ASTR110: Introduction to Astronomy

Professor: Jon HoltzmanTAs: Sten Hasselquist, Laura Mayorga

MWF 11:30-12:20M02: M 3:30-5:30M03: T 1:30-3:30M04: T 3:30-5:30

Plan for today

• Motivation– Why is astronomy interesting?– A brief history of the Universe– Is astronomy relevant?

• Goals for the class• Class logistics

Why is astronomy interesting?

• A question to think aboutWhat substance (molecule) are people mostly made

of?A. FatB. WaterC. DNAD. Protein

Answer: here

People are mostly water!

(98% of molecules)

People as atomsWhat element are people mostly made of (If you could

count the number of each type of atom in your body, which one would get the most of)?A. HydrogenB. CarbonC. NitrogenD. OxygenE. Iron

Answer: here

Water is H2O, so people are mostly Hydrogen (63%), then Oxygen (24%)

People by weight • Different atoms are made up of different numbers of protons and

neutrons, and thus have different masses (protons and neutrons have about the same mass and electrons hardly count for any mass).– Hydrogen: 1 proton– Carbon: 6 protons + 6 neutrons– Nitrogen: 7 protons + 7 neutrons– Oxygen: 8 protons + 8 neutrons

What element makes up most of the mass of people?

A. HydrogenB. CarbonC. NitrogenD. OxygenE. Iron

Oxygen (>50% of mass!)

Where do we come from?

When were the oxygen atoms in our bodies assembled (when were the protons, neutrons, and electrons put together?

A. Within the past day, e.g. from food you ateB. Within the past century, e.g. when you were bornC. When the Sun and Earth were formed, about 4.5

billion years agoD. Before the Sun was formed but after the beginning of

the UniverseE. They have existed since the beginning of the

Universe

A (very) brief history of the Universe

• Universe hasn’t always been the same: our Universe “started” about 14 billion years ago as pure energy

• After a few minutes, atoms were formed, but contents were very different: hydrogen, helium, bit of lithium and beryllium

• Early matter formed into stars– Stars are nuclear reactors: elements are changed into others by nuclear fusion in

their cores, producing energy (light) in the process– Stars have lives and some, when their lives are done, explode!

• Material from inside the star is released and mixes with other gases• New stars are formed• Around many stars some bits are left over and form into planets• On some (at least one!) planets life evolves from the raw material. Through all different

sorts of processes (geological, chemical, biological), atoms are rearranged in and out of molecules, but not created or destroyed (with just a few exceptions, namely, radioactivity)

• On (at least) one planet, humans come into existence! – We study the stars

Where do we come from?When was the oxygen in our bodies assembled into atoms

(when were the protons, neutrons, and electrons put together?

A. Within the past day, e.g. from food you ateB. Within the past century, e.g. when you were bornC. When the Sun and Earth were formed, about 4.5 billion years

agoD. Before the Sun was formed, but after the beginning of the

UniverseE. They have existed since the beginning of the Universe

• Human connection with astronomy– We come from stars!– Humans have used observations of stars– Humans are affecting astronomical objects

• Astronomy is at an exciting time• Astronomy is a crossroads science (geology,

chemistry, physics, and math all play a role)• Telescopes are “time machines” and astronomers are

“time travellers”• New Mexico is a great place to look at the sky

Why is astronomy interesting?

Is astronomy practical/relevant?• Certainly, some aspects of astronomy have been relevant for

humans (agriculture, navigation, technology spinoff)• Things we study may be very relevant (temperature of

Venus, dark energy?)• Astronomy is a phenomenon in our everyday life (Sun,

Moon, and sky)• Astronomy is a science, and understanding how science

works is critical to have meaningful impact on issues that affect humans

• Is curiousity, or even more broadly, non-survival skills, irrelevant? What’s the purpose of learning/college?

Goals for the class

• NM general education goals, laboratory science– Describe the process of scientific inquiry– Solve problems scientifically– Communicate scientific information– Apply quantitative analysis to scientific problems– Apply scientific thinking to real world problems

• Question: what do you think about General Education requirements, in particular the lab science?– Discuss: does your group have a consensus opinion or not?– Identify a few key points– Have someone prepared to present concisely

• My views on general education, and college education in general

My goals for the class

• Have you come out of class thinking astronomy is more interesting than when you started

• Get you to be curious about what you see around you: understand the astronomical phenomena of everyday life

• Communicate some of the interesting things we’ve learned about our Universe, and especially, how we’ve learned them

• Understand how science works

Class logistics• Read the syllabus!• Class components– Mon/Wed/Fri classes – Labs : groups + individual summaries

• TAs: Sten Hasselquist (M02, M04) and Laura Mayorga (M03)– In class questions / attendance– Online homework: Canvas. Weekly, due Friday class time.– Campus Observatory: twice per semester– Midterms: two– Final

Resources

• Class web page / class notes http://astronomy.nmsu.edu/holtz/a110

(accessible via Canvas)

• Textbook: none, but we will be consulting resources on the web. Paper textbooks available for loan!

• Classmates• TAs• Professor

To do• Homework

– Read the syllabus– Check out the class web site (accessible via Canvas)– Learn your directions: north, south, east, west: no matter

where you are, inside or out, be able to get them right– Do the online assessment on Canvas -- automatic 100%

for a homework assignment; just want to know what you know/think, don’t look anything up!

• For lab – Get lab manual: bring $10 to lab– Clickers will be supplied but if you have an iClicker, bring it