There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors
Archimedes wrote:Give me a large enough table and I will build the world's biggest computer!
There are three kinds of actuaries: those who can count, and those who can't.
Piet Souris wrote:Brilliant!
But for me, the most brilliant is: when a heavily loaded truck passes by, you end up with mere ones, no matter what input.
No more Blub for me, thank you, Vicar.
Mike Simmons wrote:...
There are no new combinations possible. Every single gate combining two of those lines results in a value already listed in one of those lines. So there is no point to adding any more gates; every possible circuit is equivalent to one of those already listed. There's no way to do a NOT, or an OR. Or a TRUE, or a NAND, or an XOR. We simply can't construct about half of the possible operations we might need. No way, without access to some other gate type.
Fun question though - thanks!
Jayesh A Lalwani wrote:
What the OP has implemented above is a NAND gate, even though he calls it AND. You can just reverse the meaning of the dominoes and it becomes a NAND gate.
Ryan McGuire wrote:In fact I would go as far as to say you can't create a NAND, a NOR gate or a NOT gate out of dominoes, regardless of the mapping of truth values you assign to the falling versus standing lines of dominoes. Why? because domino logic gates are "passive" elements. i.e. The best they can do is stop energy (a falling line of dominoes) from passing through under certain conditions. They can't spontaneously start a falling line of dominoes if none of the input lines are falling.
Mike Simmons wrote:
Ryan McGuire wrote:In fact I would go as far as to say you can't create a NAND, a NOR gate or a NOT gate out of dominoes, regardless of the mapping of truth values you assign to the falling versus standing lines of dominoes. Why? because domino logic gates are "passive" elements. i.e. The best they can do is stop energy (a falling line of dominoes) from passing through under certain conditions. They can't spontaneously start a falling line of dominoes if none of the input lines are falling.
Ah yes, excellent way of looking at it. I agree. This also suggests an out - if we require a single line of dominos to be tipped, as a "do it" command to execute an operation, then we can achieve anything else we want to. (Well, with sufficient time, care, patience, and dominos.) This would provide us with a known "true" value (notably absent on my previous list) which would also allow NOT (since T AND NOT A == NOT A) and thus enable NAND and all other binary gates we might desire. It's roughly analogous to requiring the user to press "enter" at the end of a command.
Don't get me started about those stupid light bulbs. |