Dark energy might be neither particle nor field
Everything else in the Universe is either one or the other. For the first time, we may have encountered something fundamentally different.
What is it, at a fundamental level, that makes up the universe? When we ask this question, we typically think about starting with things that we directly observe — things like stars, planets, humans, gas, dust, plasma, and other forms of the matter we know — and dividing them up until you reach something that is indivisible. Although we originally thought that atoms would be these “uncuttable” things, we soon discovered they could be further divided: into electrons and atomic nuclei, which themselves are composed of quarks and gluons.
As we mastered the laws of physics and began to manipulate these subatomic particles, we gained the ability to accelerate and collide them, enabling the creation of a wide slew of particles and antiparticles: everything described by the Standard Model of particle physics. And yet, if we add up the sum total of all of these forms of matter, including photons, neutrinos, and everything that does not compose atoms, we fall far short of what is needed to describe our universe. Two additional components are necessary: dark matter and dark energy. Moreover, although we fully expect…
