 But its strange force may be what actually holds galaxies together. But how about this? A new theory claims that dark energy's real source may be particles which violate even Albert Einstein's laws of speed limits of light. These particles, yet unconfirmed, many people may have heard of them, called tachyons. And that's a possible explanation, George, for the nature of both dark matter and the mysterious dark energy which make up 68% of our universe.