His unification of electricity, magnetism and light into one coherent mathematical whole is the inspiration for subsequent attempts - some successful, some still in their rudimentary stages […]
我还以为他要说 some successful, some failed!学到了,以后做得不咋成功的项目就说还在 rudimentary stage我国处于并将长期处于社会主义 rudimentary stage(什么
If we no longer insist on our notions of how Nature ought to behave, but instead stand before Nature with an open and receptive mind, we find that common sense often doesn’t work. Why not? Because our notions, both hereditary and learned, of how Nature works were forged in the millions of years our ancestors were hunters and gatherers. In this case common sense is a faithless guide because no hunter-gatherer’s life ever depended on understanding time-variable electric and magnetic fields. There were no evolutionary penalties for ignorance of Maxwell’s equations.
no evolutionary penalties for ignorance of Maxwell’s equations 好好笑😆
But what are these time-varying electric and magnetic fields permeating all of space? What do E and B mean? We feel so much more comfortable with the idea of things touching and jiggling, pushing and pulling, rather than ‘fields’ magically moving objects at a distance, or mere mathematical abstractions. But, as Feynman pointed out, our sense that at least in everyday life we can rely on solid, sensible physical contact to explain, say, why the butter knife comes to you when you pick it up, is a misconception. What does it mean to have physical contact? What exactly is happening when you pick up a knife, or push a swing, or make a wave in a waterbed by pressing down on it periodically? When we investigate deeply, we find that there is no physical contact. Instead, the electrical charges on your hand are influencing the electrical charges on the knife or swing or waterbed, and vice versa. Despite everyday experience and common sense, even here, there is only the interaction of electric fields. Nothing is touching anything.
https://alive.bar/@zhuxiaobao/108088310725816123
我觉得这个变种没叫 Xi 太可惜了
最近无聊的时候在skylinewebcams.com上看风景解不能出门旅行的馋。推荐几个自己比较心水的:
希腊科孚岛的海滩:清晨和黄昏都很好看,看小人人们玩水游泳很解压
https://www.skylinewebcams.com/en/webcam/ellada/ionian-islands/corfu/nisaki.html
希腊圣托里尼岛:会转动的webcam,既能看到海也能看到白色的房子,还能看到蓝顶教堂的尖。也是清晨和黄昏最美
https://www.skylinewebcams.com/en/webcam/ellada/naigaio/kyklades/santorini.html
西西里岛的海滩:一层层的海浪很好看
https://www.skylinewebcams.com/en/webcam/italia/sicilia/palermo/spiaggia-mondello.html
希腊Meteora的巨岩和修道院们:黄昏时候比较好看
https://www.skylinewebcams.com/en/webcam/ellada/thessalia/trikala/meteora.html
土耳其卡帕多奇亚的山谷:日出时分运气好能看到满天热气球
https://www.skylinewebcams.com/en/webcam/turkey/anatolia-region/nevsehir/cappadocia-uchisar.html
希腊的Lake Kremasta:湖水颜色真好看啊
https://www.skylinewebcams.com/en/webcam/ellada/evrytania/agrafa/agios-georgios-lake-kremasta.html
意大利北边的湖畔小城Alleghe:https://www.skylinewebcams.com/en/webcam/italia/veneto/belluno/lago-alleghe.html
I see cat, I photograph cat, I love cat
https://twitter.com/thomasvlinge/status/1511785936220213250?s=21&t=zSfnCsINn2fIJhxpmIMofQ