Add scientific constants
Currently excel has Euler's number and pi, but it'd be great if it had functions with precise values for other commonly used constants like speed of light, electron charge, Plancks constant, Boltzmann constant, Avogadro's number etc.
Thanks for the suggestion Rolands! I’d be curious to see, in comments, what other constants people are interested in. I’ll check back on this later, and of course the more votes it has the more likely it is to get into the product – so please keep the votes coming if you like the idea!
Best,
John [MS XL]
5 comments

Brad Yundt commented
Even though I ought to be a big user of it, I never use the CONVERT function because I can never remember which types of conversions are possible and how to specify the to units and from units.
Making a function for scientific/mathematical constants will need to overcome this problem because the function won't get used if you need to look up the syntax each time you try to use it. One way is to restrict the number of possible units for each constant. If the only choices were SI, MKS, customary metric, customary English or dimensionless, users might actually be able to remember them.
I also suggest making a single function with two parameters where the user has to specify the type of constant sought by name as well as the desired units.
To make it even more user friendly, let us choose both parameters using dropdowns in the formula wizard. Everybody from high school students through PhD researchers would find the scientific constant function discoverable if you did that.

Andre Terra commented
If we're adding PI, please make sure to add TAU https://tauday.com/taumanifesto

A.C. WILSON commented
Another one  unitless, but not mathematical in a conventional sense:
Some programming languages such as COBOL, [but not Excel,] have other special functions to indicate implementationspecific constants. A common one is "HIGHVALUE()", which indicates a "pseudoinfinity"  the highest value that can possible be stored within a numeric field [variable]; this is immensely preferable to arbitrarily hoping, and specifying in a formula, that one cannot possibly exceed "99", "99,999", or similar. "LOWVALUE()" is another.See also the "NULL Worksheet Function" suggestion:
https://excel.uservoice.com/forums/304921excelforwindowsdesktopapplication/suggestions/17265644nullworksheetfunction 
Kenneth Barber commented
I believe that for unitless constants, shouldn't need the (). For example, we should only have to type PI, not PI(). For constants with units, we should be able to specify the unit as a parameter. Of course, there are many ways to express the same unit, so that'll be a fun one...

Kenneth Barber commented
I think that we should stay away from constants with units for now until the Excel team figures out a way to integrate units into numbers:
https://excel.uservoice.com/forums/304921excelforwindowsdesktopapplication/suggestions/9607794integrateunitsintocellsfordisplayandmathemaAnother unitless value to add might be the golden ratio.