Astronomy current events question: Solar Dynamics Observatory launch

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

NASA news release, "New Eye on the Sun," February 11, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=9416

NASA's Solar Dynamics Observatory was recently launched, and its mission is to:
(A) understand the effect of the sun on Earth's atmosphere and climate.
(B) detect the presence of dark matter within sunspots.
(C) shield Earth from global warming from the sun.
(D) determine how much longer the sun will live, before becoming a red giant.
(E) observe the effect of high energy particle beams directed onto solar flares.

Correct answer: (D)

Student responses
Sections 30678, 30679, 30680
(A) : 1 student
(B) : 3 students
(C) : 19 students
(D) : 37 students
(E) : 3 students

Astronomy current events question: Mars Express Phobos flyby

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

European Space Agency news release, "Phobos' Flyby Season Starts Again," February 17, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=9437

The European Space Agency Mars Express spacecraft will soon pass very near Phobos, the largest moon of Mars, in order to:
(A) look for remnants of the failed Russian Mars probe Phobos 2.
(B) slingshot itself over to Deimos, the smallest moon of Mars.
(C) look for ice hidden in shadowed craters on its polar caps.
(D) map Phobos' gravity field, and deduce its internal structure.
(E) detect the presence of organic molecules.

Correct answer: (D)

Student responses
Sections 30678, 30679, 30680
(A) : 0 students
(B) : 3 students
(C) : 2 students
(D) : 27 students
(E) : 1 student

Found physics: B-type 67.5 volt battery

20100220484
http://www.flickr.com/photos/waiferx/4373720517/
Originally uploaded by Waifer X


20100220484
http://www.flickr.com/photos/waiferx/4373720519/
Originally uploaded by Waifer X

Eveready(TM) "B" type battery, 67.5 volts. "Always test 'B' batteries with a voltmeter—NEVER an ammeter." Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Astronomy current events question: Cassini mission extended

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

United Press International, "NASA Extends Cassini Tour of Saturn," February 3, 2010
http://www.skyandtelescope.com/news/wires?id=140832154&c=y

What has NASA planned for the Cassini space probe in orbit around Saturn?
(A) Moving it to rendevous with Pluto in 2012.
(B) Extending its operation through 2017.
(C) Crashing into Saturn's atmosphere to gather data on its composition.
(D) Parking it in Saturn's rings until its operating budget can be restored.
(E) Sending it out of the solar system after one last pass near Saturn.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 1 student
(B) : 50 students
(C) : 3 students
(D) : 5 students
(E) : 4 students

Astronomy current events question: asteroid collision

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Astronomy.com editors, "Suspected asteroid collision leaves trailing debris," February 2, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=9113

Researchers at the University of California, Los Angeles suspect that the comet-like object P/2010 A2 in the asteroid belt is:
(A) rich with organic compounds.
(B) from the trailing, unstable edge of the asteroid belt.
(C) on a collision course with Earth in late 2012.
(D) an icy asteroid that has begun to absorb too much sunlight.
(E) the result of a head-on collision between two asteroids.

Correct answer: (E)

Student responses
Sections 30678, 30679, 30680
(A) : 2 students
(B) : 8 students
(C) : 1 student
(D) : 1 student
(E) : 51 students

Astronomy current events question: Pluto color changes

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Kelly Beatty, "New Face of Pluto," February 4, 2010
http://www.skyandtelescope.com/news/home/83606532.html

Recent images from the Hubble Space Telescope show that Pluto:
(A) has undergone rapid color changes on its surface.
(B) is much too small to reconsidered as a planet.
(C) has melted its polar ice caps.
(D) experienced a total solar eclipse from one of its moons, Charon.
(E) is spinning much faster than previously measured.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 51 students
(B) : 4 students
(C) : 3 students
(D) : 2 students
(E) : 4 students

Overheard: scotch tape

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

(Overheard in introductory astronomy lab.)

Instructor: "Use lots of scotch tape. Scotch tape is the duct tape of astronomy."

Online homework assignment: destructive thin film reflections

Physics 205B Homework Assignment 4, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problem 25.17

A thin film of oil (n = 1.50) of thickness 0.40e-6 m is spread over a puddle of water (n = 1.33). The two visible wavelengths that will destructively interfere for reflection will have values of __________ nm and __________ nm in air. (Visible wavelengths in air are in the range of 400 nm to 700 nm.)

Correct answer: 400 nm, 600 nm.

Light in air reflects off of the top of the oil film with a 180 degree phase shift ("fast off of slow"). Light in oil reflects off the top of the water with no phase shift ("slow off of fast"). The two reflections are out of phase.

