relative

Examples of relative in the following topics:

• Einstein's Postulates

  • Special relativity is based on Einstein's two postulates: the Principle of Relativity and the Principle of Invariant Light Speed.
  • The Principle of Invariant Light Speed: The speed of light c is a constant, independent of the relative motion of the source and observer.
  • Einstein accepted the result of the experiment and incorporated it in his theory of relativity.
  • Imagine that you can throw a baseball at a speed v (relative to you).
  • His work on relativity, gavity, quantum mechanics, and statistical physics revolutionized physics.

• Gallilean-Newtonian Relativity

  • In this context it is sometimes called Newtonian relativity.
  • Galilean relativity can be shown as follows.
  • Suppose S' is in relative uniform motion to S with velocity v.
  • It is this simple but crucial result that implies Galilean relativity.
  • But it is assumed to hold in absolute space, therefore Galilean relativity holds.

• Relative Velocity

  • Relative velocity is the velocity of an object B, in the rest frame of another object A.
  • Galileo observed the concept of relative velocity by using an example of a fly and a boat.
  • No, because what you measured was the velocity of the fly relative to the velocity of the boat.
  • To obtain the velocity of the fly relative to the shore, $s$, you can use the vector sum as shown: $s=u+v$
  • The concept of relative velocity has to do with your frame of reference.

• Further Reading

• The Doppler Effect

  • The Doppler effect is a periodic event's change in frequency for an observer in motion relative to the event's source.
  • Relative to an onlooker behind the vehicle, the second wave is further from the first wave than one would expect, which suggests a lower frequency.
  • In the example above, the siren moved relative to a stationary observer.
  • If the observer moves relative to the stationary siren, the observer will notice the Doppler effect on the pitch of the siren.
  • Quantitatively, the Doppler effect can be characterized by relating the frequency perceived (f) to the velocity of waves in the medium (c), the velocity of the receiver relative to the medium (vr), the velocity of the source relative to the medium (vs), and the actual emitted frequency (f0):

• Addition of Velocities

  • As learned in a previous atom, relative velocity is the velocity of an object as observed from a certain frame of reference.
  • demonstrates the concept of relative velocity.
  • The girl is riding in a sled at 1.0 m/s, relative to an observer.
  • When she throws the snowball forward at a speed of 1.5 m/s, relative to the sled, the velocity of the snowball to the observer is the sum of the velocity of the sled and the velocity of the snowball relative to the sled:
  • The concept of relative velocity can also be demonstrated using the example of a boat in a river with a current.

• Simultaneity

  • The relativity of simultaneity is the concept that simultaneity is not absolute, but depends on the observer's reference frame.
  • The question of whether the events are simultaneous is relative: in some reference frames the two accidents may happen at the same time, in other frames (in a different state of motion relative to the events) the crash in London may occur first, and still in other frames, the New York crash may occur first.
  • If the two events are causally connected ("event A causes event B"), then the relativity of simultaneity preserves the causal order (i.e.
  • He deduced the failure of absolute simultaneity from two stated assumptions: 1) the principle of relativity–the equivalence of inertial frames, such that the laws of physics apply equally in all inertial coordinate systems; 2) the constancy of the speed of light detected in empty space, independent of the relative motion of its source.
  • Formulate conclusions of the theory of special relativity, noting the assumptions that were made in deriving it

• The Relativistic Universe

  • Special relativity indicates that humans live in a four-dimensional space-time where the 'distance' $s$ between points in space-time can be regarded as:
  • In 1916, Einstein found the importance of these space-times in his theory of general relativity.
  • General relativity, or the general theory of relativity, is the geometric theory of gravitation published by Albert Einstein in 1916.
  • General relativity generalizes special relativity and Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time, or space-time.

• A Quantitative Interpretation of Motional EMF

  • A a motional EMF is an electromotive force (EMF) induced by motion relative to a magnetic field B.
  • An electromotive force (EMF) induced by motion relative to a magnetic field B is called a motional EMF.
  • Therefore, the motional EMF over the length L of the side of the loop is given by $\varepsilon_{motion} = vB \times L$ (Eq. 1), where L is the length of the object moving at speed v relative to the magnet.
  • In fact, the equivalence of the two phenomena is what triggered Albert Einstein to examine special relativity.
  • In his seminal paper on special relativity published in 1905, Einstein begins by mentioning the equivalence of the two phenomena:

• Shifting the Paradigm of Physics

  • Special relativity changed the way we view space and time and showed us that time is relative to an observer.
  • After 1905, however, the Special Theory of Relativity destroyed this old, but intuitive, view.
  • In order to examine this we must know the founding principles of relativity.
  • The Principle of Relativity: The laws of physics for observers which are not accelerating relative to one another should be the same.
  • This factor shows up frequently in special relativity.