DARK MATTER

PEPE VINAIXA KINNEARGABRIEL HAN PORRAS

LUCIA TRILLO CARRERAS

WHAT?

• Dark matter is an invisible phenomenon that acts on the visible matter( a pencil, a table…) allowing us to notice its existence

• Throughout the universe, there is 6 times more dark matter than normal matter

• The string theory gives a better explanation for this

When?

• In 1933, a Swiss astronomer called Fritz Zwicky discovered some kind of “invisible matter” meanwhile examining the Coma galaxy.

• In the 1970’s, an astronomer called Vera Rubin was sure about the existence of dark matter and she started to understand the universe in a proper way.

• Although neither of them were mistaken, they were disregarded

Fritz Zwicky and Vera Rubin

Dark Matter Nowadays

• The mystery of dark matter has drawn the attention of many scientists in such an impressive way that many improvements have been made.

• In contrast, nature doesn’t agree that we’ll ever be able to detect dark matter.

DARK ENERGY

WHAT IS DARK ENERGY?

• As same as dark matter, dark energy has been one of the most mysterious issues it exists in science.

• Dark energy is a hypothetical form of energy that permeates all of space and produces a negative pressure, resulting in a repulsive gravitational force. Dark energy may account for accelerated expansion of the universe, as well as most of its mass.

It can not be seen with today technologies, as dark matter

TYPES OF DARK ENERGY

• Two possible forms of dark energy are the cosmological constant and quintessence, the first static and the second dynamic. To distinguish between the two very precise measurements of the expansion of the universe is needed to see if the expansion rate changes over time. These measurements are a topic of current research.

WHAT IS ITS FUNCTION?• Dark energy produces an effect

opposite to the force of gravity, thus opposing the approach and subsequent collision of all the elements that make up the cosmos, and by contrast is responsible for the continued expansion of the universe accelerating and causing separation the above elements of the percentage of the visible universe.

DIFFERENCES BETWEEN

• We shouldn´t confuse dark matter with dark energy dark matter is a form of matter as dark matter´s existence explains the gravitational effects (is matter) while dark energy is a field that fills all space.

STRING THEORY

String theory holds several possibilities for the existence of dark matter. It provides a natural candidate for dark matter in super symmetric particles which scientists have never observed

Probably the simplest explanation of dark matter would be a vast sea of supersymmetric particles residing inside galaxies, but we can’t see them

Supersymmetry implies that every particle science knows about has a superpartner.

A computer simulation, reported in the journal Nature in November 2008, offers dark matter in the halo of the Milky Way galaxy should produce detectable levels of gamma rays. This simulation indicates a direction to start looking for such tell-tale signs, at least.

Another possible dark matter candidate comes from the various brane world scenarios. Though the details still have to be worked out, it’s possible that there are branes that overlap with our own 3-brane.

Perhaps where we have galaxies, there are gravitational objects that extend into other branes.

Finally, the 4-dimensional string theories present

yet another possibility, Bringing string theory down to four dimensions seems to greatly expand the number of particles that physicists would expect to find in the universe, and (if they exist) these could account for dark matter.

String Theory Features• String theory is a work in progress, so trying to pin down

exactly what the science is, or what its fundamental elements are, can be kind of tricky. The key string theory features include:

• All objects in our universe are composed of vibrating filaments (strings) and membranes (branes) of energy.

• String theory attempts to reconcile general relativity (gravity) with quantum physics.

• A new connection (called supersymmetry) exists between two fundamentally different types of particles, bosons and fermions.

• Several extra (usually unobservable) dimensions to the universe must exist.