions.
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Unique as compared to Pioneer, Voyager, or the Mars Rovers?
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The radiation around Jupiter comes from various sources, but is essentially due to charged particles trapped in Jupiter's magnetosphere. Some do come from the solar winds, and others from Jupiter itself.
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FTFA
"For the 15 months Juno orbits Jupiter, the spacecraft will have to withstand the equivalent of more than 100 million dental X-rays," said Bill McAlpine, Juno's radiation control manager, based at NASA's Jet Propulsion Laboratory in Pasadena, Calif., in a release.
According to NASA Jupiter has sizzling radiation belts surrounding its equatorial region and extend out past one of its moons, Europa, about 650,000 kilometers (400,000 miles) out from the top of Jupiter's clouds. Juniper has 63 moons.
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So it's not the transit, it's the orbiting.
Jupiter sounds like fun.
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Most likely a unique requirement as the article goes in to mention that Jupiter has stronger radiation fields then Mars, a planet supposably known for strong radiation.
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The main component to shield against in the Jovian environment are high energy electrons. It turns out that shields made out of higher charge elements are better at shielding electrons per mass. Aluminum is the defacto spacecraft material. You want something higher on the periodic chart than Al (for the best shielding to mass ratio), so they chose Titanium due to
NASA Juno site (Score:2)
The mission site is here: http://www.nasa.gov/mission_pages/juno/spacecraft/index.html [nasa.gov] Includes pictures and better information, including Monday's press release, (which happens to be the source of the ft^3 m^3 units in the linked article): http://www.nasa.gov/mission_pages/juno/news/juno20100712.html [nasa.gov]
Shielding is titanium, as lead wouldn't survive liftoff "too soft to withstand the vibrations of launch" and other materials were "were too difficult to work with".
Cables between electronics are shielded in c
This is America! (Score:3, Funny)
What, expecting a metric system rant?
Too dangerous (Score:2)
Summary bad, but not as bad as you might think (Score:5, Interesting)
The article links to some kind of 'ooh, look at me' article instead of NASA's own page on Juno.
Juno Armored Up to Go to Jupiter [nasa.gov]
Not exactly good maths there, so probably a PR piece from a 'journalist'.
9 foot^2 = 0.84 m^2 [google.com]. Could be correct, though I wouldn't use "nearly" for something that far off. And it's impossible to tell if the walls are really 9 foot^2 and they just made a very rough guestimate of the metric equivalent.
1/3 inch = 0.85 cm [google.com]
Again, that could be right. It might be exactly 1/3rd inch and they guestimated that to about 1 cm. But it's still 15% off.
40 lbs = 18.14 kg [google.com]
And then you hit something where the weight is actually correct. But since they've messed up that much on the other two, we now don't know if it's exactly 40 lbs or exactly 18 kg.
Hell, we don't even know if the NASA guys who wrote this are incompetent or not. Well, we know they're incompetent, we even know how much (about 15%).
However, the NASA page seemingly being written by an 8-year-old with a bad understanding of units, doesn't really justify linking to an article that is essentially a copy of NASA's page, and especially not when there is no attribution or links to the original article.
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Or it was information given by a scientist who was keeping things to one significant digit [wikipedia.org] because anything else really is just wasted text in a such an article especially when none of the measurements come out
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Those are all low-accuracy numbers. Note that 0.8 m^2 could be described as "nearly a square meter" and "nearly 9 square feet". Equally, a third of an inch is "about 1 cm".
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Aha! (Score:2)
I get it. The linked-to blog post (what is supposed to be TFA) is being supplied as an example of how to break every rule of English grammar, right? Likewise, the summary is an example of how to make a Slashdot summary by copying and pasting the first paragraph of TF"A".
Senate vote on NASA bill tomorrow;Bill Nye on NASA (Score:3, Informative)
On a related note, there's a bill in the Senate which will be voted on tomorrow (Thursday) morning which threatens to reduce the proposed funding for robotic missions (like the one described in the summary), commercial crew, and space technology in favor of building a government-designed heavy-lift rocket instead. The Planetary Society has an update describing the situation and is urging people who care about space exploration to call their Senators immediately:
http://www.planetary.org/blog/article/00002584/ [planetary.org]
More background info on the bill: http://www.spacepolitics.com/2010/07/14/a-quick-review-of-the-senate-nasa-authorization-bill/ [spacepolitics.com]
For the curious, Bill Nye the Science Guy (the new director of the Planetary Society) and Louis Friedman are hosting a webcast/discussion at 5pm ET today about the future direction of NASA:
http://planetary.org/about/press/releases/2010/0712_Where_Should_We_Go_in_Space_Tell_Bill.html [planetary.org]
A modest suggestoin (Score:2)
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4 Square meters is not a square with 4m sides but with 2m sides so the parent is correct and you buddy are wrong
Re:Unit conversions (Score:5, Funny)
So one square meter isn't a square with 1 meter sides?
