Categories: Astronomy

High Energy Gamma Rays Go Slower Than the Speed of Light?

The speed of light is the speed of light, and that’s that. Right? Well, maybe not. Try and figure this out. Astronomers studying radiation coming from a distant galaxy found that the high energy gamma rays arrived a few minutes after the lower-energy photons, even though they were emitted at the same time. If true, this result would overturn Einstein’s theory of relativity, which says that all photons should move at the speed of light. Uh oh Einstein.

The discovery was made using the new MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescope, located on a mountain top on the Canary island of La Palma. Since gamma rays are blocked by the Earth’s atmosphere, astronomers have figured out a clever trick to see them from the ground. When the gamma rays strike the atmosphere, they release a cascade of particles and radiation. The Cherenkov technique detects this cascade, and then works backwards to calculate the direction and energy level of the gamma rays. With a 17-metre detector, MAGIC is the largest telescope of its type.

The international team of researchers pointed the telescope at Markarian 501, a galaxy 500 million light-years away that contains a blazar – a supermassive black hole that periodically releases bursts of gamma rays. More material is falling into the black hole than it can consume, and so it gets squeezed into jets that fire off from the poles of the black hole at close to the speed of light. What astronomers call a “blazar” is when the jets of a supermassive black hole are pointed directly at the Earth.

Researchers sorted high- and low-energy gamma ray photons coming from the blazar with each flareup. Since all the radiation was emitted at the same time, and the speed of light is the speed of light, you would expect the high-energy photons to arrive at the same time. But nope, the high-energy photons showed up around 4 minutes later.

So what’s happening? Nobody knows, and this could turn into an entirely new field of physics. The researchers are proposing that maybe the radiation is interacting with “quantum foam”. This is a theoretical property of space itself, and predicted by quantum gravity theory – a competitor to string theory.

Original Source: UC Davis News Release

Fraser Cain

Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay. Here's a link to my Mastodon account.

Recent Posts

The Last Arecibo Message Celebrates the Observatory and One of its Greatest Accomplishments

The Arecibo Message, transmitted on November 16th, 1974, from the Arecibo Observatory, was humanity's first…

11 hours ago

A Nearby Supernova Could Finally Reveal Mark Matter

Despite 90 years of research, the nature and influence of Dark Matter continue to elude…

12 hours ago

Astronomers Find a 3 Million Year Old Planet

Astronomers have just found one of the youngest planets ever. At only 3 million years…

1 day ago

There was Hot Water on Mars 4.45 Billion Years Ago

Mars formed 4.5 billion years ago, roughly the same time as the Earth. We know…

2 days ago

Axion Dark Matter May Make Spacetime Ring

Dark matter made out of axions may have the power to make space-time ring like…

2 days ago

Earth’s Old Trees Keep A Record of Powerful Solar Storms

Most of the time the Sun is pretty well-mannered, but occasionally it's downright unruly. It…

2 days ago