Preview

Interactions of Light and Matter

Good Essays
Open Document
Open Document
4055 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Interactions of Light and Matter
Physics notes –
Interactions of light and matter

Young was able to explain this result as a wave-interference phenomenon – the double-slit interference pattern demonstrates the wave-like nature of light.

Free download and print from www.itute.com
©Copyright 2009 itute.com

Explaining the interference pattern using the wave model

Light has been described both as a particle and as a wave.
Isaac Newton (~1665) made up a particle model of light to explain many of the known behaviours of light at that time. He was able to explain
- straight line propagation of light
- the intensity of light
- the reflection of light from flat and curved surfaces
- the refraction of light as it crosses the interface between two media.

The single slit provides the double slits with coherent light waves (Refer to page 2).
The bright bands are formed when light waves from the two slits arrive at the screen in phase, i.e. wave crest combines with crest and wave trough combines with trough. This is known as constructive interference. The following diagram shows the sum of the two waves as a function of time at a bright band.
Amplitude

He was unable to explain
- partial reflection and partial transmission of light at an interface - the existence of Newton’s rings and other related phenomena due to the interference of light.

0

Time

Christiaan Huygens (~1678) considered light as a wave. Using a wave model he was able to explain all the known phenomena of light mentioned above as well as interference and diffraction of light.

Constructive interference results in greater amplitude
The dark bands are formed when the two waves arriving at the screen are half a cycle out of phase, i.e. wave crest combines with wave trough. This is called destructive interference.
The following diagram shows the sum of the two waves at a dark band.

Young’s double-slit experiment, 1801
Screen

Amplitude

Sunlight

0

Time

If light consists of

You May Also Find These Documents Helpful

  • Satisfactory Essays

    A good example of refraction of light and reflection of light is a rainbow. Sunlight enters the rain droplet at a specific angle and the rain droplet separates the white light into many different colors. This angle is a fixed measurement between your eye and the sun. What color is refracted depends upon the critical angle, which is the angle the sunlight strikes the back of the rain droplet. Red light bends the least while violet light bends the most all the other colors bend at an angle that is between the two. Each rain droplet reflects all colors at a given point and time, but only one color comes back to your eye, requiring millions of rain droplets to create a rainbow. As the rain droplets fall…

    • 395 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Starting at the slit and going outward, what colors do you see in the spectrum? List them all!…

    • 1694 Words
    • 7 Pages
    Good Essays
  • Satisfactory Essays

    Note: Read all the instructions for this lab before you begin working! Pre-reading the procedures will give you a mental picture of what you will be doing and a better understanding of the process.…

    • 509 Words
    • 3 Pages
    Satisfactory Essays
  • Good Essays

    Essentially, two of our experiments did incorporate the same fundamental laws of physics; the “Magic Penny” and “ Rainbow in a Dish” experiments. In particular, both experiments studied the concept of refraction, that is the bending of light from one medium to another which involves light and its constituents such as the electromagnetic spectrum and the concept of waves. Both the “Magic Penny” and the “Rainbow in a Dish” experiment showed what happens when light passed through water and how it was going from one medium, air to another, water. When you look at the mirror in the dish without any water and shine the flashlight you only see the light reflecting back up. It is not until the water is added to the…

    • 125 Words
    • 1 Page
    Good Essays
  • Good Essays

    The introduction of both the light and electron microscope had a dramatic effect on the development of the cell theory and the study of cells altogether. Microscopes enabled cells to be viewed and studied in order to explain their functions and structures. The understanding of the human, plant and animal anatomy was then improved and scientists were then able to answer certain questions concerning the structure of plants, animals and humans.…

    • 428 Words
    • 2 Pages
    Good Essays
  • Satisfactory Essays

    Light We Cannot See

    • 300 Words
    • 2 Pages

    In the book, All the Light We Cannot See, by Anthony Doerr, many of the characters stories can seem fascinating to the modern reader. Marie’s story deals with her blindness, and how her father attempts to assist her by making a model of the neighborhood they used to live in, making puzzle boxes for her to solve on her birthdays, and even traveling with her on his back through the French countryside to Saint-Malo when the Germans attacked their town. Werner’s story, which is quite fascinating, deals with the grim, bleak, and cloudy lifestyle that he used to live in when he was an orphan. Eventually, through his innovative ingenuity, he manages to impress a German military official, and gets caught in the brutal trap that is the Wehrmacht. Werner…

    • 300 Words
    • 2 Pages
    Satisfactory Essays
  • Powerful Essays

    Laws of Physics

    • 3579 Words
    • 15 Pages

    The following are the types of questions you can expect on the Midterm. The questions on the midterm, however are NOT limited to these questions. The following questions do not include the material in the California Supplement, or matters we may have discussed in class. Anything in chapters 1-3 and 5 in the California Supplement and anything we have discussed in class is covered in the midterm.…

