Nature of Astronomy Assessment

1. pseudoscience: a collection of beliefs or practices mistakenly regarded as being based on scientific method.

   Annotations:

   • Psuedoscience is a form of nonscience.
   • Astrology and ghosts are a form of pseudoscience.
   1. Click the grey notes on the top right corner of the nodes!

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• The kilometer is the smallest unit. For example, we would measure from Florida to California. 

1. astronomical unit: a unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun.

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   • AU is second smallest.
   1. light year: a unit of astronomical distance that light travels in one year. 9.4607 × 10^12 km

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      • You measure things like the distance from the Sun to close stars like Proxima Centauri.
      1. parsec: a unit of distance used in astronomy, equal to about 3.26 light years. Parallax seconds.

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• Pseudoscience starts out with a hypothesis to prove the reality but doesn't get anywhere else.

1. theory: describes an observation and is not a fact but a strong idea.

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   • A theory starts as a hypothesis. The difference is that a theory has a lot of time and proven experiments to back it up.
   • The difference between a theory and a law is that a theory explains the WHY. 
   • Both a theory and a law can be proven wrong

1. law: describes what nature does under certain conditions, and will predict what will happen based on those conditions.

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   • a law describes an observation.

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• This is seen on the absorption spectrum.

1. continuous spectrum: an emission spectrum that consists of a continuum of wavelengths.

   Annotations:

   • when the spectrum doesn’t have any breaks or gaps.
   1. emission spectrum: a spectrum of the electromagnetic radiation emitted by a source.

      Annotations:

      • a spectrum of colored lines on a dark background. Also known as a bright line spectrum. This happens when elements produce light at specific wavelength. 
      • Usually seen in nebulae.
      1. absorption spectrum : a spectrum of electromagnetic radiation transmitted through a substance, showing dark lines or bands due to absorption of specific wavelengths.

         Annotations:

         • a spectrum that has black lines on a continuous spectrum. This happens when a star is passing nearby gas. 
         • The dark lines are the absorption of color by elements. Also called a dark-line spectrum.
         1. electromagnetic spectrum: the range of wavelengths or frequencies electromagnetic radiation extends.