More from Tikalon Blog by Dev Gualtieri
Tikalon Blog is now in archive mode. Here's a directory of links to easily printed and saved articles. If you're willing to wait a while for the download, a zip file of all the blog articles can be found at the link below. Note, however, that these articles are copyrighted and can't be used to train artificial intelligent agents. Individuals are free to republish single articles on their personal websites.
"Form follows function" is a maxim that an object's shape and appearance should be defined only by its purpose or function. A quick perusal of any antique shop will show that this maxim is generally ignored. Humans (Homo sapiens) have been called "naked apes," but we and our close species cousins quickly adopted the concept of wearing the fur skins of animals for protection. Our ancestors were likely much more interested in how they would obtain their next meal than how stylish they appeared in hyena fur. As human culture progressed, people desired to distinguish themselves from others; and, what could be an easier way to do that than through dress. This is accomplished by the simple technique of dyeing drab natural fibers, but the simple sewing needle is a technical innovation that's lead to a means of producing more ornate dress. A recent open access article in Science Advances investigates the use of delicate eyed needles in the Paleolithic as the means for producing refined, ornamented dress. One argument for clothing's becoming a means of decoration is that traditional body decoration, such as body painting with ochre, weren't effective in cold climates, since clothing was needed all the time for survival. Homo sapiens arrived in Europe at around 45,000 BC, and the earliest known eyed needles appeared in Siberia around 40,000 BC, in the Caucasus around 38,000 BC, in West Asia around 30,000 BC, and in Europe around 26,000 BC. Clothing the human body regardless of climate is a social practice that's persisted to this day. The eyed needle combined the processes of hole puncture and threading to allow finer and more efficient sewing.
Deep thought is what distinguishes humans from other animals. The brain is the medium for thought; so, there's the idea that brain size is important, with larger brains allowing more profound thought. Larger brains in hominids appears to have an evolutionary advantage, but the largest animals do not have proportionally larger brains. For the last century, conventional wisdom was that body mass in mammals could be described by a power law. A British research team has created a large dataset of brain and body sizes from about 1,500 species to determine the trend in brain size evolution, finding that the trend is brain size and body mass is not log-linear, but rather log-curvilinear, plateauing at high body mass. The research team found that all groups of mammals demonstrated rapid bursts of evolutionary change, not only towards larger brain size, but smaller as well. Bats very rapidly reduced their brain size, suggesting that flight may have imposed an evolutionary constraint. Homo sapiens has evolved more than twenty times faster than all other mammalian species, resulting in the massive brain size of modern man. Primates, rodents, and carnivores show a tendency for increase in relative brain size as they evolved. It appears that there is something preventing brains from getting too big, perhaps because big brains beyond a certain size are simply too costly to maintain. This upper limit of brain size applies to animals with very different biology.
In today's bigger is better world, you don't order a large coffee, you order a 20 fluid ounce Venti coffee. From 1987 through 2004, McDonald's restaurants had a supersize option for larger than large portions of its French fries and soft drinks. The prefix, super, has been used to describe supercooling, the unexpected cooling without a phase change when liquids can be cooled below their freezing points without solidifying. Water has many unusual properties, and these are most probably the result of water molecule being small, and the force holding these molecules together in a liquid or solid arising from hydrogen bonding. Supercooled water is a hazard to aviation, since supercooled water droplets often existing in cumulus and stratus clouds will instantly freeze on aircraft surfaces and plug the Pitot tubes that indicate airspeed. It's easy to create supercooled water in the laboratory. You just need to purify the water to remove contained minerals. The mineral crystals act as nucleation sites. Bacteria and fungi are efficient natural ice nucleators because of the way their proteins act as ice templates. The best such natural ice nucleators the Pseudomonas syringae bacterium, which is used to make artificial snow. Larger protein molecules are usually better at ice nucleation, but small fungal proteins are good at ice nucleation when they clump into larger aggregates. Scientists at the University of Utah have developed a model for prediction of the nucleation temperature of ice on a given surface. Model parameters include the shapes of surface defects, and appropriately sized and shaped surface bumps and depressions can squeeze water molecules into configurations that make it easier or harder for ice to form.
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