Albert Einstein - Biography

Nationality: German

Born: March 14, 1879
Death: April 18, 1955

Spouse:

Mileva Maric (1903 - 1919)
Elsa Lowenthal (1919 - 1936)

1921 Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect" (from the official Nobel Prize announcement)
Albert Einstein - Early Work:

In 1901, Albert Einstein received his diploma as a teacher of physics and mathematics. Unable to find a teaching position, he went to work for the Swiss Patent Office. He obtained his doctoral degree in 1905, the same year he published four significant papers, introducing the concepts of special relativity and the photon theory of light.
Albert Einstein & Scientific Revolution:

Albert Einstein's work in 1905 shook the world of physics. In his explanation of the photoelectric effect he introduced the photon theory of light. In his paper "On the Electrodynamics of Moving Bodies," he introduced the concepts of special relativity.

Einstein spent the rest of his life and career dealing with the consequences of these concepts, both by developing general relativity and by questioning the field of quantum physics on the principle that it was "spooky action at a distance."
Albert Einstein Moves to America:

In 1933, Albert Einstein renounced his German citizenship and moved to America, where he took a post at the Institute for Advanced Study in Princeton, New Jersey, as a Professor of Theoretical Physics. He gained American citizenship in 1940.

He was offered the first presidency of Israel, but he declined it, though he did help found the Hebrew University of Jerusalem.
Misconceptions About Albert Einstein:
The rumor began circulating even while Albert Einstein was alive that he had failed mathematics courses as a child. While it is true that Einstein began to talk late - at about age 4 according to his own accounts - he never failed in mathematics, nor did he do poorly in school in general. He did fairly well in his mathematics courses throughout his education and briefly considered becoming a mathematician. He recognized early on that his gift was not in pure mathematics, a fact he lamented throughout his career as he sought out more accomplished mathematicians to assist in the formal descriptions of his theories.

What Is Quantum Physics?:

Quantum physics is the study of the behavior of matter and energy at the molecular, atomic, nuclear, and even smaller microscopic levels. In the early 20th century, it was discovered that the laws that govern macroscopic objects do not function the same in such small realms.
What Does Quantum Mean?:
"Quantum" comes from the Latin meaning "how much." It refers to the discrete units of matter and energy that are predicted by and observed in quantum physics. Even space and time, which appear to be extremely continuous, have smallest possible values.
Who Developed Quantum Mechanics?:
As scientists gained the technology to measure with greater precision, strange phenomena was observed. The birth of quantum physics is attributed to Max Planck's 1900 paper on blackbody radiation. Development of the field was done by Max Planck, Albert Einstein, Niels Bohr, Werner Heisenberg, Erwin Schroedinger, and many others. Ironically, Albert Einstein had serious theoretical issues with quantum mechanics and tried for many years to disprove or modify it.
What's Special About Quantum Physics?:
In the realm of quantum physics, observing something actually influences the physical processes taking place. Light waves act like particles and particles act like waves (called wave particle duality). Matter can go from one spot to another without moving through the intervening space (called quantum tunnelling). Information moves instantly across vast distances. In fact, in quantum mechanics we discover that the entire universe is actually a series of probabilities. Fortunately, it breaks down when dealing with large objects, as demonstrated by the Schroedinger's Cat thought experiment.
Quantum Optics:
Quantum optics is a branch of quantum physics that focuses primarily on the behavior of light, or photons. At the level of quantum optics, the behavior of individual photons has a bearing on the outcoming light, as opposed to classical optics, which was developed by Sir Isaac Newton. Lasers are one application that has come out of the study of quantum optics.
Quantum Electrodynamics (QED):
Quantum electrodynamics (QED) is the study of how electrons and photons interact. It was developed in the late 1940s by Richard Feynman, Julian Schwinger, Sinitro Tomonage, and others. The predictions of QED regarding the scattering of photons and electrons are accurate to eleven decimal places.

What Is Physics?

Physics is the scientific study of matter and energy and how they interact with each other.

