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125 Years of Longitude 0 0' 00" At Greenwich
An anonymous reader writes "This week marks the 125th anniversary of the International Meridian Conference, which determined that the prime meridian (i.e., longitude 0 0' 00") would travel through Greenwich, UK. One of the reasons that Greenwich was agreed upon 'was that 72% of the world's shipping already depended on sea charts that used Greenwich as the Prime Meridian.' Sandford Fleming's proposal of a single 24-hour clock for the entire world, located at the center of the Earth and not linked to any surface meridian, was rejected / not voted on, as it was felt to be outside the purview of the conference."
And don't forget the 180th meridian that came with it. When you cross the 180th meridian, you have to set your watch back/forward 23 hours !
Quite a few people are unaware of it ;-))
http://adsabs.harvard.edu/full/1919PA.....27..416F
Everything I write is lies, read between the lines.
It's a wonderful thing to live a phlegms breath away from such a staple part of our species everyday lives.
I wonder how much longer it will take for the US to catch up?
For example, we continue to teach date formatted in a completely nonsense format (MM/DD/YYYY) instead of either high to low (YYYY/MM/DD) or low to high (DD/MM/YYYY) like the rest of the world. Plus using AM/PM instead of 24 hour ("Military Time") again like the rest of the civilised world.
Don't even get me started on our lack of metric....
It is worth noting that in the coordinate system most used today (WGS84), this is no longer true.
See this explenation or check google maps.
It's called Riyadh Solar Time - look it up. It last one year year before they realised how much of a pain in the arse it was. Also, Japan used to have per-city time zones in five-minute increments, and that was a real pain for doing business, or calculating journey travel/arrival times. Discrete time zones for relatively large areas are just more practical in general.
Clearly you're not a woodworker. Small measurements are where the metric system shines... large measurements people just estimate anyway.
"Growing old is inevitable; growing up is optional."
I have tried finding a reference to this and can't. What does it mean by being located at center of the Earth and not linked to any surface meridian? Time zones are linked to surface meridian's right? So how would a system work that was not linked to anyplace on the surface?
stores [open] 3 hours before local midday
You imply that the entire population can consistently and correctly subtract 3 from a number.
Quickly, convert from 1234 kiloinch to miles! The beauty of the metric system is that there is one unit for distance, which is a meter. All others are just prefixes. A kilometer is just a kilo meters, so 1000 meters. All you have to do is move the decimal point. With the imperial system, going from the small distance unit (inch) to the large one (miles) requires a lot of conversion. And then you have a third, medium unit called the feet, just to make it a little more unwieldy.
Because there's also a London, Ontario.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Anybody wondering why it's doesn't run through Paris? Take a look here
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
It's what makes time travel POSSIBLE!
Quickly, convert from 1234 kiloinch to miles!
$ time units -v '1234 kiloinch' miles
1234 kiloinch = 19.47601 miles
1234 kiloinch = (1 / 0.051345219) miles
real 0m0.046s
user 0m0.040s
sys 0m0.008s
That didn't take to long at all!
Seriously, the metric system has a lot going for it in some ways, but is harder in others. For example, while 10 is a great multiplier (since we tend to think in base 10), it doesn't have a lot of factors. For example, dividing by 3 doesn't work so well. Sure, you and I know that 1/3 meter is 33.33333 cm, but that's not as easy as 1/3 foot being 4 inches. 5280 (the number of feet in a mile) is divisible by 2, 3, 4, 5, 6, 8, 10, 11, 12, 15 and a lot more. Not that a 15th of a mile comes up a lot, but if it does, you can be assured that it's exactly 352 feet!
The metric system units are also more calibrated to scientific use than everyday use. The meter is too long and the gram is too light (the liter is about right). Other things, like degrees Celsius are too big (not to mention as arbitrary as Fahrenheit). And metric time never really took off -- you still have seconds, minutes, hours, etc.
All in all, the metric system is optimized for scientific work where conversions between units happen more often, and knowing that 100 million micrograms is .1 kilograms is useful. But it doesn't work so well for common, human scale use.
"Save the whales, feed the hungry, free the mallocs" -- author unknown
The reason is that this kept the 90 degree west meridian in the same place the the original. Guess where that is...
Tells you where the power and money was when the GPS system was set up.
First, the article you linked says nothing about why it was moved other than GPS was more accurate. Care to cite a source on your claim? There's someone in the comments saying it, but that's also not sourced.
Also, I love that you say that but ignore this, from the article you linked. This is about selecting Greenwich as the prime meridian back in the day:
Rival 1: Washington was a key competitor, but the US threw its weight behind Greenwich, taking it out of the race.
Any chance to bash the US, eh?
In my younger days I was pretty damn good with wood, and working with sixteenths of an inch (or a thirty-second of an inch, or tighter, with a wood that sawed and sanded clean), was cake. So was sliding between an eighth and five thirty-seconds in my head. Approximations were something along the lines of 'a fat eighth.' It was all easy. On the other hand, people who can read perl like it was a second grade textbook frighten me. Although I'm sure it's cake for them.
As for estimations, what is your value for 'large'?
