Table of Contents April 2015


A century ago Albert Einstein changed the way we view the world with his theory of general relativity — and his theories still captivate physicists today. In our special Einstein section, we spotlight researchers pushing his theory to its breaking point to solve physics' most persistent questions. We’ll give you a hint: Most experts are still betting on Einstein.

Plus, go back to a time when camels — yes, camels — called the Arctic home. By learning more about Earth's ancient climate, scientists hope to get a glimpse of what’s likely to occur in the future. And if you’re reading this before bed, get some shut-eye! We dive into the science of sleep and why skimping on rest could be a matter of life and death. 

Read all those and more in the April issue of Discover.

Order this issue
Digital editions


After a century of testing general relativity, physicists still strive to achieve what the genius who formulated the theory could not.
Six examples of how Einstein's general theory of relativity has stood the test of (space-)time.
Powerful telescopes and huge gravitational wave detectors will test a theory that one man worked out a century ago with a pencil and paper.
Researchers are pushing Einstein's theory to the max, trying to see where it falters in order to connect gravity with the rest of physics.
Einstein's brain, preserved during autopsy, has been studied for decades. Some say it's time to give it a rest.
As Earth warms the Arctic faces troubling consequences. To predict that future, scientists are turning to fossils of a warmer past.
Amidst our national sleep crisis, researchers are urgently trying to understand why we sleep and what goes wrong when we don't.


Bioelectronic devices surgically implanted on nerves interfere with and change the body’s own processes to make them function better.
A healthy, stable woman with asthma suddenly finds herself considering suicide despite landing a dream job in a city she loves. What went wrong?
Fossils are just one piece of the puzzle at the oldest hominid site outside Africa. Will it rewrite human evolution?
What happens when our allegiances conflict?
New theories question just about everything we thought we knew about nature’s bottomless pits.
dust broom
Dust is so much more than a mess to clean up before the in-laws arrive.


What's behind the steady algal takeover of these aquatic treasures?
Darwin’s finches are icons of evolution, but scientists disagree about what exactly they represent.
Astrophysicist Mario Livio talks about the math underlying life, the universe and everything.
This month: Lie down on the couch, reveal your hedonism and get the real truth on food.
When it comes to staying clean, bumping is better than shaking.
NASA launched the Hubble Space Telescope 25 years ago this month, and it has done nothing short of rewrite how we see the universe.
Cell-sized particles could help with blood clotting in the face of donor shortages.
Since 2013 an artificial intelligence named NEIL has been scouring the Internet to learn to recognize the subjects of images.