Hm, I don't think so, Efee. I will show you why ok?
certus, a, um - certain, fixed, sure
aliquis,qua,quid -some, someone/something, anyone/anything...
some people/things, I'd translate
1. "certi homines/certae res", when we talk about definite/particular people/things, who we know..
or:
2. "aliqui homines/ aliquae res" - when we talk about indefinite people/things, who we don't know...
I think that in this case we say about definite/particular things...We know what things will stay the same... But, of course, you can understand it in different way too: that we don't know... Hm.. I guess it is a matter of interpretation.