    • 3579 Words
    • 15 Pages
    Powerful Essays
  • Good Essays

    Light Dependent Reactions

    • 660 Words
    • 3 Pages

    During the Light Dependent Reactions, activity occurs within the thylakoids of the chloroplast. NADP+ accepts two high energy electrons and an H+ ion and then converts into NADPH. This process ultimately traps some of the sunlight in chemical form. Then, NADPH is able to carry the energy it absorbs to the rest of the cell. The reaction produces O2 gas and converts ADP to ATP and NADP+ to NADPH. First, pigments in Photosystem II absorb light, which is then absorbed by electrons, which are then passed along the Electron Transport Chain. Chlorophyll loses an electron, but interestingly, those missing electrons are replaced through enzymes in the thylakoid membrane, which divide H20. Secondly, electrons move through the Electron…

    • 660 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Matter And Energy Dbq

    • 784 Words
    • 4 Pages

    Advances in modern science have had great impacts on our ability to understand how matter and energy cycle throughout systems. The cycling throughout networks can be explained by the Law of Conservation of Matter and Energy, which states that matter and energy cannot be created or destroyed, only changed. This cycle applies to many things, such as energy cycling through a food web, carbon traveling through the biosphere in the carbon cycle, and the movement of energy and materials that are used during photosynthesis and cellular respiration. The cycling of matter and energy is essential for life and has great effects on a number of processes.…

    • 784 Words
    • 4 Pages
    Good Essays
  • Good Essays

    The most prominent theme of the novel highlights war. Doerr’s work of fiction uses physical symbols to showcase the effects of war on people, of resistance to oppression, and the effort of citizens trying to maintain normality, creating a whole better understanding for readers about the outcomes of war. Historians, philosophers, and writers alike can attest to the human struggle to follow a certain moral code; history shows a constant rift between what humans claim they should do and what they actually do. If this rift did not exist, many a crisis and war could be averted, but humanity would not be its beautifully flawed self. In the novel All the Light We Cannot See, Doerr is raved over for “masterfully and knowledgeably recreating the deprived civilian conditions of war-torn France and the strictly controlled lives of the military occupiers” (Hooper 23). However, the use of literary devices in the novel reflects a message deeper than that of just another war-time story. Doerr utilizes the war setting as a means of further exploring the nature of humanity in a distinct context. He does not define the characters by war; he defines the characters and gives them a war to respond…

    • 868 Words
    • 4 Pages
    Good Essays
  • Good Essays

    gases. When the gases were released the disks would float. The rate at which this…

    • 378 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Orb Essay

    • 1525 Words
    • 7 Pages

    The main issue of the early theories of light was to resolve whether it was a wave or a particle, and this proved to be a difficult task. It started as a particle from the ancient Greeks, then it became a wave with Huygens, then Newton suggested a particle theory again, then Fresnel and others suggested a wave theory again, then Einstein suggested a particle theory once more, until finally Quantum Mechanics settled it down: it is both a wave and a particle! Now everyone is happy except for the fact that no one understands what that really means...Huygens vs. NewtonChristian Huygens was born in 1629, while Isaac Newton was born in 1643. Huygens was the first to build a mechanical clock, making use of Galileo's realization that a swinging pendulum kept a regular rhythm. He built the first of this type of clock at the age of 28, and a year later his design was used in all of the major churches in Holland. At 45 he built the first watch, winning the race from Hooke, Newton's great rival. At 1690, when he was 61, he fully published his wave theory of light, suggesting that it propagates as a disturbance (spherical pressure wave) in the air. One of the most important predictions of his theory was that light should propagate slower in a denser medium, something that was not experimentally confirmed until the next century.Newton was working on his particle theory of light at the same time as Huygens. Due to the enormous power of his theory of gravity, he was already considered a grandmaster of science. Therefore his particle theory of light won the battle with Huygens' theory of waves and was widely accepted in the scientific community. He assumed that light consisted of particles, which he called corpuscles. In 1669, in a series of lectures he delivered in Cambridge, he explained his theory of colors and specifically how a prism alters the…

    • 1525 Words
    • 7 Pages
    Good Essays
  • Good Essays

    With as much time and energy that readers divest into reading, they certainly want what they read to be worthwhile. According to Jago, literature is defined as works that are worthwhile, texts that “we’re likely to remember—ones that may, in fact, influence who we are”. By this definition, Anthony Doerr’s All the Light We Cannot See is a marvelous piece of literature. Doerr crafts a story as complex as reality with characters as complicated as real people. The story will linger in the mind, the words somehow leaving behind an unexplainable trace. All the Light We Cannot See is a captivating book.…

    • 1176 Words
    • 5 Pages
    Good Essays
  • Satisfactory Essays

    Light and Photosynthesis

    • 1279 Words
    • 6 Pages

    2. Select the BAR CHART tab. On the graph, notice the Oxygen production bar. Move the Light intensity slider back and forth. How does light intensity affect oxygen production?…

    • 1279 Words
    • 6 Pages
    Satisfactory Essays
  • Good Essays

    Einstein

    • 1255 Words
    • 4 Pages

    In 1905 Einstein published a paper that described experimental data from the photoelectric effect as being the result of light energy being carried in discrete quantized packets. This led to the quantum revolution and later earned him his Nobel Prize.…

    • 1255 Words
    • 4 Pages
    Good Essays