080702-1020011

http://www.flickr.com/photos/waiferx/2676922593/

Originally uploaded by Waifer X

60 second exposure of Halema'uma'u Crater at night, using night scene setting on a Panasonic Lumix DMC-LZ8. Hawai'i Volcanoes National Park, HI, July 2, 2008. Click on the link for a larger view, with Corona Australis.

## 20080725

## 20080720

### Accretion disk radiation

"Brewster Rockit: Space Guy!" by Tim Rickard

July 5, 2008

There would probably be x-rays rather than near-UV rays emitted from the accretion disk surrounding a black hole, or perhaps beta particles (whether electrons or positrons) from Hawking radiation, especially if the black hole was sufficiently small.

July 5, 2008

There would probably be x-rays rather than near-UV rays emitted from the accretion disk surrounding a black hole, or perhaps beta particles (whether electrons or positrons) from Hawking radiation, especially if the black hole was sufficiently small.

Labels:
accretion disk,
black hole,
blackbody

## 20080719

## 20080718

## 20080717

### "Teach the Controversy" t-shirts

"Classical Periodic Table, by Jeremy Kalgreen

controversy.wearscience.com

"Geocentric Universe" by Jeremy Kalgreen

controversy.wearscience.com

"Intelligently designed t-shirts urging you to show both sides of every story..."

controversy.wearscience.com

"Geocentric Universe" by Jeremy Kalgreen

controversy.wearscience.com

"Intelligently designed t-shirts urging you to show both sides of every story..."

Labels:
geocentrism,
heliocentrism

## 20080716

### Mars Phoenix Mission

"Mars...robot arm grabs handful of soil"

The Sun

June 2, 2008

How did the scoop mark wind up looking like a footprint?

"It puts the mars soil sample in the scoop" by Unknown

punditkitchen.com

July 2, 2008

The Sun

June 2, 2008

How did the scoop mark wind up looking like a footprint?

"It puts the mars soil sample in the scoop" by Unknown

punditkitchen.com

July 2, 2008

Labels:
Mars

## 20080715

### The Sun--Brightening Your Days For 5x10^9 Years

Photoshop Phriday: Unnecessary Advertisements, by the_ruiner

somethingawful.com

June 20, 2008

Also, do not taunt the Sun...

somethingawful.com

June 20, 2008

Also, do not taunt the Sun...

Labels:
Sun

## 20080714

### Astronomy snow-globe

"Traveler 87 At Night (Between Too Much And Me)"

("Traveler" series, 2001-2007)

by Walter Martin and Paloma Muñoz, 2004

martin-munoz.com

Perhaps one of the less ironic artistic snow-globes by these two artists.

("Traveler" series, 2001-2007)

by Walter Martin and Paloma Muñoz, 2004

martin-munoz.com

Perhaps one of the less ironic artistic snow-globes by these two artists.

Labels:
telescopes

## 20080713

### Hawking vs. Einstein, part four

Stephen Hawking at the Lido, Avenue Champs-Elysees, Paris, France

The Pop Culture Travel Guide (jaunted.com)

Stephen Hawking...triumphant!

The Pop Culture Travel Guide (jaunted.com)

Stephen Hawking...triumphant!

Labels:
general relativity,
gravity

## 20080712

## 20080711

### Hawking vs. Einstein, part two

"A Long-Awaited Taste of Outer Space," by Steve Boxall

WashingtonPost.com, April 27, 2007

"Einstein in Schpace," by robotlick

Worth1000.com

Ultimate Comebacks contest.

"So, how do you like them apples, eh?"

WashingtonPost.com, April 27, 2007

"Einstein in Schpace," by robotlick

Worth1000.com

Ultimate Comebacks contest.

"So, how do you like them apples, eh?"

Labels:
general relativity,
gravity

## 20080710

## 20080709

### The downside of astrology

"The Stars Are Against Me Tonight" by Dan-ah Kim (dkim-art.com)

Mixed Media, 15" by 19"

"Departing Flights" exhibit at Thinkspace Art Gallery

Los Angeles, CA, June 13 to July 4, 2008

The fault, dear reader, is not within us, but in the stars themselves...

Mixed Media, 15" by 19"

"Departing Flights" exhibit at Thinkspace Art Gallery

Los Angeles, CA, June 13 to July 4, 2008

The fault, dear reader, is not within us, but in the stars themselves...

Labels:
astrology

## 20080708

### Over easy, or scrambled?

"But They Only Warn You About One" by Jessica Hagy

indexed.blogspot.com, June 10, 2008

Of course, everyone knows that in order to make scrambled eggs, you must first beat them.

indexed.blogspot.com, June 10, 2008

Of course, everyone knows that in order to make scrambled eggs, you must first beat them.

