Yes, Virtual Particles Can Have Real, Observable Effects
The nature of our quantum Universe is puzzling, counterintuitive, and testable. The results don’t lie.
Although our intuition is an incredibly useful tool for navigating daily life, developed from a lifetime of experience in our own bodies on Earth, it’s often horrid for providing guidance outside of that realm. On scales of both the very large and the very small, we do far better by applying our best scientific theories, extracting physical predictions, and then observing and measuring the critical phenomena.
Without this approach, we never would have come to understood the basic building blocks of matter, the relativistic behavior of matter and energy, or the fundamental nature of space and time themselves. But nothing matches the counterintuitive nature of quantum vacuum. Empty space isn’t completely empty, but consists of an indeterminate state of fluctuating fields and particles. It’s not science fiction; it’s a theoretical framework with testable, observable predictions. 80 years after Heisenberg first postulated an observational test, humanity has confirmed it. Here’s what we’ve learned.
Discovering that our Universe was quantum in nature brought with it a lot of unintuitive consequences. The better you measured a particle’s position, the more fundamentally indeterminate its momentum was. The shorter an unstable particle lived, the less well-known its mass fundamentally was. Material objects that appear to be solid on macroscopic scales can exhibit wave-like properties under the right experimental conditions.
But empty space holds perhaps the top spot when it comes to a phenomenon that defies our intuition. Even if you remove all the particles and radiation from a region of space — i.e., all the sources of quantum fields — space still won’t be empty. It will consist of virtual pairs of particles and antiparticles, whose existence and energy spectra can be calculated. Sending the right physical signal through that empty space should have consequences that are observable.