|
Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today. |
28th December 2017, 05:58 AM | #1 |
Graduate Poster
Join Date: Oct 2006
Posts: 1,353
|
Metric Vs imperial
Inanother topic - huffpost area man uses basic math to work something out
Someone has brought up usage of imperial units in the US, it is strange that in the UK we use miles for distance and stones/pounds for people's weight and feet/inches for people's height (and there are other examples) but at school, university and work I've only ever worked with metric and have no idea how to calculate or convert imperial units. For example, occasionally at work I have to calculate the weights of blocks given the dimensions in mm and the density in kg/m³ and to me that's done very easily, how easily can that be done by someone used to imperial units given dimensions in feet/inches/fractions of inch and density in pounds/foot³? |
__________________
The secret NASA doesn't want you to know - God makes rockets work in space. |
|
28th December 2017, 06:08 AM | #2 |
Seeking Honesty and Sanity
Join Date: Oct 2001
Location: Charleston, WV
Posts: 14,588
|
The process is a bit tedious, but it can be done with accuracy.
What I do is convert the feet, inches and fractions of an inch into decimal feet, then plug-and-chug. Once upon a time, I used a spread-sheet to make the conversions that way I could explicitly see each step. |
__________________
A man's best friend is his dogma. |
|
28th December 2017, 06:17 AM | #3 |
Graduate Poster
Join Date: Oct 2006
Posts: 1,353
|
Thanks, I didn't doubt it could be done with accuracy, one thought I had was to convert everything into fractions but again, tedious, and wondered if there were particular methods to working with imperial units for calculating things like volumes.
|
__________________
The secret NASA doesn't want you to know - God makes rockets work in space. |
|
28th December 2017, 06:43 AM | #4 |
Seeking Honesty and Sanity
Join Date: Oct 2001
Location: Charleston, WV
Posts: 14,588
|
The way I do such things is:
Measurement Value > Feet - Inches - Inch Fractions To convert the above value to Decimal Feet use: Decimal Feet Measurement = (Feet) + (Inches)/12 + (Inch Fractions)/12 For example: Measurement Value = 12 feet, 5 3/16 inches Then, ... Decimal Feet Measurement = (12) + (5)/12 + (3/16)/12 Decimal Feet Measurement = (12.000) + (0.417) + (0.016) Decimal Feet = 12.432 I hope this helps. |
__________________
A man's best friend is his dogma. |
|
28th December 2017, 06:56 AM | #5 |
Graduate Poster
Join Date: Oct 2006
Posts: 1,353
|
Thanks again, is that a common method and is it common historically?
And are there measuring instruments (rulers tapes micrometers etc) that measure decimal feet? |
__________________
The secret NASA doesn't want you to know - God makes rockets work in space. |
|
28th December 2017, 07:07 AM | #6 |
Penultimate Amazing
Join Date: Apr 2003
Location: 16 miles from 7 lakes
Posts: 11,098
|
Yes. We used them all the time in the oil drilling game.
They are available. But why bother? Everybody has a calculator on them if they have a cell phone. (A hint for conversions; do the calculations in whatever units you are given, THEN convert to whatever you need. Helps prevent inaccuracies from cerrping in) |
__________________
"Political correctness is a doctrine,...,which holds forth the proposition that it is entirely possible to pick up a turd by the clean end." "I pointed out that his argument was wrong in every particular, but he rightfully took me to task for attacking only the weak points." Myriad http://forums.randi.org/showthread.php?postid=6853275#post6853275 |
|
28th December 2017, 07:09 AM | #7 |
Seeking Honesty and Sanity
Join Date: Oct 2001
Location: Charleston, WV
Posts: 14,588
|
|
__________________
A man's best friend is his dogma. |
|
28th December 2017, 07:13 AM | #8 |
Alta Viro
Join Date: Jan 2005
Posts: 2,307
|
As an engineer in the US, we have to work with both Imperial and SI units. We have several suppliers in the US that will use Imperial units for fabrication drawings, and then our customers are mostly international and require interface dimensions in SI. Certainly, the metric system is much easier to use and requires less rote memorization for conversion. Crossbow's method above is correct and how I deal with the units.
