For the first time, a group of researchers have detected magnetic fields that stretch millions of light years between clusters of galaxies. This hints at a potential solution to one of the biggest problems in our current understanding of the universe: why does it expand much faster than our predictions can account for?

 

Astronomer Tessa Vernstrom and her team in Perth, Australia, have found these fields in regions of the universe devoid of almost any matter. Detecting magnetic fields that emerge from galaxies is common practice in astronomy. But finding them in the void regions which surround groupings of galaxies is new and could mean they have been sitting there since the dawn of time. This is something our current theories do not account for.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

 

 

 

 

Our current cosmological theories predict the rate of expansion of the universe to be much slower than the one we actually observe. What’s remarkable about these ancient fields is that when added as an ingredient in computer simulations, the result is a universe that expands at a rate much closer to the one we physically measure. This shows the potential these magnetic fields could have in filling the gaps in our current understanding of the cosmos.

 

But if these fields really exist - and more observations will be needed to confirm Vernstrom’s findings - they should be very weak and that is a challenge for their detection. Magnetic fields are often measured by their effect on particles that travel through them. And since there are barely any particles in voids, this detection becomes very difficult. 

​

Surveying the sky for very strong radio sources might do the trick. Radiation coming from these sources should be strong enough that its distortion would be detected. A future generation of radio telescopes will help with this mission. For now, Vernstrom’s findings are promising. Matched with future observations, they could mean the breakthrough many cosmologists have been waiting for.