Exploring Doppler Effect and Red Shift in Universe Formation
Delve into the Doppler Effect and Red Shift phenomena in the context of universe formation theories, from limitations to practical applications, with interactive examples and questions to enhance understanding.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
You are allowed to download the files provided on this website for personal or commercial use, subject to the condition that they are used lawfully. All files are the property of their respective owners.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.
E N D
Presentation Transcript
Target tracker Update your current level Write in the new target for Universe (you ll get your grade for waves after the test on Wednesday) A*:Evaluate the limitations of Red-Shift and the Big Bang A: Compare different theories for the formation of the Universe B: Explain why red shift can be observed C: Describe the Doppler Effect D: Describe the Big Bang theory for the origin of the Universe
LO: To Explain the Doppler effect and Red Shift Success Criteria: Explain what happens in the Doppler effect. Explain what is meant by red-shift . Key words: Doppler Effect, red shift, wavelength, frequency, increasing, decreasing, source.
Do now: 1) If I increase a wave s wavelength, how will this affect the pitch? 2) If I decrease a sound s wavelength, how will this affect the pitch Answer in full sentences and draw diagrams!
Hypothesis time The Doppler Effect as a diagram. http://astro.unl.edu/classaction/animations/light/dop plershift.swf The Doppler Effect in every day life. http://www.youtube.com/watch?v=a3RfULw7aAY http://www.youtube.com/watch?v=08nRXajUJ6o
Now you can explain, what happens in the Doppler effect. Thinking about and answering this questions will help you write your explanation. Check your diagram. 1) How did the sound of the horn change? 2) Which sound was higher pitched, when the car was approaching or going away? 3) Which sound had a shorter wavelength? key words: approaching, travelling away, source, compresses, stretches, wavelength, pitch, frequency.
The Doppler Effect Relative velocity between the source and the observer Compresses and stretches the wavefronts http://parallax.sci.csupomona.edu/pics/OW-B-DC.jpg Link Relative velocity = 0 Relative velocity > 0 Link
The Doppler effect When a wave source approaches you; the wave you receive will be higher in frequency, the wave you receive will be shorter in wavelength When a wave source travels away from you; the wave you receive will be lower in frequency. the wave you receive will be longer in wavelength
http://www.colorado.edu/physics/2000/apple ts/doppler.html http://www.youtube.com/watch?v=Kg9F5pN5 tlI
In conclusion: Doppler Effect As the waves compresses, what happens to the wavelength? Decrease How does this affect the frequency? increases it so the PITCH increases As the waves stretches, what happens to the wavelength? Increase How does this affect the frequency?
Success Criteria: Explain what happens in the Doppler effect Explain what is meant by red-shift
Quick fire questions Answer in full sentences Can you guess what red shift means? 1) Which has a longer wavelength, infrared or ultraviolet light? 2) If I took a light wave and stretched it, would it get redder or bluer? Clue: What happens to the wavelength when you stretch the wave?
In astronomy the Doppler effect is used to measure the motion of the galaxies. Light and sound are both waves and exhibit this effect... But when we apply it to light we call it red shift
Light and all electromagnetic waves shift Galaxies emit light in specific frequencies. The light we observe is at lower frequencies and longer wavelengths. The light is red-shifted . This means the distance between us and the galaxy has increased. The galaxy is moving away from us.
Wavelength Shift (draw diagram) Object moving away from observer ..(positive relative velocity) Object moving towards observer ..(negative relative velocity)
Watch the video and be ready to answer these questions! 1) How does Brian Cox describe red shift? 2) Why do stars appear red? 3) What is happening to our universe? 4) What happens if you rewind? 5) What is The Big Bang Theory ? http://www.bbc.co.uk/science/space/universe/q uestions_and_ideas/big_bang#p00fz5z4
Almost all galaxies exhibit red-shift, and the further away from us they are, the more they are red-shifted. 1 How would things look from galaxy 1? 1 If every galaxy is moving away from every other galaxy, the universe is expanding. Therefore at some point in the past everything must have been very close together.
Cosmological Red shift The light from distant stars & galaxies can be shown to have shifted slightly towards the red end of the spectrum when compared to atomic spectra Far away galaxy/star Us Link
Red Shift or Blue Shift! 1. The wavelength is increasing 2. The wavelength is decreasing 3. The frequency is increasing 4. The frequency is decreasing 5. The amplitude is increasing
Plenary The effect that wave frequency .and wavelength . as the source approaches you, and the opposite when the source is moving away is known as ... . . One example of this is .which shows that the universe is ., therefore supporting the .. .. theory describing a universe that initiated at a small point and expanded to the universe we see today.
Red shift Practice question 1. In2005 a space telescope detected a star that exploded 13 billion years ago. The light from the star shows the biggest red-shift ever measured. a)What is red-shift? (1 mark) b)What does the measurement of its red-shift tell scientists about this star? (1 mark)
Mark scheme (c) (i) wavelength (of light) increases accept frequency decreases or light moves to red end of spectrum accept redder but do not accept red alone 1 (ii) it is the star (detected) furthest from the Earth accept galaxy for stars or it is moving away the fastest ignore reference to universe expanding 1
Success Criteria: Explain what happens in the Doppler effect Explain what is meant by red-shift
Success Criteria Explain what happens in the Doppler effect Explain what is meant by red-shift Self Evaluation Grid Number Correct Number attempted Effort Level Confidence Write a revision comment to yourself
Key word definitions Electromagnetic spectrum is a range of frequencies or wavelengths that electromagnetic radiation can have. Electromagnetic waves move very fast and can travel through a vacuum. Intensity the amount of energy arriving on a unit area of surface each second Vacuum is a place where there is no matter at all empty space Doppler Effect a change in wavelength (and frequency) of a wave caused by relative movement of the wave source and the observer Red-shift is the increase in wavelength (decrease in frequency) of EM radiation from distant, receding galaxies due to Doppler effect & expanding universe
