Our Machines Now Have Knowledge We’ll Never Understand
By David Weinberger
Apr 18 2017
The new availability of huge amounts of data, along with the statistical tools to crunch these numbers, offers a whole new way of understanding the world. Correlation supersedes causation, and science can advance even without coherent models, unified theories, or really any mechanistic explanation at all.
So wrote Wired’s Chris Anderson in 2008. It kicked up a little storm at the time, as Anderson, the magazine’s editor, undoubtedly intended. For example, an article in a journal of molecular biology asked, “…if we stop looking for models and hypotheses, are we still really doing science?” The answer clearly was supposed to be: “No.”
But today — not even a decade since Anderson’s article — the controversy sounds quaint. Advances in computer software, enabled by our newly capacious, networked hardware, are enabling computers not only to start without models — rule sets that express how the elements of a system affect one another — but to generate their own, albeit ones that may not look much like what humans would create. It’s even becoming a standard method, as any self-respecting tech company has now adopted a “machine-learning first” ethic.
We are increasingly relying on machines that derive conclusions from models that they themselves have created, models that are often beyond human comprehension, models that “think” about the world differently than we do.
But this comes with a price. This infusion of alien intelligence is bringing into question the assumptions embedded in our long Western tradition. We thought knowledge was about finding the order hidden in the chaos. We thought it was about simplifying the world. It looks like we were wrong. Knowing the world may require giving up on understanding it.
Models Beyond Understanding
In a series on machine learning, Adam Geitgey explains the basics, from which this new way of “thinking” is emerging:
[T]here are generic algorithms that can tell you something interesting about a set of data without you having to write any custom code specific to the problem. Instead of writing code, you feed data to the generic algorithm and it builds its own logic based on the data.”
For example, you give a machine learning system thousands of scans of sloppy, handwritten 8s and it will learn to identify an 8s in a new scan. It does so, not by deriving a recognizable rule, such as “An 8 is two circles stacked vertically,” but by looking for complex patterns of darker and lighter pixels, expressed as matrices of numbers — a task that would stymie humans. In a recent agricultural example, the same technique of numerical patterns taught a computer how to sort cucumbers.
Then you can take machine learning further by creating an artificial neural networkthat models in software how the human brain processes signals. Nodes in an irregular mesh turn on or off depending on the data coming to them from the nodes connected to them; those connections have different weights, so some are more likely to flip their neighbors than others. Although artificial neural networks date back to the 1950s, they are truly coming into their own only now because of advances in computing power, storage, and mathematics. The results from this increasingly sophisticated branch of computer science can be deep learning that produces outcomes based on so many different variables under so many different conditions being transformed by so many layers of neural networks that humans simply cannot comprehend the model the computer has built for itself.
Yet it works. It’s how Google’s AlphaGo program came to defeat the third-highest ranked Go player in the world. Programming a machine to play Go is more than a little daunting than sorting cukes, given that the game has 10^350 possible moves; there are 10^123 possible moves in chess, and 10^80 atoms in the universe. Google’s hardware wasn’t even as ridiculously overpowered as it might have been: It had only 48 processors, plus eight graphics processors that happen to be well-suited for the required calculations.