(no subject)

[dreamer_easy]

If two spheres intersect at a single point, is there a technical mathematical term for that point?

Comments

[antikythera.livejournal.com]

...I can't find any terms for it, with a quick google. If it was a flat plane intersecting with a sphere it would be called a point of tangency. If they're actually intersecting at more than one point, there's a 'circle of intersection'. If they're just bumped into each other you could probably say that they have a point of intersection, but I can't find a fancier name for it than that.

[outsdr.livejournal.com]

It's been a long time since high school maths, but i thought it was just called the intersect, or the point of intersection.

[outsdr.livejournal.com]

Possibly what you're looking for is Circle-Circle Intersection at a Single Degenerate Point.

http://mathworld.wolfram.com/Circle-CircleIntersection.html

Or, considering this:

"In geometry, two or more lines are said to be concurrent if they intersect at a single point."

you may be able to get away with calling them Concurrent Spheres.

And while I was looking, I found this, which is beautiful:

http://en.wikipedia.org/wiki/Morin_surface

I love math.

[southerndave.livejournal.com]

I asked my mother (retired mathematics teacher) and got this:

"Normally two spheres intersect in a circular disc so that if there is only one point it will be that point where they touch. When two circles intersect at one point it is said that their two points of intersection coincide at their common tangent, so the best I can suggest is that the spheres 'intersect' on their common tangential plane."

Hope this is of some sort of use.

[dreamer-easy.livejournal.com]

Quite a bit, actually - thanks to you both!

[iblis-kukl.livejournal.com]

[acelightning.livejournal.com]

I believe the word you're looking for is osculate (http://dictionary.reference.com/browse/osculate).

[iblis-kukl.livejournal.com]

[dreamer-easy.livejournal.com]

Ah! Not quite, but that led me to point of tangency.

"Kiss"! :D

[acelightning.livejournal.com]

I last studied geometry in 1962... that's where I remember the word from...

[southerndave.livejournal.com]

... The only place I have ever seen that word before was in an old newspaper report concerned with ... a particularly unhygienic courtroom activity of the late 19th century...

[acelightning.livejournal.com]

The only "unhygienic" association I can think of is the osculum infame (http://en.wikipedia.org/wiki/Osculum_infame)...

[southerndave.livejournal.com]

... Not quite that unhygienic, but rather unhygienic (http://paperspast.natlib.govt.nz/cgi-bin/paperspast?a=d&d=NOT18940129.2.10&e=-------10--1----0-all) all the same. (About three fifths' down the page, in a paragraph beginning "The other day in the local Court...")

[acelightning.livejournal.com]

I think the custom of swearing an oath by kissing (rather than just placing one's hand on) the Bible came into vogue before the knowledge of the germ theory of disease. Personally, I'm almost more revolted by the spiritual contamination I might be exposed to if I were compelled to kiss a scripture that doesn't apply to me...