All About Space
What are the possible explanations?
Dark energy’s early influence
Dark energy, which makes up about 70 per cent of our universe, could have provided an unexpected input of energy after the
Big Bang which caused the universe to expand faster than predicted. This is called the ‘early dark energy’.
A new subatomic particle
This could provide a new objective for the next generation of particle accelerators. The discrepancy could be explained by the existence of a subatomic particle that moves close to the speed of light, which when influencing the universe collectively is also referred to as ‘dark radiation’.
Stronger dark matter interaction
Dark matter, which makes up approximately 25 per cent of our universe, could interact with ordinary matter, which makes up just five per cent, with more intensity than originally thought. The issue is that dark matter cannot be observed directly. It emits no light and only interacts with ordinary matter through the medium of gravity.
Waiting for a new theory
This is a complete mystery, and while astronomers stay determined to provide a figure for the Hubble constant with as little uncertainty as possible – the aim being less than one per cent – the same people could be coming up with new and groundbreaking theories that could bind the two observations.