New discovery could revolutionise physics

Groundbreaking: The breakthrough was made at the Large Hadron Collider in Geneva. © Getty

Have scientists glimpsed something completely new in nature? A recent discovery in Switzerland could transform physics and upend everything we think we know about the universe.

“We may be on the road to a new era of physics”. This is how physicist Professor Chris Parkes described a new scientific discovery that promises to revolutionise our understanding of the universe.

If his team is right, then they might have discovered a whole new force in nature, comparable to gravity or magnetism. And yet this discovery took place at a level so tiny that even the most powerful microscope would be unable to see it.

This is the level of a type of subatomic particle called a quark. Quarks are the very smallest form of existence that we have been able to detect, and physicists have long believed that they might hold the key to understanding the laws of the universe.

There are six types, or flavours, of quark: up, down, charm, strange, top and bottom (or beauty). All of these decay: they break down into different kinds of particles.

According to the Standard Model of particle physics, we expect beauty quarks to decay into an equal number of two different subatomic particles: electrons and muons. But scientists at the Large Hadron Collider in Geneva observed beauty quarks producing a greater number of muons than electrons.

This suggests a flaw in the Standard Model, which has defined our understanding of physics for the last five decades. The Model explains three of the four fundamental forces in the universe: electromagnetism, the weak force that causes radioactivity, and the strong force that binds atoms together (but not the fourth force, gravitational pull).

However, scientists have long been aware that the Standard Model cannot explain everything. As well as gravity, it is unable to account for the existence of dark matter, which makes up around 85% of the mass of the universe, or dark energy, which is believed to be responsible for the expansion of the universe.

The new findings might be the first step in discovering a fifth force of nature, one that dictates how particles break down. That would bring us closer to a “theory of everything”, a model that could explain everything that happens in the universe.

But scientists warn that the results are not yet certain. For that, they would need to have a significance of 5 sigma, meaning that the chance they came about through a computer error is just 1 in 3.5 million. These results have a significance of just 3.1 sigma, meaning the chance of a computer error is 1 in 1,000 – small, but not entirely implausible.

Quarks are not easy to study, and not just because of their size. Quarks are held together by an extremely powerful forcefield. Separating them takes a vast amount of energy, and results in the creation of an antiquark, which is impossible to measure and bonds to the quark before we can see it.

Of the six types of quark, only two, up and down, appear naturally: the rest have to be created. In fact, quarks are so complex, some scientists have suggested that they do not actually exist at all: they are an illusion that we invented to explain the unexplainable.

Have scientists glimpsed something completely new in nature?

The Force Awakens

Yes, say some. This new discovery could be as significant as Newton’s explanation of gravity or Einstein’s theory of general relativity. We can use it to develop a new model of particle physics that could ultimately explain everything we do not know about gravitational pull, the make-up of the universe, and the causes of the Big Bang. We have peeked into a whole new dimension of our reality.

Not so fast, say others. The scientists who made the discovery have been eager to play down its significance. They point out that they cannot even be completely certain that the discovery was not a computer error. And even if the effect they observed was real, this is only the first step down a long road of scientific research, likely to throw up as many new questions as it answers.

You Decide

  1. What do you think is the most important scientific discovery of all time?
  2. Is a scientific “revolution” still a possibility, or can our knowledge now only advance in small steps?

Activities

  1. Write a diary entry from the perspective of one of the scientists who made this discovery.
  2. Imagine you are due to interview one of the scientists behind the new discovery. Prepare five questions that you could ask them to help a general audience understand its significance.

Some People Say...

“The most exciting phrase to hear in science, the one that heralds new discoveries, is not ‘Eureka!’ but ‘That's funny...’.”

Isaac Asimov (1920 – 1992), American writer and scientist

What do you think?

Q & A

What do we know?
Most people agree that scientific discovery is a long, meticulous process. Scientists first noticed that beauty quarks were decaying in unexpected ways in 2014, although at that time there was too much uncertainty around the result to draw any conclusions. In 2019, a new experiment returned the same results, but with no more certainty. Even yesterday’s results are not yet certain enough for scientists to accept them absolutely: now more work will be needed to verify them absolutely.
What do we not know?
There is some debate over how scientific discoveries are actually made. The philosopher of science Karl Popper believed that the only valid scientific hypothesis is one that is falsifiable: that is, it must be possible to prove that it is untrue. But Thomas Kuhn thought this was too idealistic. In reality, he argued, science advances through paradigm shifts: every so often, all scientists start seeing information in a wholly new way, and this produces new discoveries.

Word Watch

Quark
A type of elementary particle that, when they combine together, form hadrons, which in turn combine to form protons and neutrons, two of the constituent parts of atoms.
Electrons
Negatively charged subatomic particles that form an essential part of any atom, revolving around its positively-charged nucleus.
Muons
Another negatively-charged subatomic particle, like an electron but with a much greater mass.
Large Hadron Collider
A vast particle accelerator, with a circumference of 27km. It is used to fire beams of particles directly at each other, making them collide and form new particles.
Electromagnetism
The force that holds atoms and molecules together, without which matter could not exist.
Weak force
The force that causes radioactive substances to decay. Without it, stars could not exist.
Strong force
The force that holds together protons and neutrons in the nucleus of every atom.
Dark matter
A hypothetical substance, undetectable by human perception and any human instruments. Its existence can only be inferred from anomalies in the universe’s gravitational fields that seem to imply the presence of much greater amounts of mass than we can perceive.
Dark energy
An unknown form of energy that is thought to be responsible for accelerating the expansion of the universe ever since the Big Bang.
Antiquark
A mirror image of a quark, identical in mass but with an opposite electric charge.

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