Talk:Helicoid

Latest comment: 8 years ago by 140.112.54.158 in topic unclear sentence

It said "cylindrical coordinates;" I changed this to Cartesian and linked it, since it is a parametrization leading to (x, y, z) not (r, T, h), obviously. (Sorry, wasn't logged in. -- entropix)

unclear sentence

edit

Could someone explain what exactly the following sentence mean? "Since it is considered that the planar range extends through negative and positive infinity, close observation shows the appearance of two parallel or mirror planes in the sense that if the slope of one plane is traced, the co-plane can be seen to be bypassed or skipped, though in actuality the co-plane is also traced from the opposite perspective." — Preceding unsigned comment added by 140.112.54.158 (talk) 02:54, 11 March 2016 (UTC)Reply

Err, it was described by Euler...

edit

... in 1774.

refimprove VS unsourced

edit

This article DOES have a single reference / citation (though at the bottom, the relevant section is currently titled "notes") As such, I would like to gently urge fellow wikipedia editors out there: Please use {{refimprove}} where appropriate in place of misuing {{Unreferenced}} (the later of which is meant for articles with ZERO citations) --Kuzetsa (talk) 22:35, 22 October 2008 (UTC)Reply

I took the liberty to remove the {{refimprove}} as for two years nobody has neither argued against the contents nor added references, and as one reference seem perfectly sufficient. Bo Jacoby (talk) 11:59, 26 September 2010 (UTC).Reply

Infinite by definition

edit

Article says: "The helicoid is shaped like Archimedes' screw, but extends infinitely in all directions."

I wonder if this is quite right? On Wolfram math world (http://mathworld.wolfram.com/Helicoid.html) it's described as "The (circular) helicoid is the minimal surface having a (circular) helix as its boundary.", and their parametrization mentions nothing about infiniteness.

If no one objects I'm changing this. --Riyaah (talk) 07:07, 19 September 2010 (UTC)Reply

If you truncate it, it can no longer be called a ruled surface. Tkuvho (talk) 09:15, 19 September 2010 (UTC)Reply

File:Helicatenoid.gif to appear as POTD soon

edit

Hello! This is a note to let the editors of this article know that File:Helicatenoid.gif will be appearing as picture of the day on November 13, 2011. You can view and edit the POTD blurb at Template:POTD/2011-11-13. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page so Wikipedia doesn't look bad. :) Thanks! howcheng {chat} 00:27, 12 November 2011 (UTC)Reply

An illustration of how two mathematical surfaces, the helicoid and the catenoid, may be transformed into one another. This transformation is a local isometry. The catenoid was the first minimal surface to be discovered, by Leonhard Euler in 1744. Jean Baptiste Meusnier discovered the helicoid in 1766, and its name derives from its similarity to a helix.Image: Wickerprints