Labels:
quantum mechanics

## 20080707

### Physics quiz question: Mountain Dew AMP(TM) caffeine consumption rate

Physics 8A Quiz 1, Fall Semester 2005

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.1

(Cf. Young and Freeman, University Physics,

[3.0 points.] Suppose that you drank a Mountain Dew AMP(TM) beverage (containing 113 mg of caffeine) twice a day. Which one of the following choices best describes your average intake of caffeine in grams per second, if you do not drink any other caffeinated beverage?

(A) 2.62 x 10^-6 g/s.

(B) 5.12 x 10^-5 g/s.

(C) 1.95 x 10^-4 g/s.

(D) 0.382 g/s.

Correct answer: (A)

The intake in grams per second can be determined from converting the units from the given rate of 226 mg per day:

(226 g/1 day) * (1 g/1,000 mg) * (1 day/24 h) * (1 h/3600 s).

Response (B) is the result of 1,000/(226*3600*24); response (C) is 226*3,600*24/1000, but with the resulting 10^4 exponent switched to 10^-4; while response (D) is 3,600*24/(226*1,000).

Student responses:

(A) : 31 students

(B) : 3 students

(C) : 5 students

(D) : 0 students

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.1

(Cf. Young and Freeman, University Physics,

*11/e*, Exercise 1.6.)[3.0 points.] Suppose that you drank a Mountain Dew AMP(TM) beverage (containing 113 mg of caffeine) twice a day. Which one of the following choices best describes your average intake of caffeine in grams per second, if you do not drink any other caffeinated beverage?

(A) 2.62 x 10^-6 g/s.

(B) 5.12 x 10^-5 g/s.

(C) 1.95 x 10^-4 g/s.

(D) 0.382 g/s.

Correct answer: (A)

The intake in grams per second can be determined from converting the units from the given rate of 226 mg per day:

(226 g/1 day) * (1 g/1,000 mg) * (1 day/24 h) * (1 h/3600 s).

Response (B) is the result of 1,000/(226*3600*24); response (C) is 226*3,600*24/1000, but with the resulting 10^4 exponent switched to 10^-4; while response (D) is 3,600*24/(226*1,000).

Student responses:

(A) : 31 students

(B) : 3 students

(C) : 5 students

(D) : 0 students

## 20080706

### Physics quiz question: gas consumption rate

Physics 8A Quiz 1, Fall Semester 2005

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.1

(Cf. Young and Freeman, University Physics,

[3.0 points.] The gasoline consumption of a small sedan is advertised as 30.0 miles per gallon. Which one of the following choices best corresponds to this value in meters per milliliter?

(A) 4.93 x 10^-5 m/mL.

(B) 12.8 m/mL.

(C) 70.6 m/mL.

(D) 78.4 m/mL.

Correct answer: (B)

The gasoline consumption can be expressed in meters per milliliter using unit conversions:

(30 mi/gal) * (1.609 km/1 m) * (1,000 m/1 km) * (1 gal/3.785 L) * (1 L/1,000 mL) = 12.8 m/mL.

Response (A) is (30/(1,609*3.785)); response (C) is (30*3,785)/1,609; response (D) is 3,785/(30*1,609).

Student responses:

(A) : 28 students

(B) : 0 students

(C) : 0 students

(D) : 0 students

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.1

(Cf. Young and Freeman, University Physics,

*11/e*, Exercise 1.9.)[3.0 points.] The gasoline consumption of a small sedan is advertised as 30.0 miles per gallon. Which one of the following choices best corresponds to this value in meters per milliliter?

(A) 4.93 x 10^-5 m/mL.

(B) 12.8 m/mL.

(C) 70.6 m/mL.

(D) 78.4 m/mL.

Correct answer: (B)

The gasoline consumption can be expressed in meters per milliliter using unit conversions:

(30 mi/gal) * (1.609 km/1 m) * (1,000 m/1 km) * (1 gal/3.785 L) * (1 L/1,000 mL) = 12.8 m/mL.

Response (A) is (30/(1,609*3.785)); response (C) is (30*3,785)/1,609; response (D) is 3,785/(30*1,609).

Student responses:

(A) : 28 students

(B) : 0 students

(C) : 0 students

(D) : 0 students

## 20080705

### Physics quiz question: unit conversion discrepancies

Physics 8A Quiz 1, Spring Semester 2005

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.2

(Cf. Young and Freeman, University Physics,

[3.0 points.] Compare the exact relation of 1 inch = 2.54 cm with the approximate relation 39.37 inches = 100 cm. Which one of the following choices best corresponds to the percent discrepancy between using these relations to determine how many inches there are in one meter?

(A) 0 %.

(B) 0.0002%.

(C) 0.0079%.

(D) 0.01%.

Correct answer: (A)

The "observed" value of inches in one meter would be 39.37 inches, while the "expected" value would be based on the 1 inch = 2.54 cm relation:

1 m * (100 cm/1 m) * (1 inch/2.54 cm) = 39.370078740157... inches.