There are 12 inches in a foot, three feet in a yard, 5280 feet in a mile. It's not the most useful system. Then you get into pound force and pound mass, the use of slugs (which most Americans are not even aware of). I wish the US would have followed through with the conversion to metric in the '70s. |
28th December 2017, 08:38 AM | #9 |
Penultimate Amazing
Join Date: Nov 2003
Location: Port Townsend, Washington
Posts: 39,057
|
I can do a lot of conversions reasonably accurately in my head. That said, I have apps on both my phone and PC that will do it simply and accurately.
A British ex-pat co-worker taught me a neat trick for C to F: Double it. Subtract 10%. Add 32. That's actually exactly correct. The other direction is a bit more complicated. |
__________________
Cum catapultae proscribeantur tum soli proscripti catapultas habeant. |
|
28th December 2017, 10:52 AM | #10 |
Meandering fecklessly
Join Date: Dec 2008
Posts: 8,428
|
|
28th December 2017, 11:27 AM | #11 |
Penultimate Amazing
Join Date: Nov 2003
Location: Port Townsend, Washington
Posts: 39,057
|
When I'm King of the World (KotW) (TM), we'll stop counting on our fingers and use Octal. It makes much more sense and common fractions work perfectly.
|
__________________
Cum catapultae proscribeantur tum soli proscripti catapultas habeant. |
|
28th December 2017, 05:34 PM | #12 |
Gentleman of leisure
Tagger
Join Date: May 2005
Location: Flying around in the sky
Posts: 28,092
|
|
__________________
This signature is for rent. |
|
29th December 2017, 05:44 AM | #13 |
Graduate Poster
Join Date: Oct 2006
Posts: 1,353
|
There's a few reasons hex is used, each hex digit corresponds directly to 4 bits so if you know the bit patterns for 0-F it's easy to go between binary and hex in your head, not so easy with decimal and binary, also hex just requires 2 digits per byte and is easier to read and input than binary or decimal which is why you get hex editors. Things like addressing and memory maps make much more sense in hex too.
If you're working with 24 or 32 bit colour values, each pair of hex digits correspond to the RGB channels, it would be a nightmare trying to work with those colour values in decimal. |
__________________
The secret NASA doesn't want you to know - God makes rockets work in space. |
|
29th December 2017, 08:07 AM | #14 |
Penultimate Amazing
Join Date: Nov 2003
Location: Port Townsend, Washington
Posts: 39,057
|
Hex requires new number digits. Using alpha characters would confuse the public. For octal, we just need to teach people that thumbs are not fingers. Or amputate the pinky from every newborn for a couple of generations. It's only useful for extending when you hold a teacup anyway.
The one "Imperial" measure I strongly prefer is Fahrenheit. The range of zero to 100 nicely approximates the normal range of temperatures in temperate climes. And the gradations in Celsius are too coarse. Anyhow, Celsius himself wanted zero to be hot and 100 cold. |
__________________
Cum catapultae proscribeantur tum soli proscripti catapultas habeant. |
|
29th December 2017, 11:21 AM | #15 |
Penultimate Amazing
Join Date: Dec 2008
Location: Central City, Colorado, USA
Posts: 10,589
|
The one thing Jimmy Carter got right and it unfortunately went nowhere. I even remember some right-wingers claiming conversion to metric was a Communist plot. I think it's slightly more likely that the opposition to it was a Communist plot to keep us handicapped by using a crappy system of measurement.
|
29th December 2017, 01:20 PM | #16 |
Mafia Penguin
Join Date: Dec 2007
Location: Netherlands
Posts: 19,579
|
And hex fits better than octal because one byte fits exactly in 2 hex digits, a 16-bit word in 4 hex digits and so on. There's one notable exception: PDP-11 machine language. The PDP-11 had 8 registers and 8 addressing modes which were each coded as a sequence of 3 bits, so writing out the value of an instruction in octal neatly gave you one octal digit for the (source or target) register and one octal digit for the addressing mode.
|
__________________
"I think it is very beautiful for the poor to accept their lot, to share it with the passion of Christ. I think the world is being much helped by the suffering of the poor people." - "Saint" Teresa, the lying thieving Albanian dwarf "I think accuracy is important" - Vixen |
|
29th December 2017, 01:32 PM | #17 |
Gentleman of leisure
Tagger
Join Date: May 2005
Location: Flying around in the sky
Posts: 28,092
|
|
__________________
This signature is for rent. |
|
29th December 2017, 01:38 PM | #18 |
Penultimate Amazing
Join Date: Feb 2011
Location: Republic of Ireland
Posts: 23,499
|
|
__________________
Who is General Failure? And why is he reading my hard drive? ...love and buttercakes... |
|
29th December 2017, 01:48 PM | #19 |
Philosopher
Join Date: Mar 2007
Location: The Connecticut School for Rumpology.
