Pawelk198604 Posted October 19, 2013 Share Posted October 19, 2013 With curiosity, I noticed that - 40 C equal to equal to - 40 FI wonder where it comes from Link to comment Share on other sites More sharing options...
Luigi Broglio Posted October 19, 2013 Share Posted October 19, 2013 With curiosity, I noticed that - 40 C equal to equal to - 40 FI wonder where it comes fromEasy.The relation between celsius and fahreneit degrees follows this consideration: ice point for water (1atm) is 0 celsius, that is by definition of fahreneit degrees 32F; boiling point is at 100C or 180F (by definition of F).So, relation is cel=1.8*far+32, that is a linear law of conversion. You find for this line a fixed-point (cel=far) near (-40, -40).http://www.wolframalpha.com/input/?i=y%3D1.8x%2B32%2C+y%3Dx Link to comment Share on other sites More sharing options...
Ralathon Posted October 19, 2013 Share Posted October 19, 2013 As the poster above me said, they're both linear scales with different slopes. So they need to meet somewhere. Fahrenheit has always seemed a bit of an arbitrary rollercoaster though. Picking 32 for freezing water and 0 for a 1:1:1 mixture of ice, water and ammoniumchloride seems so random to me. Link to comment Share on other sites More sharing options...
maltesh Posted October 19, 2013 Share Posted October 19, 2013 As the poster above me said, they're both linear scales with different slopes. So they need to meet somewhere. Fahrenheit has always seemed a bit of an arbitrary rollercoaster though. Picking 32 for freezing water and 0 for a 1:1:1 mixture of ice, water and ammoniumchloride seems so random to me.Well, as I recall, when the scale was being made, that 1:1:1 solution was an easy laboratory method to make a consistent, cold temperature. Subsequently pinning the freezing point of water at 32 degrees makes the gradiations easy to mark, because 32 = 2^5 power, so you bisect the distance along your thermometer between those two pinned points five times, and you've got a length that will match up to 1 Fahrenheit degree of temperature on your homemade thermometer, and you can start scribing the lines on. Take that 32-degree length, measure it out twice more, and 32 + 64 = 96, which is where Fahrenheit pinned human body temperature.It is the 17th century. It's going to be some time before you can go to the store and buy a thermometer. Link to comment Share on other sites More sharing options...
MK3424 Posted October 19, 2013 Share Posted October 19, 2013 (edited) Von Braun designed in metric, so ...?Yes, the entire measurement was done in Metric internally in the AGC but converted to Imperial for easy readings. Edited October 19, 2013 by MK3424 Link to comment Share on other sites More sharing options...
ZedNova Posted October 19, 2013 Share Posted October 19, 2013 Okay guys, cut it out... lets try to act like civilized human beings... Link to comment Share on other sites More sharing options...
Kerbart Posted October 19, 2013 Share Posted October 19, 2013 As the poster above me said, they're both linear scales with different slopes. So they need to meet somewhere.They do meet, obviously, but not necessarily. Theoretically there could be two temperature scales with different slopes that have an intersection at, say, -200K. In that case scale "A" and scale "B" do not meet somewhere as that temperature doesn't exist. Link to comment Share on other sites More sharing options...
Jackissimus Posted October 19, 2013 Share Posted October 19, 2013 I am a service engineer in Europe. My service case is twice as big and heavy as it needs to be, because I need to carry two sets of every tool - normal and american. I just laugh it off, but my hands hurt Link to comment Share on other sites More sharing options...
ZedNova Posted October 19, 2013 Share Posted October 19, 2013 I am a service engineer in Europe. My service case is twice as big and heavy as it needs to be, because I need to carry two sets of every tool - normal and american. I just laugh it off, but my hands hurt Why do you carry imperial tools? I thought every country in Europe uses the metric system. Link to comment Share on other sites More sharing options...
Kryten Posted October 19, 2013 Share Posted October 19, 2013 Depends what exactly he does engineering on. Plenty of e.g. sewer infrastructure predates metrication, in places by centuries. Link to comment Share on other sites More sharing options...
