It’s actually filled with quantum energy and particles that blink in and out of existence for a fleeting moment – strange signals that are known as quantum fluctuations.
That’s important, because one of the biggest problems with quantum mechanics – and our understanding of it – is that every time we measure and observe a quantum system, we destroy it, which doesn’t bode well when we want to tease out what’s really going on in the quantum world.
A byproduct of one of the most fundamental principles in quantum mechanics, Heisenberg’s uncertainty principle, states that there’s a limit to how much we can know about quantum particles, and as a result, a vacuum isn’t empty, it’s actually buzzing with its own strange energy, and filled with particle-antiparticle pairs that appear and disappear randomly.
These quantum fluctuations produce randomly fluctuating electric fields that can affect electrons, which is how scientists first indirectly demonstrated their presence back in the 1940s.
It’s a claim that’s still being debated, but the researchers have now taken their experiment to the next level by ‘squeezing’ the vacuum, and say they’ve been able to observe the strange changes in the quantum fluctuations as a result.
The same thing happens in a vacuum, to a certain extent – as the vacuum gets squeezed in one place, the distribution of the quantum fluctuations changes, and they can speed up or slow down as a result.
Even though the results so far are impressive, there’s still a chance the team might have only achieved a so-called weak measurement – a type of measurement that doesn’t disturb the quantum state, but doesn’t actually tell researchers very much about a quantum system.