This energy can take the form of motion, light, electricity, radiation, gravity . . . just about anything, honestly. Physics deals with matter on scales ranging from sub-atomic particles (i.e. the particles that make up the atom and the particles that make up those particles) to stars and even entire galaxies. How Physics Works
As an experimental science, physics utilizes the scientific method to formulate and test hypotheses that are based on observation of the natural world. The goal of physics is to use the results of these experiments to formulate scientific laws, usually expressed in the language of mathematics, which can then be used to predict other phenomena.

The Role of Physics in Science
In a broader sense, physics can be seen as the most fundamental of the natural sciences. Chemistry, for example, can be viewed as a complex application of physics, as it focuses on the interaction of energy and matter in chemical systems. We also know that biology is, at its heart, an application of chemical properties in living things, which means that it is also, ultimately, ruled by the physical laws.

An expandable molecular sponge

Zinc ions and some other metal ions can bind to three or four organic molecules at once. If those molecules are long and attach to zinc at both ends, it's possible to create a metal–organic framework (MOF), an open sheet of linked molecules with ions at the vertices. And if those sheets bind to each other and stack in register, the result is a material whose columnar pores can store, catalyze, or otherwise usefully process small molecules. Matthew Rosseinsky and his coworkers at the University of Liverpool in the UK have made a MOF material, but with a new twist. For its linker, the Liverpool team used a dipeptide—that is, two peptide-bonded amino acids (glycine and alanine; see figure). The team made two versions of the material, one incorporating a solvent (a mix of water and methanol) and one not. X-ray diffraction and nuclear magnetic resonance spectroscopy revealed that adding the solvent caused the dipeptide linkers to straighten, widening the pores to accommodate the solvent ions. Glycine, alanine, and the 18 other naturally occurring amino acids are characterized by side chains that are polar, nonpolar, positively charged, or negatively charged. Given that variety, the Liverpool experiment suggests that peptide-based MOF materials might find uses as expandable sponges for a wide range of molecules.

Electromagnetic Induction

Introduction

Ørsted had discovered that electricity and magnetism were linked, electric current gave rise to magnetic fields. However no one had succeded in generating electricity by using magnetic fields, until Michael Faraday found that moving a conductor in a magnetic field (or by moving the magnet field near a stationary conductor) created a voltage. The wire must be part of an electrical circuit. Otherwise the electrons have no place to go. In other words, there is no electrical current produced with a wire with open ends. But if the ends are attached to a light bulb, to an electrical meter or even to each other, the circuit is complete and electrical current is created.

Figure 1. Inducing a current in a wire by moving the wire in a magnetic field.
Direction of Current

The direction of the current is determined by Flemming's Right hand rule. The left-hand rule is used for motors and motion produced by a magnetic field. The right-hand rule is used for generators and current generated by a motion. Using the right-hand, the thumb is in the direction of the motion, the first finger points in the direction of the field and the second finger points in the direction of the current.
Flux and Flux Linkage

To create electricity all that was required was a coil of wire, ends of which may be connected to a voltmeter. The voltage created depends on the density of the magnetic field and the area of the loop cutting the magnetic field lines.

A quantity called the flux measures this and is give by &phi = BA where B is the magnetic flux density and A is the area of the coil in the magnetic field.

If there are more turns in the coil then the flux is termed the magnetic flux linkage. It is given by Nφ =BAN. This assumes that the loop cuts the magnetic field lines at an angle of 90°. If the loop cuts the magnetic field lines at a different angle say, θ then the flux linkage is defined as N&phi = BANcos θ where theta is the angle by the normal to the area and the magnetic field lines as shown in Figure 1.
Faraday's Law of Induction

We said that a voltage or Electro-Motive Force (EMF), is produced when the loop is moved in the magnetic field but more qualitatively, the voltage is produced is in responce to the change in the motion. The voltage produced depends on the rate of change of flux-linkage with time. In mathematical terms,


where E is the EMF. The other symbols have their usual meanings. The minus sign is a consequence of Lenz's Law which we shall discuss in the following section.
Lenz's Law

When we move a conductor in a magnetic field the current generated creates it's own magnetic field. If the magnetic field created had an additive effect to the original magnetic field then the magnetic field would become even stronger and this would create an even stronger current which would create an even strong magnetic field, and so on. If this were to happen we could get energy for free although the universe might explode. Unfortunately we cannot make free energy the reason is down to the Lenz's law. When a current is generated, the magnetic field produced by the current is in opposition to the original magnetic field. This produces a force opposes the motion of the conductor and brings it to a halt. This is why it becomes more difficult to turn a dynamo on a bicycle as you increase in speed. We express Lenz's law in as part of Faraday's Law by inserting a minus sign.

