Do you know what ultra violet radiation, microwaves, and so forth are?
They do exist you know. Science can prove that any day of the week. And yet, you cannot see ultraviolet or microwave radiation.
On to another science FACT....it is estimated by cosmologists and physicists that there is MORE dark matter (by about 95% MORE) than there is regular matter ( as in radiant matter). Yet, physicists who know it has to exist in order to balance the mass of the universe, have NEVER SEEN, TOUCHED or MEASURED dark matter!
No one has EVER seen, a back hole. It is aways measured indirecty.
Atoms and molecules do not really exist. Any quantum physicist can tell you that one and can prove it.
And so, what is your point about being invisible? Do you think that if something is unseen, it does not exist? No, it is you who doesn't know what you are talking about.