Posts: 6,036
|
I was in school when President Carter tried to change us over to that European mumbo jumbo metric system. I took pride in doing my part to see that stupid ass system was sent packing. The rest of the world should just go American. That crap system never sent a man to the moon or stopped the Germans.
|
29th December 2017, 02:04 PM | #20 |
Illuminator
Join Date: Oct 2003
Location: I'M IN THE PHONEBOOK! I'M SOMEBODY!!!
Posts: 4,802
|
|
__________________
"Let me guess, my theories appall you, my heresies outrage you, I never answer letters, and you don't like my tie." - The Doctor "I heard some things I can't prove from someone I don't know, and God dammit, that's enough for me." - Penny Arcade "Any sufficiently analyzed magic is indistinguishable from Science!" - Agatha Heterodyne |
|
29th December 2017, 02:09 PM | #21 |
Penultimate Amazing
Join Date: Feb 2011
Location: Republic of Ireland
Posts: 23,499
|
|
__________________
Who is General Failure? And why is he reading my hard drive? ...love and buttercakes... |
|
29th December 2017, 02:13 PM | #22 |
Illuminator
Join Date: Oct 2003
Location: I'M IN THE PHONEBOOK! I'M SOMEBODY!!!
Posts: 4,802
|
|
__________________
"Let me guess, my theories appall you, my heresies outrage you, I never answer letters, and you don't like my tie." - The Doctor "I heard some things I can't prove from someone I don't know, and God dammit, that's enough for me." - Penny Arcade "Any sufficiently analyzed magic is indistinguishable from Science!" - Agatha Heterodyne |
|
29th December 2017, 02:18 PM | #23 |
Master Poster
Join Date: Oct 2005
Location: Oregon, USA
Posts: 2,261
|
Please, each hand obviously comes equipped for a 4 digit magnitude with a sign bit, two hands have 8 bit magnitude, 1 sign, and 1 overflow/underflow. Directly translatable into hexadecimal.
As for feet and yards, they've been defined in terms of meters since 1959. So, we're all using the metric system anyway, just with added obfuscation. |
__________________
Knowing that we do not know, it does not necessarily follow that we can not know. |
|
29th December 2017, 02:32 PM | #24 |
Penultimate Amazing
Join Date: Feb 2011
Location: Republic of Ireland
Posts: 23,499
|
It isn't exactly obvious compared to the other digits on one's hand. It is, however easy to demonstrate. Using only the two obvious thumb joints, touch each of your other fingertips on one of either hand, left or right. One cannot without using the thumbs third joint.
It's an odd bit of anatomical trivia. What I found odd about it was that even making the attempt using just the two obvious thumb joints formed my hand into a pose I have seen before, in chimpanzees. Try it, it's a bit strange. To me, it reinforced our common ancestor. |
__________________
Who is General Failure? And why is he reading my hard drive? ...love and buttercakes... |
|
29th December 2017, 09:54 PM | #25 |
Graduate Poster
Join Date: Mar 2007
Posts: 1,438
|
There's another exception. The UNIVAC (subsequently Sperry Univac, then Sperry, now UNISYS) mainframes (1100 series) had 36-bit words; octal was always used for binary data. Neither hex nor octal is an exact fit, of course, and the design is so old (yes, it's still used, I believe, in a few shrinking markets) that hex was unheard of anyway. Original character set was 6 bit (no lower case); "bytes" are 9 bit.
Did quite a bit of assembly programming on them back in the late 80s, including a stint working on the first C compiler for them. |
__________________
"Hello. My name is Inigo Skywalker. You are my father. Prepare to die." |
|
29th December 2017, 10:26 PM | #26 |
Self Employed
Remittance Man Join Date: Nov 2009
Location: Florida
Posts: 46,649
|
Oh come on it's not our fault, pirates stole our meter.
