Last summer, the gravitational wave observatory known as LIGO caught its second-ever glimpse of two neutron stars merging. The collision of these incredibly dense objects — the hulking cores of long-ago supernova explosions — sent shudders through space-time powerful enough to be detected here on Earth. But unlike the first merger, which conformed to expectations, this latest event has forced astrophysicists to rethink some basic assumptions about what’s lurking out there in the universe. “We have a dilemma,” said Enrico Ramirez-Ruiz of the University of California, Santa Cruz.

The exceptionally high mass of the two-star system was the first indication that this collision was unprecedented. And while the heft of the stars alone wasn’t enough to cause alarm, it hinted at the surprises to come.

In a paper recently posted to the scientific preprint site arxiv.org, Ramirez-Ruiz and his colleagues argue that GW190425, as the two-star system is known, challenges everything we thought we knew about neutron star pairs. This latest observation appears to be fundamentally incompatible with scientists’ current understanding of how these stars form, and how often. As a result, researchers may need to rethink years of accepted knowledge.

The global collaboration that delivered us not one but two pictures of supermassive black holes has now peered into one of the brightest lights in the Universe.

The Event Horizon Telescope (EHT), a telescope array comprising radio antennae around the world, studied a distant quasar named NRAO 530, whose light has traveled for 7.5 billion years to reach us.

The resulting data show us the quasar’s engine in incredible detail and will, astronomers say, help us understand the complex physics of these incredible objects, and how they generate such blazing light.

It’s a hot new early dark energy summer.

---

We’re still not sure exactly what dark energy is, but it may have played a key role in the early universe.

Physicists can’t see or measure dark energy (hence the name). The only clue that it exists is how it affects the rest of the universe; dark energy is the force that’s driving the universe to keep expanding faster. Physicists Florian Niedermann of Stockholm University and Martin Sloth of the University of Southern Denmark propose that if dark energy formed bubbles in the dark plasma of the early universe, it could solve one of the biggest mysteries in modern physics.

They describe their idea in a recent paper in the journal Physics Letters B.

A small team of astrophysicists affiliated with several institutions in China has found evidence that suggests if wormholes are real, they might magnify light by 100,000 times. In their paper published in the journal Physical Review Letters, the group describes the theories they have developed and possible uses for them.

Prior theoretical efforts have suggested that wormholes might exist in the universe, described as tunnels of a sort, connecting different parts of the universe. Some in the physics community have suggested that it may be possible to traverse such tunnels, allowing for faster-than-light travel across the universe. The researchers note that prior research has shown that black holes have such a strong gravitational pull that they are able to bend light, a phenomenon known as microlensing. They then wondered if wormholes, if they exist, also exhibit microlensing.

Proving that wormholes cause microlensing would, of course, involve first proving that wormholes exist. Still, the researchers suggest that general relativity and other theories could clarify whether the idea is even possible. In their work, they discovered that it was possible to calculate how an electric charge associated with a wormhole would warp the light passing by it. They also found theoretical evidence that wormhole microlensing would be similar to black hole lensing, which, they note, would make it difficult to tell the two apart.