Model Boat Mayhem

Mess Deck: General Section => Chit-Chat => Topic started by: Norseman on January 06, 2016, 03:26:51 pm

Title: Two Spheres
Post by: Norseman on January 06, 2016, 03:26:51 pm

Hi


Just a random couch thought, but does anyone know the name of the point at which two spheres touch? I don't know the answer but I'm sure we will have a 'magicmagician' somewhere on Mayhem - probably in Oz  :embarrassed:


To make the question explicit let's say the spheres are identical, perfect, and are also imaginary so there is no issue of not being spherical at a molecular level.


Dave

Title: Re: Two Spheres
Post by: Netleyned on January 06, 2016, 03:32:48 pm

Simply the 'point' I would have thought.


Ned

Title: Re: Two Spheres
Post by: Norseman on January 06, 2016, 03:39:48 pm

You could well be right Ned but scientists engineers and magicmajicians seem to have a name for everything and I wondered?

Title: Re: Two Spheres
Post by: kinmel on January 06, 2016, 03:50:10 pm

In an arranged group of spheres each contact is at a "lattice point", no idea about just 2 spheres.

Is it different if they touch internally, rather than externally ?

Title: Re: Two Spheres
Post by: Norseman on January 06, 2016, 04:39:38 pm

I was just thinking externally but there may be a difference. I'm having knee pains today and resting them has me bored silly, hence the idle question.

Title: Re: Two Spheres
Post by: essex2visuvesi on January 06, 2016, 05:17:36 pm

I thought it was an intersection

Title: Re: Two Spheres
Post by: kinmel on January 06, 2016, 05:36:13 pm

It could well be.

Title: Re: Two Spheres
Post by: Bob K on January 06, 2016, 05:36:32 pm

Also having little to do I have been googling at length.  It appears it is just a "point" where they meet.

Title: Re: Two Spheres
Post by: Netleyned on January 06, 2016, 06:14:33 pm

There seems to be a great deal of complicated maths to calculate the size
of the point, but no terminology as to a name other than point.

Ned

Title: Re: Two Spheres
Post by: ballastanksian on January 06, 2016, 11:09:49 pm

Why can't they meet at a cafe or go for a pint?

Seriously though: Accordong to Wiki, the intersection of two disks is called the 'Lens'. Given that the exterior of a sphere is curved, and lenses are also basically a curved face, it is logical to call the pit that two spheres meet a 'Lens'.

(http://imagizer.imageshack.us/v2/640x480q90/903/mEsA3B.png) (https://imageshack.com/i/p3mEsA3Bp)

Title: Re: Two Spheres
Post by: Norseman on January 07, 2016, 01:50:01 am

Ah from your diagram it becomes obvious that it is the kissing point  :kiss:
I've finally found a use for that emoticon.

Title: Re: Two Spheres
Post by: Bob K on January 07, 2016, 07:29:12 am

Quote from: ballastanksian on January 06, 2016, 11:09:49 pm

Seriously though: Accordong to Wiki, the intersection of two disks is called the 'Lens'. Given that the exterior of a sphere is curved, and lenses are also basically a curved face, it is logical to call the pit that two spheres meet a 'Lens'.

That only applies if they intersect, otherwise a theoretical point contact is still a 'point'.