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Philosophy

Can We Grasp Reality?

Reality may forever evade us, says astrophysicist Marcelo Gleiser.
Dieter Spears/iStockphoto
Reality may forever evade us, says astrophysicist Marcelo Gleiser.
Dieter Spears/iStockphoto

We may believe that we know what's going on around us. After all, we can see, hear, touch, smell and taste what's around.

Our senses are like antennas, grabbing information about our surroundings and bringing this information into our brains. The brain is this amazing organ capable of synthesizing this information and giving us a sense of the real.

The problem is, and we all know this, we can tinker with this notion of reality by messing with brain chemistry: alcohol, drugs — you pick one — will change the way we sense the world. Some drugs, like mescaline or LSD, will give people the impression that now they really understand what's going on, as if these chemicals could, somehow, open a portal to the nature of reality. No wonder Aldous Huxley called his book narrating his experiments with hallucinogenic drugs The Doors of Perception.

But what perception is this?

From science, in particular physics and biology, we know that what we sense of reality is but a mere fraction of what's really going on. Naked-eye astronomy or naked-eye biology can only go so far. We need tools, what I like to call reality amplifiers, to grasp what's going on beyond our sensorial perception. Telescopes, microscopes, particle detectors, spectrometers, MRIs — these are all tools we use to see what's not apparent. And, if we are lucky, once in a while a tool will be so powerful that it will trigger a revolution in how we see the world and our place in it.

World views depend on what we see of the world; change our perception in some radical way, by looking at powerful telescopes or microscopes or particle detectors such as those at CERN, the European Center for Nuclear Research where the Higgs boson was discovered, and our worldview will need revision. Same with the remarkable discovery of gravitational waves in February. To think that two black holes colliding over a billion years ago could make space and time quiver ever so slightly — by less than an atomic diameter — and that these ripples could be detected in this small planet by an intelligent species is mind-boggling, to say the least.

By the way, when those ripples passed by you also waved. Not that anyone noticed, of course.

What this tells us is that science amplifies our perception of reality in amazing ways, but that there is always more to see out there, the stuff that escapes our various detectors. As technology advances, and our models and theories are vindicated or tossed away, we learn more about the world and how we fit in. But there is always going to be what's beyond the reach of our machines, that elusive part of reality, that escapes us.

To imagine that we can cover the gap, that we can get to the bottom of this, is just naïve optimism, perhaps nurtured by a fear of the unknown. We can, however, think of this in a different way, and celebrate our myopic view of reality. After all, what fun would it be to arrive at the endpoint, to proclaim, one day, that we get it all, that we now understand what reality is. Much better to be humble about what we can understand, siding with Einstein, who knew well enough that our understanding of the world is necessarily imperfect. The commitment is not with finding the final answer but with wanting to know; that's what makes us matter.


Marcelo Gleiser is a theoretical physicist and cosmologist — and professor of natural philosophy, physics and astronomy at Dartmouth College. He is the co-founder of 13.7, a prolific author of papers and essays, and active promoter of science to the general public. His latest book is The Island of Knowledge: The Limits of Science and the Search for Meaning. You can keep up with Marcelo on Facebook and Twitter: @mgleiser.