Pawelk198604 Posted October 19, 2013 Author Share Posted October 19, 2013 Easy.The relation between celsius and fahreneit degrees follows this consideration: ice point for water (1atm) is 0 celsius, that is by definition of fahreneit degrees 32F; boiling point is at 100C or 180F (by definition of F).So, relation is cel=1.8*far+32, that is a linear law of conversion. You find for this line a fixed-point (cel=far) near (-40, -40).http://www.wolframalpha.com/input/?i=y%3D1.8x%2B32%2C+y%3DxThanks very much Link to comment Share on other sites More sharing options...
Pawelk198604 Posted October 19, 2013 Author Share Posted October 19, 2013 The funniest thing is that Gabriel Fahrenheit was a German physicist coming from Gdansk a city that now belongs to Poland Link to comment Share on other sites More sharing options...
Jackissimus Posted October 19, 2013 Share Posted October 19, 2013 Why do you carry imperial tools? I thought every country in Europe uses the metric system.I service scientific instruments and most of them come from either Japan, Europe or the US. Link to comment Share on other sites More sharing options...
Seret Posted October 19, 2013 Share Posted October 19, 2013 Fahrenheit has always seemed a bit of an arbitrary rollercoaster though. Picking 32 for freezing water and 0 for a 1:1:1 mixture of ice, water and ammoniumchloride seems so random to me.That's because it is arbitrary. Fahrenheit based his scale on the work of a Dane called Ole Romer. Romer chose 0ºF as the point which it never went below in Denmark, based on the records he had available. So it wasn't really based on anything scientific at all.Fahrenheit, like most legacy Imperial units, is a silly system. The sooner it's completely gone the better. The world has moved on. Link to comment Share on other sites More sharing options...
PakledHostage Posted October 20, 2013 Share Posted October 20, 2013 Coincidentally, I was looking at a website the other day that generates maps, by country, of a variety of parameters. Here are two from that website that show which countries in the world use Metric officially and for road distance & speed units: Link to comment Share on other sites More sharing options...
Specialist290 Posted October 20, 2013 Share Posted October 20, 2013 Out of curiosity, what's the one country that uses mixed units on the second map? I can't find it. Link to comment Share on other sites More sharing options...
PakledHostage Posted October 20, 2013 Share Posted October 20, 2013 Out of curiosity, what's the one country that uses mixed units on the second map? I can't find it.The only one that I could find is Puerto Rico. Here's the link to the interactive map: http://chartsbin.com/view/5261 Link to comment Share on other sites More sharing options...
tipsyMJT Posted October 20, 2013 Share Posted October 20, 2013 Well there is one argument for imperial. It is a lot easier to design a house with feet being divisible by 3, 4, and 2 opposed to the meter being divisible by 10. It's just that threes pop up a lot more often than 5's Link to comment Share on other sites More sharing options...
LaydeeDem Posted October 20, 2013 Share Posted October 20, 2013 Fahrenheit and Celsius suck. Kelvin master race. Link to comment Share on other sites More sharing options...
K^2 Posted October 20, 2013 Share Posted October 20, 2013 Well there is one argument for imperial. It is a lot easier to design a house with feet being divisible by 3, 4, and 2 opposed to the meter being divisible by 10. It's just that threes pop up a lot more often than 5'sThat's just an environment bias. You are used to measurements that are a whole number of feet, so yeah, it's easy to divide by 3. What if I gave you a plank that's 120cm long. Is that any harder to divide by 3 than a 4-foot long one? But I can divide that by 5 as well. Or by 10. Working in metric, you aren't going to have things that are just 1m long even. If it's necessary to make something for construction that's easily divided by some number of pieces, lengths can be easily adjusted to have these numbers built in already. Link to comment Share on other sites More sharing options...
jfx Posted October 20, 2013 Share Posted October 20, 2013 Well there is one argument for imperial. It is a lot easier to design a house with feet being divisible by 3, 4, and 2 opposed to the meter being divisible by 10. It's just that threes pop up a lot more often than 5'sHouses are usually constructed with cm as unit. I'm not sure what you want to achieve with rule of thumb measurements when you build a house like this. Link to comment Share on other sites More sharing options...
sjwt Posted October 20, 2013 Share Posted October 20, 2013 The best part about facts is that they are, and thus not something that can be argued. Link to comment Share on other sites More sharing options...
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