32 | SCIENCE ILLUSTRATEDI
n 2012, a small team of Hungarian
physicists were ecstatic. A simple
experiment had provided them with a
very unexpected result. What the
scientists had observed did not
comply with any existing theory, and the
explanation could be that the team had
discovered an unknown particle.
Physicist Attila Krasznahorkay and his small
team of colleagues from the Institute for
Nuclear Research in Debrecen, Hungary, had
used a simple particle detector to capture aparticle with a mass corresponding to 34
electrons. Such a particle does not exist in the
standard model, which is physicists’ system for
describing the universe. The model describes
the characteristics of the universe’s tiniest
building blocks, elementary particles, and the
forces of nature that work between them: The
electromagnetic force, the strong nuclear
force, and the weak nuclear force. Gravity can
still not be explained according to the model.
After years of repeated experiments, the
Hungarian scientists are now sure that themysterious particle is something as
sensational as a new elementary particle – a
dark photon. And that is not all. According to
the Hungarians, the dark photon hints that
the universe contains a fifth, unknown force
of nature that works between the invisible
particles that make up dark matter.
In CERN’s Large Hadron Collider, physicists
have been trying to find the proof of dark
matter for years. Other physicists have been
looking for dark matter from space in large
underground detectors. The projects costInfi nite force controls all life
processes on EarthTHE ELECTROMAGNETIC FORCE THE STRONG NUCLEAR FORCE
Nature’s strongest force holds
the atomic nucleus togetherThe electromagnetic force is
the force of nature that makes
two magnets either attract or
reject each other, but the force
also works at the atomic level.
Around all atoms, there is a
cloud of orbiting electrons, and
thanks to their electromagnetic
charge, they combine with the
electrons of other atoms.
Consequently, the force plays a
main role in all chemical
reactions, including the
biochemical life processes in
humans and animals. The force
has an infinite range and
causes phenomena such as
electricity and light.The strong nuclear force holds
the tiniest building blocks of the
atomic nucleus – quarks –
together in protons and
neutrons. Each proton and
neutron consists of three
quarks. The strong nuclear force
works via gluons, which are a
type of glue particles. The range
of the nuclear force is so short
that it does not reach beyond
the atomic nucleus, but on the
other hand, it is the strongest
force of nature. The strength of
the gluon bindings increases,
when quarks are pulled apart.
So, extreme energy is required
to split an atomic nucleus.Power produces magnetism
Magnetism and electricity are two results
of the same force. Their close relationship
is revealed by an electromagnet.Nuclear power uses the
strong nuclear force
Nuclear power uses the energy from
the splitting of atoms such as
uranium. When the atomic nucleus
is split, the strong nuclear force is
interrupted, releasing lots of energy.A wire coiled
around an iron rod
is not magnetic, when
the power is switched off. Magnetic fieldPower sourceWhen uranium-235 is
struck by a neutron,
the atom is converted into
unstable uranium-236.The strong nuclear
force cannot hold the
nucleus together, so it is
divided into smaller atoms.1
(^12)
12
When a current flows
through the wire, the
iron rod immediately
becomes magnetic.
2
In the splitting,
three neutrons
and lots of energy are
released as radiation.
3
The electromagnetic
force is transmitted
between charged particles
by photons. The exchange
of photons produces either
attraction or rejection.
Force carrier:
PHOTON
Electron
Gluon bindings hold
together the 3 quarks that
are the building blocks of
protons and neutrons.
Unlike gravity, the force
gets stronger with distance.
Force carrier:
GLUON
Quark
Gluon
Atomic nucleus
THE UNIVERSE PHYSICS