Suppose Alice and Bob are both asked to prepare a meal. Alice likes Chinese, Bob likes Italian. They each pick their favorite recipe, shop at the local specialty store, and carefully follow the instructions. But when they take their dishes out of the oven, they are in for a big surprise. The two meals turn out to be identical. We can imagine the existential questions Alice and Bob must ask themselves. How can different ingredients produce the same dish? What does it even mean to cook Chinese or Italian? And is their approach to preparing food totally flawed?
This is exactly the perplexity experienced by quantum physicists. They have found many examples of two completely different descriptions of the same physical system. In the case of physics, instead of meats and sauces, the ingredients are particles and forces; the recipes are mathematical formulas encoding the interactions; and the cooking process is the quantization procedure that turns equations into the probabilities of physical phenomena. Just like Alice and Bob, quantum physicists wonder how different recipes lead to the same outcomes.
Did nature have any choice in picking its fundamental laws? Albert Einstein famously believed that, given some general principles, there is essentially a unique way to construct a consistent, functioning universe. In Einstein’s view, if we probed the essence of physics deeply enough, there would be one and only one way in which all the components — matter, radiation, forces, space and time — would fit together to make reality work, just as the gears, springs, dials and wheels of a mechanical clock uniquely combine to keep time.
The current Standard Model of particle physics is indeed a tightly constructed mechanism with only a handful of ingredients. Yet instead of being unique, the universe seems to be one of an infinitude of possible worlds. We have no clue why this particular combination of particles and forces underlies nature’s structure. Why are there six “flavors” of quarks, three “generations” of neutrinos, and one Higgs particle? Furthermore, the Standard Model comes with 19 constants of nature — numbers like the mass and charge of the electron — that have to be measured in experiments. The values of these “free parameters” seem to be without any deeper meaning. On the one hand, particle physics is a wonder of elegance; on the other hand, it is a just-so story.
If our world is but one of many, how do we deal with the alternatives? The current point of view can be seen as the polar opposite of Einstein’s dream of a unique cosmos. Modern physicists embrace the vast space of possibilities and try to understand its overarching logic and interconnectedness. From gold diggers they have turned into geographers and geologists, mapping the landscape in detail and studying the forces that have shaped it.
The game changer that led to this switch of perspective has been string theory. At this moment it is the only viable candidate for a theory of nature able to describe all particles and forces, including gravity, while obeying the strict logical rules of quantum mechanics and relativity. The good news is that string theory has no free parameters. It has no dials that can be turned. It doesn’t make sense to ask which string theory describes our universe, because there is only one. The absence of any additional features leads to a radical consequence. All numbers in nature should be determined by physics itself. They are no “constants of nature,” only variables that are fixed by equations (perhaps intractably complicated ones).
Which brings us to the bad news. String theory’s space of solutions is vast and complex. This is not unusual in physics. We traditionally distinguish between fundamental laws given by mathematical equations, and the solutions of these equations. Typically, there are only a few laws, but an infinite number of solutions. Take Newton’s laws. They are crisp and elegant but describe an incredibly wide range of phenomena, from a falling apple to the orbit of the moon. If you know the initial conditions of a specific system, the power of these laws allows you to solve the equations and predict what is going to happen next. We do not expect, nor demand, an a priori unique solution that describes everything.
In string theory, certain features of physics that we usually would consider laws of nature — such as specific particles and forces — are in fact solutions. They are determined by the shape and size of hidden extra dimensions. The space of all of these solutions is often referred to as “the landscape,” but that is a wild understatement. Even the most awe-inspiring mountain vistas pale in comparison with the immensity of this space. Although its geography is only marginally understood, we know it has continents of huge dimensions. One of the most tantalizing features is that possibly everything is connected — that is, every two models are connected by an unbroken path. By shaking the universe hard enough, we would be able to move from one possible world to another, changing what we consider the immutable laws of nature and the special combination of elementary particles that make up reality.
