The Planck interplanetary satellite recently provided data leading to glorious images of microwave radiation in our cosmos, providing information about the fundamental nature and origins of our universe. Here's one of those, that we grabbed from the Wikipedia article on the report:
The non-uniformity provides esthetic beauty and to physicists and cosmologists, information about what happened just after the time of conception (the Big Bang), and subsequently, in our universe. One apparent aspect of the findings was that so-called dark matter makes up an even greater proportion of all the stuff the universe is made of than had been thought. According to the Wikipedia page reporting the 2013 results the universe is "contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy."
Dark matter is rather dark to us, and beyond what we personally know much about. But we understand that it isn't directly detectable by the scales and meters that we use to detect the regular stuff, the atoms and energy that we know about. It supposedly neither emits nor absorbs electromagnetic energy nor has gravity of its own, but does affect ordinary mass -- but a minority, the 10% we know about!
Astrophysicists knew it was likely to be there because, unless there was some other mistake in physics theory, such as an incorrect basic physical parameter value, darkness affected the things we can see, even if we can't see the dark matter itself. For example, the effects of gravity upon the behavior of energy (like light) and matter, that we can see, don't predict what would be errors or distortions--the differences seem to physicists to be able to be accountable if we posit a different kind of matter and energy, which since we can't directly see it is called 'dark'.
About a year ago we heard a cosmologist talking about this on the BBC (can't now remember the show or interviewee) who pointed out, rather melodramatically, that we're infused with fluxes of Darkness all the time. But, not to worry, she said--it doesn't affect us. But how would she know?
Could darkness shed light on life?
Now, we see (and remark--complain?--about) countless genetic studies, like GWAS mapping attempts, finding that genome regions, only identifiable by huge studies with various problematic aspects, finding weak statistical support for tiny effects. Even these typically only account for a usually small fraction of the overall genetic effect as estimated by the correlation of the trait among relatives. Could there be a 'dark' explanation for such findings?
We think the BBC interviewee's point was that dark matter and energy may make up the vast bulk of the stuff of the universe, but its effects are very, very small--far too small to affect the 'light' matter we're (aware that we're) made of. Of course, we're not physicists nor cosmologists, so we cannot make knowledgeable comments about that value judgment. But we can ask how it can be known, if it isn't even 100% sure that there is dark matter and energy, that if it exists it can't affect us?
One might imagine that it provides an unseen 'molasses' that affects the cellular processes, the speed or nature of interactions of molecules, and so on. Or perhaps it can somehow mimic our DNA as a form of modeling of its shape, some sort of 'dark DNA' that affects cells and their behavior and is variable in some way (like, on a micromicro scale, the lumpiness of things in space in the microwave image above) and is inherited. It could affect our traits, be inherited (and hence generate correlation among relatives, but if it is not directly shackled to DNA it would not show up in mapping studies or, the weak evidence for genetic contributions may implicate specific DNA locations strictly as an artifact of the statistical methods used that assume location in DNA is everything that matters.
This is, of course, fanciful and we have absolutely no reason to assert such things with any confidence at all. But the deeper point is that such unknown stuff or forces or factors could exist and could be confounding us, given that we believe that we know of all the possible factors that may contribute to our traits, their inheritance, or their evolution.
Some such transforming discovery could immediately allow many unknowns to fall into place, as the major 'revolutions' in science have done in the past. Whether we are currently in the mode of trying to force our explanations to fit a crippled model of reality, or are correctly assuming that bigger conventional studies will eventually bring the entire truth to light, or are putting ourselves willfully in the dark by believing so rather than that the complexity of very weak but ordinary factors is the reality, are things that we cannot know.
One can play this mind game: Of course we can't know what we don't know, but could we learn about it by questioning our very basic assumptions, asking: suppose it isn't so? Suppose there is some other explanation for this or that fact or observed pattern: what might that be? If we were serious about asking that question about the frayed edge of what we know that stubbornly refuses to be hemmed into the fabric of our current theory, perhaps some deep insight could result.
But the discovery of very subtle but important aspects of the physical universe should be a sobering tempering for our confidence that we already know what's what when it comes to the living universe.