Notes, summaries, assignments, exams, and problems for University

Properties of Laser Light

1. Monochromaticity

Unlike discharge lamps that emit on all atomic transitions, laser emission typically corresponds to a single atomic transition of the gain medium. The spectral line width can be much smaller than the atomic transition's due to the influence of the optical cavity.

2. Coherence

Laser beams exhibit high spatial and temporal coherence.

Spatial coherence describes the regularity of the optical phase across a beam's cross-section.

Temporal coherence refers to the duration over which the beam's phase remains well-defined. The temporal coherence time (t_c) is generally the reciprocal of the spectral linewidth (ν). Consequently, the coherence length (l_c) is: l_c = ct_c = c/ν.

3. Directionality

A key characteristic... Continue reading "Properties of Laser Light: Monochromaticity, Coherence, and More" »

Harmonic Oscillator

In classical mechanics, a harmonic oscillator (also known as a linear oscillator or simple oscillator) is a physical system bound to a position of stable equilibrium by a restoring force proportional to the displacement from this position. A typical example of a harmonic oscillator is a mass attached to a spring. The restoring force is the elastic force F given by Hooke’s law:

F = −kx,

where x is the displacement and k is the spring constant. The motion of a body of mass m attached to the spring is governed by Newton’s second law:

[m*(d²/dt²)] * x(t) = −kx

whose general solution is:

x(t) = Acos(ωt + φ).

Here, ω = rad(k/m) is the natural oscillating frequency, A is the amplitude of the oscillation, and φ is the phase... Continue reading "Harmonic Oscillator: Definition, Applications, and Quantum Mechanics" »

South Africa

• Three Writers from South Africa: Nelson Mandela, Nadine Gordimer, John Maxwell Coetzee
• Number of Official Languages in South Africa: 11
• Johnny Clegg: South African musician
• South African Independence: 1961
• Helen Sebidi: South African artist
• Leader in Diamond Production: South Africa

New Zealand

• Two New Zealand Cities: Wellington, Auckland
• New Zealand Population: 4.8 million
• Jane Campion: New Zealand screenwriter, producer, director
• Janet Frame: New Zealand author of short stories
• New Zealand Flag Description: Blue with the Union Jack in the top left, four red stars on the right
• "All Blacks": New Zealand national rugby team

Australia

• Patrick White: Australian poet
• Geoffrey Rush: Australian actor
• Largest City in Australia: Sydney
• Number of Indigenous

It is claimed that money is the only thing that motivates entrepreneurs

I can clearly say that entrepreneurs have different types of motivations. Some of them are related to the desire to earn money and others with the illusion of turning your dream into reality.

At present, the development of new companies has become very fashionable. With this, many entrepreneurs dream of becoming the next millionaire genius like Mark Zuckerberg. They also dream of traveling by private jet, partying in Las Vegas and having a Ferrari.

Although money is a great motivator and is very necessary to boost entrepreneurs, recent research concludes that people who only seek to earn money have a personality more prone to individualism, lack of willingness to work in teams... Continue reading "Motivations of Entrepreneurs: Beyond Money" »

The Rapid Pace of Technological Change

In recent years, technological breakthroughs have occurred so quickly that many adults have struggled to adapt. However, young people, especially the youngest ones, have rapidly grasped these new forms of communication.

Digital natives can spend hours on their computers, and even when away from home, they often walk down the street while typing on their phones. This rapid integration of technology can be seen as either amazing or concerning, depending on the beholder.

For them, it is fantastic how quickly they can connect with friends, stay constantly in touch, and receive the latest news instantaneously.

Communication Challenges for the Digital Generation

In my opinion, this generation seems to have lost the... Continue reading "Technology's Impact on Youth: Communication & Fitness" »

Challenges of International Matrimony

Durkheim's Theory of Social Facts and Religious Foundations

Firstly, Durkheim established that sociology is the science of social facts. These social facts have the following characteristics:

Characteristics of Social Facts

• Social facts are ways of thinking and acting.
• Social facts are normative: they rule and they are coercive.
• Social facts are external to the individual; they have an independent existence.
• Social facts are general because they encompass the whole society.

Religion as the Fundamental Social Fact

Durkheim also stated that religion is the social fact that makes society exist. To understand what religion is, his starting points for his investigation were:

• There are no true or false religions; they are all true in their own way.
• All religions

Master key terms and phrases for your next trip or career in the tourism industry. This comprehensive resource covers everything from basic travel logistics to advanced business concepts and cultural nuances.

Tourism & Travel Core Concepts

• Boom: A period of rapid economic growth.
• Demand: The desire of consumers for a good or service.
• Launch: To start or introduce something new.
• Market: The area of commercial dealing or a group of potential customers.
• Package: A set of related items or services sold together.
• Tour: A journey for pleasure in which several different places are visited.
• Supply: The amount of a good or service available (oferta).
• Supplier: A person or entity that provides goods or services (proveedor).
• Resort: A place where people go