But how do we explore the vast landscape of physical models of the universe that might easily have hundreds of dimensions? It’s helpful to visualize the landscape as a largely undeveloped wilderness, most of it hidden under thick layers of intractable complexity. Only at the very edges do we find habitable places. In these outposts, life is simple and good. Here we find the basic models that we fully understand. They are of little value in describing the real world, but serve as convenient starting points to explore the local neighborhood.
A good example is QED, the theory of quantum electrodynamics that describes the interactions between matter and light. This model has a single parameter, called the fine-structure constant α, which measures the strength of the force between two electrons. Numerically, it is close to $latex ^1/_{137}$. In QED, all processes can be seen as arising out of elementary interactions. For example, the repulsive force between two electrons can be visualized as an exchange of photons. QED asks us to consider all possible ways that two electrons might exchange a photon, which in practice would mean that physicists have to solve an infinite sum of great complexity. But the theory also offers a way out: Each additional photon exchange adds a term that includes α raised to an additional power. Since this is a relatively small number, the terms with many exchanges make only a small contribution. They can be neglected in an approximation to the “real” value.
We find these weakly coupled theories at the outposts of the landscape. Here the strength of the forces is small and it makes sense to talk about the shopping list of elementary particles and the recipe that computes their interactions. But if we leave the immediate environment and travel more deeply into the wilderness, the couplings become large and each additional term in the expansion grows more important. Now we can no longer distinguish the individual particles. Instead they dissolve into an entangled mesh of energy like the ingredients of a cake in a hot oven.
However, not everything is lost. Sometimes the path through the dark wilderness ends at another outpost. That is, at a different well-controlled model, this time made out of a completely different set of particles and forces. In such cases, there are two alternative recipes for the same underlying physics, just as with Alice and Bob’s dishes. These complementary descriptions are called dual models, and the relation between them a duality. We can consider these dualities as a grand generalization of the famous particle-wave duality discovered by Heisenberg. For Alice and Bob, it takes the form of a translation between Chinese and Italian recipes.
Why is this all so exciting for physics? First of all, the conclusion that many, if not all, models are part of one huge interconnected space is among the most astonishing results of modern quantum physics. It is a change of perspective worthy of the term “paradigm shift.” It tells us that instead of exploring an archipelago of individual islands, we have discovered one massive continent. In some sense, by studying one model deeply enough, we can study them all. We can explore how these models are related, illuminating their common structures. It is important to stress that this phenomenon is largely independent of the question of whether string theory describes the real world or not. It is an intrinsic property of quantum physics that is here to stay, whatever the future “theory of everything” will turn out to be.
A more dramatic conclusion is that all traditional descriptions of fundamental physics have to be thrown out. Particles, fields, forces, symmetries — they are all just artifacts of a simple existence at the outposts in this vast landscape of impenetrable complexity. Thinking of physics in terms of elementary building blocks appears to be wrong, or at least of limited reach. Perhaps there is a radical new framework uniting the fundamental laws of nature that disregards all the familiar concepts. The mathematical intricacies and consistencies of string theory are a strong motivation for this dramatic point of view. But we have to be honest. Very few current ideas about what replaces particles and fields are “crazy enough to be true,” to quote Niels Bohr. Like Alice and Bob, physics is ready to throw out the old recipes and embrace a modern fusion cuisine.
FAQs
Do the laws of physics exist? ›
Several general properties of scientific laws, particularly when referring to laws in physics, have been identified. Scientific laws are: True, at least within their regime of validity. By definition, there have never been repeatable contradicting observations.
Do the laws of physics apply outside the universe? ›Astrophysicists have found that the laws of physics in outer space are different to those in our galaxy. By analysing a quasar signal from 13 billion years ago, they found that in addition, the magnitude of changes in these laws of physics in the Universe varies. Professor Mariusz P.
What are the 3 basic laws of physics? ›In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.
