zlacker

>>tromp+(OP)
IEEE754 64-bit representation already has infinity:

    uint64_t x = 0x7ff0000000000000ULL;
    printf("%f\n", *(double *)&x);

output:

    inf

But you could use a representation where 0 is 0, and 1 is infinity, saving 63 bits...

>>matja+5c6
Fair, but also an uninteresting answer.

>>toxik+bh6
It's about as interesting as the other answers proposed in TFA, and it gets to the meat of it: they are all just representations invented by people, and there's nothing stopping us from inventing our own representations that fit into 64 bits (or 1 bit).