Editing 697: Tensile vs. Shear Strength

Jump to: navigation, search

Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.

The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision Your text
Line 10: Line 10:
 
This comic is set in the future, where engineers have successfully constructed a space elevator, until Black Hat decides to cut the cable linking the ground and space using pruning shears. This demonstrates how tensile and shear strength are not the same. Tensile strength represents how hard you can pull on something without it breaking. Shear strength represents how hard you can try to cut it without it breaking. Many materials have great tensile strength but low shear strength (such as dental floss — try to break it by just pulling on two ends), including whatever this space elevator is made of. The material clearly has extremely high tensile strength because it can hold the elevator in place, with one end on the ground and one in space, but it can be cut with a simple pair of pruning shears. This also highlights the fact that "shear strength" and "shears" are [https://www.etymonline.com/word/shear etymologically related].
 
This comic is set in the future, where engineers have successfully constructed a space elevator, until Black Hat decides to cut the cable linking the ground and space using pruning shears. This demonstrates how tensile and shear strength are not the same. Tensile strength represents how hard you can pull on something without it breaking. Shear strength represents how hard you can try to cut it without it breaking. Many materials have great tensile strength but low shear strength (such as dental floss — try to break it by just pulling on two ends), including whatever this space elevator is made of. The material clearly has extremely high tensile strength because it can hold the elevator in place, with one end on the ground and one in space, but it can be cut with a simple pair of pruning shears. This also highlights the fact that "shear strength" and "shears" are [https://www.etymonline.com/word/shear etymologically related].
  
A {{w|space elevator}} is a proposed construction that would make space travel easier. It consists of a long string attached to the Earth (near equator) on one end and a counterweight (beyond the {{w|geostationary orbit}}) on the other end, kept taut and in one place by the gravity and centrifugal forces. This would make it possible to carry spacecraft into the orbit by simple mechanical means, as opposed to requiring the use of rockets as is the case nowadays, saving a lot of energy and resources.
+
A {{w|space elevator}} is a proposed construction that would make space travel easier. It consists of a long string attached to the Earth (near equator) on one end and a counterweight (beyond the {{w|geostationary orbit}}) on the other end, kept taut and in one place by the gravity and centrifugal forces. This would make it possible to carry spacecraft into the orbit by simple mechanical means, as opposed to requiring the use of rockets as is the case nowadays, saving lot of energy and resources.
  
The phrase "a modern Babel" refers to the biblical story of the {{w|Tower of Babel}} (later referenced in [[2421: Tower of Babel]]), in which humans endeavor to build a tower reaching heaven. Their arrogance angers God and prompts him to sabotage the project. A space elevator can be seen as a modern equivalent of a tower to heaven. Additionally, the expression "a modern Babel" may be used figuratively to describe huge projects (especially buildings or human-made structures) that fail because they are too ambitious.  
+
The phrase "a modern Babel" refers to the biblical story of the {{w|Tower of Babel}}, in which humans wanted to build a tower reaching the sky, which angered God and caused him to sabotage the project. The Tower of Babel is also referenced in [[2421: Tower of Babel]]. A space elevator can be seen as a modern form of a "tower reaching the sky". Additionally, the expression "a modern Babel" may be used figuratively to describe huge projects (especially buildings or human-made structures) that are too ambitious and therefore fail.  
  
 
The title text makes the point that even before [[Black Hat]] cut the space elevator's ribbon-like cable in two, it was ruined by the holes in it for the banner. The holes would reduce the surface area of the cross section of the ribbon, reducing its ability to keep the elevator attached to the ground. The flag and holes would also potentially make it impossible for the elevator to travel up the ribbon, making the entire elevator useless.
 
The title text makes the point that even before [[Black Hat]] cut the space elevator's ribbon-like cable in two, it was ruined by the holes in it for the banner. The holes would reduce the surface area of the cross section of the ribbon, reducing its ability to keep the elevator attached to the ground. The flag and holes would also potentially make it impossible for the elevator to travel up the ribbon, making the entire elevator useless.

Please note that all contributions to explain xkcd may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see explain xkcd:Copyrights for details). Do not submit copyrighted work without permission!

To protect the wiki against automated edit spam, we kindly ask you to solve the following CAPTCHA:

Cancel | Editing help (opens in new window)