Lightning

Electrostatic induction: A normal uncharged piece of matter has equal numbers of positive and negative electric charges in each part of it, located close together, so no part of it has a net electric charge.  However, when a conductor is near a charged body, it will develop a positive charge on one end and a …

Why perpetual motion machines never work

First Law of Thermodynamics - energy can't be created or destroyed. It is impossible to extract more energy than the energy you put in. Second law of Thermodynamics - energy tends to spread out through processes like friction. Any real machine would have moving parts or interactions with air or liquid molecules that would generate …

Schrodinger’s Cat

A cat, a flask of poison and a radioactive source are placed in a sealed box. If an internal monitor detects radioactivity, the flask is shattered, releasing the poison, which kills the cat. The Copenhangen interpretation of quantum mechanics implies that after a while, the cat is simultaneously alive and dead, in a quantum superposition. …

Time Dilation

A train with velocity v is moving forward. A light beam shoots from the bottom and bounces it off the ceiling, returning back to the original point inside the train. The distance between the bottom and the ceiling is S. What is the light travel time to a man standing on the train? t0 = …

Rainbow Phenomenon

A rainbow is a meteorological phenomenon that is caused by reflection, refraction, and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky.   https://www.youtube.com/watch?v=chHblV9ddWk

The 4 Fundamental Forces of Physics

Strong nuclear - forces that bind neutron and proton together in the nuclear Weak nuclear Electromagnetism Gravity

Electromagnetic spectrum

c = λ f c = speed of light = electromagnetic wave velocity = 3 * 10^8 m/sec Therefore, the longer the wavelength, the higher the frequency.   From high frequency (low wavelength) to low frequency (high wavelength) gamma-rays x-rays light ultraviolet visible light infra-red thermal IR microwaves radio  

US Visa Types

Student Visa F-1. Students who wish to engage in academic studies at an approved school or English Program. M-1. Students who plan to engage in non-academic or vocational study or training at a US institution. Business/Tourist Visa B-1/B-2. B-1 visa is for travelers consulting with business associates, attending scientific, educational, professional, or business conventions, etc. B-2 visa …