July 13, 2023: Different types of infinity, spinning apes and the forgotten history of the world's first female anatomist. Enjoy! —Andrea Gawrylewski, Chief Newsletter Editor | | | The quick answer to the question "What is the largest number?" might be "infinity." But as with many things in mathematics, things are not that simple. You can always add 1 to infinity. AND there are different types of numbers (whole numbers, even numbers, integers), each with their own versions of infinity. "Real" numbers, for example, can be expanded infinitely by decimal values, and yet mathematicians cannot prove how many real numbers themselves truly exist.
How it works: This all means that there are different kinds of infinities. You can reason it this way: if you count 1, 2, 3, 4 and so on, you certainly could go on infinitely. But the number set 1.1, 1.2, 1.3, 1.4 would have a higher total number count than the first set, so by comparison would have a larger infinity (send help).
Why this is cool: It took humanity millennia to figure out that normal rules of counting cannot be applied to infinity–and that it isn't, well, finite. The concept of infinity is unsettling by itself (at least for non-mathematicians like me) but the idea that different numbers have different sizes of infinity is diabolical. | | | One of the favorite types of play of wild chimpanzees and gorillas is spinning, usually by twirling around while holding onto a rope or vine. Gorillas in particular will spin themselves until they drop and fall over from dizziness. Examining video clips of 400 apes spinning, primatologists measured that the apes spun at 1.43 revolutions per second on average, and the fastest speed they reached was 3.3 turns per second.
Why this is cool: These spinning speeds could induce physiological "highs" in humans. So it's worth wondering if the apes spin for the same reason we do: to feel a little topsy-turvy for the fun of it.
What the experts say: "I can imagine this being sort of elaborated over millennia and over the course of human evolution," says Marcus Perlman, a linguist and researcher of communicative gesturing at the University of Birmingham in England. "That basic drive to seek altered perception and altered mental states could be common to our primate cousins." | | | Credit: Wirestock, Inc./Alamy Stock Photo | | | • People with dementia often experience paranoia and delusions as the disease progresses. Learning a new way to listen and interact with people with dementia helps the family cope with the disease, writes Steve Silberman, a journalist and author of a new book on neurodivergence. | 6 min read | | | I try to include discoveries from many branches of science in this newsletter. But tell me what you like or would like to see more of! Email me directly at newsletters@sciam.com. See you tomorrow! | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
One New York Plaza, New York, NY, 10004 | | | | | | Support our mission, subscribe to Scientific American | | | | | | | | | |
