The size of the universe is determined by the laws of nature. Where these laws end, at the boundary, the universe ends, space itself ends - nothing can exist beyond the border. All the matter and energy that strike the boundary are absorbed. At the same time new massless matter is created to replace the absorbed matter.

Ever since Copernicus placed the Sun at the center of the universe instead of the Earth, scientific discoveries have been repeatedly making our home planet less special and more ordinary. But could the "principle of mediocrity" turn out to be wrong in one critical recent discovery--dark energy--and could that discovery really mean something other than what physicists have suggested?

Anatoly Logunov has set out a relativistic theory of gravity that is not the same as the orthodoxy of the "general theory of relativity". What do we make of this?

When researching my history of physics in the twentieth century that was recently published by Facts On File, my best source of authoritative information was the American Institute of Physics Center for the History of Physics and the Neils Bohr Library and Archives.

The long-time director of that Center, Spencer Weart, is retiring, and I got the following notice of a symposium in his honor.

HP says its researchers have proven the existence of what had previously been only theorized as the fourth fundamental circuit element in electrical engineering.

This news release from the Max Planck Institute describes evidence that supports the existence of gravitational waves, which at least one blogger here has insisted do not exist.

Superkick: Black hole expelled from its parent galaxy

Gravitational rocket propelled the monster at a speed of thousands of kilometres per second

By an enormous burst of gravitational waves that accompanies the merger of two black holes the newly formed black hole was ejected from its galaxy. This extreme ejection event, which had been predicted by theorists, has now been observed in nature for the first time.

Click "read more" for the full release.

Countless romance novels begin with a hero and heroine who initially repel each other, only to find them thrown together in uncomfortable circumstances and ultimately rejoicing as their antagonism switches to ardor.

Through the ages, the sound of music in myriad incarnations has captivated human beings and made them sing along, and as scholars have suspected for centuries, the mysterious force that shapes the melodies that catch the ear and lead the voice is none other than math.

Peer review has become the gold standard of the scientific community. Bring up a scientific finding, and the first thing you may be asked is, "Ah, well, is this peer reviewed?"

Is peer review all that it's cracked up to be?

When a tiny, quantum-scale, hypothetical balloon is popped in a vacuum, do the particles inside spread out all over the place as predicted by classical mechanics? The question is deceptively complex, since quantum particles do not look or act like air molecules in a real balloon. Matter at the infinitesimally small quantum scale is both a wave and a particle, and its location cannot be fixed precisely because measurement alters the system.