It's Cold on Mars
mars.nasa.gov
mars.nasa.gov
This CGI is confusing. When it comes to Mars rovers, I never know which images are real or fake. They could at least have a mark in the corner to indicate CGI.
Edit: I found an animation for you that actually shows the process! It's on NASA JPL's Instagram account, though: https://www.instagram.com/p/6k4pUMFbys/
The full video is at https://mars.nasa.gov/layout/helicopter/images/Helicopter_ta... - the part I'm refer to is 5 seconds in.
-130 Fahrenheit = -90 Celsius
(PS America uses "US customary" or "English" units. Imperial units means the ones after standardization across the British Empire in 1824, which by then did not include the USA.)
A base 12 distance unit also has some pleasant properties.
Uh let me do some primary school math for you:
>30 Degrees Celsius: hot/summer weather. 20 Degrees Celsius: warm spring, t-shirt weather. 10 Degrees Celsius: light jacket. 0 Degrees Celsius: literally freezing. Winter clothing. -15 Degrees Celsius: requires heavy & layered clothing to avoid hypothermia and/or frostbite. -30 Degrees Celsius: arctic gear.
Look, the turning point between light clothing and winter clothing is literally built into the system: 0 degrees is the triple point of water as you said so yourself. There are many arguments why the US hasn't seen a wide-scale adoption of metric temperature, but I'd posit that "objective ease of use" isn't it. You lot are just used to a legacy system with all it's warts and it's more convenient to go with the joneses than try to force change. I think trying to advance arguments how it's more convenient is a fools errand because it's literally just force of habit.
I can promise you that the various feet, inches, fluid ounces and other shenanigans are mind-bogglingly confusing for anyone who is used to metric. Doubly so given the very annoying ratios that emerge with square/cubic/volume units.
What is 5/8ths of 2 ounces, 4 drams and 5 grains? :-)
She was an immigrant from Czechia and had to learn the British Apothecary system when she arrived in the 1950s. To her credit she had mastered it but it was lunacy.
Of course there are fun questions like “which ounce?” Not knowing that I don’t think I can do better.
But I understood "2 ounces, 4 drams and 5 grains" to be a single measurement.
An apothecary dram (ʒ) is 60 grains, and an apothecary ounce (℥) is 480 grains, so we have 1205 grains. ⅝ of that is 753⅛ gr, which is 1 ℥ 4 ʒ 33⅛ gr.
I think these measurements would have been in common use by pharmacists ... although [1] says they're still in use some times in the USA, or have only recently fallen out of use.
It's also interesting to see the mixtures of units in common use there. The UK has Imperial units for several daily things (body height and weight, road distance and speed) yet the medical profession actively avoids use of the system -- equipment is only metric. This is to avoid any errors made during conversion, and ensure day-to-day familiarity with the units.
[1] https://nursekey.com/u-s-customary-units-and-the-apothecary-...
Correct. Three columns required, similar to the old British money system of Pounds, Shillings and Pence.
(Sidebar: the turning point between very warm and hot is literally built into the system at 100F. If you think 30C is hot, you’ve clearly not spent much time here in the summer... and it doesn’t feel really cold until you’re down around 0F anyway.)
> various feet, inches, fluid ounces and other shenanigans are mind-bogglingly confusing for anyone who is used to metric
This isn’t relevant—no one is asking you lot to change from metric, and it isn’t confusing to our lot. We manage quite easily not to get our minds getting boggled... we’re even able to switch between multiple units, no problem, it’s not as confusing or challenging as you make it sound.
On the other hand, you too are arguing against points I haven't made. I'm not saying the imperial system is bad on it's own. I have no opinion on this. Anyone who is used to it will find it intuitive. However, saying that it's somehow objectively more geared for humans is also incorrect, because as I wrote it is exactly as convenient to use for people used to metric as metric is for people used to imperial.
> the turning point between very warm and hot is literally built into the system at 100F. If you think 30C is hot, you’ve clearly not spent much time here in the summer... and it doesn’t feel really cold until you’re down around 0F anyway
Again, this is subjective. 30C is hot for many people in the Nordics, and business as usual for someone in the tropics. The same will apply whether we use the imperial system or not. But I personally have no intuition how 0F or 100F feels like. It's all subjective (how it feels like).
