HTTPSConnectionPool(host='translate.google.com', port=443): Max retries exceeded with url: /m?sl=en&tl=zh-cn&hl=zh-cn&q=All%20right,%20now%20we're%20going%20to%20talk%20about%20the%20idea%20of%20an%20electric%20current,%20and%20the%20story%20about%20current%20starts%20with%20the%20idea%20of%20charge,%20so%20we've%20learned%20that%20we%20have%20two%20kinds%20of%20charges,%20positive%20and%20negative%20charge,%20we'll%20just%20make%20up%20two%20little%20charges%20like%20that,%20and%20we%20know%20if%20they're%20the%20opposite,%20opposite%20sign,%20that%20there%20will%20be%20a%20force%20of%20attraction%20between%20them,%20and%20if%20they%20have%20two%20like%20signs,%20here's%20two%20charges%20that%20are%20both%20positive,%0Aand%20these%20charges%20are%20going%20to%20repel%20each%20other,%20so%20this%20is%20the%20basic%20electrostatics%20idea,%20and%20the%20same%20thing%20for%20two%20minus%20charges,%20they%20also%20repel,%20so%20like%20charges%20repel,%20and%20unlike%20charges%20attract,%20that's%20one%20idea,%20so%20we%20have%20the%20idea%20of%20charge,%20and%20now%20we%20need%20a%20place%20to%20get%20some%20charge,%0Aand%20one%20of%20the%20places%20we%20like%20to%20get%20charge%20from%20is%20copper,%20copper%20wires,%20a%20copper%20atom%20looks%20like%20this,%20copper%20atom%20has%20a%20nucleus%20with%20some%20protons%20in%20it,%20and%20it%20also%20has%20electrons%20flying%20around%20the%20outside,%20electrons%20in%20orbits%20around%20the%20outside,%0Aso%20we'll%20draw%20the%20electrons%20like%20this,%20so%20there'll%20be%20orbits%20around%20this%20nucleus,%20pretty%20good%20circles,%20and%20there'll%20be%20electrons%20in%20these%20little%20minus%20signs,%20there's%20electrons%20stacked%20up%20in%20this,%20and%20even%20farther%20out%20there's%20electrons,%20so%20there's%20a%20kind%20of%20a%20interesting%20looking%20copper%20atom,%20copper,%20the%20symbol%20for%20copper%20is%20cu,%20and%20its%20atomic%20number%20is%0Atwenty-nine,%20twenty-nine,%20that%20means%20there's%20twenty-nine%20protons%20inside%20here,%20and%20there's%20twenty-nine%20electrons%20outside,%20and%20it%20turns%20out,%20just%20as%20a%20coincidence%20for%20copper,%20that%20the%20last%20orbital%20out%20here%20has%20just%20one%20electron%20in%20it,%20that%20guy%20right%20there,%20and%20that's%20the%20one%20that%20is%20the%20easiest%20to%20pull%20away%20from%20copper,%20and%20have%20it%20go%20participate%20in%0Ain%20conduction,%20in%20electric%20current,%20so%20when%20every,%20if%20I%20have%20a%20chunk%20of%20copper,%20every%20copper%20atom,%20every%20copper%20atom%20will%20have%20the%20opportunity%20to%20contribute%20one,%20this%20one%20lonely%20electron%20out%20here,%0Aif%20we%20look%20at%20another%20element%20like,%20for%20instance,%20silver,%20silver%20has%20this%20same%20kind%20of%20electron%20configuration,%20where%20there's%20just%20one%20out%20here,%20and%20that's%20why%20silver%20and%20copper%20are%20such%20good%20conductors,%20alright,%20so%20now%20we're%20gonna%20build,%20let's%20build%20a%20copper%20wire,%20here's%20sort%20of%20a%20copper%20wire,%20it's%20just%20made%20of%20solid%20copper,%20it's%20all%20full%20of%20copper%20atoms,%20and%20I'm%20gonna%20put%20a%20voltage%20across%20this,%20there's%20our%20little%20battery,%0Athis%20is%20the%20minus%20sign,%20this%20is%20the%20plus%20sign,%20and%20we'll%20hook%20up%20a%20battery%20to%20this,%20and%20what's%20going%20on%20