Then the difference between the observed and expected value would be:

39.37 inches - 39.370078740157... inches = 0.000078740157... inches,

or two decimal places, 0.0 inches. This makes the percent discrepancy 0%, to the correct number of significant figures.

Response (B) uses too many significant figures; response (C) does not divide by the expected value in converting the discrepancy into percent discrepancy; response (D) is as (C), but rounded up.

Student responses:

(A) : 15 students

(B) : 34 students

(C) : 10 students

(D) : 10 students

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.2

(Cf. Young and Freeman, University Physics,

*11/e*, Exercise 1.15.)[3.0 points.] Compare the exact relation of 1 inch = 2.54 cm with the approximate relation 39.37 inches = 100 cm. Which one of the following choices best corresponds to the percent discrepancy between using these relations to determine how many inches there are in one meter?

(A) 0 %.

(B) 0.0002%.

(C) 0.0079%.

(D) 0.01%.

Correct answer: (A)

The "observed" value of inches in one meter would be 39.37 inches, while the "expected" value would be based on the 1 inch = 2.54 cm relation:

1 m * (100 cm/1 m) * (1 inch/2.54 cm) = 39.370078740157... inches.

Then the difference between the observed and expected value would be:

39.37 inches - 39.370078740157... inches = 0.000078740157... inches,

or two decimal places, 0.0 inches. This makes the percent discrepancy 0%, to the correct number of significant figures.

Response (B) uses too many significant figures; response (C) does not divide by the expected value in converting the discrepancy into percent discrepancy; response (D) is as (C), but rounded up.

Student responses:

(A) : 15 students

(B) : 34 students

(C) : 10 students

(D) : 10 students

## 20080703

### Physics quiz question: monolith surface area

Physics 8A Quiz 1, Spring Semester 2004

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.2

(Cf. Young and Freeman, University Physics,

[Version 1]

[3.0 points.] A solid model of a monolith has rectangular dimensions of 1.00 units x 4.00 units x 9.0 units. Which one of the following choices best describes the total surface area (in units^2) of this monolith?

(A) 9.8 x 10^1 units^2.

(B) 9.80 x 10^1 units^2.

(C) 1.0 x 10^1 units^2.

(D) 1.00 x 10^1 units^2.

Correct answer: (A)

Student responses:

(A) : 28 students

(B) : 8 students

(C) : 4 students

(D) : 0 students

[Version 2]

[3.0 points.] A solid model of a monolith has rectangular dimensions of 1.000 units x 4.000 units x 9.00 units. Which one of the following choices best describes the total surface area (in units^2) of this monolith?

(A) 9.8 x 10^1 units^2.

(B) 9.80 x 10^1 units^2.

(C) 1.0 x 10^2 units^2.

(D) 1.00 x 10^2 units^2.

Correct answer: (B)

Student responses:

(A) : 6 students

(B) : 27 students

(C) : 2 students

(D) : 1 student

The dimensions of the monolith from Arthur C. Clarke's

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.2

(Cf. Young and Freeman, University Physics,

*11/e*, Exercise 1.14.)[Version 1]

[3.0 points.] A solid model of a monolith has rectangular dimensions of 1.00 units x 4.00 units x 9.0 units. Which one of the following choices best describes the total surface area (in units^2) of this monolith?

(A) 9.8 x 10^1 units^2.

(B) 9.80 x 10^1 units^2.

(C) 1.0 x 10^1 units^2.

(D) 1.00 x 10^1 units^2.

Correct answer: (A)

Student responses:

(A) : 28 students

(B) : 8 students

(C) : 4 students

(D) : 0 students

[Version 2]

[3.0 points.] A solid model of a monolith has rectangular dimensions of 1.000 units x 4.000 units x 9.00 units. Which one of the following choices best describes the total surface area (in units^2) of this monolith?

(A) 9.8 x 10^1 units^2.

(B) 9.80 x 10^1 units^2.

(C) 1.0 x 10^2 units^2.

(D) 1.00 x 10^2 units^2.

Correct answer: (B)

Student responses:

(A) : 6 students

(B) : 27 students

(C) : 2 students

(D) : 1 student

The dimensions of the monolith from Arthur C. Clarke's

*2001: A Space Odyssey*are, of course, known to much more significant figures than given here.## 20080702

### Physics quiz question: elapsed round-trip distances

Physics 8A Quiz 1, Spring Semester 2004

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.1

(Cf. Young and Freeman, University Physics,

[Version 1]

[3.0 points.] Suppose that the round-trip mileage between your home and Cuesta College is 48.0 miles. If you were to travel to and from campus five days a week, and there are 18 whole weeks of class in a semester, which one of the following choices best describes the number of semesters that you would need to drive a total of 6,000 miles between your home and campus?

