Tidal Forces and Its Effects On Our Galaxy

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Tidal Forces and Its Effects On Our Galaxy

• Alfred Pirovits
• Richard Leung
• Kimmy Voong
• Tuan Mai
• Robin Hester
• Marco Santari

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What are Tides?

• Regular rising and falling of oceans surface
  caused by the moons gravity (to a lesser degree
  also the Sun)

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TIDAL FORCES

• Astronomers refer to tides as a shorthand for
  Tidal Force
• Tidal Force is a secondary effect of the force of
  gravity
• All follow inverse cube law derived from Newtons
  Law of Gravity

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Inverse Cube Law

• M is mass of primary body
• M is mass of orbiting body
• r is orbital radius
• G is gravitational constant

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HOW ARE TIDES CREATED?

• Differential Forces gravity is different from
  one side (near moon) to the other (far from moon)
• Near side ? stronger gravitational pull

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2 HIGH, 2 LOW

• Calculate force of the Moons gravity relative to
  the barycenter (Earth/Moon center of mass) will
  result in 2 tidal bulges
• Net result 2 high tides and 2 low tides
• High tides occur approx. 12 hrs apart

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Earth is slowing down!!

• Tidal bulges oppose rotation of earth (like
  brakes on wheels)
• Days getting longer

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Moon is going away??

• Conservation of angular momentum (example
  spinning ice skater)

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Other Interesting Effects

• Saturn Rings
• Ios Volcanoes
• Black Holes

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Got it? Questions?