All cities used to have their own local time. The railroads were the first to push for standardized time-zones.
I used to leave near New Orleans.
My bet is "this guy's house in Belleville, IL"
So why not have a "London" and a "London, Ontario"? I thought it was pretty common in english to assign the minor version a secondary title to differentiate it... not to assign every other possible version a secondary title as well. Do americans really say they're going to "Paris, France" for their honeymoon, or do they just assume people will know that no-one would want to go to Texas for a romantic holiday?
Moderation Total: -1 Troll, +3 Goat
What was it fahrenheit was measured by? 32 F = water freezes, 100 F = body temperature, 212 F = water boils?
For reference, 0F is when salt water freezes, 32F is when fresh water freezes, and 100F is human body temperature (or at least that of Dan Fahrenheit.) The boiling point of water was not taken into account for creating the scale, it was just placed upon the scale later on.
I will grant that your point remains intact however.
One neat detail about the Celsius scale making more sense: Originally it was reversed, as in 0C was the boiling point of water, and 100C was the freezing point. It was only 'reversed' years later and against his will (Well, I believe he was dead by then, but still.)
It should also be kept in mind that both Fahrenheit and Celsius scales were created before 'temperature' was really understood. At that point in history, heat and cold were both forces that were believed to exist separately. Today we know there is only heat and lack of heat, but at the time it was believed there wasn't really an upper OR lower bound on temperature, and the scales were made accordingly.
Once the concept of heat as energy was realized, and there was a lower bound (absolute zero) but still no real upper bound, a new scale for scientific purposes was made to match, called Kelvin.
- Video. The PAL standard is better quality than NTSC (Never The Same Color), so why did the Americas adopt an inferior option?
That's sort of like asking why we adopted the clearly inferior analog STDV standard instead of digital HDTV. NTSC was standardized in 1953, PAL was not standardized until 1963. Naturally, PAL was the superior standard...it was based around technology that was ten years more advanced.
So how much does a gallon of water weigh? How about that 2 gallon/10l gas can, how much will that weigh when it's full? In metric it's easy since 1l of water = 1 kg Gasoline has a relative density of 0.71-0.77 (lets call it 0.75) so in metric 10l of gasoline is 7.5kg All without a calculator or writing anything down, lets see if you can do that in pounds and inches. Yes you might have to deal with learning to use 1.25 1.6 and 2.5 more often but it's no less work then learning how many feet are in a mile or fluid oz in a pint etc. Not to mention that the UK and US numbers are often different.
You miss the point. The advantage of using the same base across all measurements is not merely that it goes well with the digits we use, but it means different type of measurements work well together. A cubic meter works out to exactly a thousand liters, which when filled with water would weigh 1 metric tonne, which is 1 thousand kilograms. The pressure of 10 metres of water works out to 1 atmosphere, which is approximately 100,000 Pascal, which is 100,000 Newtons per square meter. At sea level the acceleration due to gravity is approximately 10 M/s so 1kg is roughly 10 newtons worth of weight. If you have a force of 1 Newton over 1 meter , you get 1 joule worth of energy, which is the energy drawn per second by 1 ampere of electric current at an electric potential of 1 volt.
Now, lets say you have a pool of water that is 10 feet deep and 10x20 yards by the sides. You want an electric engine operating at 230V to drive a pump that can empty the pool through a pipe that has a diameter of 3inches. The drain is at ground level. You don't want to leave it on unsupervised at night so you want it to take no more than 2 hours. How many amperes of current will your engine draw? What's the total amount of energy necessary to empty the pool? How much pressure does the pump have to handle?
I would STRONGLY suggest you convert to SI units before trying to solve that problem.
All in all, the metric system is optimized for scientific work where conversions between units happen more often, and knowing that 100 million micrograms is .1 kilograms is useful. But it doesn't work so well for common, human scale use.
I would disagree. People will adapt to any unit system they know. Really the proof of this is the system we use in america. It is quite possibly the worst collection of units I could think of, with there being NO consistency in conversions. While you say that the gram is too light, I doubt that people that use it think so. Mainly because they know the system. I know I would much rather use a system where the units make sense.
right handed versus left handed traffic. solution best decided by vanuatu:
http://upload.wikimedia.org/wikipedia/en/9/9b/Vanuatu_driving.png
rail gauge. there's european and chinese, standard, but russia uses a broad gauge, which is a serious problem for economic development:
http://www.chinapost.com.tw/business/2008/01/11/138592/Beijing-to.htm
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Using the same base across all measurements is really convenient - parent is correct about that.
But GP is also correct in that it is super convenient for your measurement base to have many factors. A unit comprising 10 smaller units can be smoothly divided in half, but not in thirds or fourths. For that purpose, 12 is a much more useful number than 10. You guys are debating the orthogonal advantages of two different systems: both are correct.
So the ideal would be a base 12 metric system, with all units scaling by twelves and grosses, ideally paired with a base-12 arithmetic system.
Sadly, that's a pipe dream. The cultural inertia of base 10 is so strong we don't even think about it --- it makes the "strong" US attachment to imperial units look weak.
I stole this sig from someone cleverer than me.