Equilibrium

A body which is in equilibrium is either moving at constant velocity in a straight line, or it is not moving. If it is not moving, it said to be in static equilibrium. The reason why the body does not move is because the forces acting on it cancel each other out. In this simple phrase we are expressing the two conditions necessary in order for a body to be in equilibrium:
The sum of rotational forces or moments must add to zero.
The vector sum of all external forces, is zero.

In mathematical terms, ΣFrot = 0 and ΣF = 0
Proving Equilibrium

To prove that a body is in equilibrium, we can follow a set proceedure.
Draw the free-body diagram, which shows the forces acting on the object.
Resolve the forces in any two conveinient directions, for example, ΣFx= 0 and ΣFy = 0, which will result in two equations from which the two unknowns can be found.
Theorems on Equilibrium

If three forces are in equilibrium, then the lines of force pass through a single point.
Equilibrium in three Dimensions

So far we have discussed equilibrium where the forces are coplanar. In three dimensions we need to ensure that the sum of the moments in the three independent directions are zero the sum of the vector forces also must be zero.

Σ Fx,y,z = 0

Στx,y,z = 0

Useful Mathematics

The Binomial Theorem

(1 + x)n = 1 + nx + [n(n-1) x2]/(2!) + [n(n-1)(n-2) x3]/(3!) + ...

If x << 1, then

(1 + x)n ≅ 1 + n x

(1 + x)-n ≅ 1 - n x

These approximations are useful when x2 is negliable.
Quadratic Equations

ax2 + bx + c = 0 has the solution,

x ={[-b ± (b2 - 4ac)]1/2} / (2a)
Trigonometry

π rad = 180 °

1 rad = 57.3 °

The quadrants in which trigonometrical functions are positive. Is shown below:

Figure 1. Signs of trigonometric functions.

A good way to remember this is the phrase clockwise ACTS. Clockwise gives the direction from the first quadrant is clockwise and each letter from the word ACTS stands for a trigonometric function: All, Cos, Tan and Sin. The direction of the angle increases in an anti-clockwise sense.

If A and B are angles then

tan A = sin A/cos A

sin2 A + cos2 A = 1

sec2A = 1 + tan2 A

cosec2 A = 1 + cot2 A



sin (A ± B) = sin A cos B ± cos A sin B

cos(A ± B) = cos A cos B -/+; sin A sin B

tan (A ± B) = (tan A ± tan B)/(1 ∓ tan A tan B)

If t= tan (1/2) A, sin A = (2t) / (1 + t2), cos A = (1 - t2) / (1 + t2)



2 sin A cos B = sin (A + B) + sin (A - B)

2 cos A cos B = cos (A + B) + cos (A - B)

2 sin A sin B = cos (A - B) - cos (A + B)



sin A + sin B = 2 sin [(A + B)/2] cos [(A - B)/2]

sin A - sin B = 2 cos [(A + B)/2] sin [(A - B)/2]

cos A + cos B = 2 cos [(A + B)/2] cos [(A - B)/2]

cos A - cos B = 2 sin [(A + B)/2] sin [(A - B)/2]
Power Series

for all x
ex = exp x = 1 + x + x2/(2!) + ... + xr/(r!) + ... for all x

(-1 < x <et; 1)
ln (1 + x) = x - x2/ 2 + x3/3 - ... + (-1)r+1xr/r + ... (-1 < x <et; 1)

for all x
cos x = (eix + e-ix)/2 = 1 - x2/(2!) + x4/(4!) - ... + (-1)rx2r/(2r)! + ... for all x

for all x
sin x = (eix - e-ix)/(2i) = x - x3/(3!) + x5/(5!) - ... + (-1)rx2r+1/(2r + 1)! + ... for all x

for all x
cosh x = (ex + e-x)/2 = 1 + x2/(2!) + x4/(4!) + ... + x2r/(2r)! + ... for all x

for all x