Galaxies & Cosmology winter trimester  2011 - 2012

galaxies & cosmology syllabus   &  course expectations
safety, tardy, classroom computer use, and honesty

 Astronomy Picture of the Day         what's up in the sky this week

February 13
February 17


last Friday in class,
we covered a two big eras of the universe
WHY they happened exactly when they did
(including some mistakes on p. 46 of the BLUE book)
1) formation of first atoms
2) formation of first nuclei

if you missed class, because get the notes

(always done before class)

Universe 27(4, 5) actually has good physics/conclusion
(as opposed to most of the entire rest of chapter 27,
which is rampant speculation)

questions you should know
the answer to
before coming to class
despite the fact that some in class Friday wanted to read
Fourier series in the calculus textbook
 in an attempt to understand Universe p.     ;
however, I don't think that will be very productive;
(I am not discouraging you from reading
about Fourier series, but understanding fig.  26-21    ,
even with Fourier series knowledge,
would take far more than one class period....
I am writing a web page on using Fourier series to understand fig 26-21    ;
it is here, but still in progress)

instead, we will examine a limited amount of other issues:

when did the last anti-matter appear in the universe?

what anti-particle was the last to disappear?

in what form is the anti-matter now?

when did the big-bang neutrinos stop acting with matter in the universe?

(written assignments
to be turned in)

web stuff


of the week


February 6
February 7
February 8
February 9
February 10

make sure that you have your BLUE book all this week,
in particular, you need
a) the last 5 pages of the book
b) page 44 of the book

butchered schedule

make sure that you have the proper page of the blue boox for class today

(always done before class)
on observational tests
of which universe we live in:

the first paragraph on page 710 (the last assigned reading)
through the end of the chapter

first day on Big Bang:
26(4, 5)

questions you should know
the answer to
before coming to class

what are the three observational tests
the determine our universe's place
on the ΩΛ-vs-ΩM plot?
do the observations agree?

questions to test your knowledge of
kinds of universes:

1) what regions of the ΩΛ-vs-ΩM plot are occupied
by universes that have the properties
of one of the three classical/Newtonian universes
(e.g., what part of the plot has the properties
of a Newtonian closed universe:
spherical geometry; does not expand forever;
ΩM greater than 1)....
it's not just part of the horizontal line at ΩΛ = 0 !)

2) some universe properties that were
mutually exclusive in Newtonian cosmology
are no longer mutually exclusive in universes
with dark energy
(e.g., ΩM   > 1 and hyperbolic geometry
were mutually exclusive
in Newtonian cosmology, but they are no
longer mutually exclusive in
general relativity)

3) how many regions of the ΩΛ-vs-ΩM plot
can you find that represent universes
that have one property that matches
the classical closed universe;
one property that matches classical open;
and a third property that matches classical flat?
or are there any?

what are the three pieces of evidence that imply that the universe
had a hot, dense origin?
(bring a written list to class !)

how is the universe now
different from the
universe before the first atoms formed?
(at least three differences are
discussed in the book!)

where did those plots of density-
or temperature-vs-age of the universe
come from?

why do the plots of matter
differ from those of radiation?

has it occurred to you that we spent more time in class yesterday talking about the Big Bang
than it took to actually happen?


some of yesterday's of questions are still unanswered!


have you calculated the slopes of the straight-line portions of the two graphs (density and temperature vs time) that we looked at in class yesterday?

why are there two straight-line portions for each graph?
what do they each represent?

can you explain where those slopes came from?

another day, same exact questions

no point in going farther if we dont understand what the physics is or why we are using it

here is a help page on matter and radiation in the early universe
(which summarizes some of what we have done)

each blank box with an "x" is something for you to calculate and or fill in
(I have done one example for you: "definition of density; density now")

the rest is up to you

(a hard copy of this help page on orchid paper is in the black box; it also has a photocopy of the two diagrams from the book whose slope we habe been trying to calculate; you can use to draw straight lines and thus calculate the slope!)

(written assignments
to be turned in)

web stuff


of the week

The Wild Early Lives of Today's Most Massive Galaxies

LOFAR to begin hunt for earliest star formation, galaxies, supermassive black holes

and yet again: newfound alien planet best bet to support life....

Hubble zooms in on a magnified galaxy...

supernova remnant associated with powerful kick

"School Success:  class size doesn't matter ...."
(what 5 things do?)

"I hate homework, but I assign it anyway"

ok, so you've lost the ability
to do simple math without a calculator....
you've lost the ability to concentrate
long enough to read a book....

here's how to lose something else


January 30
January 31
February 1
February 2
February 3

make sure you have BLUE BOOK in class for rest of week
1st project presentations

presentations (executive summaries, at least)
moved to bulletin board: due tomorrow by 5 pm

project work submitted to me by friday
(word processed and/or in lab book);
1 report per group

begin thinking
about final project
bring computers to work on project 2
(always done before class)

begin reading the article from last week:
Look Back Time: Observing Cosmic History

finish article, Look Back Time: Observing Cosmic History

can you determine how they obtained the formulas for distance to a galaxy (both now and in the past)?

review reading for last wednesday

since some people still haven't read that article,
(and why did i hand it out, rather than put an electronic copy of moodle?
so you could write on it!
so you could show how to get from one step to another!
but I can't make you, can I?

questions you should know
the answer to
before coming to class

yesterday in class we wrote down the two GR equations that describe cosmology

(0) in 1916, Einstein kept the "integration constant"
provided by GR in order to prop up the universe from collapsing under gravity;
so, why did he later come to realize that it was a mistake,
and ask for a do-over?

(1) do the GR equations in your text
[(the ones with Ω in them at the end of section 26(6)] 
agree with those I wrote in class yesterday?

(2) by looking at each of these two equations
(we will continue to call one the acceleration equation, but we will re-name the "energy equation" as the "curvature equation" because that's the name of the  term we labeled Ωk yesterday), you should be able to
describe qualitatively how the dark energy behaves:

does it behave like matter or "opposite" to matter?
how did you know?

(3) how many straight lines are there in the  ΩΛ-vs-ΩM plot?
can you see where they came from using the GR equations?

(written assignments
to be turned in)

web stuff

"Is the Universe Leaking Energy"

(Scientific American, July 2010)
is now in moodle
(as it is still under copyright protection)


of the week

january astro pages
december astro pages
november astro pages
october astro pages
september astro pages

January astro pages