The Search for New Physics: Misteries That the Standard Model Can’t Explain
The Standard Model comprehends only 4% of our surroundings. Discover the 4 deepest misteries that modern physics can't answer.
The Standard Model stands as one of the most remarkable achievements of modern physics, encapsulating our current understanding of matter’s most fundamental constituents and interactions. This theoretical framework elegantly describes a symphony of 17 particles and 4 forces that shape our physical reality.
And yet, like any scientific theory, the Standard Model is incomplete. As we peer deeper into matter’s inner workings, profound mysteries emerge that lie beyond the Standard Model’s purview. Tantalizing questions about antimatter, dark matter, quantum gravity, and the genesis of cosmic structure beckon scientists to forge ahead into uncharted theoretical territory.
The answers to these riddles have the potential to revolutionize our comprehension of the quantum world and the cosmos at large. Let’s explore some of the biggest unsolved puzzles that researchers are striving to crack open.
Where Has All the Antimatter Gone?
Of all the mysteries about our cosmic origins, the striking disappearance of antimatter ranks among the most confounding. In the infant moments of the Big Bang, matter and antimatter emerged in perfect symmetry, only to later fall radically out of balance.
Why does our universe, as we observe it today, appear to be dominated by matter while antimatter seems to have all but vanished?
Today, antimatter remains astonishingly scarce, making up only trace amounts of natural radiation. Yet the lopsided leftover matter went on to form everything we observe in the universe, from stars to galaxies to life itself. Pinpointing what mechanism disrupted the original symmetry could reveal profound insights about the evolution of cosmic structure.
Physics suggests matter and antimatter should have mutually annihilated in equal measure in the early universe, leaving just energy behind. Yet here we are, made purely of matter. Uncovering why nature exhibits this stark asymmetry drives experimental efforts such as CERN’s ALPHA collaboration, which traps and studies elusive antimatter particles called antihydrogen.
Solving the antimatter riddle may require expanding the Standard Model to incorporate new processes that could have tipped the scales in matter’s favor after the Big Bang. Discovering the source of this asymmetry ranks among the most urgent mysteries at the intersection of cosmology and particle physics.
What Makes up 95% of the Universe?
Beyond the ordinary matter of the Standard Model lies an even more perplexing puzzle – the true identity of dark matter and dark energy. Together, these invisible components make up a staggering 95% of the universe’s total mass and energy.
The existence of dark matter is inferred through its gravitational pull on galaxies and clusters, which proves there is far more mass than we can see. Directly detecting dark matter particles has continued to confound scientists for decades. Leading hypotheses suggest axions or WIMPs may account for this missing mass, but these candidates remain unproven.
Even more mysteriously, dark energy appears to drive the accelerating expansion of the cosmos through an unknown mechanism. Unravelling the nature of these two giant unknowns would transform our comprehension of cosmic evolution and the role of matter and energy at the largest scales.
Experiments such as XENON, LUX-ZEPLIN, and SuperCDMS lie at the cutting edge of the hunt for dark matter, while projects like DESI map galaxies to better understand dark energy. We may need to extend physics beyond the Standard Model into new theoretical territory to make sense of these enormous cosmic puzzles.
How does Gravity Exactly Work?
Of the four fundamental forces, only gravity remains aloof from the Standard Model, refusing to reconcile with the quantum rules governing particles. Developing a quantum theory of gravity ranks among the holy grails of modern physics.
The hypothesized graviton particle would neatly align gravity with the other forces by acting as a mediator of gravitational interactions. While not yet observed, gravitational waves – ripples in spacetime from violent cosmic events – provide evidence that gravitons likely exist.
The hypothesis of the graviton received a resounding endorsement with the groundbreaking discovery of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO). These ripples in the fabric of spacetime, generated by cataclysmic cosmic events, provided direct evidence of the existence of gravitational waves and bolstered the theoretical foundation of the graviton.
Incorporating gravity into the quantum fold could also help explain phenomena like the singularity at the heart of a black hole. Formulating a complete theory of quantum gravity would stand as a monumental leap in our understanding.
What Happened right after the Big Bang?
Perhaps the greatest mystery of all lies at the origin of our universe. The Standard Model falls silent when confronted with the question: what sparked the Big Bang? Researchers are left to speculate about the precursor to our cosmic genesis.
Leading hypotheses propose our observable universe bubbled forth from a quantum fluctuation in an eternal inflationary multiverse, a realm that extends infinitely beyond what we can see. Other radical ideas suggest our cosmos repeatedly expands and contracts through “Big Bounce” cycles. Or perhaps the Big Bang was not a beginning at all, but instead an emergence from a previously collapsed state.
Theorists have abundant creativity, but scarce data, to work with in exploring the ultimate question mark. Our current physics theories simply cannot probe the extreme conditions close to the Big Bang’s initial singularity. We must await new breakthroughs – possibly arising from string theory or quantum loop gravity – before the first moments of genesis come into focus.
