Are there any search engines where you can use non-alpnanumeric characters (like mathematical symbols) in your searches? Google evidently ignores these characters, or treats them as some sort of wildcard characters. For example, searching for “a+b” will give you results containing “a = b”, “a,b,c”, etc.
Can you give a better example of what you’re looking for? If you’re looking for information on “a+b” (where + is not meant to act as a boolean operator in the search algorithm), you should use the name of the operation (addition) in your search.
I’m not trying to do it right now . . . I thought of it because in this thread, someone said:
This reminded me of several times in the past where I’d tried to search for equations online and hadn’t been able to figure out how to do it. For instance, suppose I’d seen a math or physics equation and I wanted to know what it meant? Sure, if I knew the name of the equation I could just enter that, but not all equations have names, and sometimes I wouldn’t know the name. I swear this has come up before, but I can’t remember a specific example.
Anyway, maybe there isn’t any way to do this, but it just seems like someone might have invented a search engine that accepts mathematical symbols. What would be ideal is one where you could enter something like (-[HBar][sup]2[/sup]/2m)[Del][sup]2[/sup] and have it link to pages on the Schrödinger equation, for example.
You could try “negative hbar squared divided by two times m, times del squared” but that’s too long and I have no idea if it would even work.
In an equation like the one above with unique variables (well, I’m calling them variables, because I’ve never used that equation so I’m not sure what each part is), you could search ‘HBar 2m Del’ like I did and get correct results. Search as much information as you can.
Just for the record, h-bar is a physical constant (Planck’s constant, or Planck’s constant over 2 Pi if you want to get picky about it), m is a variable (mass), and Del is the gradient operator (also called “nabla” depending where you’re from), so Del squared is the Laplacian operator. Technically speaking I guess it would be better to call m a parameter, since it’s typically constant for a given problem (as opposed to x, y, and z, or whatever coodinates are being used). At any rate, I think you can get away with calling all of them variables except for Del squared (since it doesn’t have a value independent of what it’s acting on).
Of course, I wouldn’t actually search for the Schrödinger equation, because I know what it is, but it’s good to see that at least for a well-known equation like that it is possible to find it without knowing the name.
If you know the latex-based shorthand that’s used on physics newsgroups, then you could proably type the expression in and turn up a post from a newsgroup, but thew problem is that google tends to ignore symbols.
You might also be interested in http://www.wolframalpha.com/
And so, after 7 long years wandering in the bitly wilderness, the internet heeds tim314’s call to action.
I wonder if **tcf628 **used his new tool to find this thread?
You can try looking for the symbols in one of the following tables. Once you know the name you can search for it that way. But in terms of searching for equations that contain the symbol, Wolfram Alpha is probably the best choice.
HTML symbol codes
Math symbols in HTML and TEX
Table of alt-codes