(A) 0.576 semesters.

(B) 0.720 semesters.

(C) 1.39 semesters.

(D) 1.74 semesters.

Correct answer: (C)

This can be solved by ensuring that units cancel to result in 6,000 miles:

6,000 mi = (48.0 mi/1 trip) * (5 trips/1 week) * (18 weeks/1 semester) * N,

where N is the number of semesters.

Response (B) is the inverse of the correct response (C).

Student responses:

(A) : 0 students

(B) : 4 students

(C) : 31 students

(D) : 0 students

[Version 2]

[3.0 points.] Suppose that the round-trip mileage between your home and Cuesta College is 48.0 miles. If you were to travel to and from campus only four days a week, and there are 18 whole weeks of class in a semester, which one of the following choices best describes the number of semesters that you would need to drive a total of 6,000 miles between your home and campus?

(A) 0.576 semesters.

(B) 0.720 semesters.

(C) 1.39 semesters.

(D) 1.74 semesters.

Correct answer: (D)

This can be solved by ensuring that units cancel to result in 6,000 miles:

6,000 mi = (48.0 mi/1 trip) * (4 trips/1 week) * (18 weeks/1 semester) * N,

where N is the number of semesters.

Response (A) is the inverse of the correct response (D).

Student responses:

(A) : 2 students

(B) : 1 student

(C) : 1 student

(D) : 32 students

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.1

(Cf. Young and Freeman, University Physics,

*11/e*, Exercise 1.1.)[Version 1]

[3.0 points.] Suppose that the round-trip mileage between your home and Cuesta College is 48.0 miles. If you were to travel to and from campus five days a week, and there are 18 whole weeks of class in a semester, which one of the following choices best describes the number of semesters that you would need to drive a total of 6,000 miles between your home and campus?

(A) 0.576 semesters.

(B) 0.720 semesters.

(C) 1.39 semesters.

(D) 1.74 semesters.

Correct answer: (C)

This can be solved by ensuring that units cancel to result in 6,000 miles:

6,000 mi = (48.0 mi/1 trip) * (5 trips/1 week) * (18 weeks/1 semester) * N,

where N is the number of semesters.

Response (B) is the inverse of the correct response (C).

Student responses:

(A) : 0 students

(B) : 4 students

(C) : 31 students

(D) : 0 students

[Version 2]

[3.0 points.] Suppose that the round-trip mileage between your home and Cuesta College is 48.0 miles. If you were to travel to and from campus only four days a week, and there are 18 whole weeks of class in a semester, which one of the following choices best describes the number of semesters that you would need to drive a total of 6,000 miles between your home and campus?

(A) 0.576 semesters.

(B) 0.720 semesters.

(C) 1.39 semesters.

(D) 1.74 semesters.

Correct answer: (D)

This can be solved by ensuring that units cancel to result in 6,000 miles:

6,000 mi = (48.0 mi/1 trip) * (4 trips/1 week) * (18 weeks/1 semester) * N,

where N is the number of semesters.

Response (A) is the inverse of the correct response (D).

Student responses:

(A) : 2 students

(B) : 1 student

(C) : 1 student

(D) : 32 students

## 20080701

### Physics quiz question: speed conversion

Physics 8A Quiz 1, Fall Semester 2003

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.1

(Cf. Young and Freeman, University Physics,

[3.0 points.] Consider the pop rock group t.A.T.u's album title

(A) 124 ft/s.

(B) 136 ft/s.

(C) 182 ft/s.

(D) 322 ft/s.

Correct answer: (C)

To convert km/h into ft/s:

(200 km/h) * (1,000 m/1 km) * (3.28 ft/1 m) * (1 h/3,600 s) = 182 ft/s.

Response (A) is 200/1.609; response (B) is 200*(3,600/5,280); while response (D) is 200*1.609.

Student responses:

(A) : 1 student

(B) : 1 student

(C) : 35 students

(D) : 1 student

Cuesta College, San Luis Obispo, CA

Physics 8A learning goal Q1.1

(Cf. Young and Freeman, University Physics,

*10/e*, Exercise 1-7.)[3.0 points.] Consider the pop rock group t.A.T.u's album title

*"200 km/h In The Wrong Lane."*Which one of the following choices best describes this speed in feet per second?(A) 124 ft/s.

(B) 136 ft/s.

(C) 182 ft/s.

(D) 322 ft/s.

Correct answer: (C)

To convert km/h into ft/s:

(200 km/h) * (1,000 m/1 km) * (3.28 ft/1 m) * (1 h/3,600 s) = 182 ft/s.

Response (A) is 200/1.609; response (B) is 200*(3,600/5,280); while response (D) is 200*1.609.

Student responses:

(A) : 1 student

(B) : 1 student

(C) : 35 students

(D) : 1 student

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