INTRODUCTION TO ASTRONOMY What is Astronomy Astronomy is

INTRODUCTION TO ASTRONOMY • What is Astronomy ? • Astronomy is NOT Astrology • Why do we study Astronomy ?

Astronomy - the scientific study of the Universe beyond Earth Astronomy is a true science. It includes the topics of the history of astronomy, human space exploration, our Sun and Moon, planets, other stars, galaxies, and cosmology (the origin, structure, and fate of the whole Universe).

Astronomy is a True Science • Astronomy is based on observations and experiments that can be repeated, and that give the same results no matter who does the experiment or makes the observation. • Astronomy makes precise predictions about our Universe that can be tested to see if the predictions are true or not. • Astronomy makes use of other well-established sciences like physics and chemistry.

Astrology is NOT a Science • Seeks to discover “hidden knowledge” by the interpretation of omens (like reading tea leaves). • Results are not repeatable. • Predictions are vague and not testable. • Does not incorporate sciences like chemistry and physics.

Why do we study Astronomy ? • • • Natural disasters Recreation and esthetics Scientific inquiry and curiosity Education of an informed society (you !) Our place in the Universe Origin and fate of the Universe (Cosmology) • True Science versus science fiction

Natural Disasters • Comet and meteorite impacts, for example.

BOOM !!

Recreation and Esthetics • The Universe is beautiful.

Scientific Inquiry and Curiosity • For example – our instruments can see what our eyes cannot. • Space exploration.

Saturn – Different Kinds of Light

Saturn – Different Kinds of Light Ultraviolet Visible Infrared Radio

Space Exploration

Education of an Informed Society

Our Place in the Universe • Where are we?

12 ½ light years away

250 light years away

5 thousand light years away

50 thousand light years away

500 thousand light years away

5 million light years away

100 million light years away

1 billion light years away

14 billion light years away

Origin and Fate of the Universe • This part of Astronomy is called Cosmology. • Cosmology seeks a scientific explanation for how the Universe began and how it might end (or will it go on forever? ).

The Beginning – The Big Bang

100 billion years from now the Universe will appear frozen in time as we look out into space. Only the light from the Local Group of galaxies will remain visible, if anyone is still around to see it.

True Science versus Science Fiction • Some astronomy stuff may be weird, BUT IT’S TRUE/Present. ØBlack Holes. ØRadiation from the beginning of the Universe. • Science fiction is just weird. ØFavorite movies.

A Spinning Black Hole

Radiation from the Beginning of the Universe 13. 7 billion years ago