Do black holes break the laws of physics? ›Black holes obey all laws of physics, including the laws of gravity. Their remarkable properties are in fact a direct consequence of gravity. In 1687, Isaac Newton showed that all objects in the Universe attract each other through gravity. Gravity is actually one of the weakest forces known to physics.
Has any law of physics been broken? ›However, the strong force, which holds together subatomic particles, was thought to adhere to the law of parity, at least under normal circumstances. Now this law appears to have been broken by a team of about a dozen particle physicists, including Jack Sandweiss, Yale's Donner Professor of Physics.
Can a law of physics be broken? ›Laws of physics cannot be "broken" per se, and there are no real consequences for doing so. Demonstrating a physical law invalid would necessitate investigation into the phenomenon, and if the "breaking" of the law is shown to be reproducible, new physics will be discovered to further our understanding of the world.
Are the laws of nature the same everywhere? ›The laws of nature are the same everywhere and something that can unite people. When you study physics, it does not matter where you come from, we can all unite behind the science.
What came before the universe? ›In the beginning, there was an infinitely dense, tiny ball of matter. Then, it all went bang, giving rise to the atoms, molecules, stars and galaxies we see today. Or at least, that's what we've been told by physicists for the past several decades.
Can anything defy the laws of physics? ›While it is certainly not possible to circumvent the laws of physics, figuring out ways that try to break these laws often helps in learning something new about the universe. Here's a list of 9 such objects/devices that makes us question the physics as we know it!
What is the 4th law of physics? ›Newton's Law of gravitation is called Newton's fourth law. It states that every point mass attracts every other point mass by a force acting along the line intersecting both points.
What is the most popular law in physics? ›
Law of conservation of energy
It states that energy can neither be created nor destroyed but it can be transformed from one form to another. Since energy cannot be created or destroyed, the amount of energy present in the universe is always remain constant.
Basic Principles of Physics
Newton's Laws of Motion. Gravity Theory. Work, Energy and Power. Force, Mass and Weight.
Black holes are so massive that they severely warp the fabric of spacetime (the three spatial dimensions and time combined in a four-dimensional continuum). For this reason, an observer inside a black hole experiences the passage of time much differently than an outside observer.
Does time stop in a black hole? ›Near a black hole, the slowing of time is extreme. From the viewpoint of an observer outside the black hole, time stops. For example, an object falling into the hole would appear frozen in time at the edge of the hole.
What is the only thing that can destroy a black hole? ›Black holes, the insatiable monsters of the universe, are impossible to kill with any of the weapons in our grasp. The only thing that can hasten a black hole's demise is a cable made of cosmic strings, a hypothetical material predicted by string theory.
Can time be stopped physics? ›In order for you to stop time, you would have to be traveling infinitely fast. Nothing can travel faster than light (let alone infinitely fast) without gaining infinite mass and energy, according to Einstein's theory of relativity.
Does quantum mechanics disprove Newton's laws? ›Yes, We now know that Newton's "Laws" of Motion cannot be used in the realm of very large speeds (approaching the speed of light), nor at the microscopic level. In these cases, they have been superseded by Einstein's theory of Relativity and Quantum Mechanics, respectively.
Can energy be destroyed physics? ›The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another. This means that a system always has the same amount of energy, unless it's added from the outside.
Is Karma a law of physics? ›The law of karma can be understood as the ethical application of the third law of physics: for every action there is a reaction. Science has been investigating the power of vibrations that come from thought.
What objects break the laws of physics? ›An curved arrow pointing right. A new study suggests subatomic particles called muons are breaking the laws of physics.
Are laws of physics inevitable? ›
There is some inevitability to the laws of physics. To figure out what behavior is possible for particles of a given spin, bootstrappers consider simple particle interactions, such as two particles annihilating and yielding a third. The particles' spins place constraints on these interactions.
What violates the laws of nature? ›For example, smoking cigarettes introduces known carcinogenic compounds which cause DNA mutation, and cancers to form in the bronchii and lungs. Smoking is thus an example of an action that “violates natural law,” an action that stimulates certain laws of nature to produce undesirable consequences.
