字幕列表 影片播放 列印英文字幕 Ever wondered exactly what energy is? Does it come from fire, electricity, the energy drinks we drink? Actually, it comes from all of those things! Energy is what keeps the world going. Let me break it down for you. The first thing you need to know is the law of conservation of energy. It sounds hard but it’s actually simple. It means that energy cannot be created or destroyed... ...but only converted between different forms. Yes, you heard it right! Energy lasts forever. I’m serious! It changes but never disappears entirely. So let’s look at some different forms of energy. There’s electrical energy... ...which is the current that goes from your plug point... ... all the way to your lamp and lights it up. Then there’s mechanical energy or what scientists call kinetic energy. That’s the energy of movement. Like when you walk across the road... ...or when a car’s wheels turn. Oops. Well that was kinetic energy being transferred from the moving car to the pedestrian. But that’s a whole other lesson. Let’s look at some more forms of energy. Next, we have thermal energy. The biggest source is obviously the sun’s rays... ...but it’s also the heat that cooks your food. There’s also chemical energy... ...which comes in the form of gasoline, oil and even the food we eat. Finally, there’s nuclear energy... ...which comes from the splitting of atoms... ...like they do in nuclear power plants. Pretty cool, right? So now you know some of the basics about energy. We know it comes in many forms. Electrical, kinetic, thermal, chemical and nuclear. And don’t forget the most important part. Energy cannot be created or destroyed; it can only be converted between different forms. And that’s the basic of energy! It’s so simple!