For destructive interference of these two out of phase reflections, the path difference condition is:

delta(l) = m*lambda_oil,

where the path difference between the two reflected waves is twice the thickness of the oil film, or 2*t, and lambda_oil is related to the lambda_air wavelengths in air:

lambda_oil = lambda_air/n_oil,

as wavelengths are shorter in slower media, compared to the longest in air (or vacuum).

Substituting delta(l) = 2*t, and lambda_oil = lambda_air/n_oil into the destructive interference condition for out of phase reflections:

2*t = m*(lambda_air/n_oil),

2*t*n_oil/m = lambda_air,

with m = 0, 1, 2, 3, 4, ..., possible wavelengths in air that would destructively interfere would be infinite, 1200 nm, 600 nm, 400 nm, 300 nm, ..., respectively, of which only 400 nm and 600 nm are in the visible range in air.

Student responses
Section 31988
537 nm, 637 nm: 1 response
400 nm, 600 nm: 2 responses
429 nm, 687 nm: 1 response
(Blank/no work submitted: 9 responses)

Found physics: hair diffraction pattern

100212-1140932
http://www.flickr.com/photos/waiferx/4351928565/
Originally uploaded by Waifer X

Laser illuminating a tape-mounted human hair, with the resulting diffraction pattern projected on a distant screen. Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Found physics: hair diffraction diagnostic test

100212-1140924
http://www.flickr.com/photos/waiferx/4351922065/
Originally uploaded by Waifer X

Dramatization of "Fermiscan®" x-ray diffraction of human hairs, being developed as a diagnosis tool for screening for breast cancer. All rights reserved by original copyright holders. Photo-montage by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Found physics: varying double slit separation distance

100207-1140877
http://www.flickr.com/photos/waiferx/4344082697/
Originally uploaded by Waifer X

Increasing, then decreasing the spacing d between two slits illuminated by a laser beam, resulting in decreasing, then increasing the angular spacing between maxima and minima fringes on a distant screen. Video by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Astronomy current events question: recurrent U Scorpii nova

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Astronomy.com editors, "Long-Anticipated Eruption of U Scorpii Has Begun," January 28, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=9020

U Scorpii is a star that is starting a recurrent nova explosion. What causes this?
(A) A star is feeding hydrogen onto the outer layers of a white dwarf.
(B) The core of a massive star has finally exhausted its hydrogen supply.
(C) The eruption of magnetic fields surrounding an unstable supergiant.
(D) Too much iron in the core of a supergiant.
(E) Bipolar jets from a companion neutron star.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 45 students
(B) : 13 students
(C) : 6 students
(D) : 1 student
(E) : 3 students

Astronomy current events question: listening for Phoenix lander

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Alicia Chang (Associated Press), "NASA Listens for Silent Mars Lander," January 17, 2010
http://www.skyandtelescope.com/news/wires?id=140109382&c=y

NASA will begin listening for signals from the Phoenix lander on Mars, which has been silent since November 2008 because:
(A) of budget cuts.
(B) it was buried by layers of dry ice.
(C) of a software failure.
(D) its radio dish is stuck pointing in one direction only.
(E) it was quietly listening for signs of intelligent life.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 1 student
(B) : 30 students
(C) : 2 students
(D) : 3 students
(E) : 0 students

Astronomy current events question: Spirit rover now lander

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Kelly Beatty, "Spirit Morphs into a Martian Lander," January 26, 2010
http://www.skyandtelescope.com/news/82759442.html

Because the NASA Mars Spirit rover is stuck, it will:
(A) become buried by shifting sands caused by winter windstorms.
(B) sink further into quicksand-like material.
(C) keep transmitting its location, so Mars' rotation can be tracked.
(D) drill further into a nearby rock to investigate its core.
(E) wait until the Mars Opportunity rover arrives to give it a nudge.

Correct answer: (C)

Student responses
Sections 30678, 30679, 30680
(A) : 7 students
(B) : 1 student
(C) : 21 students
(D) : 1 student
(E) : 2 students

Misprint: first or third quarter moon?

100131-1140788
http://www.flickr.com/photos/waiferx/4319990633/
Originally uploaded by Waifer X

Comparison of misprinted and corrected versions of lunar phase cycle, Michael A. Seeds and Dana E. Backman, Perspectives in Astronomy, 1/e, Brooks/Cole, 2008, p. 25. Photo by Cuesta College Physical Sciences Division instructor Dr. Patrick M. Len.

Found physics: simple magnifier

100130-1140785
http://www.flickr.com/photos/waiferx/4317202635/
Originally uploaded by Waifer X

Wire cutters brought closer to enlarge its angular size, but much closer than the near point of the camera lens (focused at infinity to simulate a relaxed eye). A magnifying glass is then placed in front of the camera lens to project a virtual image of this wire cutters out at infinity, which subsequently becomes an object for the camera lens to be able to focus on. Photo by Cuesta College Physical Science instructor Dr. Patrick M. Len.