in%20here,%20inside%20this%20copper,%20inside%20this%20copper%20is%20a%20whole%20bunch%20of%20electrons%20that%20are%20associated%20with%20atoms,%20it's%20a%20neutral,%20it's%20a%20neutral%20piece%20of%20metal,%20there's%20the%20same%20number%20of%20protons%20as%20there%20is%20electrons,%20but%20these%20electrons%20are%20a%20little%20bit%20loose,%20so%20if%20I%20put%20a%20plus%20over%20here,%20that's%20this%20situation%20right%20here,%20where%20a%20plus%20is%20attracting%20a%20minus,%0Aand%20so%20an%20electron%20is%20gonna%20sort%20of%20wander%20over%20this%20way,%20and%20go%20like%20that,%20and%20that's%20gonna%20leave%20sort%20of%20a%20net%20positive%20charge%20in%20this%20region,%20and%20so%20these%20electrons%20are%20all%20gonna%20start%20moving%20in%20this%20direction,%20and%20down%20at%20the%20end,%20here,%20an%20electron's%20gonna%20come%20out%20of%20this%20battery,%20travel%20in%20here,%20and%20it's%20gonna%20go%20in%20there%20and%20make%20up%20the%20difference,%20so%20if%20I%20had%20a%20net%20positive%20charge%20here%20from%20the%20electrons%20leaving%20and%20going%20to%20the%20left,%0Athis%20battery%20would%20fill%20those%20in,%20and%20I'm%20gonna%20get%20a%20net%20movement%20of%20charge,%20of%20negative%20charge,%20around%20in%20this%20direction%20like%20this.%0AThe%20question%20is,%20how%20do%20I%20measure%20that?%20How%20do%20I%20measure,%20or%20give%20a%20number%20to%20that%20amount%20of%20stuff%20that's%20going%20on?%20So%20we%20wanna%20quantify%20that,%20we%20wanna%20assign%20a%20number%20to%20the%20amount%20of%20current%20happening%20here.%0ASo%20what%20we%20do%20is,%20in%20our%20heads,%20we%20put%20a%20boundary%20across%20here,%20so%20just%20make%20that%20up%20in%20your%20head,%20and%20it%20cuts%20all%20the%20way%20through%20the%20copper,%0Aand%20what%20we%20know,%20we're%20gonna%20stand%20right%20here,%20and%20we're%20gonna%20keep%20our%20eye%20right%20on%20this%20boundary%20down%20in%20here,%20and%20as%20we%20watch,%20what%20we're%20gonna%20do%20is%20we're%20gonna%20count%20the%20number%20of%20electrons%20that%20move%20by%20here,%0Aand%20we're%20gonna%20have%20a%20stopwatch,%20and%20we're%20gonna%20time%20that,%20and%20so%20we're%20gonna%20get,%20basically,%20this%20is%20charge,%20it's%20negative%20charge,%0Aand%20it's%20moving%20to%20the%20side,%20and%20what%20we're%20gonna%20do%20is,%20at%20one%20little%20spot%20right%20here,%20we're%20just%20gonna%20count%20the%20number%20that%20go%20by%20in%20one%20second,%0Aand%20so%20we're%20gonna%20get%20charge%20per%20second,%20and%20it's%20gonna%20be%20a%20negative%20charge%20moving%20by,%20and%20that's%20what%20we%20call%20current,%0Aand%20it's%20the%20same%20as%20water%20flowing%20by%20in%20a%20river,%20that's%20the%20same%20idea.%0AAlright,%20now%20I'm%20gonna%20set%20up%20a%20different%20situation%20that%20also%20produces%20a%20current,%20and%20this%20time%20we're%20gonna%20do%20it%20with%20water,%0Awater%20and%20salt.%20So,%20here's,%20here's%20just,%20let's%20build%20a%20tube%20of%20salt,%20of%20salt%20water,%20like%20this.%0ASo%20we're%20gonna%20pretend%20this%20is%20some%20tube%20that's%20all%20full%20of%20water.%20I'm%20also%20gonna%20put%20a%20battery%20here,%20let's%20put%20another%20battery, (Caused by ConnectTimeoutError(, 'Connection to translate.google.com timed out. (connect timeout=300)')):Google
=====
Windows-10-10.0.26100-SP0
version:v3.78
frozen:True
language:zh