Level 5: Independent Learners (Age 16–18, Grades 11–12)
Which generates more energy, your body or a 60-watt light bulb? You may be surprised to learn that the answer is your body. While sleeping or resting, a human body generates about one hundred watts of power just to stay alive. During exercise, that amount can jump as high as three hundred to four hundred watts. If you do nothing for an entire day, your body will churn through about 2.3 kWh of energy. (An average US home uses 30 kWh per day).
What do a DVD player, supermarket scanner, printer, fiber optic internet connection, and industrial metal cutter have in common? They
激光的特性、原理和用途 Continue reading »
Emily Hanley rubs her face, then takes a breath. “I recently lost my job to AI,” she says, in a video she shared on TikTok. She was a copywriter, or someone who writes the text for brands’ webpages, online articles, email campaigns, and other marketing materials. New generative AI tools such as OpenAI’s ChatGPT, Google’s Bard, or Baidu’s Ernie excel at generating text for all sorts of purposes, including this one. Generative AI can also write code. And it’s far cheaper than hiring a person to do the same thing. In an article for Business Insider about the ordeal, Hanley wrote, “While I and countless other out-of-work copywriters are the first wave of AI collateral, the collapse of my profession is probably just the tip of the AI iceberg. ”
人工智能会抢走所有工作吗 Continue reading »
Inside a living cell, something remarkable is happening. A very tiny machine cuts the cell’s DNA. Next, the cell repairs the broken DNA, but the segment where the cut happened no longer works the same way. The tiny machine has edited the DNA—the code of life.
基因编辑技术—合成生物学的基本工具 Continue reading »
You wake up and open your eyes, your head is pounding. Maybe a little breakfast will help. You try a few bites of an egg on toast, but your head hurts too much to eat. Maybe you’re getting sick? With a groan, you walk to the medicine cabinet. You find a bottle of Tylenol. (The technical name of this medicine is acetaminophen). You pop a pill in your mouth, take a gulp of water and swallow. Then you lie down and wait. As the medicine starts to work, your headache will go away.
药物之旅：药理学的奥秘 Continue reading »
The surface of our planet is populated by living things. Despite their apparent diversity, living things are fundamentally similar inside. Cells are the fundamental units of life. As emphasized by the cell biologist Edmund Beecher Wilson, “The key to every biological problem must finally be sought in the cell; for every living organism is, or at some time has been, a cell.”
You toss some bananas and milk into a blender. Then you plug it into the wall and press start. Soon, you have a delicious smoothie. While you’re sipping and scrolling through TikTok, you notice your phone’s battery is low. So you plug that into the wall and the battery charges.
The next big thing in nuclear energy is small. Designs for dozens of small modular reactors have been developed or are in progress . And a few small reactors are already operating in India, Pakistan, Russia, and elsewhere. A small modular reactor can produce up to 300 megawatts (MW) of electricity (many designs produce much less). But size isn’t the only thing that makes these new, advanced reactor designs stand out.
Everyone can see that, from birth through adolescence, humans get taller and their bones get longer. And then all th at stops around the end of the teen years. In the past, the mechanism of growth was a mystery. In the fourth century, there was a common belief that children’s natural character was hot and liquid, partly because of the blood that went into their creation. Thus, a physician to the Roman emperor believed that children grew because of their excessive heat. Twelve hundred years later, it was understood that food provided the material that allowed growth. A French physician, however, pointed out that even when sick children didn’t eat, they continued to grow.
