When it comes to the Universe, it’s easy to make the incorrect assumption that what we see is an accurate reflection of all that’s out there. Certainly, what we observe to be out there really is present, but there’s always the possibility that there’s far more out there that’s unobservable. That extends to radiation outside of the visible light spectrum, matter that neither emits nor absorbs light, black holes, neutrinos, and even more exotic forms of energy. If something truly exists in this Universe and carries energy, it will have non-negligible effects on quantities that we can actually observe, and from those observations, we can go back and infer what’s truly there. But there’s a danger: perhaps our inferences are incorrect because we’re fooling ourselves somehow. Could that be a legitimate worry for dark energy? That’s what this week’s question-asker, Bud Christenson, wants to know:
“As one who has studied physics, I have been able to wrap my brain around some ideas that at one time were considered crazy… But dark energy is the most whacked idea I’ve heard. I know I’m not the sharpest knife in the drawer, and not getting any smarter as I age. But if so many of you are convinced that this intuitively impossible idea is valid, maybe I need to investigate instead of rejecting it out of hand.”