No seriously in 1793 an official "Meter" was sent from Paris to Thomas Jefferson, then the Secretary of State and a fan of the metric system. But, through various shenanigans involving storms and shipwrecks and pirates, the Meter never made it to us. (FTR, I'm a proponent of the United States adopting the metric system.) |
__________________
"If everyone in the room says water is wet and I say it's dry that makes me smart because at least I'm thinking for myself!" - The Proudly Wrong. |
|
30th December 2017, 02:22 AM | #27 |
Philosopher
Join Date: Aug 2007
Location: As far away from casebro as possible.
Posts: 7,070
|
Metre, please.
|
__________________
There is no secret ingredient - Kung Fu Panda |
|
30th December 2017, 03:09 AM | #29 |
Penultimate Amazing
Join Date: Nov 2003
Location: Port Townsend, Washington
Posts: 39,057
|
|
__________________
Cum catapultae proscribeantur tum soli proscripti catapultas habeant. |
|
30th December 2017, 03:24 AM | #30 |
Illuminator
Join Date: Jun 2007
Location: South Africa
Posts: 3,485
|
|
__________________
This signature is intended to imitate people. |
|
30th December 2017, 03:26 AM | #31 |
Director of Hatcheries and Conditioning
Join Date: Jul 2002
Location: Waiting for the pod bay door to open.
Posts: 46,328
|
|
__________________
We do these things not because they are easy, but because we thought they were going to be easy. Everything is possible, but not everything is probable. Perception is real, but the truth is not. - Imelda Marcos |
|
30th December 2017, 03:30 AM | #32 |
Penultimate Amazing
Join Date: Aug 2001
Location: Sorth Dakonsin
Posts: 29,368
|
For what it's worth, with the wind chill it's going to be 40 degrees below zero in my area this weekend.
C or F, you say? Doesn't matter, they're the same! |
__________________
Science is self-correcting. Woo is self-contradicting. |
|
30th December 2017, 10:00 AM | #33 |
Master Poster
Join Date: Mar 2010
Location: Blackstone River Valley, MA
Posts: 2,298
|
All the microprocessors and micro-controllers currently used in volume exclusively use binary because they can only efficiently and accurately store electrical or magnetic fields in two states. Decimal, hexadecimal, octal, etc, are only used by the humans who input numeric values to the computers, where they are promptly stored and manipulated by the micro in binary.
|
30th December 2017, 11:15 AM | #34 |
Graduate Poster
Join Date: Apr 2011
Posts: 1,499
|
|
30th December 2017, 12:13 PM | #35 |
Banned
Join Date: Sep 2006
Location: NZ
Posts: 21,318
|
Nautical measurements have always done my head in
Knots. Fathoms. Leagues etc |
30th December 2017, 01:49 PM | #36 |
Master Poster
Join Date: Oct 2005
Location: Oregon, USA
Posts: 2,261
|
|
__________________
Knowing that we do not know, it does not necessarily follow that we can not know. |
|
30th December 2017, 02:34 PM | #37 |
Gentleman of leisure
Tagger
Join Date: May 2005
Location: Flying around in the sky
Posts: 28,092
|
Let us compare the two systems. Starting with length.
Imperial 12 inches make a foot 3 feet make a yard 1760 yards make a mile Metric 1000mm make a meter 100cm make a meter 1000 meters make a kilometer All common measurements. Yet one uses almost random numbers to convert and the other uses powers of 10. That is one advantage of metric. I could use almost any type of measurement and my argument would still work. Then how do you express a length? In imperial it might 2 feet 5 inches. In metric it would 1.24 meters. |
__________________
This signature is for rent. |
|
30th December 2017, 04:14 PM | #38 |
Philosopher
Join Date: Aug 2007
Location: As far away from casebro as possible.
Posts: 7,070
|
No it would be 73 and a bit cm.
|
__________________
There is no secret ingredient - Kung Fu Panda |
|
31st December 2017, 01:17 AM | #39 |
Loggerheaded, earth-vexing fustilarian
Join Date: Sep 2006
Location: Wales
Posts: 31,398
|
I was raised on Imperial, but science at school/Uni was all metric so I'm happy in both systems. Apart from temperatures, where °F no longer mean very much to me. BBC World News slowly flips the numbers in C and F for their N American weather forecasts and I'm always a little surprised at the C-to-F conversion.
|
__________________
"There ain't half been some clever bastards" - Ian Dury |
|
31st December 2017, 01:46 AM | #40 |
Philosopher
Join Date: Mar 2007
Location: The Connecticut School for Rumpology.
Posts: 6,036
|
|
Thread Tools | |
|
|