What are dark matter and dark energy? Do our current theories of physics need to be reworked to account for them? Since humans first looked up, we’ve wondered about our place in the cosmos, yet everything we’ve learned has shown that our ignorance still outstrips our knowledge. Neil deGrasse Tyson explores two of these areas of mystery: dark matter and dark energy. Read more to find out what we do and don’t know about these scientific frontiers.
What Are Dark Matter and Dark Energy? Cosmological Placeholders










