Difference between revisions of "975: Occulting Telescope"

Explain xkcd: It's 'cause you're dumb.
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| number    = 0975
| number    = 975
| date      = November 09, 2011
| date      = November 09, 2011
| title    = Occulting Telescope
| title    = Occulting Telescope

Revision as of 00:15, 13 September 2012

Occulting Telescope
Type II Kardashev civilizations eventually completely enclose their planetary system in a Dyson sphere because space is way too big to look at all the time.
Title text: Type II Kardashev civilizations eventually completely enclose their planetary system in a Dyson sphere because space is way too big to look at all the time.


In this comic Cueball takes the useful practice of occulting stars beyond its intended purpose. Occulting is often used to block the light from a star so that the surrounding extrasolar planets (planets outside of our solar system) might be more visible and thus can be more clearly examined. Here instead of using the technique to gain access to less visible stars and planets, Cueball proposes blocking the light from all stars. The rationale is that there are just too many stars and he would feel better presumably if he could look at the night sky without being overwhelmed by the great volume of stars visible, each representing its own solar system.

File:Dyson Swarm.png
A relatively simple arrangement of multiple Dyson Rings of the type pictured above, to form a more complex Dyson Swarm. Rings' orbital radii are spaced 1.5 x 10^7 km with regard to one another, but average orbital radius is still 1 AU. Rings are rotated 15 degrees relative to one another, around a common axis of rotation.(from Wikipedia Commons)

The title text refers to a Type II Kardashev civilization that encloses its solar system in a Dyson sphere not to trap all emitted energy from its star for its own use but because there are just too many stars to look at.

  • A type II civilization has trapped all energy from its sun. (Type I has only the energy available from its own planet and a type III would have access to energy from its entire galaxy).
  • A Dyson sphere is currently only a theoretical network of satellites that would be designed to orbit and completely surround a star to capture and transmit all of the available solar energy back to a planet.


[A person is giving a lecture in front of a white board, pointing to a diagram with a pointer.]
Lecturer: The occulting observatory consists of two parts -- the telescome and the discs.
When the telescope sees a star, a disc is carefully steered to block its light.
[A diagram of a satellite (labeled "telescope") with waves going from it on the left, across to the other side of the diagram (labeled "light from star") on the right. In the middle is a small vertical line (labeled "disc"), stopping some of the light waves from the right traveling to the left of the diagram.]
This procedure is repeated until all stars are covered.
[The lecturer looks down at a student.]
Student (off screen): Wait, all? Why?
Lecturer: I'll feel better.
[Close-up on lecturer.]
Student (off-screen): I thought the point was to image extrasolar planets.
Lecturer: The point is that there are too many stars. It's been freaking me out.
Student: What?
Student#2 (in smaller letters): He has a point...

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A personal lesson I've learned long ago that I would like to share with Mr. XKCD and others: Don't worry about things you don't have direct control over, try to help people that do have control better understand the challenge they are facing and you will feel great with every accomplishment (similar to remembering to bring that reusable bag of yours to the store). If you don't know anyone with control, but feel you have a lesson to teach about the universe around us, put it in fiction form for future generations to learn from, and we will reward you with riches for it. - e-inspired 15:51, 27 February 2013 (UTC)