How a silent cosmos got us thinking about the future.
Your senses give you the only evidence you have that anything around you exists, but that evidence is pretty flimsy, if you ask me. Your senses lie to you all the time; that’s just science. In fact, the more you learn about how your sense organs work, the more amazing it is that we’re able to function at all. Look at how …
Your Eyes See Barely Anything At Any One Time
Your eyes feel about as big as they need to be, letting you see mountains, oceans, or your entire mom all at once. Except you’re not really seeing much of any of those. The light-sensitive cells in your eyes are mostly concentrated in a section called the fovea, and as we’ve mentioned before, the fovea is super tiny. Imagine a one-degree-wide cone opening outward from your eye. Everything you see in detail fits in that narrow cone. As proof, keep your eyes totally still and try reading this entire page. You can’t. Everything beyond “You can’t” is just a blur.
It’s just as well that most of your light-sensitive cells (called “cones,” not to be confused with the imaginary vision cone from the last paragraph) are all dedicated to the exact thing you’re concentrating on, because you don’t have many to spare. You have about 6 million cones total, and since each is sensitive to just one primary color, that’s the equivalent of about 2 million pixels, or the same as a 1080p image.
A 4K image, by comparison, has 8 million pixels. “Wait,” you ask, “then how can I even see 4K?” Answer: You can’t. A 4K movie looks good because the tiny section of it you’re focusing on at any moment looks awesome, and you don’t see the rest in detail. If every bit of the image other than those few centimeters were at a much lower resolution, you wouldn’t even notice.
That is a black-and-white photo with some colored lines laid on top, but you perceive colored clothes, colored seats, etc. If you look closely at any one small part, you will correctly note the gray image and the colored lines, but everything outside your fovea’s range is a blur, so your brain mashes it all together. The tiny size of the fovea is also responsible for a lot of classic optical illusions. There’s some debate among eye scientists about precisely why it is that you see imaginary gray circles in the intersections of this grid:
They are laughing about a recent cartoon in the New Yorker offering an unlikely explanation for a slew of missing public trash cans across New York City. The cartoon had depicted “little green men” (complete with antenna and guileless smiles) having stolen the bins, assiduously unloading them from their flying saucer.
By the time the party of nuclear scientists sits down to lunch, within the mess hall of a grand log cabin, one of their number turns the conversation to matters more serious. “Where, then, is everybody?” he asks. They all know that he is talking—sincerely—about extraterrestrials.
The question, which was posed by Enrico Fermi and is now known as Fermi’s Paradox, has chilling implications.
But you sure don’t see any in the specific intersection you’re focusing on. You can read designer Yurii Perepadia’s explanation for what’s going on with all this brain-teasing mind sorcery, but the relevant part for us right now is that you perceive whichever part you’re focusing on correctly. Everything else is outside your fovea, and is thus total guesswork.
Related: 5 Optical Illusions That Prove You Can’t Trust Your Own Mind
Your Taste Buds Sense Almost Nothing
Taste buds are pretty good at detecting whether something you put in your mouth is poison or not, but that’s about it. When it comes to distinguishing flavors, smell plays a big part, as you probably know. But it’s shocking just how bad your tongue is at its job. Chop up some cubes of apples and onions, pinch your nose totally shut, close your eyes, and pop some into your mouth. You won’t be able to tell the two apart. Please try it. It’ll be super funny … um, I mean, scientific.
Many factors affect how you conclude something tastes, beyond the wimpy perceptions of your taste buds. We’ve told you about some already, and others are being discovered by food scientists all the time. Change the color of a dish, and mousse will taste sweeter. Turn on some low-pitched music, and toffee will taste more bitter. If you hear chips loudly breaking, you’ll think the ones you’re eating taste and feel fresher, even if they’re exactly the same as before. And I bet researchers are working hard at proving that sometimes sandwiches just taste better when you eat ’em on the toilet.
Bin-stealing UFOs notwithstanding, humanity still hasn’t found any evidence of intelligent activity among the stars. Not a single feat of “astro-engineering,” no visible superstructures, not one space-faring empire, not even a radio transmission. It has been argued that the eerie silence from the sky above may well tell us something ominous about the future course of our own civilization.
Such fears are ramping up. Last year, the astrophysicist Adam Frank implored an audience at Google that we see climate change—and the newly baptized geological age of the Anthropocene—against this cosmological backdrop. The Anthropocene refers to the effects of humanity’s energy-intensive activities upon Earth. Could it be that we do not see evidence of space-faring galactic civilizations because, due to resource exhaustion and subsequent climate collapse, none of them ever get that far? If so, why should we be any different?
A few months after Frank’s talk, in October 2018, the Intergovernmental Panel on Climate Change’s update on global warming caused a stir. It predicted a somber future if we do not decarbonize. And in May, amid Extinction Rebellion’s protests, a new climate report upped the ante, warning: “Human life on earth may be on the way to extinction.”