This sentence is attributed to the brilliant philosopher of language Ludwig Wittgenstein (1889 - 1951).
I had seen this before and commented on the un-measurable and un-testable theory of a Multiverse (many parallel universes, of which ours is the lucky one with physical parameters finely-tuned enough to allow it to host thinking life).
I encountered the Wittgenstein quote again in a fascinating (and very nearly complete) summary of current cosmological knowledge assembled by UCLA Astronomer Ned Wright (which I highly recommend - it's short, readable, and largely non-technical).
The point that Wright was making was that if you can't ever test a theory to see if it's even true (like the Multiverse), then wisdom would suggest you don't talk about it.
Makes sense: don't talk about something you know nothing about.
I could suggest that to a number of outspoken opinionaivers who think they "know Mormonism" (sic).
Back to Wright's FAQ: it's refreshing to see this level of humility and honesty in a scientist (yes, despite what science is supposed to seek, the level of honesty among scientists is about the same as found in the general population).
However, it is just basic human nature - perhaps it's a distinguishing characteristic of human nature - to want to know more.
And actually, there IS a way to know more, much more. Dallin H. Oaks, in an article titled "Knowledge encourages obedience, and obedience enhances knowledge." points out (a bit indirectly) that scientific testing and analysis will only work in a fairly narrow sphere of Knowledge (capital K). He reminds us that there are other pathways to gain information over a wide range of things important to me - important to you. (Mor 10:5 and D&C 8:1-2 come to mind). The secular (narrowly-focused) world would call this sort of approach "inspiration" - such as the famous "Eureka moment" of the philosopher-scientist Archimedes. People who have lots of these inspirations (or a few that shift paradigms significantly) are sometimes called geniuses. It does NOT mean that they are smarter than their peers - I am myself proof of that lack of correlation (I just have an unfair advantage over my secular peers). In the official story, Watson and Crick earned the Nobel Prize when they came up with the structure of DNA in 1953. Truth is, they had a lot of unacknowledged help from Rosalind Franklin. Without making a moral judgement here - the full story is probably not known to anyone living - I will just say that there are many avenues to knowledge, some more acknowledged than others (pun intended).
I have garnered an immense amount of knowledge in my life, both in my search for things of personal interest, and in my professional scientific career. The "secret" has helped me avoid years mining scientific dead ends, and has guided me past numerous research blocks. An example: I was able to finally get a marine induced polarization system operational - and earn two patents for it - by developing optical isolation and a floating ground, among other things.
The "secret"? Live your life in such a way as to open the door to these understandings coming to you. Even purely secular scientists understand most of these principles. This means being obedient to a number of "rules": (a) live a life of honesty and service to others, and (b) conduct your physical life wisely, availing yourself of existing scientific knowledge. A cynic would say that (a) is why others will often offer to help you with figuring out certain things, making certain types of necessary measurements, etc., while (b) is now established as fundamental requirements for the full functioning of the human brain. Incidentally, this particular knowledge-set was available to Latter-Day Saints in 1835, about 130 years before the Surgeon General's famous 1964 report.
There are other, even more direct sources of understanding and knowledge.
The take-home here: you can get an answer to whatever is important to you - if you are patient enough, if you are obedient enough - and if you are humble enough. For starters, do not ever consider the science you now understand as the final answer. The history of science itself will immediately paint you the fool.