The night sky is always full of sparkling stars for you to observe from almost anywhere on the planet. What would it be like if you looked up at night, and didn’t see those shining diamonds anymore? Maybe you’ll think to yourself: we can build rockets to go and visit the planets and see the stars again. Or we could send probes through the atmosphere to send us back images of the wonders of space. Unfortunately, billions of years from now, humans will be asking themselves these very questions. Due to the way our universe is expanding, and some other unexplained forces of space, we won’t be able to reach any the surrounding galaxies billions of years from now.
Objects in Space are Farther than They Appear
Our universe began as a singularity, and rapidly expanded to create the building blocks of our universe. This energy that propels our universe in all directions has continued since the beginning of time. Despite modern technology, and even the future of technology, we will never be able to explore planets, or galaxies out of our own. To put it in perspective, if we tried to send a group of humans from Earth to the nearest star, it would take thousands of years before they actually made it there. While it is true that the Local Group is as far as humans will be able to travel, it is actually a very large expanse of space with much for us to explore.
Even the Power of the Millenium Falcon Wouldn’t be Enough
If the universe were static, we might have a fighting chance of finding the end. Unfortunately, the universe contains copious amounts of dark energy, which is one of the main reasons for us being stranded. Dark energy came into being about six billion years ago, and is the driving force behind the increasing expansion of the universe. Despite not knowing what dark energy is, scientists are able to observe its effects to create theories about universal expansion. Millions of years ago, we were surrounded by other young galaxies. These galaxies were not bound to ours, and so dark energy eventually pushed them light years away. The more the universe ages, the more space there is between our galaxy cluster in relation to others. Because all other galaxy clusters are moving away from us at, one day they will be so far away that we won’t be able to detect them.
Dark Energy Helps us Understand Space
Observations from the Hubble Telescope showed that the universe is actually expanding at an increasing rate. Physicists still don’t know the exact answer as to why the universe is expanding, but they have dubbed this strange force “dark energy”. We know that dark energy affects the universes expansion, and that it composes about 68% of the universe. There are several explanations as to why dark energy exists. One is that it is a property of space. According to the prediction in Einstein’s gravity theory, empty space can have energy. Because the energy is a property of space, it would be constant as the space continues to expand. All of this energy would accelerate the expanding space.
Dark Matter Makes up the Majority of Space
Dark matter is also an important topic to discuss. Scientists believe that the universe is approximately 68% dark energy, 27% dark matter and 5% normal matter. We credit a large portion of the universe to being dark matter, but we don’t even have a full grasp of what it is. It is virtually non-detectable by human eyes. Furthermore, it is not in the form of the matter that makes up the normal dark clouds in our universe. If it was, we would be able to detect it through various forms of scientific testing. We know that dark matter is not anti-matter, because of how it interacts with normal matter. In other words, we cannot detect the gamma rays that antimatter emits when destroying normal matter. It is possible that baryonic matter is dark matter.
In final analysis, you could learn something new every day about the universe for the rest of your life, and still not even scratch the surface. Dark energy and dark matter are just the beginning of the complex problems that we’ll be solving for generations. It may seem disconcerting that humans won’t ever make it out of their corner of the universe. Science fiction movies make it seem easy to just hop in a spaceship, and zoom off into the galaxy. However, just in our Local Group alone there are so many exoplanets to discover and explore. I think we’ll be content to explore our little slice of the universe for a long time to come.