How K-Ar dating can be used to date very old volcanic rock and the things that might be buried in between. Created by Sal Khan.
Clarifying the effect of axial precession on the calendar and the date of perihelion and aphelion. Created by Sal Khan.
These projects can be used in any introductory astronomy sequence. All projects are designed to be done individually. Follow-up can be done in various ways: 1) with peer-review components online through forums or in class; 2) through in-class discussions; 3) through presentations. All projects except the Research Project are intended to be short (take about 1-2 hours or less).
This is one part of an astronomy resource collection by Lane Community College. This collection was built by Andrea Goering (goeringa@lanecc.edu) and Richard Wagner (wagnerr@lanecc.edu), instructors of physics and astronomy at Lane Community College in Eugene, Oregon, USA. Development of these resources was funded through LCC's OER Initiative (https://inside.lanecc.edu/oer). We'd love to hear about your use of these resources! Let us know what you're using, sign up for updates, and submit corrections, suggestions, or comments here: https://forms.gle/un49RUNs55GU3ZNF6
Find the full collection here: https://docs.google.com/spreadsheets/d/142FgVMDHZ7bu53gihe3kJ_-5PzsnuzfMklJ1ZLMFk2E/edit#gid=315930953
The 1935 edition published by R. T. Gunther was based on only three or four local manuscripts, and as such is defective in many places. Missing phrases, or mis-copies or mis-read phrases at times makes that text unintelligible.
This edition is based on the collation of a significant number of manuscripts (over 80, and eventually, it is hoped, all manuscript copies). What is now being published here is the text of the Prologue and of the first sixteen chapters (Version 1.1).
The edition is available in five PDF files:
Part I: Introduction contains the preface and introductory material, including manuscript information;
Part II: Critical Edition contains the Latin text and diagrams, the critical apparatus and a facing English translation;
Part III: Latin Text contains the Latin text and diagrams, without the apparatus criticus, but maintaining the line numbers of the critical edition;
Part IV: English Text contains the English text and diagrams, for those who are interested in consulting only the translation.
Appendix I: Catalogue of Stars contains information about the all the stars mentioned in the text.
Over time these texts will be updated and expanded, when the remaining manuscript copies are collated, and when the editing of further sections have been completed. However, it is not expected that the present version will change – the rest of the manuscripts will expand the apparatus criticus but are unlikely to modify the text itself.
The editor is interested in the receiving comments on the text, and further insights into its interpretation, from others. He is willing to incorporate such additions into future versions for the benefit of others who would consult this edition in the future. Comments can be sent to thomson@chass.utoronto.ca.
Permission is given for scholars to print out (and bind) any or all of these texts for non-commercial uses: research, study, criticism and citation. Commercial reproduction of all or part of the texts is not permitted without the prior consent of the copyright owner.
Quasar Correction. Created by Sal Khan.
Quasars. Created by Sal Khan.
I propose to create as sort of "Wikipedia" of exam bank questions that focus on the general education courses associated with the first two years of college. I believe enough courses would benefit from such a bank that it could significantly reduce the cost of higher education. A physics and astronomy bank has already been constructed, and a user-friendly exam-writing code has been written.
Radius of Observable Universe. Created by Sal Khan.
(Correction) Radius of Observable Universe. Created by Sal Khan.
Sal's random predictions for the year 2060. Created by Sal Khan.
Students will learn about the twin STEREO spacecraft and how they are being used to track solar storms through reading a NASA press release and viewing a NASA eClips video segment. Then students will examine data to learn more about the frequency and speed of solar storms traveling from the Sun to Earth. This activity is part of the Space Math multimedia modules that integrate NASA press releases, NASA archival video, and mathematics problems targeted at specific math standards commonly encountered in middle school textbooks. The modules cover specific math topics at multiple levels of difficulty with real-world data and use the 5E instructional sequence.
This is a set of four, one-page problems about the size of planets compared to earth. Learners may use ratios to compare planets within our solar system or those outside of our solar system with the earth. Options are presented so that students may learn about the MESSENGER mission to Mercury through a NASA press release or by viewing a NASA eClips video [6 min.]. This activity is part of the Space Math multi-media modules that integrate NASA press releases, NASA archival video, and mathematics problems targeted at specific math standards commonly encountered in middle school.
Many astronomical images show galaxies, nebulae and other objects in bright rainbow colors, but these are not the colors we would see if looking at these objects with our eyes, since the light from these objects may not be visible to us. Scientists chose the colors in the image to represent the invisible wavelengths of light. This activity explores the ideas of invisible light and representational color and lets participants create their own representational color map of the temperature of a surface.
An introduction to red shift
Refraction of Seismic Waves. Created by Sal Khan.
Students write a short essay using relative age principles to describe a fictional set of geologic events and processes (specified in the exercise) that occur in a hypothetical area. The essay is used to develop a geologic profile, and then it is given to another student who is tasked with producing the correct geologic profile (as a quiz), based on the essay information. A teacher-designed rubric is used to score the quiz and to allow students to complete a self-evaluation of their learning.
Visionlearning uses a variety of diffferent technology to innovate and make learning fun. This module explains the browser plug-ins and other programs that can be helpful when using Visionlearning.
For decades, the media have given enormous attention to sensational claims that vague lights in the sky are actually extra-terrestrial spacecraft. Recently, there has been a flurry of misleading publicity about UFOs on military photographs. A sober examination of these claims reveals that there is a lot LESS to them than first meets the eye: when there is enough evidence, UFO claims can be explained by terrestrial or celestial phenomena (including lights from human craft and re-entering space junk). This up-to-date guide provides key resources available free on the Web, to help scientists, educators, students, and journalists learn about the skeptical perspective (and the background stories) behind these claims.
In this exercise, sudents write a series of three stories that explain and/or illustrate rock-forming processes. As an alternative, they may write a single story that addresses the rock cycle. Describing these processes at a level appropriate for their target audience (second graders) requires an adequate understanding of the geologic processes involved and can reveal problems or misconceptions in the students' ideas of how rocks are formed. Teacher's notes and rubrics for teacher and peer review are provided.
Students learn how and why engineers design satellites to benefit life on Earth, as well as explore motion, rockets and rocket motion. Through six lessons and 10 associated hands-on activities, students discover that the motion of all objects everything from the flight of a rocket to the movement of a canoe is governed by Newton's three laws of motion. This unit introduces students to the challenges of getting into space for the purpose of exploration. The ideas of thrust, weight and control are explored, helping students to fully understand what goes into the design of rockets and the value of understanding these scientific concepts. After learning how and why the experts make specific engineering choices, students also learn about the iterative engineering design process as they design and construct their own model rockets. Then students explore triangulation, a concept that is fundamental to the navigation of satellites and global positioning systems designed by engineers; by investigating these technologies, they learn how people can determine their positions and the locations of others.