It seems, from what I understand, that by combing fundamental constants we can arrive at some measurements that may have some deep physocal significance. For example, the Planck length:
(courtesy wiki media)
may be the smallest possible physical length which has any meaning, according to some models. Similarly, Planck time (about 5.4 x 10^-44 s), discusses in another thread, has a similar significance.
Then there is the Planck mass, about 2.2 x 10^-8 kg ... wait what? 22 micrograms? That's huge! You can see 22 µg of stuff without a microscope! Does the Planck mass have any metaphysical significance like its siblings do, or is it just a trick of dimensional analysis?