What if I told you that you could buy a Bluetooth speaker than you would never need to charge again? “Charlie!” you would say, “Have you lost your mind? Have you been drinking again?” To which I would answer “No” and “Yes” respectively. Because such a speaker does indeed exist. It’s called the Rukus Solar, and it gets its power from the 620 million metric tons of hydrogen fused each second by the Sun’s nuclear furnace.