697: Tensile vs. Shear Strength

Explain xkcd: It's 'cause you're dumb.
Jump to: navigation, search
Tensile vs. Shear Strength
Although really, the damage was done when the party planners took the hole punch to the elevator ribbon to hang up the sign.
Title text: Although really, the damage was done when the party planners took the hole punch to the elevator ribbon to hang up the sign.

[edit] Explanation

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 etymologically related.

The title text makes the point that even before Black Hat cut the space elevator's 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 pole, dwarfing its ability to keep the elevator attached to the ground.

[edit] Transcript

[A banner flutters in the breeze, evidently attached to the elevator it mentions in its text. It reads "SPACE ELEVATOR" "GRAND OPENING".]
[A space elevator occupies the height of the frame, consisting of a base, a ribbon extending out into space, and an elevator unit with standard elevator features such as sliding doors and up/down buttons.]
[The following lines appear split across the elevator itself, the rhyming portions of the text separated from the others.]
After countless engineers
Spend trillions over fifty years,
A modern babel disappears
Because some fuck brought pruning shears
[Five individuals stand at the base of the elevator: Megan, Cueball, Ponytail who has recently opened a bottle of champagne, an alarmed man, and Black Hat, who has smuggled the aforementioned shears into the ceremony and unceremoniously turned it into a ribbon cutting.]
comment.png add a comment! ⋅ Icons-mini-action refresh blue.gif refresh comments!


Does anyone know the tensile vs. shear strength of nanotubes? Djbrasier ([[User talk:Djbrasier|talk]]) 20:33, 3 September 2013 (UTC)

"but it can be cut with a simple pair of pruning shears (also a pun on shear strength)" - I don't know the precise etymology of the word shears, but I would assume they are called such precisely because they operate on a shearing principle. While it is fair to assume that the use of the words 'pruning shears' is intentional (rather than 'scissors' or similar) , I wouldn't call it a pun (exploiting multiple meanings of words). --Pudder (talk) 16:07, 11 September 2014 (UTC) (Retroactively signed)

I agree, it's not a pun. I'm going to change that. Spiral phi (talk) 19:32, 27 August 2014 (UTC)

I can't immediately think of any other rhyming comics. Are there any others? --Pudder (talk) 16:07, 11 September 2014 (UTC)

At least 206: Reno Rhymes, 491: Twitter and 805: Paradise City, and probably others. Pelosujamo (talk) 17:32, 23 September 2014 (UTC)

Though the thing would have buckled before all this could even have a chance to happen 16:22, 11 October 2014 (UTC)

Buckling is specifically a failure under compressive load. I'm assuming we are looking at a cable under tensile load caused by centrifugal force. (The old swinging a bucket on a rope trick). Wikipedia has an interesting Space Elevator article. --Pudder (talk) 12:23, 12 December 2014 (UTC)
Aargh! The first line lacks a syllable... E.g. THEN after countless engineers...Mumiemonstret (talk) 10:31, 17 October 2014 (UTC)
Personal tools


It seems you are using noscript, which is stopping our project wonderful ads from working. Explain xkcd uses ads to pay for bandwidth, and we manually approve all our advertisers, and our ads are restricted to unobtrusive images and slow animated GIFs. If you found this site helpful, please consider whitelisting us.

Want to advertise with us, or donate to us with Paypal or Bitcoin?