Research Tip: Simple Wikipedia: Simple Answers to Complex Questions
Simple English Wikipedia is a, well, simpler version of regular ol’ Wikipedia. It’s great for finding the answers to complex questions because Simple Wikipedia uses mostly basic English words from a list known as the Basic English 850. I really enjoy the refreshingly short and to-the-point articles. A godsend if you’re tired of Wikipedia’s long-winded pages.
Obviously, it’s not for deep research, but I think you’ll find Simple Wikipedia explanations far easier to grasp thanks to their shorter length and use of basic English words. At least I do.
It seems that dark matter is not made of the same thing as the matter we see every day on Earth. The only way we can tell if dark matter is there, is by how it affects things we can "see" by gravity.
Dark matter is a form of matter thought to account for approximately 85% of the matter in the universe and about a quarter of its total energy density. The majority of dark matter is thought to be non-baryonic in nature, possibly being composed of some as-yet undiscovered subatomic particles. Its presence is implied in a variety of astrophysical observations, including gravitational effects which cannot be explained by accepted theories of gravity unless more matter is present than can be seen.
Designed for beginning English speakers, but useful for anyone who regularly looks things up, Simple English Wikipedia is an official part of the Wikipedia Foundation.