Do the laws of physics apply in other galaxies? ›All parts of the universe are subject to the same simple laws of nature that we find here on Earth. Planets, stars, and galaxies move according to the same law of gravity that governs the flight of a baseball. Light from distant galaxies reveals the same atomic and nuclear physics that we observe in our laboratories.
Can the laws of nature ever be broken? ›It's true that you cannot “violate” a law of nature, but that's not because the laws of nature 'force' you to behave in some certain way. It is rather that whatever you do, there is a true description of what you have done.
How will the universe end? ›Eventually, the entire contents of the universe will be crushed together into an impossibly tiny space – a singularity, like a reverse Big Bang. Different scientists give different estimates of when this contraction phase might begin. It could be billions of years away yet.
How did the universe come from nothing? ›The Big Bang was the moment 13.8 billion years ago when the universe began as a tiny, dense, fireball that exploded. Most astronomers use the Big Bang theory to explain how the universe began.
What created the universe? ›Our universe began with an explosion of space itself - the Big Bang. Starting from extremely high density and temperature, space expanded, the universe cooled, and the simplest elements formed. Gravity gradually drew matter together to form the first stars and the first galaxies.
Does Spider Man obey the laws of physics? ›While superheroes such as Spider-Man and Superman can teach the world a lot about physics, the superheroes also defy the laws of physics, Dennin said.
Are laws of physics absolute? ›In theory, the laws of physics are absolute. However, when it comes to the laws of thermodynamics —- the science that studies how heat and temperature relate to energy -— there are times where they no longer seem to apply.
What science does not become laws? ›Theories can never become laws, because laws form the body of evidence upon which we base theories. Laws can help with formulating theories, but theories do not develop into laws. Page 3. 58 Science and Children. Finally, hypotheses, while a natural part of the scientific process, do not generally evolve into theories.
How many laws of physics are there? ›
There are 12 basic laws of physics, though there are many other laws of physics too. The 12 basic laws of physics are: The four laws of thermodynamics. Newton's three laws of motion.
What is the first rule of physics? ›Newton's first law: An object at rest remains at rest, or if in motion, remains in motion at a constant velocity unless acted on by a net external force.
What is the quantum law? ›Quantum is the amount of damages that are awarded to a successful party in a claim. For further information, see Measure of damages in contract and Measure of damages in tort. Resource ID w-006-5766.
What is the most famous equation in physics? ›Kane and Morton M. Sternheim,' says: The equation E = Mc2 is perhaps the most famous equation of twentieth- century physics. It is a statement that mass and energy are two forms of the same thing, and that one can be converted into the other (ibid., p.
What is the most accepted theory of physics? ›Big Bang theory is the most accepted theory to explain the origin of universe.
What are the four pillars of physics? ›The four fundamental forces are gravity, electromagnetism, weak nuclear force, and strong nuclear force.
What are the 4 basic concepts of physics? ›- Classical Mechanics (The Laws of Motion) If you've studied any sort of science, you've probably heard the story of Isaac Newton sitting under an apple tree and formulating the basic laws of motion. ...
- Electromagnetism. What is light? ...
- Relativity. ...
- Thermodynamics.
Physics is the branch of science that deals with the structure of matter and how the fundamental constituents of the universe interact. It studies objects ranging from the very small using quantum mechanics to the entire universe using general relativity.
How long is 1 minute in a black hole? ›The closer an observer moves toward a black hole, the more dilation of time they would experience. One hour for a black hole observer would equate to 100,000,000 years for a person on Earth. Therefore one minute in a black hole would be roughly 1,700,000 years.
Is it possible to travel backwards in time? ›Traveling backward in time is much harder, but mathematics says it is possible through geometric structures called closed timelike curves. A wormhole is one such curve. You would enter it through a spherical opening. Once inside, everything you observed in space would be normal and so would the passage of time.