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I understand the math. I was being sarcastic, actually. yeah, I know it doesn't communicate well over the internet. The point is that 1 square meter is considerbly more than 9 square feet. The actual article is poorly written. If the topic weren't so terribly interesting, I wouldn't have wasted my time. However, I would have linked directly to NASA's page instead of the hack that wrote the article.
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I think the writer was trying to convey a square yard, which is about the same as a square meter.
Maybe.
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See, you take the square root of your area to determine your side length.
Maybe you do, but I just use a tape measure. ;-)
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Nobody told us there was going to be math.
Is it too late for me to drop this class and take Poly Sci instead?
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So one square meter isn't a square with 1 meter sides?
It is, but two square meters is not a square with 2 meter sides. :)
He he... I'm suddenly reminded of having to teach my wife how fractions actually work. (They are just unresolved division solutions with useful properties...)
There are times in life when I wish I could just forget math and be a Joe Sixpack. Am I the only one who has to resist the temptation to teach cashiers how to optimize change giving to involve the least number of coins?
Re:Unit conversions (Score:5, Funny)
Close enough for government work.
aka
"Mars Polar Lander"
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It was a long, long time ago, but if I recall correctly Mars Polar Lander was a "Class C" project (meaning that QA requirements weren't very strict, and it didn't have to pass the much more stringent requirements like dual-fault tolerance, etc., that are enforced for class A and class B projects). The breadboard for the meteorology subsystem was a one hundred dollar 8031 CPU board purchased off the Internet from some company whose name I forget. The project couldn't even afford an In Circuit Emulator for th
Re:Unit conversions (Score:5, Informative)
One square meter is about 10.8 square feet. They got everything right except for the "nearly" part (it should be "over"). Squaring the unit does square the number.
NASA Misspoke (Score:2)
Just don't confuse metric with english units lest you miss Mars by a few 100,000 units of whatever
(oh, that's already been done: ref http://www.jamesoberg.com/mars/loss.html [jamesoberg.com] )
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Let's drop meter to feet conversions and go with 1 square yard to square feet.
There are 3 feet in a yard.
1 yard^2 * (3 feet/yard) * (3 feet/yard) = 9 feet^2
9 square units means you can fit nine 1 square units in the space (dependent on geometry you might have to modify the actual shapes of those pieces as a square unit doesn't necesary have equal length sides, or sides at all).
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10.8 feet square is the same as a square with sides measuring 10.8 feet.
10.8 square feet is an area that can hold the equivalent of 10.8 squares whose sides are 1 foot.
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And carrying through on the math: 10.8 feet square would be 116.64 square feet. A square of 10.8 square feet would be about 3.29 feet square.
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I learned many years ago that converting units for the metrically challenged does them no service. They need to learn to convert them themselves, so they can speak to the rest of the world in units we all understand.
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It's not a big deal like you all make it out to be. Conversion between number systems is rudimentary math.
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The math itself is easy but the exact conversion factors between Imperial units, Customary units and SI units isn't common knowledge.
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What the heck are you talking about? A square foot, say, is a measure of area. Scale the linear dimensions and the value of the area goes up by the square of the linear dimensions. A square foot = 144 square inches. Same thing with european units, presumably.
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Re:Unit conversions (Score:5, Informative)
In English, the unit m^2 is written (and said) "square meter(s)" and the unit ft^2 is written "square foot [feet]".
So, one square meter is 1 m^2, which is an area 1 m x 1 m = 3.28 ft x 3.28 ft = 10.8 ft^2, which is 10.8 square feet.
There's an acceptable, albeit annoying, construction in English (or at least American English) that's completely different: "3 feet square" refers to an area 3 ft. x 3 ft., which is 9 ft^2.
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[in American English] "3 feet square" refers to an area 3 ft. x 3 ft
I'm no expert in your language on that side of the big wet thing, but in Finglish the phrase would be "3 foot square", modulo hyphens. Which just further proves your point about the construction being annoying, I guess :-)
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That's also very common here.
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Your unit conversion is incorrect. 1 ft = 0.3048 m (exact).
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Yes. Because 3 feet are in a yard. And as a tool we can get these things called Yard Sticks and then we can usually easily envision 3 of those back to back to grasp the general size.
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I don't know what you mean by "take off the square from the unit" but I can assure you we're doing it the same way it's done in metric, and there's only one right way. Just as one square meter is 10,000 square centimeters rather than 100, one square meter is ~10.8 square feet rather than ~3.3
Maybe it'll help to draw it on graph paper.
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It later uses kg as mass and reads that the sides had a mass of 18kg each. Which at 1cm thick would make them about 4 square feet each side and if they add up to 200kg then presumably the whole thing has 11 sides.
I really think the whole article should be done over in more commonly used units such as slugs or parsecs.
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No, each square foot is a 1'x1' area, which is the standard unit of measure. There would be nine in a 1 meter tile.
Three foot square would describe an square area measuring 3 feet on a side, but people don't like the math. Wherever possible, the "^2" is removed so people don't need to do the calculation. So, the "9 square feet" is how it's usually described -- already multiplied. The single square foot is the base unit of measure when doin
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that number isnt nearly as far off as the conversions from kilograms to pounds. 200 kilos = 500 pounds, but 18 kilos = 40 pounds??? There is a very liberal use of significant digits and rounding going on here. Or maybe its that one of these units was called mass, but the other weight.
