 You may be surprised to learn that there are at least two ways to do this! Method 1: Travel to the Future On another page we examine Einstein's Theory of Relativity, which shows that if you can move fast enough, at speeds approaching the speed of light, then time will slow down for you. The implications of this theory, which quite properly should be called a 'Law' since it has been proven (see more here) are many, but for our purposes, there is one important result: we can travel into the future! Would you like to 'arrive' in the year 2723? You will need to travel somewhere for a few years at 90% of the speed of light or more, and return. When you get back, it will be 700 years later! The catch? It's a big one. We don't yet have the technology to build a spacecraft that will go that fast. But it is possible! In fact, we even have feasible designs for such craft. If you're interested in learning more, visit 'Travel' for some fascinating information. Method 2: See the Past Can we travel into the past? Unfortunately, physical travel seems to be impossible. However, it is definitely possible to see the past! Because light and radio waves travel at a finite (albeit very large) speed, they take time to get where they are going. Over distances as large as between stars, light and radio waves make take years to make the journey. What this means is that when we look at nearby stars in the sky, we are looking into the past, seeing them the way they existed when the light left them years ago. We can now, with our largest telescopes, just barely make out the images of large planets orbiting some nearby stars. We are seeing those planets the way they looked years ago. With larger telescopes, it may be possible to watch what went on, on those planets, years ago. We could watch the past of some other civilization, should it exist. How far can we look into the past? The sun is 151 million km from us. Light travels at 300,000 km per second, which means that light from the sun takes 8.3 minutes to get here. We are seeing the sun the way it looked 8.3 minutes ago. Saying this a different way, we are looking into the past at a sun that existed 8.3 minutes ago. The nearest star to us is Alpha Centauri, and at 4.3 light years distant, means we are seeing it the way it looked 4.3 years ago. The most distant thing we can see with the unaided eye is the Andromeda galaxy, the nearest galaxy to our own Milky Way, which is just over 20,000,000,000,000,000,000 km away, or 2.5 million light-years. What we see is the Andromeda Galaxy the way it looked 2.5 million years ago. We are looking into the far distant past of this galaxy. The most distant things we can see with our most powerful telescopes are tens of billions of years old. We can look through a telescope and see the past, almost as far back as the beginning of the universe itself! More information on this, and other, astronomical topics can also be found at 'We Are Not Alone'. |