1 / 109

Name the waves of the electromagnetic spectrum in order from longest to shortest wavelength

Name the waves of the electromagnetic spectrum in order from longest to shortest wavelength. Describe our place in the universe:. What is a galaxy?. A vast collection of stars, gas & dust all held together by gravity and orbiting a common center. M31, The Great Galaxy in Andromeda.

denver
Download Presentation

Name the waves of the electromagnetic spectrum in order from longest to shortest wavelength

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Name the waves of the electromagnetic spectrum in order from longest to shortest wavelength

  2. Describe our place in the universe:

  3. What is a galaxy? A vast collection of stars, gas & dust all held together by gravity and orbiting a common center M31, The Great Galaxy in Andromeda

  4. What is a Light-year? • The distance light can travel in one year (about 10 trillion km or 6 trillion miles).

  5. If we reduce the size of the sun to a large grapefruit (14 cm in diameter) How far away would the nearest star be? • the nearest star (Alpha Cenauri) is 2500 miles away (about as wide as the US).

  6. About how many stars are estimated to be in the Universe? As many stars as grains of (dry) sand on all Earth’s beaches…

  7. In what way are IR & UV telescopes different from visible light telescopes? • Infrared and ultraviolet-light telescopes operate like visible-light telescopes but need to be above atmosphere to see all IR and UV wavelengths

  8. Describe the movement of the Earth The Earth - rotates around its axis once every day.Revolves around the sun once every 365 days.

  9. How many stars can we see with the naked eye? • We can see a few thousand (as well as the Milky Way).

  10. How do we mark the progression of the seasons? summer solstice winter solstice spring (vernal) equinox fall (autumnal) equinox

  11. What is a Constellation? A constellation is a recognized pattern of stars that refers to a region of the sky.

  12. How do we measure the altitude of an object? An object’saltitude is measured up from the horizon (in degrees).

  13. How many arc-seconds are there in a degree? 1º = 60 (arcminutes) x 60 (arcseconds) = 3600 (arcseconds)

  14. How do we calculate an object’s Angular Size?

  15. What is a circumpolar star? A circumpolar star never sets Your Horizon

  16. How can you determine your latitude using the pole star? • Altitude of the celestial pole = your latitude

  17. What causes seasons? Seasons depend on how Earth’s axis affects the directness of sunlight

  18. What is timing? A study that measures how light output varies with time

  19. Why do we see phases of the Moon? • We see a changing combination of the bright and dark areas on the moon as it orbits around the earth

  20. Why do we see only one side of Moon? Synchronous rotation: the Moon rotates exactly once with each orbit

  21. What causes eclipses? • The Earth and Moon cast shadows. • When either passes through the other’s shadow, we have an eclipse.

  22. When can a lunar eclipse occur? • Lunar eclipses can occur only at full moon.

  23. When can a solar eclipse occur? • Solar eclipses can occur only at new moon.

  24. What is apparent retrograde motion? • This is when planets appear to go westward (backwards) relative to the stars. (Planets usually move slightly eastwardfrom night to night relative to the stars).

  25. What causes Apparent Retrograde Motion? • occurs when we “lap” another planet (or when Mercury or Venus laps us)

  26. What causes spring tides? • Gravitational effects of sun & moon reinforce each other

  27. How did astronomical observations benefit ancient societies? • Keeping track of time and seasons • for practical purposes, including agriculture • for religious and ceremonial purposes • Aid to navigation

  28. What did Copernicus do? • Proposed Sun-centered model (published 1543) Copernicus (1473-1543):

  29. How did the Greeks explain planetary motion? • Geocentric model - Earth at the center of the universe • Heavens must be “perfect”: Objects moving on perfect spheres or in perfect circles.

  30. What did Johannes Kepler (1571-1630) do? • determined planets move in elliptical orbits • Kepler’s Laws

  31. How does gravity cause tides? • Moon’s gravity pulls harder on near side of Earth than on far side • Difference in Moon’s gravitational pull stretches Earth

  32. Using his telescope, Galileo saw what 4 things? • Sunspots on Sun (“imperfections”) • Mountains and valleys on the Moon (proving it is not a perfect sphere) • moons orbiting Jupiter • phases of Venus

  33. What are the Hallmarks of Science? • Seeks explanations for observed phenomena that rely on natural causes. • Progresses through the creation and testing of models that explain the observations as simply as possible. • Model must make testable predictions that would force us to revise or abandon the model if the predictions do not agree with observations.

  34. What is Newton’s Law of Gravitation?

  35. What is Occam’s Razor? • This is the idea that we prefer the simplest explanation.

  36. Does astrology have any scientific validity? • No, scientific tests have shown that astrological predictions are no more accurate than we should expect from pure chance.

  37. What did Tycho Brahe do? • Compiled the most accurate (one arcminute) naked eye measurements ever made of planetary positions. (1546-1601)

  38. Why do objects rotate faster as they shrink in radius? Conservation of angular momentum. Angular momentum depends on mass, velocity and radius. If the momentum is constant, then if the radius decreases the velocity must increase. m x v x R = m x V x r

  39. What does Gravitational Potential Energy depend on? • object’s mass (m) • strength of gravity (g) • distance object could potentially fall

  40. What are particles of light called? • Particles of light are called photons

  41. What does the law of Conservation of Energy say? • Energy can be neither created nor destroyed. It can change form or be exchanged between objects.

  42. Where in their orbits do planets have the most gravitational energy and the least kinetic energy? More PE; Less KE Less PE; More KE aphelion Perihelion

  43. Spring tides occur during which phase(s) of the moon? • Happens at either new moon or full moon

  44. What causes neap tides? • the tidal effects of the Sun and Moon partially cancelled each other

  45. What are the colors of visible light? • ROYGBIV

  46. What is the structure of matter? Electron Cloud Atom Nucleus

  47. What is the law of reflection? The angle of incidence equals the angle of reflection

  48. Why is a red chair red? Pigments in the chair absorb all colors of light except red, which they reflect. So the chair looks red.

  49. What is the range of wavelengths for visible light? (longest to shortest) 700 nm (red) – 400 nm (violet)

  50. Neap tides occur during which phase(s) of the moon? • Happens at either first quarter or third quarter

More Related