There’s a mystery in science that has confounded some of the world’s brightest minds for years.

It seems to undermine everything we think we know about how the universe works, and calls into question the very nature of reality itself. And, if science is your basis for not believing in God, understanding the implications of this single experiment might cause you to reconsider just how “knowable” the rules of the universe really are.

If you have a few minutes, check out the two videos below (or, at least one of them) for a clear understanding of the double-slit experiment.

If you don’t have time to watch the demonstrations, here’s a brief (extremely simplistic) explanation of why it is so strange: The simple act of observing a photon seems to change the way it behaves.

Depending on whether or not scientists are observing a photon (using extremely delicate equipment), it either acts like a particle or both a particle and a wave at the same time. And, no one knows with absolute certainty why. The only way anyone has ever captured a glimpse of the dual behavior was by essentially “tricking” the particles.

‘Spooky’ Science

The more you learn about quantum mechanics, the field that tries to understand baffling things like wave-duality, the more you realize that aspects of how the universe operates are still far beyond our understanding.

Erwin Schrödinger was one of the greatest minds the world of math and science has ever known. The famous thought experiment that now bares his name—“Schrödinger’s Cat”—is a testament just how absurdly counterintuitive the universe can really be.

The hypothetical scenario demonstrates how strange the quantum physics idea of “superposition” really is, and why it’s so strange that the act of measuring and observing the universe can actually determine the reality around us.

The thought experiment (for obvious reasons, he never actually conducted the experiment) goes like this (again, this is an extremely simplified version):

A cat is placed inside of a box along with a device that may or may not randomly release poison gas that will kill the cat. According to the illustration, because one of two outcomes will happen (but are unknown to anyone just looking at the outside of the box), the cat is both alive and dead at the same time until someone opens it up and looks inside.

In other words, until we observe reality, the two realities exist at once.

Why would he propose something so (seemingly) insane? According to some quantum theories, that’s how the universe seems to work: Until it is observed, matter exists in various states at the same time. (By the way, even though Schrödinger questioned if it was real, many scientist think the illustration is a relatively accurate way to describe quantum mechanics).

Chen Wang, postdoctoral associate in Yale’s department of applied physics and physics and the author of a new study on the topic, told HowStuffWorks, “Not only does the [Schrödinger’s] cat ‘paradox’ no longer feel absurd conceptually to physicists [but] even more exotic quantum states are becoming commonplace and attainable.”

Einstein himself was disturbed by areas of quantum physics. He was particularly baffled by something we know as quantum entanglement—which again, when you hear the details, sound like the stuff of science fiction.

Two particles, which can exists completely independent of each other across the entire universe, can dictate each others’ behavior. In other words, if two particles are “entangled” on a quantum level, they somehow seem to share the same existence. It’s like the same particle exists in two places at once. When one moves, so does the other, even though they are physically separated by galaxies.

Unsettled? So was Einstein. He called it, “spooky action at a distance.”

What It Means About God

Quantum physics don’t prove the existence of God.

God can’t be seen, measured or observed in the scientific sense of the word. But “proving.” His existence with science is beyond the point.

Faith, by its very nature, requires some degree of uncertainty. Otherwise, belief in God wouldn’t require faith at all.

But even though science gives us answers about our universe, the more we know, the more we realize that there are things we don’t know. Science is about observation and certainty, but also realizing that some things are still uncertain.

The more we understand, the more there is a possibility that something we don’t understand is also operating in the universe.

Science isn’t about looking for evidence of God. It’s about what we can observe and predict. But, that also might lead us to finding proof that there are still mysteries that we don’t understand, and new possibilities that we must be open to.

Religion and science aren’t at odds. They’re actually looking for the same thing: truth. And, this why quantum mechanics may make you believe in God, because, even though it doesn’t prove His existence, it leaves open the possibility that He (or something else beyond our current understanding) could exist. Because, at their most fundamental level, quantum physics tells us we might not know as much as we think we do.

As Einstein wrote, “Even though the realms of religion and science in themselves are clearly marked off from each other, nevertheless there exist between the two strong reciprocal relationships and dependencies … The situation may be expressed by an image: science without religion is lame, religion without science is blind.”