Black Hole Breaking Law?:Cosmic speed limit crossed

The same as on our roads, when flying planes or steering boats, this universe has a speed limit. It applies to everything, at least in theory, and makes sure nothing is able to travel faster than light (the fastest thing in our universe, as far as we are concerned). However, recent research on the black hole at the centre of the milky way galaxy, our home, has shown that its rate of spinning is rapidly approaching this cap. If the vacuum supersedes the speed of light, everything we thought we knew about the universe will be torn apart.

Can’t Break the Cosmic Speed-limit

As far as we are aware, light is the fastest thing in our universe. For context; that is around 299,792,458 metres per second. This number truly shows how large our universe really is, as even with that incredible speed, it still takes light from the sun 8 minutes to get to us. Now that’s a long way!

The point is, nothing can best this rate of travel. Equations that are the basis of all the basic knowledge we have of our universe rely on this assumption. Namely, Einstein’s theory of special relativity, which explains how speed effects space and time, along with how the speed of light defines the relationship between energy and matter. The theory of special relativity states that an object’s mass becomes infinite as it approaches the speed of light, and along with it the energy required to move it becomes infinite as well. Because of this, we can assume that no matter is capable of travelling faster than light. Overall, pretty important stuff. If anything does break this cosmic speed limit, a lot of what we know will be thrown out of the window.

Sagittarius A: Rebel of the Milky Way

At the centre of every galaxy is a supermassive black hole. This is an ordinary black hole that has lived for so long, and taken in so much mass, that it has grown to astronomical proportions. Literally! The Milky Way’s black hole, Sagittarius A, is around 51.8 million kilometres wide, has a mass of 4.154 million suns and could be up to 13.6 billion years old. On top of this, it’s spinning very, very quickly.

The spin rate of a black hole is measured on a scale of 0 to 1, where 1 is the maximum speed (that being close to light-speed). Physicist Ruth Daly conducted research that approximated  Sagittarius A’s rotation to be between 0.84 and 0.96, placing it dangerously close to the cosmic limit we have set. If this line is crossed and our supermassive black hole does overtake the speed of light, then almost everything that we think we know about the universe could be completely wrong. Theoretical physicist Xavier Clamet told LiveScience.com that “Discovering that Sgr A* is rotating at its maximum speed has far-reaching implications for our understanding of black hole formation and the astrophysical processes associated with these fascinating cosmic objects,”.

Not only this, but black holes also tend to warp the fabric of space time due to the speed at which they spin and the gravitational pull it emits, dragging any matter close by into its centre. This is an effect called Lensing-Thirring or frame dragging, and is the cause of the distorted light shining around the edge of a black hole. Frame dragging is made much worse when the rate of rotation is increased. Who knows what effects this will have on our universe if the speed limit is breached.

Cosmic Questions

As it stands, there is nothing for us to fear when thinking about the oddity of Sagittarius A. Whatever happens will not do us any harm. It will, however, lead us all to rethink the way we have viewed the universe for so many years and consider not only how science acts inside our galaxy, but outside it as well. Scientists will be brought back to problems we long have thought solved, problems such as the formation of galaxies, the evolution of the universe and the relationship between gravity and matter. We thought we had begun to understand the intricacies of our universe, but with this possible new information, we know we have barely scratched the surface