Buzz
Science has evolved so much that it almost seems laughable when we think of ancient beliefs. Back then, humans often confused correlation with causation, which led them to believe that sneezing could summon lightning, and that child sacrifices made crops flourish. They even worshipped cats as divine beings, not realizing they were just ordinary, indifferent creatures. Yet, despite how far we’ve come—from proving the Earth is a globe (and not flat) to advances like genomic research—we still find ourselves with numerous unresolved questions. Some of these mysteries are so significant, so basic, and so commonly observed that it’s hard to believe we haven’t unraveled them. Here are ten of those astonishing scientific puzzles.
10. What is Life?
Given that we experience life every day—ours, that of others, our pets, and even the food we eat—you might find it surprising that we still can’t agree on a concrete definition of what life actually is. We’ve proposed hundreds of definitions, but none seem to fully fit the bill.
One definition suggests that life maintains internal stability, but smart thermostats do that too. Another criterion is that life must be cellular, but lipids spontaneously form vesicles in water, with no living organisms or genetic instructions involved. Reproduction is often listed as essential, but 99.99% of ants on Earth are unable to reproduce—does that make them not alive? There’s also the tricky issue with viruses: despite being made of organic material, having genes, evolving through natural selection, and being capable of self-replication, we don’t consider them alive. This is because they need a host and don’t engage in metabolism. Still, we remain uncertain about where the line is drawn between life and non-life.
9. Why Do We Need Sleep?
We have a limited time on Earth, yet for some mysterious reason, we spend a full third of it asleep (and hopefully not much more). From an evolutionary perspective, sleep doesn’t seem to make much sense. Whatever benefits it offers must be weighed against the fact that we lose a third of our time foraging for food or seeking out mates. Worse, we’re left defenseless to predators during that time. So, why do we sleep?
The answer remains unclear. We know sleep offers numerous benefits, like memory consolidation, hormone regulation, and passive skill development, but why does it require us to be unconscious? Some creatures, like dolphins, alternate shutting down halves of their brains, keeping one side alert at all times. Others sleep deeply but only need a few hours. It seems that early humans who slept for long periods were more vulnerable to predators and less likely to pass on their genes for longer sleep. So, how did such a trait become widespread? What hidden advantage of sleep makes it worth the risks?
8. Does Time Really Exist?
We can glance at our watch and see time ticking away, so it seems real. But is time something we’ve invented, or is it an intrinsic part of the universe, like mass and energy? Physicists remain divided: some believe time is a genuine phenomenon but they’re unsure how it works, while others argue that time doesn’t exist at all (though most lean toward the first perspective).
Scientists often regard time as the fourth dimension: every object can be defined by four coordinates (X, Y, Z, and time). However, according to general relativity, time is experienced differently by different observers, as gravity can warp and stretch time depending on location. If every observer experiences time uniquely, can time itself truly have a single, consistent definition? Some physicists argue that it doesn’t; rather, we simply impose sequences onto events to make sense of them, due to the inherent flaws in our perception.
7. Why Do Some People Favor One Hand Over the Other?
For an unknown reason, humans tend to favor one hand over the other. The mystery of why this happens persists. Even more puzzling, about 85-90% of people prefer their right hand, leaving only 10-15% as left-handed. But the intrigue doesn’t end there: many other animals, such as dogs, cats, and kangaroos, also show handedness. So what’s behind this phenomenon?
The exact cause remains elusive. There are theories that explain why most people prefer one hand: as tool use became essential to survival, and because humans are social creatures, it makes sense to craft tools in the most universally useful way. But this assumes that handedness was already a trait for both hands—so how did that come to be? And why is the right hand preferred over the left? If the right is indeed more advantageous, why do 10-15% of individuals continue to favor their left hand?
6. How Many Planets Are There in Our Solar System?
This isn't some wild conspiracy claiming Pluto is a planet, because it isn’t—it's a dwarf planet (Jerry); but even though Pluto lost its place as the ninth planet, many astronomers think another planet rightfully deserves that title.
