SCIENCE

• YALIANT


  Acronym for "Yet Another Light and Intensity Attribute Narrative"
• Hat


  • The measurement of Light in terms of its perceived brightness to the human eye
• Intensity of Light


  Quantitative expression of the brightness of light
• Brightness of Light


  Qualitative expression of light intensity, a visual perception in which a light source appears visible
• Brightness of Light


  Depends on the source and the distance from it, but is subjective and dependent on the person's perception
• Luminous intensity


  The quantitative measurement of the brightness of light, with the unit of candela
• The unit "candela" came from the fact that one candle can approximately represent the amount of visible radiation emitted by a candle flame
• The speed of light is 299,792,458 meters per second, or approximately 3 x 10^8 meters per second
• Photons


  The smallest unit of visible light, a form of energy
• Sources of light


  • Natural: Sun
  • Artificial: Lamp, Candle, Light bulb
• Isaac Newton


  Light behaves like a particle
• Louis De Broglie


  Light can be a particle and a wave
• Christian Huygens


  Light behaves like a wave
• James Clerk Maxwell


  Electromagnetic theory of light
• Dual Nature


  Light has both particle nature and wave nature
• Amplitude


  The measure of the energy the wave carries
• Colors


  The different colors of visible light have specific frequencies and wavelengths, with red having the longest wavelength and violet having the shortest wavelength
• Dispersion


  The phenomenon in which a prism separates white light into component colors
• Light


  A form of energy that travels in electromagnetic waves
• Light intensity


  The power of light, the quantity that measures the amount of light illuminating a surface
• Photometry


  The branch of science that measures the intensity or brightness of light
• The origin of light was the moment of first light in the universe, between 240,000 and 300,000 years after the big bang, known as the "Eve of Recombination"
• Historical views on the nature of light

  • Aristotle: Light is something that goes through the space between the eye and the object
  • Pythagoras: Light is made of fine particles coming from a luminous object
  • Plato and Euclid: Light is something given off by the eye
  • Empedocles: Light is a very high-speed wave
  • Christian Huygens: Light is a wave propagating in either direction
  • Isaac Newton: Light consists of tiny particles emitted by a luminous object
  • Max Planck: Light can be a particle or a wave
  • James Clerk Maxwell: Light is part of the electromagnetic spectrum
• There are two different types of energy explored in previous videos: sound energy and light energy, which also exist in the form of waves.
• In this video, we will explore heat energy and how heat transfer can occur.
• When the woman fills the mug with boiling coffee, the mug and the metal spoon will feel hotter.
• The mug and metal spoon feel hotter


  Because of heat transfer
• Thermal energy


  The energy possessed by an object or system due to the movement of particles within the object or the system
• Heat


  The energy that is transferred from a body with a higher temperature to a body with a lower temperature
• Temperature


  The relative hotness or coldness of an object, measured by a thermometer
• The three common temperature scales are Celsius, Fahrenheit, and Kelvin.
• The SI unit for heat is Joules.
• The natural flow of heat is always from a hotter substance to a colder substance or from a substance with a higher temperature to a substance with a lower temperature.
• Heat transfer


  • It is the process where thermal energy is exchanged between two objects due to their temperature differences.
• The three methods of heat transfer

  • Conduction
  • Convection
  • Radiation
• Conduction


  Heat transfer between objects that are in contact with each other, where heat energy is directly transferred through a material.
• Good conductors of heat

  • Silver
  • Copper
  • Steel
  • Aluminum
• Insulators


  Materials that transfer heat poorly
• Convection


  Heat transfer through the circulation of liquid and gas, where energy is transferred by the rising or sinking of matter due to density differences.
• Convection in boiling water

  • Heated water molecules at the bottom rise, while cooler and denser molecules from the surface sink, creating convection currents.