Quantum 101: What is Quantum Physics?

An Introduction for Everyone

Quantum physics is a fascinating branch of science that explores the behavior of matter and energy at the smallest scales of our universe. Imagine a world where objects can exist in multiple places at once, where “entangled” particles separated across vast distances have intertwined fates, and where the very act of observing something can change its nature. This is the strange and captivating realm of quantum physics.

Quantum physics is the foundation of much of the technology we use today, and its principles shape our understanding of the universe at the smallest scales. This article will break down quantum physics in a way that is simple, approachable, and hopefully, a little fun.

The Basics of Quantum Physics

Quantum physics is the science of how the universe behaves at the smallest scales—think atoms, electrons, and photons (particles of light) and the coldest temperatures (around what is referred to as “absolute zero”, beyond which there is nothing colder). It’s a branch of science that allows us to understand and predict the behavior of particles that are so tiny, we can’t see them with the naked eye or most microscopes. Unlike the world we see around us, which is referred to as “Classical Physics” these particles don’t behave in ways we’d expect. Instead, they follow their own set of rules, which often seem bizarre to us humans living at human temperatures and sizes. For example:

• A particle can exist in multiple places at once (this is called superposition).
• Two particles can be mysteriously linked so that what happens to one affects the other—even if they’re miles apart (this is called entanglement).
• Uncertainty is fundamental; there are some things that the universe just won’t let us know. For example, you can’t measure certain combinations of properties to absolute precision, like a particle’s position and speed, at the same time (this is called Heisenberg’s Uncertainty Principle).
• Matter exhibits properties of both particles and waves, a phenomenon known as wave-particle duality.
• The energies of matter exist at only “quantized” or discrete values. This would be like saying the temperature of your coffee may be 120 degrees or 125 degrees but not in between.

To us “Classical” beings, these ideas are strange, but they’ve been confirmed by countless experiments and are at the heart of technologies we use every day (we’ll explore these in more detail in the next blog).

The History of Quantum Physics

Quantum physics emerged in the early 20th century as scientists struggled to explain behaviors they observed that could not be explained by classical physics. Some key moments include:

• 1900: Max Planck proposed that energy is not continuous but comes in tiny packets called “quanta.” This was the first step toward quantum theory.
• 1905: Albert Einstein explained the photoelectric effect, showing that light behaves both as a wave and a particle.
• 1925–1927: Erwin Schrödinger and Werner Heisenberg developed mathematical frameworks to describe quantum systems, such as wave mechanics and matrix mechanics.
• 1935: Einstein, along with Boris Podolsky and Nathan Rosen, described the concept of entanglement, calling it “spooky action at a distance.”

Our understanding and our “ability to exploit” the quantum world continue to evolve, enabling technologies and informing philosophies.

Why Is Quantum Physics Important?

Quantum physics isn’t just a theoretical exercise for scientists; it’s the backbone of modern technology. Without it, we wouldn’t have:

• Lasers (think barcode scanners, DVD players, laser eye surgery, and the backbone of the internet)
• Semiconductors (which make up the chips in your smartphone and computer)
• MRI machines in hospitals
• GPS systems that guide you to your destination

More importantly, quantum physics is paving the way for revolutionary advancements, including quantum computing and quantum networking. These technologies have the potential to transform industries like healthcare, finance, and cybersecurity.

Everyday Quantum Physics 

Did you know that you’re already using quantum physics in your daily life? Here are a few examples:

LEDs and Solar Panels: Quantum mechanics explains how electrons move through materials to produce light in LEDs or generate electricity in solar panels.

Your Smartphone: The transistors in microchips are governed by quantum principles, allowing your phone to function.

Modern Medicine: Techniques like magnetic resonance imaging (MRI) rely on quantum principles to provide detailed images of the human body.

Your Toaster Oven: The red coils you see glowing when you make toast is a quantum effect.

How Does It All Work? A Simple Analogy

Think of the quantum world as a playground. In the classical world, we experience a ball rolling down a slide in one predictable path. You can see where it is and where it’s going at any given moment. In the quantum world, however, the ball can roll down multiple paths at once—until someone looks at it. The act of observing the ball forces it to “choose” a path. This is a key feature of quantum mechanics and one of the reasons it’s so fascinating (and confusing!).

Quantum Physics and the Future

Understanding quantum physics isn’t just for scientists or academics. It’s becoming increasingly important for policymakers, business leaders, and everyday people to grasp its basics. Why? Because the next wave of innovation—whether in technology, medicine, or national security—will be powered by quantum principles.

Here are some exciting possibilities on the horizon:

• Quantum Computing: Imagine computers that can solve problems in seconds that would take today’s most powerful supercomputers millions of years.
• Quantum Networking: This could enable completely secure communication, protecting sensitive information in ways beyond classical network security including classical cryptography.
• Quantum Sensors: Ultra-sensitive devices could lead to breakthroughs in areas like early disease detection and environmental monitoring.
• Advanced Materials: Quantum physics could lead to the discovery of new materials with properties we can’t even imagine today.

Breaking Barriers: Quantum for Everyone

One of the biggest challenges in quantum physics is making it accessible. For a long time, it’s been seen as the domain of physicists and mathematicians. But as quantum technologies move from the lab to real-world applications, it’s crucial for everyone—especially decision-makers—to understand its implications. The good news is you don’t need a degree in physics to appreciate its beauty and potential—just a little curiosity and an open mind.

This blog is part of QED-C’s Quantum 101 series. In these blogs, we’ll unpack the concepts, applications, and exciting possibilities of quantum. Stay tuned for the next post, where we’ll demystify terms like superposition, entanglement, and uncertainty.