01. What is The Deep?
Deep Time is how scientists describe and conceptualize the full breadth of geological time, eg the time scale on which the planet Earth has arisen, developed, and changed, and become host to a diverse range of fascinating life forms. Human history is constrained to a tiny slice of this massive span, and an individual's life span in turn is an even tinier sliver. We, as biological organisms, lack any intuitive sense of these scales, and only through study, and example, is our ability to conceive, to conceptualize these vast arrays of time able to form into something cogent.
Weber and Fechner's laws relate to the ability of humans to perceive differences in numerosity. At a small scale, we can distinguish and track several distinct individual objects at once, and this dwindles rapidly once you reach about five discrete elements. So if you toss five balls in the air, your brain can track each of them and keep that count effectively, but if you throw ten, you may be able to count them, and you may be able to track them, but they quickly become an ensemble of objects, a group, rather than individuals. At this point a second cognitive system comes into play, the approximate number system (ANS). This is what allows for you to at a glance distinguish a jar that has ten jellybeans in it as having less than one with fifteen, or the larger of two crowds of people even if they only have a few more members of their group. The ANS improves as we age, and so by adults we can distinguish group size at a ratio as fine as 25:29, while young children will only be able to functionally distinguish approximate numbers at a 1:2 ratio. The core of the Weber-Fechner laws is that it is this ratio that is important, not the absolute number, once you start using your ANS.
How this becomes especially important in the discussion of deep time, as well as most large-scale concepts, is that once the numbers become large enough, your ANS also begins to fail, and suddenly increasingly large ratios become indistinguishable, in part because they're rarely things we physically see, and rather become concepts we have to abstractly compare. A great example of this is comparing one million to one billion.
Let's take a look at those numbers written down next to each other:
1000000 and 1000000000
Your ANS will probably allow you to recognize on a glance that the second number has more zeroes, but you'll find that the exact ratio isn't something you can see in a glance. If we add commas (and in many other languages and cultures other symbols, usually periods, fulfill this same function):
1,000,000 and 1,000,000,000
Our discrete number abilities and our ANS work together to allow us to see that there is one more set of three zeroes in one billion than in one million. But this still just allows us to see that one number is larger than another. Conceptually, it still doesn't mean that much. Finally, if we simply place them over each other:
We can at a glance recognize that one billion is one thousand times one million.
But still, there is no conceptual familiarity with what that means, and our ANS may recognize they are different, but the size of that difference is meaningless because we very rarely have to deal with discrete physical counts of such a drastic ratio. To fully illustrate this, let us examine these numbers to describe time, namely, seconds:
1 million seconds is 11.574 days.
So a little short of two weeks.
1 billion seconds is 31.7 YEARS.
On a glance, a million and a billion are just both big big big numbers. But when presented in this way, you suddenly can grasp the vast difference in the amount of time involved. So when we look at the history of the Earth, which is approximately 4.5 Billion years, a span of tens, or even hundreds of millions of years is just a tiny slice. So just as our lifespans are small in relation to the scope of human history, with an approximate scaling of 3:20,000 (if we use the first use of clothing by Neanderthals ~500,000 years ago as our arbitrary time mark), the time scales in which the narratives produced by the process of evolution (those that The Deep is all about) are equally tiny in the grand scale of the geological annals of our planet.
So while we as humans have existed in a period of time incomprehensibly larger than our own lifespans, this period in turn is dwarfed endlessly by the lives of all the organisms that have come before, and so in Deep Time, in time's chasm, we find that almost every truly important biological event has occurred long before anything resembling a living animal roamed the oceans, and that as we plunge into the deeps, we continue to find newer and darker depths, with stranger and more fabulous stories to be told within.