Some physicists are pushing back against ideas like string theory and the multiverse. Here, we see a computer-generated image of a black hole, which might, ultimately, be explained by ideas like string theory.
The Dark Sector Lab (DSL), located 3/4 of a mile from the Geographic South Pole, houses the BICEP2 telescope (left) and the South Pole Telescope (right).
Steffen Richter/Harvard University
Observing the multitude of galaxies in our own universe is a piece of cake. Observing the multiverse, if such a thing exists, seems impossible. Above, the Milky Way rises above the ESO's ALMA observatory in Chile.
This image released Monday by Harvard-led researchers represents the gravitational waves in the Cosmic Microwave Background in the microsecond after the Big Bang.
Harvard-Smithsonian Center for Astrophysics
A computer simulation of the formation of large-scale structures in the Universe, showing a patch of 100 million light-years and the resulting coherent motions of galaxies flowing towards the highest mass concentration in the centre. The snapshot refers to an epoch about 10 billion years back in time.
Klaus Dolag/VIMOS-VLT Deep Survey/ESO
Don't panic! The end of the Universe (as we know it) isn't likely to hit us for billions of years, if it comes at all. Pictured: the Milky Way rises above the ESO's ALMA facility in Chile.
José Francisco Salgado/ESO
An illustration shows the Earth's night sky 3.75 billion years from now, with the Andromeda galaxy (left) beginning to distort our own Milky Way as the two collide. While galactic collisions are eye catching, could something bigger be just over the horizon?
Z. Levay/R. van der Marel/T. Hallas/A. Mellinger/NASA/ESA