World Science Festival wants Ars readers to explore the Fabric of the Universe
Brian Greene is a theoretical physicist and co-founder of the World Science Festival. In his spare time, Greene also writes books and hosts television shows intended to bring modern physics to a popular audience. His latest ef......
Galaxy clusters back Einstein, leave Newton’s descendants in the cold
Relativity is the reigning theory of gravity. In situations where we can measure it directly, such as binary neutron stars, its predictions match the real world with remarkable precision. And, when supplemented with...
Violating relativity by breaking equivalence
One of the tenets of
Einstein's theory of general relativity is that an observer, carrying
out local measurements, cannot determine if they are being accelerated in the absence of gravitational fields or
stationary but in t...
When universes collide, how will we know when it happens?
From a certain perspective, the Universe looks as smooth and uninteresting as a billiard ball—the smoothest billiard ball ever made. What do I mean by this? The radiation from the Big Bang, now so deeply...
The earliest stars may not have been emo loners
"Let there be light." The dark
ages of the Universe ended when the first stars began their nuclear
fusion of hydrogen, giving off heat and light about 100
million years after the Big Bang. Current understanding of these
Populatio...
Gravity’s lenses may skew surveys of early galaxies
Astronomers have shown that, at high red shifts, gravitational lensing might have a dominant effect on the number of galaxies counted in upcoming surveys. As astronomers peer deeper into the sky, they will have...
Theorists seek dark matter in hot neutron stars
Dark matter is an enigma wrapped in a conundrum. We have lots of gravitational evidence for the presence of dark matter. In fact, the evidence is from so many different types of observations, and is all so consistent, that...
Cosmology and dark energy revealed by geometry of galaxy pairs
The Universe strikes a balance between simplicity and complexity that cosmologists are increasingly coming to understand. Recent observations of supernovae and the large-scale distribution of galaxies leave us with the confoundi...
Is it now or never for dark matter WIMPs?
For several decades, astronomers and cosmologists have been piling up data that indicates most of the matter in the Universe is dark, interacting only via gravity. As modified theories of gravity failed to account for observatio...
Cheap and cheerful gravity wave detector on the horizon
Gravity waves seem to be the ultimate in hard-to-detect phenomena. Currently, we have a couple of rather large laser interferometers and a giant suspended pendulum looking for them, so far without success. Furthermore, astronome...
Astronomy and particle physics race to replace Standard Model
If energy issues seem to be attracting the attention of a lot of physicists, the Large Hadron Collider seems to be drawing the attention of many of the rest of them, including people in fields...
A short history of the history of the Universe
John Mather, along with George Smoot, won the Nobel Prize for his work on the Cosmic Background Explorer (COBE), the probe that first caught glimpses of fluctuations in the Cosmic Microwave Background (CMB) left over...
