Are some black holes wormholes in disguise? Gamma-ray blasts may shed clues. - Livescience.com

Unusual flashes of gamma rays could reveal that what appear to be giant black holes are actually huge wormholes, a new study finds.

In many ways, wormholes resemble black holes.

The main difference is that no object can theoretically come back out after crossing a black hole's event horizon — the threshold where the speed needed to escape the black hole's gravitational pull exceeds the speed of light — whereas any body entering a wormhole could theoretically reverse course.

Video: Last 500 years around Milky Way's supermassive black hole.

Assuming wormholes might exist, researchers investigated ways that one might distinguish a wormhole from a black hole.

They focused on supermassive black holes with masses millions to billions of times that of the sun, which are thought to dwell at the hearts of most, if not all, galaxies.

The scientists reasoned that meant that matter entering one mouth of a wormhole could potentially slam into matter entering the other mouth of the wormhole at the same time, a kind of event that would never happen with a black hole. .

The researchers compared the outbursts from such wormholes with those from a kind of supermassive black hole known as an active galactic nucleus (AGN), which can spew out more radiation than our entire galaxy does as they devour matter around them, and do so from a patch of space no larger than our solar system.

Moreover, although jets from AGNs can emit gamma rays, these would mostly travel in the same direction as the jets — any traveling out in a sphere might suggest they came from a wormhole, he noted.