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Its 8.something square feet which converts to about 1 +/- 1 square meter.
The odd part is, in this day and age, I can't find anything but two or three pics and some super-fluffy PR trash. I searched google for awhile looking for info, couldn't find any.
Fifteen years ago, when I was on the internet, I was pleased to see I could download multi-hundred page "press kits" for shuttle launches, full of all kinds of detail, diagrams, writeups of each experiment and team, measurements, diagrams and blueprints. I w
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Sigh, I agree...
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When something becomes "popular" it has to attempt to reach the "people"
Joe six pack and his daughter Buffy need stuff for the common salt-of-the-earth types... you know, morons.
What saddens me is that with all these gee-whiz computers and trillion of sites, we can't have simplistic Joe six pack summaries with Jimmy Neutron details for those who wish to click a bit further.
Meh. Guess I should just shut up and chew my paste.
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Uh - Juno is scheduled to be launched in in 2011. August of 2011. More than a year from now.
How far in advance would you like all your press kits prepared? Should we have blueprints publicly available before we've even designed the device? Admittedly, Juno is quite a bit past the design stage right now -- but that exactly means that right now folks are busy building the thing, not making web-pages. That's stuff that we can think about when we've gotten the hardware under control.
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Presumably unless they're making it up as they go along, they could release all the blueprints right now. It's not like they have to keep it secret to prevent copies from the far east. Or do they?
As for preparing press kits now, well, "the press" aka /. is reporting on it now, so give us our kits.
And release early, and release often, seems to work in certain other intellectual pursuits.
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If they release blueprints and specifications some bright individual will notice there is radiation shielding on the probe. The light goes on and they realize there migth be radiation associated with this probe, perhaps in a more stealthy way than was done with the disaster that was the Cassini probe launch.
Therefore, any public release of this information would likely lead to the launch being cancelled or delayed.
Why do you think they aren't releasing more detailed information about it yet?
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Oh yeah, try this...
weighs about 200 kilograms (500 pounds) ... and 18 kilograms (40 pounds) in mass.
So does the vault weigh 40 or 500 lbs?
I hope the article is correct and it's just the summary or we're gonna have a problem getting Juno where it needs to go!
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The summary is BS because it is a direct quote of the article that is also BS which has no bearing whatsoever on the quality of the work done at NASA.
Just because some retarded journalist at networkworld doesn't know his ass from a hole in the ground doesn't mean that people or institutions he's writing about are somehow to blame for his incompetence.
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3.2 square feet is wrong in the same sense that a square kilometer doesn't contain one thousand square meters, but a million of them.
But a meter is indeed more than three feet, so it should be "over nine square feet" instead of "nearly".
Errors like this are the price they pay for non-metric units, I guess.
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Americans say everything with at least two units of measure and fractions.
So 1 square metre is 10 sqare feet, 110 and 3/1024th square inches... give or take.
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A square meter is the area of a square with 1 meter long sides. A square foot is the area of a square with 1 foot long sides.
9 square feet, would be the area of 9 squares with 1 foot long sides. Which if it was a square would be 3x3 feet.
It isn't nearly 9 square feet, it's over 10 square feet - though they are probably converting the "about a square meter" part not the "square meter" part.
Re:Unit conversions (Score:5, Funny)
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Not as much as non-Americans need English explained, apparently.
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We don't need conversions explained, its just the pedants jerking it to an imperfect approximation in a public-facing article. Starting in elementary school, you are taught both imperial and metric in the US, and 99% of rulers have two sides with both systems. However, most non-scientific things are still displayed in imperial and their sizes fit imperial units (construction materials, household items, baking). Ounces, cups, gallons, 1/4'', feet, yard, etc, are all seen daily by even the starving artist
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However, most non-scientific things are still displayed in imperial and their sizes fit imperial units (construction materials, household items, baking). Ounces, cups, gallons, 1/4'', feet, yard, etc, are all seen daily by even the starving artist who failed algebra 1.
I think you need to go look at a can of stewed tomatoes or a box of cake mix or a bottle of Coca Cola.
100% of all commercial goods sold in the US have both metric and "US customary system" measurements. No, it's not "Imperial". US fluid measurements are not the same as English/Imperial fluid measurements that use the same names, e.g. gallon, quart, pint.
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Wow, the British are the weird ones, here! Lets do some exercises:
Exercise 1: What is the area of a triangle with a base of 3m and height of 5m?
Mathematically: (3 * 5) / 2 = 7.5
American: That's 7.5 meters squared
Let me fix this for you:
That's 7.5 square meters.
British: That's sqrt(7.5) square meters?????
WTF? No, they'd say the same thing we'd say.
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He was selling IBM laptops [youtube.com] a while ago.
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Dammit, you beat me to it.
Well played sir, well played.
DG
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So apparently there are 9 planets after all! MVEMJJSUN