I was merely arguing that trying to lean on subjective/intuitive feel for the units to make a general case of them being useful for daily life is still just subjective. Imperial is intuitive for people who are used to it and highly unintuitive for anyone who isn't. Conversely, metric is intuitive for people who are used to it - even for daily life and imperial is not.
maybe we can agree that both Celsius and Fahrenheit are subjectively easier to relate to everyday life than Kelvin...
Based on all conversations I've had so far, it seems Americans just think their intuition being tied to Fahrenheit (because that's what they're familiar with) make Fahrenheit intrinsically more intuitive.
I live in the North West of Germany, so based on the local climate this is how temperature works for me:
180°C/200°C (365°F/392°F): oven temperature; this is a good default for most frozen goods, e.g. store bought frozen pizza
Roughly 100°C (212°F): boiling water; this is what comes out of your kettle
Roughly 60°C (140°F): hot water; anything above this will probably scald you
Above 30°C (86°F): warm summer; without wind chill it's probably going to be humid so loose-fitting clothing is a must
Around 25°C (77°F): warm bordering on hot; above this temperature it's probably going to be annoying indoors without ventilation or AC, a few degrees more and I'll find it hard to focus while working
Roughly 20°C (68°F): "room temperature"; legs and hands may get cold after sitting for prolonged times but otherwise it's warm enough to wear a t-shirt outdoors but too cold for shorts
Around 15°C (59°F): a bit chilly; may feel warmer in spring but below this temperature it's probably getting a bit too cold for t-shirts
Below 10°C (50°F): cold; you should wear a jacket and with a bit of wind it can get uncomfortable
Around 0°C (30°F): freezing point; risk of black ice and there might be snow, so you'll need proper footwear
Below -10°C (14°F): very cold; you probably want to invest in proper winter clothing because those jeans might get a bit chilly
Below -20°C (-4°F): extremely cold; it doesn't get this cold normally so you're probably not equipped to handle this, time to bring out that winter gear you bought for your last skiing vacation
Note that this is aligned with the metric scale because that's what I've grown up with and hence what I've tied my intuitions to. If you looked at the Fahrenheit temperatures in isolation they would seem completely arbitrary so it's not surprising the inverse is true (e.g. 80°F is 26.7°C -- and this also settles the "more increments" argument as Celsius temperatures are usually given with a decimal and rounded in casual conversation).
That's a bit unfair. You're coming from Celsius. If someone we're coming from Farenheit, they could round your scale to the nearest tens then complain how Celsius's fractions are so arbitrary for these cutoffs. (Not including your boiling water references since this is about weather.)
E.g. to be pedantic, room temperature is usually given as 19°C (66.2°F) and many prefer 21°C (69.8°F) or even 22°C (71.6°F) and I could have also stated my cut-off for unpleasant warmth as around 27°C (80.6°F). Your intuitive scale likely doesn't perfectly line up with either of the two systems but you project it onto whichever you are used to.
I’m personally comfortable with both. I prefer customary in the USA and metric in Europe. This is no more uncomfortable for me than speaking English in the USA and one of the other languages I know when in Europe. This might be because I’m native bilingual. I think and dream in both languages.
Edit: Interestingly Americans are quite willing to use metric on a syncretic basis in a way somewhat analogous to how polytheistic religions incorporate foreign beliefs. For example Americans are quite comfortable with the liter as a beverage volume. And certain American subcultures actually use the gram as a subunit of the ounce for small masses.
The B scale would be useful for talking about the outdoor air temperature in Bremen. Would the B temperature scale be useful for talking about atmospheric temperature on Mars? Not any more or less so than C... there's no real inherit advantage to either. The choice you make would likely be based on what your primary audience is more familiar with. If you wanted to force your readers to read a unit that would somehow promote scientific literacy you'd probably go with the Kelvin scale since 0 K is not arbitrary (although the unit magnitude still is).