For years, there have been theories suggesting the existence of planets beyond Neptune. Pluto itself was once purely theoretical. While many of these proposed planets have been ruled out, scientists continue to suggest new possibilities, and they have good reason: things just don’t seem right beyond Neptune. Many objects out there—mostly dwarf planets and minor planets—are arranged in an oddly uneven manner. They aren’t distributed randomly as you might expect. Instead, it appears that a large body beyond Neptune is influencing their movement with its gravity, and this hypothetical body is often referred to as planet nine.
5. What Are Fingerprints?
Our fingerprints, like handedness, are so common and mundane that we rarely pause to question them. They're just those little ridges on our fingertips. So, what's the mystery? Actually, there are a few.
First, fingerprints are almost completely unique to each person. Even identical twins have distinct fingerprints. How or why this happens remains a mystery. While some might argue it’s a product of random development and life experiences, this theory is disproven by the fact that fingerprints remain exactly the same throughout a person’s life. They form uniquely and stay fixed. Furthermore, we don't know when or why they evolved. One popular theory suggests they help with grip during tree-climbing, but research has shown that fingerprints actually reduce grip by decreasing skin-to-object contact, thus lowering friction. And even if this theory holds, why would each person’s fingerprints be so different?
4. Why Does Physics Just Seem to Fall Apart Sometimes?
Just when physicists thought they were on the right track, quantum entanglement came along. It’s so perplexing that Einstein famously referred to it as ‘spooky action at a distance.’
At its core, entanglement is the mind-boggling phenomenon where two particles become so closely linked that whatever happens to one instantly affects the other—no matter how far apart they are. For instance, individual photons can split into entangled pairs. If one of these photons were taken to another room, or even to distant galaxies, and something altered it, the other photon would feel the change immediately (or at least far faster than the speed of light). This means information travels between the two particles faster than light, which defies the laws of physics. And yet, this is happening.
3. What Exactly Is Gravity?
As Blood, Sweat, and Tears aptly put it, ‘What goes up must come down.’ The strange part? We still don’t know why or how this happens. Gravity, the fundamental force that’s so intuitive that even young children grasp its basic principles, remains one of the most perplexing mysteries in science.
Newton provided us with a solid equation to predict and calculate gravity by describing it as a force. Then Einstein offered a more plausible explanation, stating that gravity isn’t actually a force, but rather the result of mass bending spacetime. However, particle physics and quantum mechanics have since suggested that the way we understand gravity either doesn’t hold up or requires more refinement. While mass, energy, and the three other fundamental forces are composed of particles, gravity doesn’t seem to follow this pattern—at least, not that we can prove. The elusive ‘graviton,’ if it exists, has yet to be discovered.
2. What Is Most of the Universe Made Of?
We often think of the universe as mostly empty (hence the term ‘space’), with planets, stars, and similar objects scattered throughout. However, the matter contained in all these objects accounts for less than 5% of the entire universe’s mass. The remaining 95% consists of dark matter and dark energy, and we have no clear understanding of what these mysterious forces are. We only know they exist because we can detect their influence on the universe’s expansion.
We’re certain that dark matter and dark energy don’t account for planets, stars, or any other visible matter. We also know it isn’t antimatter, as we can detect the explosive interactions between antimatter and matter. Beyond that, we’re left with a few competing theories, but with so little concrete evidence to support them, it’s unlikely any of them will definitively explain the mystery anytime soon.
1. Um… Turtles?
Among the many unanswered questions that evolution has yet to solve, the origin of turtles stands out as particularly baffling. With the advancements in genetic research, developmental technology, and an ever-growing body of fossil evidence, we're inching closer to an answer. Yet, the mystery endures. This isn’t cutting-edge quantum science we’re talking about—it’s the origin of turtles. It’s surprising that we still haven’t figured it out.
Turtles are remarkably unique from a skeletal standpoint. Their shells are formed from dramatically altered ribs, vertebrae, and pelvic bones. These bones develop underneath the turtle's skin, covered by a keratin layer—the same substance that makes up our nails. Additionally, turtles are anapsids, meaning they lack a skull hole that nearly every other vertebrate possesses. No close relatives of theirs—who we still debate the exact nature of—share these distinct features. It’s such an unusual and extreme adaptation, and due to the scarcity of transitional forms, the question of how turtles came to be remains open.
