1) Albert Einstein developed the theory of relativity, which describes the laws of physics for both non-accelerating and accelerating frames of reference. 2) The theory of special relativity, published in 1905, describes motion at constant velocity while general relativity, published in 1915, describes accelerated frames and gravity. 3) One of the most famous equations in physics, E=mc2, comes from the theory of relativity and shows that mass and energy are equivalent and interconvertible.

1. Albert Einstein
By: Sergio Gorcio
Andreas Lopez
Alejandro Lofuente

2. He was born the 14th of March of 1879 in
Ulm ( Baden-wurftemberg Tubinger;
Germany)- and die the 18th of April of 1955
in Princenton (USA) at the age of 76.

3. ► He developed the general theory of relativity, one of
the two pillars of modern physics. ► He is best known
in popular culture for his massenergy equivalence
formula E = mc2 (which has been said to be “ the
world's most famous equation") ► He was jewish

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http://youtu.be/fEZupmc
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Those two videos will help us to understand better what is the
relativity theory
Where does e=mc2 come from?
httD:"voutu.be/ComZbnDHsuE

6. Relativity Theory

7. WHAT IS THE RELATIVITY THEORY ?
► It is a theory developed by Albert Einstein which says that the way that anything except
light moves through time and space depends on the position and movement of
someone who is watching.
► The term "theory of relativity" was based on the expression "relative thecxy"
used in
1906. It emphasized how the theory uses the principle of relativity.
There are really three theories of
relativity:
• Relativity pre-Einstein (Galileo)
• Special Theory of Relativity (1905)
General Theory of Relativity (1915)

8. Concepts introduced by the theories of relativity include: Measurements of
various quantities are relative to the velocities of observers. In particular, space
contracts and time dilates. Spacetime: space and time should be considered together
and in relation to each other.
The speed of light is nonetheless invariant, the same for all observers.

9. Theory of special relativity and the
general relativity
► The theory of relativity includes the theory of special relativity and the the theory of
general relativity, formulated by Albert Einstein in the early twentieth century, which
sought to solve the incompatibility between Newtonian mechanics and
electromagnetism.
► The theory of special relativity, published in 1905, deals with the physics of motion of
bodies in the absence of gravitational forces, which were made compatible Maxwell's
equations of electromagnetism with a reformulation of the laws of motion.
► The theory of general relativity, published in 1915, is a theory of gravity that replaces
Newtonian gravity, although numerically coincides with it for weak gravitational fields
and "small" speeds. The general theory reduces to the special theory in the absence of
gravitational fields.

10. Main concepts
► The basic assumption of the theory of relativity is that the location ot physical events,
both in time and space are relative to the state ot motion of the observer: thus, the
length of a moving object or the instant something happens, unlike what happens in
Newtonian mechanics, are not absolute invariants, and different observers moving
relative to each other will differ about them.

11. Special relativity
► The theory of special relativity, also called theory of relativity, was published by Albert
Einstein in 1905 and describes the physics of movement in the context of a tlat
spacetime. This theory coaectly descnbes the motion of bodies even at high speeds and
electromagnetic interactions and is used primarily to study inerliol reference systems
(not applicable to astrophysical problems where the gfovitotionol field plays on important
role).
► Following publication of the article by Einstein‘s new theory of special relativity was
accepted In o few years by almost oil physicists and mathematicians. In fact. Poincare
and Lorentz had been very close Io reaching the same result as Einstein. The final
geometric form of the theory is due to Hermann Minkowski. Einstein former teacher at
the Polytechnic of Zurich: coined the term "spacetime" (Raumzeiy and gave the
apropiate mathematical form . Minkowski spacetime is a four-dimensional array in which
interlaced of an insoluble way the three spatial dimensions and time. In this Minkowski
spacetime, the molion of a particle is represented by its world line (Weltlinie), a curve
whose points are
determined by four different variables: the three spatial dimensions (x . y . z ) and time
(t ). The new scheme of Minkowski forced to reinterpret existing
concepts metric before. The three-dimensional concept ot point was replaced by the
event. The magnitude of distance is replaced by the scale interval.

12. General relativity
► The General relativity was published by Einstein in 1915. and was presented as a
lecture at the Prussian Academy of Sciences on November 25th. The theory
generalizes the principle of relativity of Einstein for an arbitrary observer. This implies
that the equations of the theory should have a more general Lorentz covariance used in
the theory of special relativity covariance. In addition, the theory of general relativity
suggests that the geometry of spacetime is affected by the presence of matter, which is
a relativistic theory of the gravitational field. In fact the theory of general relativity
predicts that space-time is not flat in the presence of matter and the curvature of
spacetime will be perceived as a gravitational field.
► Einstein said the purpose of the theory of general relativity to fully implement the
program of Ernst Mach in the relativization of all inertial effects, even adding so-called
cosmological constant to his equations of field for this purpose. The
actual contact point of the influence of Ernst Mach was clearly identified in 1918. when
Einstein distinguishes what he termed the principle of Mach (inertial effects arising from
the interaction of bodies) the principle of general relativity, which it is now interpreted as
the principle of covariance general.

13. Formalism of the theory of relativity:
1-Particles
► In the theory of relativity a point particle is represented by a gamma where gamma is
(tau) par: is a differentiable curve, called world line of the particle, m isa scalar that
represents the rest mass. The tangent vector to this curve is a temporary vector colled
cuadrivelocidad. the product of this vector by the rest mass of the particle is precisely the
cuadrimomento. This cuadrimomento is a vector of four components, three of these
components ore called spatial and represent the relativistic analog of linear momentum
of classical mechanics, the other
component called temporal component represents the relativistic generalization of
kinetic energy. Moreover, given an arbitrary curved spacetime can be defined along
she called relativistic interval, obtained from the metric tensor. Relativistic interval
measured along the path of a particle is proportional to the proper time interval or
interval of time received by said particle.

14. Intervals
► intervals can be classified into three categories: spatial intervals (when dsA 2 is
negative), temporary (if ds △ 2 is positive) and null (where / scriptslyle as A 2 = 0). As
the reader will have noticed, null intervals are those that correspond to particles moving
at the speed of light, as photons: The dl A distance 2 traveled by the photon is equal to
the speed (c) multiplied by the time scripfstyle dt and therefore the interval scriptstyle
ds = cA2A2A2dt-dlA2 becomes zero.
Null intervals con be represented as a cone of light, popularized by the renowned book
by Stephen Hawking. History of Time. Be an observer at the origin, the absolute future
(the events that will be perceived by the individual) is displayed on the fop of the vertical
axis, the absolute past (the events that have been perceived by the individual) in Part
inferior, and this perceived by the observer at point 0. the events that are outside tne
light cone not affect us, and therefore is said of them that are located in areas of
spacetime that have no causal link with ours.

15. ► The ecuaion for the theory of relativity is:
► E = Energy
► m= Mass
F =
► c= speed of light (3 * 10 A8m/s. approximareiy)
► Every body is resting energy as a function of its mass, this energy is calculated as
body mass times the speed of light squared.
The equivalence of mass and energy given by the expression of the theory of
relativity by Einstein.
► II indicates that the mass carries a certain amount of power even at rest, absent in
classical mechanics concept, namely that the rest energy of a body is the product of
its mass and its conversion factor (speed of light square), or that a certain amount
of energy from an object at rest by its own mass unit is equivalent to the speed of
light squared.