Astronomers have known where the universe’s missing matter has been hiding for the past 20 years. So why did it take so long to find it?
For decades, astronomers weren’t able to find all of the atomic matter in the universe. A series of recent papers has revealed where it’s been hiding.
High-energy neutrinos have been traced back to a flaring supermassive black hole known as a blazar. The long-sought link opens the door to an entirely new way to study the universe.
Evidence mounts that organisms without nervous systems can in some sense learn and solve problems, but researchers disagree about whether this is “primitive cognition.”
New observations of extreme astrophysical systems have “brutally and pitilessly murdered” attempts to replace Einstein’s general theory of relativity.
A recent experiment shows how quantum mechanics can make heat flow from a cold body to a hot one, an apparent (though not real) violation of the second law of thermodynamics.
Researchers are building a case that long before the nervous system works, the brain sends crucial bioelectric signals to guide the growth of embryonic tissues.
The mathematician Gil Kalai believes that quantum computers can’t possibly work, even in principle.
A mysterious object that repeatedly bursts with ultra-powerful radio waves must live in an extreme environment — something like the one around a supermassive black hole.