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Show HN: I created Units Converter that contains 5000 units across 78 categories

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Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#101

Post by mojomark »

HWR_14 wrote: post #98
mojomark wrote: post #47

Earlier quoted context omitted.

I'm not sure I understand the sarcasm (i.e. why TB/ns is an unrealistic A.) ...one gram of DNA can store up to 215 Petabytes or [215,000 Terabytes], knowing that the human being has about 600 grams of DNA [129,000,000 TB]. (1) B.) Now assume a human is traveling at the speed of sound in air on earth (~343m/s): 343 m/s * 129,000,000 TB * 1/1,000,000,000 s/ns, The result is that for every kilometer the human travels at…

Most of the DNA is redundant copies. We need the amount of DNA in a single cell.

Using a human host was just an example to show there are certainly real possible applications whe magnitudes of these units is useful. DNA-based data storage doesn't necessarily mean humane genome data - you can store any data (1) in a DNA strand and the strands in a container could all be unique datasets. Possible, albeit not yet practical - but to discuss the realm of the possible you still need appropriate units, and TB/ns seems to be appropriate for such an application.

Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#102

Post by Symbiote »

lostlogin wrote: post #78
Symbiote wrote: post #25

Earlier quoted context omitted.

15mL. Probably listed in the front of most recipe books sold in Europe, including Britain.

If recipes listed ingredients in weight I’d be a happier person. I bake a lot of bread and weights just work so much better for flour and water.

Try adding site:uk on a recipe search. Although note different countries can have slightly different grades of flour.

https://www.bbcgoodfood.com/recipes/collection/bread-recipes for example.

Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#103

Post by sigstoat »

whartung wrote: post #57

Has anyone found a more elegant treatment of calculating with units than the HP calculators? I'd love to have an HP48 CLI to do unit calcs with. .5 * 10_m/s^2 * (15_s)^2 = 1125_m Admittedly, the HPs interim results are a bit of a mess: sqrt(6.673E-11_N*m^2/kg^2 * 5.98E24_kg / 6780_km) = 242603.08_N^.5*m/(kg^.5*km^.5) But, this converts cleanly to m/s: 7671.8m/s Everything else I've found have been just super fiddly.

gnu units can do that

  You have: .5 * (10 m/s^2) * (15 s)^2
  You want: 
          Definition: 1125 m
  You have: sqrt((6.673E-11 N*m^2/kg^2) * (5.98E24 kg) / (6780 km))
  You want: 
          Definition: 7671.783 m / s

Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#104

Post by SAI_Peregrinus »

saalweachter wrote: post #85
lostlogin wrote: post #69

Earlier quoted context omitted.

Are US teaspoons actually a different size to UK ones, or just the volume measurements?

Teaspoons aren't particularly common in the US. If you do need to stir a beverage or add sugar, you typically use a tablespoon.

Tableware sets in the US commonly come with at least two different sizes of spoon. These usually bear no relation to the "measuring spoons" used to measure volume, though they are handy for stirring tea or eating soup (for the small & large spoons, respectively).

For people who cook in the US, a set of "measuring spoons" is a very common kitchen tool.

"Teaspoon" and "Tablespoon" are units of measurement of volume, not bits of silverware. "Tea spoon" and "Table spoon" or "Soup spoon" are pieces of silverware, not units of measure!

Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#105

Post by dark-star »

I randomly picked "Inductance" as category, and the "units" it provides are basically a dozen or so variants of the "Henry": Attohenry, Gigahenry, Centihenry, Exahenry, Kilohenry, Nanohenry, ....

If this is how you get to "5000 units" then that feels a bit cheaty

Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#106

Post by fsh »

ars wrote: post #91
fsh wrote: post #55

Earlier quoted context omitted.

I don't find this rambling insightful at all. Here is what the BIPM actually says about the topic: The SI unit of frequency is hertz, the SI unit of angular velocity and angular frequency is radian per second, and the SI unit of activity is becquerel, implying counts per second. Although it is formally correct to write all three of these units as the reciprocal second, the use of the different names emphasizes the di…

The Hubble Constant is also in HZ. And its reciprocal looks like the age of the universe (apparently this is just a coincidence).

No, the Hubble constant has the unit 1/s. According to SI "the hertz shall only be used for periodic phenomena".

Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#107

Post by fsh »

heisenzombie wrote: post #89
fsh wrote: post #55

Earlier quoted context omitted.

I don't find this rambling insightful at all. Here is what the BIPM actually says about the topic: The SI unit of frequency is hertz, the SI unit of angular velocity and angular frequency is radian per second, and the SI unit of activity is becquerel, implying counts per second. Although it is formally correct to write all three of these units as the reciprocal second, the use of the different names emphasizes the di…

Right, you can explain it but that doesn’t make it elegant. This is the equivalent of a function with a comment in it saying “Here be dragons!”. One very desirable property of a units system is that incompatible quantities have incompatible units. So if I try to add 1 Joule (== 1 kg⋅m^2⋅s^−2) to 1 meter, I’m obviously doing something wrong and I just can’t continue. But in SI I can take 1 Hertz (==1 s^-1) and add it…

There is absolutely no guarantee that the sum of two quantities with compatible units makes any physical sense.

The issue here is that angles are inherently unitless geometrical quantities. "Radian" is merely a reminder that a number represents an angle. There is no way to make it a consistent physical unit.

Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#108

Post by beojan »

bragr wrote: post #75
lostlogin wrote: post #69

Earlier quoted context omitted.

Are US teaspoons actually a different size to UK ones, or just the volume measurements?

1 US teaspoon is about 14.8 ml 1 UK teaspoon is about 17.8 ml. It goes on: 1 US gallon is about 0.83 imperial gallons

A teaspoon is 5 ml. I think you're thinking of tablespoons.

Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#109

Post by SAI_Peregrinus »

whartung wrote: post #57

Has anyone found a more elegant treatment of calculating with units than the HP calculators? I'd love to have an HP48 CLI to do unit calcs with. .5 * 10_m/s^2 * (15_s)^2 = 1125_m Admittedly, the HPs interim results are a bit of a mess: sqrt(6.673E-11_N*m^2/kg^2 * 5.98E24_kg / 6780_km) = 242603.08_N^.5*m/(kg^.5*km^.5) But, this converts cleanly to m/s: 7671.8m/s Everything else I've found have been just super fiddly.

TI's graphing calculators work essentially the same way. As does GNU Units.

Re: Show HN: I created Units Converter that contains 5000 units across 78 categories

#110

Post by cycomanic »

alok99 wrote: post #48
j2kun wrote: post #33

Earlier quoted context omitted.

The units list is hilarious and amazingly detailed, a sample: crocodile := megavolt // used informally in UK physics labs ... footcandle := lumen/ft^2 // Illuminance from a 1 candela source // at a distance of one foot ... // In Britain, the deal is apparently any piece of wood over 6 feet long, over // 7 wide and 2.5 inches thick. The OED doesn't give a standard size. A piece // of wood less than 7 inches wide is ca…

The editorial on Hz is particularly funny and insightful. // Beware the SI's broken definition // of Hz. You should treat the radian as being correct, as a fundamental // dimensionless property of the universe that falls out of pure math like // the Taylor series for sin[x], and you should treat the Hz as being a // fundamental property of incompetence by committee. ... // You are perfectly right. You are perfectly w…

If complaining about Hz one should really be consistent and not use tau not radian as the fundamental property of the universe. Like that we could get rid of all those bloddy factor 2s
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