86F/30C is nearly miserable
32F/0C is shorts weather if you'll be moving around at all
And I live in balmy Vancouver. But to be fair, our 30 is never dry, and some locals bundle up when it's 15.
> 32F/0C is shorts weather if you'll be moving around at all
That really depends on the wind, humidity and the amount of sunlight. I don't live that far north or south, but I certainly wouldn't consider freezing shorts weather or 30 °C/86 °F miserably hot.
Shorts and T-Shirt is every-day-of-the-year uniform.
Cairns, Tropical Queensland, Australia.
Mind you, in mid-winter it sometimes gets down to a chilly 12C over-night. (Well, maybe for a few days a year.)
If I lived in a region that uses Fahrenheit, I'd probably have picked values that are nice round numbers in Fahrenheit instead of Celsius.
The switch wasn't effective because there wasn't a concerted effort to to make people switch by the government. They could have easily made it such that weather reports use Celsius in addition to Fahrenheit, speedometers in cars display speed in kilometers per hour by default, etc.
Right now, we have a mix because certain products started using metric on their own (e.g., soft drinks with their 2 liter bottles, car manufacturers using liters to measure engine displacement instead of cubic inches, etc.).
But, genuine question, what could possibly be the advantage to using a base 12 unit for measuring distance?
Edit: I misremembered. It was the Babylonians that used base 60.
> The spacecraft encountered Mars on a trajectory that brought it too close to the planet, and it was either destroyed in the atmosphere or escaped the planet's vicinity and entered an orbit around the sun.[2] An investigation attributed the failure to a measurement mismatch between two software systems: metric units by NASA and non-metric ("English") units by spacecraft builder Lockheed Martin.
https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_...
This isn't true at all, lol. Aerospace in the US has used 'english' measurement from the start. My take on the matter is that all units are arbitrarily defined and flip flopping the units that we already use is a silly idea of progress.
The strength of the metric system is not on the particular dimension of their definition, but lies in the use of a decimal system. That is what makes it superior to the old imperial system and why the scientific community in the US uses it. Using a single base system for all your numbers, and the same base system as the one used in your numbering systems is the only way you can do complex computations without resorting to many magic numbers.
82F ≈ 28C
61F ≈ 16C
40F ≈ 04C
11F ≈ -11C
51F ~ 15C
52F ~ 25C
59F ~ 95C?
Subtract 30, divide by 2 works well enough heh
Yeah, I should have clarified—this works for those specific combinations...it’s mostly a back of the envelope way to orient yourself in the other system.
That's close enough for most purposes, but (F)5/9-32=(C) provides better precision.
81F ≈ 18C? 83F ≈ 38C?
It... Doesn't work?
0 -> 32
5 -> 41
10 -> 50
15 -> 59
20 -> 68
To speed up the process, I can use other starting points I know like 10 °C for 50 °F, 35 °C for 95 °F, -15 °C for 5 °F and, of course, at -40, it doesn't matter ;)
Why NASA doesn't give the conversions in parentheses is beyond me. Surely they know that people around the world use another system, and that even in the USA, many people consulting the website have an interest in science and therefore know about the SI system.
(Or am I wrong on the latter ... are degF, inches, pounds, etc used in science teaching in the USA?)
For a general consumption science article targeting an American audience it makes sense that Fahrenheit is used, because American's are used to it and its convenient for human temperatures. (More precision per degree, 0-100 is a common temperature range, mostly human comfortable).
Of course clearly including Celcius alongside Fahrenheit would make a lot of sense, I agree its strange that both were not included.
What led you to believe this was targeting an American audience? Do you think kids in other countries don’t know about space, or aren’t interested?
It's all about what you're used to, really.
It indeed is just about getting used to it. Precision of Farenheit actually gets in the way, usually we don't really care if it is 41F or 42F. It's the same. Wear a jacket.
I still can't get used to cm for measurement of everyday objects. Inches are just so easy for me.
In terms of weight/volume, I use ml/liters for fluids and g/kg for weight everywhere I can.
It's cold, but survivable.
Using units unfamiliar to the taxpayers supporting the mission seems counterproductive.