STEM Challenges
Explore fun and educational challenges across math, science, engineering, and coding!
Showing 6 of 209 challenges
The First Moments — Inflation and Particle Creation
Space ExplorerIn the first trillionth of a trillionth of a trillionth of a second, the universe underwent changes more dramatic than anything since. An era of explo...
What Was the Big Bang?
Space ExplorerThe Big Bang is the most tested and best-supported theory of the origin of the universe — but it is also one of the most misunderstood. What do scient...
What Expansion Really Means
Space ExplorerThe expanding universe is one of the most misunderstood concepts in all of science. There was no explosion into empty space. The universe has no cente...
Hubble's Law and the Hubble Constant
Space ExplorerIn 1929, Edwin Hubble presented one of the most remarkable graphs in the history of science: distance plotted against recession velocity, forming a st...
Redshift — Light Stretched by Expanding Space
Space ExplorerWhen astronomers look at distant galaxies, their light has been stretched to longer, redder wavelengths by the expansion of space itself. This cosmolo...
Edwin Hubble and the Scale of the Universe
Space ExplorerA century ago, astronomers debated whether the fuzzy spiral nebulae in the sky were part of our own galaxy or immensely distant island universes. The ...