C to F, ml to tsp, km to mph, m to ft etc.

[FIREmenow]

Constantly converting numbers *is* the problem. If you are going to switch, you have to go all-in - no converting allowed.

The only reason to do conversions is that if I hold 25g of something, I don't know (today) what that feels like. I can't hold up my fingers and show you 37mm.

It just comes down to familiarity. If I am "allowed" to convert it to something I am familiar with, I will never learn to hold up my fingers 37mm apart. If (somehow), I was not allowed to convert, I would quickly learn what a 100g bag of something feels like, or how far 0.75km is along the road. At that point, I would care less about converting numbers.

I think there is no real way to force people to NOT convert the numbers because of the immediacy of the need to know, and therefore we will never learn anything else fast enough to go "all-in".

[/ramble]

I was riding with a guy last year and we passed a sign on the road that said "Speed Checked by Meter". He said, "Oh, they must have switched to the metric system!"

 

[scrabbler1]

When I was in middle school in 1975-1977, we learned the basic conversions between English and Metric in math and science classes. Rulers included inches and centimeters. Soda bottles weren't 1-liter and 2-liter amounts, yet. The C-F temperature conversion I learned back then and still remember today. It comes in handy when I email a friend from the UK and mention our weather. She isn't good at converting, so I make sure to tell her our temps in Celsius.


As long as I know the rough equivalents, I can convert from one to the other okay. A Km is about .6 Mile, a Meter is about 39 inches. A liter is a little more than a quart (forgot exactly how much). A Kg is about 2.2 pounds. And C x 9/5, then add 32 gives your temp in F.

 

[scrabbler1]

Mixing imperial and metric measures may have drastic consequences, like running out of gas.

https://www.damninteresting.com/the-gimli-glider/

"When airline mechanics finally arrived at the landing site, they found all three of the 767’s fuel tanks completely dry, with no evidence of a fuel leak. A review of the day’s events traced the problem back to the manual dripstick checks in Montreal and Ottawa. In order to maintain awareness of the overall weight of the aircraft, flight crews kept track of fuel quantity based on kilograms rather than the fuel company’s liter-based measurements. Pearson and Quintal had determined the fuel weight by multiplying the the number of dripsticked liters by 1.77, as indicated by the documentation. However, unbeknownst to the pilots and the fuel crew, this multiplier provided the weight in imperial pounds; the new, all-metric 767 was based on kilograms, and required a multiplier of 0.8. As a consequence of this documentation disconnect, Flight 143 had left Montreal with roughly half the necessary fuel."

I thought about this, too. They made a movie about this in 1995 title "Freefall: Flight 174."

Falling from the Sky: Flight 174 (TV Movie 1995) - IMDb

 

[EastWest Gal]

Pediatrician here. All our medication and fluid calculations are in metric. 28 ml gm is one oz of water. Roughly 30 gm or 30 ml works pretty darn close for cooking. Can do ounces, tsp, tbsp, cups in my head for cooking. I use 30 ml = one oz, and the food scale has a grams setting. Also temperature. I still use Fahrenheit for the weather, but in Rome in 2010 43 was too warm for a walking tour. Metric is way easier when it comes to body temperature. 37 is normal, 38 is lower level of a fever, easier to remember as an intern than 98.6 and 100.4. It became second nature over the years.

 

[braumeister]

Metric is way easier when it comes to body temperature. 37 is normal, 38 is lower level of a fever, easier to remember as an intern than 98.6 and 100.4. It became second nature over the years.

IIRC, 37 degrees was initially set as "normal" body temperature, and worked fine, especially since Celsius degrees are bigger than Fahrenheit so there was a reasonable margin of error between 36 and 38.

Then someone decided to do an exact C-to-F conversion and came up with 98.6°F so we have been stuck with using the ridiculous tenths of a degree ever since.

I call it ridiculous because my own "normal" temp is generally 97.6°F (well within normal range when using C but a full degree out with F).

 

[Souschef]

My biggest conversion headache was some time ago. I wanted to make a special Xmas bread for my Czech DIL. My son sent me the recipe, but it was in Czech!
Here is what I had to do:
1. Translate from Czech to English
2. Convert from metric to English
3. Convert from weight measures to volume measures,e.g. convert ounces of flour to cups of flour.
4. Make the bread
After all that, it was supposed to look like braided bread, but it came out of the oven looking like a giant Milkbone

 

[travelover]

IIRC, 37 degrees was initially set as "normal" body temperature, and worked fine, especially since Celsius degrees are bigger than Fahrenheit so there was a reasonable margin of error between 36 and 38.

Then someone decided to do an exact C-to-F conversion and came up with 98.6°F so we have been stuck with using the ridiculous tenths of a degree ever since.

I call it ridiculous because my own "normal" temp is generally 97.6°F (well within normal range when using C but a full degree out with F).