In which dimension do we live in? ›
Physics > Thinking in Three Dimensions. We live in a world of three dimensions. We move through space , either left or right, forward or backward, up or down. Everything around us, from the houses we live in to the objects we use in everyday life, has three dimensions: height, length, and width.
Does time exist in space? ›Although there is nothing in physics that says time must flow in a certain direction, scientists generally agree that time is a very real property of the Universe. Our science is thus based on the assumption that the laws of physics, and the passage of time, exist throughout the Universe.
Can I safely orbit a black hole? ›It is possible to be near a black hole without falling into it, provided you move rapidly. This is similar to what happens in the solar system: Earth does not fall into the Sun because we move around it at a speed of some 67 thousand miles per hour.
Do wormholes exist? ›Wormholes are shortcuts in spacetime, popular with science fiction authors and movie directors. They've never been seen, but according to Einstein's general theory of relativity, they might exist.
What can destroy a star? ›Stars are so large that the gravitational forces holding them together are strong enough to keep the nuclear reactions from blowing them apart. It is the gravitational rebound that blows apart a star in a supernova.
What can destroy the sun? ›The sun will start to die when it runs out of fuel in about 5,000,000,000 years (that's five billion years).
What happens if 2 black holes collide? ›It is possible for two black holes to collide. Once they come so close that they cannot escape each other's gravity, they will merge to become one bigger black hole.
Are the laws of physics absolute? ›In theory, the laws of physics are absolute. However, when it comes to the laws of thermodynamics —- the science that studies how heat and temperature relate to energy -— there are times where they no longer seem to apply.
How accurate is the laws of physics? ›They are approximations that range from very good (we can compute the magnetic moment of the electron to 9 decimal places) to qualitative accuracy (often you are happy to get within 10% of an experiment).
Are laws of physics invented or discovered? ›These are invented, as they did not exist before the person who created the approximate formulation thought of them and wrote them down.
What is the greatest law of physics? ›
Law of conservation of energy
It states that energy can neither be created nor destroyed but it can be transformed from one form to another. Since energy cannot be created or destroyed, the amount of energy present in the universe is always remain constant.
Conservation of Mass and Energy
The first principle simply says that the laws of physics apply equally to everyone in all situations. The second principle is the more important one. It stipulates that the speed of light in a vacuum is constant.
These four basic forces are known as fundamental because they alone are responsible for all observations of forces in nature. The four fundamental forces are gravity, electromagnetism, weak nuclear force, and strong nuclear force.
Is physics a science or math? ›Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves.
Is physics constant throughout the universe? ›Instead, this 'magic number' known as the fine-structure constant -- 'alpha' for short -- appears to vary throughout the universe. A team of astrophysicists based in Australia and England has uncovered evidence that the laws of physics are different in different parts of the universe.
Are scientific laws 100% true? ›Both scientific laws and theories are considered scientific fact. However, theories and laws can be disproven when new evidence emerges. Certain accepted truths of Newtonian physics were partially disproven by Albert Einstein's theory of relativity.
Who invented laws of physics? ›Isaac Newton is popularly remembered as the man who saw an apple fall from a tree, and was inspired to invent the theory of gravity. If you have grappled with elementary physics then you know that he invented calculus and the three laws of motion upon which all of mechanics is based.
Did Albert Einstein invent physics? ›As a physicist and mathematician, Einstein wasn't an inventor in the vein of Thomas Edison or Alexander Graham Bell, but his theories of relativity led to new ways of looking at time, space, matter, energy and gravity.
Is physics the father of science? ›...
Father of Physics in India.
| Father of Physics in India | Role |
|---|---|
| Satyendranath Bose. | He specialized in theoretical physics. |
Isaac Newton's 1687 description of gravity was considered scientific law until Einstein's General Theory of Relativity, published more than two centuries later. Newton had explained gravity as a force that instantaneously acts over a distance. The result is a pull between any two objects in the universe.