Join the world’s transition to sustainable energy. Powerwall 2 is a battery for homes and small businesses that stores the sun’s energy and delivers clean, reliable electricity when the sun isn’t... continue reading

posted by newtboy 8 years 4 months 1 week ago • 279 views • 19:04

YouTube Description: When sunlight shines through a small hole, it casts an image of the sun on a wall some distance away. Therefore the size and shape of the hole have little effect on the size and... continue reading

posted by Aard Vark (oritteropo) 1 decade 2 years 2 weeks ago • 448 views • 3:32