The way I heard it, the Fahrenheit scale was set based on what he thought human blood temperature was.

History




Daniel Gabriel Fahrenheit


Fahrenheit proposed his temperature scale in 1724, basing it on two reference points of temperature. In his initial scale (which is not the final Fahrenheit scale), the zero point is determined by placing the thermometer in a mixture of ice, water, and ammonium chloride (salis Armoniaci [6]). This is a frigorific mixture which stabilizes its temperature automatically: that stable temperature was defined as 0 °F (−17.78 °C). The second point, 96 degrees, was approximately the human body's temperature (sanguine hominis sani, the blood of a healthy man).[7]

https://en.wikipedia.org/wiki/Fahrenheit

 

[tn3sport]

C to F: double it, add 20. (Not exact, but easy to do and remember)

Distances: Think track and field, which has converted in the US. A 5k run is 3.1 miles. A 10k run is 6.2 miles.

Car indicates 50 k/h, you're going 31 m/h.
Car indicates 100 k/h, you're going 62 m/h.
But, who really cares, if there's someone in your rearview mirror, you're not going fast enough...

Metric conversion is easy. Trying to figure out how much volume is in a 55 gallon drum is much more difficult... Could be 42 gallons, could be 46 gallons depending on country of origin. The things hold over 56 gallons....

 

[urn2bfree]

The only measure I never got comfortable with was litres/100 Km, that never made sense to me I always wanted distance/volume of fuel not the other way around.

Actually volume per distance is probably a better measuring stick. This problem illustrates why.
Which change saves more assuming you will drive the same amount?
Change from a 10mpg car to a 20mpg car, or
From a 20mpg car to a 50 mpg car?

Most people choose the 20->50 change based on the 30 mpg gap in the second choice. But wait. If you instead look at gallons per 100 miles it becomes as follows:

From 10 gal/100 miles to 5 gal/100 miles
Or from 5 gal/100 miles to 2 gal/100 miles?

Now it is obvious that a 5 gallon savings is better than a 3 gallons savings per 100 miles.

Substitute km and liters as needed. The point is that distance per volume is not the best "metric."

 

[Major Tom]

Growing up in England in the 70's, I learned to juggle both systems, with helpful reminders such as,


"Two and quarter pounds of jam, weigh about a kilogram" and

"A litre of water's a pint* and three quarters".


(*Imperial pint)

 

[Music Lover]

I switched over in grade school, so I'm equally proficient in both Imperial and metric and never have to convert. It doesn't matter if the thermometer says 28C or 82F, I'm perfectly comfortable either way. The same goes for gallons/pints/liters, pounds/kilos, or miles per gallon/liters per 100k.

 

[kcowan]

I was in Canada when we switched from imperial to metric in the 70's. I became perfectly comfortable with it.

Even more dramatic, I was in Edmonton, and they did the cold turkey conversion.

Cooking and building never quite made it. But wine comes in .75 and 1.5 ltr bottles. Liquor is 1.75 ltr.

2x4s never were but they are still the same size. Same with sheets of plywood/drywall. Wrenches come in both sizes now.

During our stay in Mexico, all measures are familiar. 28 is fine and 36 is hot. Local vodka is 48 p/l. Chilean wine is 95 p/l. Gas is 139 p/l (in Vancouver, it is C$1.39/l).

 

[braumeister]

"Two and quarter pounds of jam, weigh about a kilogram" and
"A litre of water's a pint* and three quarters".

A pint's a pound, the world around.

 

[mpeirce]

To me the least compelling units in SI (i.e. the metric system) are temperature units.

The Fahrenheit scale has a few real niceties.

1. 10° bands (the 50's, the 80's, etc) work out nicely to describe human comfort bands. °C doesn't have this really.

2. 0° F is "quite cold" and 100° F is "quite hot!"

3. They really didn't need to mess with Fahrenheit to fit it into the decimal based SI system.

If we were going to change from °F why not go all the way to K? Kelvins are the same size units as °C, but introduce the concept of absolute zero temperature at 0K. No "less informed" folks saying things like "the temperature doubled today" when it goes from 30 to 60.

 

[audreyh1]

Metric Conversion Act of 1975.

We almost made it. Now, the question is why didn't it happen. This tired old brain still goes into shock when, like this morning, the medicine bottle said that the recommended dose was 30ml.

So the question is, did you adapt? Would an 80km speed limit mean 50, 60 or 65MPH? How many 1/2 lb hamburgers would you get from 3kg of meat? Would 50L of gas fill a 17 gallon tank?

Did you learn conversion from school, from living in different countries, or like me, never learned it at all. Thank goodness for the internet and conversion tables, else some of us may not even be here today. Would you support new school requirements to teach metrics?... maybe in place of the lost art of cursive writing.

With medicine, everything is in liters and grams, so I'm used to it.

Same with wine, LOL!

Temps are tough. I have a vague sense in °C as I spend time in Europe each year: Below 10 wrap up, 10-15 is fresh and cool, 20-25 quite pleasant, 30 getting a bit warm, and 40s are only seen at home were I live!!!

 

[SecondCor521]

I can work with either system.

I like SI/metric (*waves hands knowing there are subtleties there I don't have to remember because I'm retired get off of my lawn kid*) for simplicity and somewhat rationality, except that degrees C are too "big"; metric thermostats address this by using half-degrees (can set the thermostat for 21.5 deg C or whatever).

Tangent: in the US, some stuff is metric and some stuff is American, so socket wrenches and such are a pain - is it an 18mm bolt or a 7/8 inch bolt? Have to grab the sockets and try them until one fits. Maybe someone knows a better way than trying to remember that my car's oil pan drain plug is metric but my bicycle seat post is American or just guess-and-check all the time.

 

[bw5972]

Metric Conversion Act of 1975.

We almost made it. Now, the question is why didn't it happen. This tired old brain still goes into shock when, like this morning, the medicine bottle said that the recommended dose was 30ml.

So the question is, did you adapt? Would an 80km speed limit mean 50, 60 or 65MPH? How many 1/2 lb hamburgers would you get from 3kg of meat? Would 50L of gas fill a 17 gallon tank?

Did you learn conversion from school, from living in different countries, or like me, never learned it at all. Thank goodness for the internet and conversion tables, else some of us may not even be here today. Would you support new school requirements to teach metrics?... maybe in place of the lost art of cursive writing.

If you were hosting a pizza party for 6 people, how many 2 liter bottles of soda what you get? 1? 2? 3? 6? 10?

Did you convert oz's to ml's or quarts to liters?

Probably you did no conversion because you KNOW and can VISUALIZE from experience.

If we had the political will to just do the right thing it would be the same. A short adjustment period followed by normalization.

Then gallons, lbs, inches, etc... would soon be like fathoms, rods, hands and furloughs.

 

[Major Tom]

A pint's a pound, the world around.

Unless you're in the UK, where an imperial pint weighs about a pound and a quarter

 

[SecondCor521]

Unless you're in the UK, where an imperial pint weighs about a pound and a quarter

Is that an avoirdupois pound or an apothecaries pound or a troy pound?

 

[Koogie]

If you were hosting a pizza party for 6 people, how many 2 liter bottles of soda what you get? 1? 2? 3? 6? 10?

Probably none, unless we were making cocktails that called for soda water.

Now, bottles of POP...

 

[Music Lover]

Unless you're in the UK, where an imperial pint weighs about a pound and a quarter

And costs about 3 pounds...

 

[braumeister]

Temps are tough. I have a vague sense in °C as I spend time in Europe each year: Below 10 wrap up, 10-15 is fresh and cool, 20-25 quite pleasant, 30 getting a bit warm, and 40s are only seen at home were I live!!!

While living in a Celsius country at one time, it suddenly occurred to me that when I heard "16" it sounded very much like "60" and the two are close enough that it works as a rough baseline, estimating how temperatures will feel some distance up and down from that point.

 

[Major Tom]

Is that an avoirdupois pound or an apothecaries pound or a troy pound?

So many standards, so little time.........

And costs about 3 pounds...

I remember paying 44p a pint in my Students' Union, but that was a long time ago..........

 

[Music Lover]

While living in a Celsius country at one time, it suddenly occurred to me that when I heard "16" it sounded very much like "60" and the two are close enough that it works as a rough baseline, estimating how temperatures will feel some distance up and down from that point.

For those who need to convert, 28C and 82F are the same, as well as 40C and 104F. And, of course, -40 is the same for both.

 

[nuke_diver]

Even more dramatic, I was in Edmonton, and they did the cold turkey conversion.

Cooking and building never quite made it. But wine comes in .75 and 1.5 ltr bottles. Liquor is 1.75 ltr.

2x4s never were but they are still the same size. Same with sheets of plywood/drywall. Wrenches come in both sizes now.

During our stay in Mexico, all measures are familiar. 28 is fine and 36 is hot. Local vodka is 48 p/l. Chilean wine is 95 p/l. Gas is 139 p/l (in Vancouver, it is C$1.39/l).

It had to be cold turkey. Though when they did it in the 70's the best April Fools joke I ever heard was a radio station saying now that people were getting used to the metric system metric time would be introduced...100 sec to a min 100 min to an hour 10 hours in a day etc...People went batshit crazy over that....until

I had to do cold turkey changes 2x once in Canada and once in the US. Actually in Canada I recall that initially there was an overlap where they would quote both temps, weights were shown both in lbs and kgs etc. Still my Grandfather thought it was stupid and he'd never change...until he did, when I moved to the US I would cover temps for him from F to C so he understood how hot it was here in the summer