Photography Showcase: A Different Perspective

[turbo]

GeoMike's #1 looks like the bottom of a thermos liner (minus the metal outer shell).

 

[GeoMike]

GeoMike's #1 looks like the bottom of a thermos liner (minus the metal outer shell).

Nope.

I cropped the original photo because there was a big clue on the section I cropped out.
So, here is the uncropped photo:
http://www.mcschell.com/guess1_full.jpg

-GeoMike-

 

[Gokul43201]

I think Gokul is showing us what a Dewar of liquid nitrogen looks like.

Zigackly! What a coincidence that Mk would start a thread on exactly the same thing!

The mouth of the LN2 dewar (with the stuff inside), allows a very pretty ball of water vapor to "crystallize" in it. You can just barely see the white, puffy cloud in those pics, the real thing is way prettier. And the neatest thing about it is that the ball, given a little time without disturbance, will develop this beautiful lattice structure. If you look hard, you can sort of tell this from the pic.

Here's a time-series of pictures taken in roughly 30 second intervals after disturbing a dewar:

1. Cloud of vapor just beginning to form:
http://img179.imageshack.us/img179/1961/img2637cx5.jpg

2. Cloud getting denser:
http://img166.imageshack.us/img166/620/img2638th4.jpg

3. Ball-shaped cloud developing "crystal" structure:
http://img218.imageshack.us/img218/3082/img2641hk1.jpg

 

[Gokul43201]

There's now some text "...L(?) I(?) F E S(?)" visible in Geo's picture, and the text is NOT reflected (laterally inverted)!

 

[turbo]

Nope.

I cropped the original photo because there was a big clue on the section I cropped out.
So, here is the uncropped photo:

-GeoMike-

Ah yes, it looks like a lightbulb in an explosion-proof housing. Operating room?

 

[GeoMike]

Ah yes, it looks like a lightbulb in an explosion-proof housing. Operating room?

Close enough! It's a shot of the glass globe that covered the light bulb above the stairs in our old home. The picture was taken under the globe while looking straight up.
I'm not sure if it was explosion-proof (it came with the house).

-GeoMike-

 

[Mk]

I'm not sure if it was explosion-proof (it came with the house).

:rofl: Ha ha, :rofl:

 

[tribdog]

Until something else comes up...

http://img454.imageshack.us/img454/3838/img2624us4.jpg

is it the lens to your camera on your cell phone?

 

[Evo]

No one has guessed this yet. Although Gokul was very close.

This one should be pretty easy for anyone with an interest in abstract geometry. You have to get the precise figure, though.

Obviously, it's a construct sitting on top of my computer.

 

[tribdog]

Is it the trajectory of the "magic" bullet? that killed kennedy?

 

[zoobyshoe]

The child that resulted from a mating of M.C. Escher and R. Buckminster Fuller?

 

[DaveC426913]

No one has guessed this yet. Although Gokul was very close.

I got it! It's a dodecahedron extended into a star.

How I figured it out: Count the struts in each vertex: each has five. That means each vertex has a pentagonal cross-section. If you cut off the tips, you get all pentagons.

(And now that I know that, I can see that it also has 12 points, which is how many faces a ddh'n has.)

Been trying to find a proper name for it. Would that be a "stellated" dodecahedron?

 

[Evo]

I got it! It's a dodecahedron extended into a star.

Every vertex has five struts. Thus, if you trace the 5 of each vertex back to a face, you get one face of a dodecahedron.

(And now that I know that, I can see that it also has 12 points, which is how many faces a ddh'n has)

Yes!, it is a dodecahedron! Dave, you're awesome.

It's actually a lesser stellated dodechahedron

 

[zoobyshoe]

Been trying to find a proper name for it. Would that be a "stellated" dodecahedron?

According to the wikipedia this is probably correct.

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

 

[Evo]

Here is his e-mail to me.

The icosahedron is one of the Platonic solids. It is almost identical
to
the lesser stellated dodecahedron (the figure I posted, which is NOT a
Platonic solid), because they both have the same number of vertices,
and
the same number of edges.

Basically, if you look at the icosahedron, you see a pentagon under
each of
the points. Beyond that is another pentagon in a parallel plane, then
the
last of the 12 points. If you take each edge leading from the central
point
to the second pentagon, not the first, and do that for all the points,
you
get the lesser stellated dodecahedron. Of course, once you've done
that to
all the points, each of the pentagons becomes a pentacle. The lesser
stellated dodecahedron is to the icosahedron exactly as a pentacle is
to a
pentagon.

I have other photos showing that aspect of the lesser stellated
duodecahedron much more clearly. Clarity was not the goal in this case.

Platonic solids are cool. They are very limited (there's only five),
but
they are very neat things.

 

[DaveC426913]

I was trying to figure out how to describe regular polyhedrons without getting long-winded and I've managed to find it in Wiki. It's the "vertex configuration". It is the number of polygons around each vertex and what polygon they are.

There are five known:
3.3.3 (tetrahedron)
4.4.4 (cube)
3.3.3.3 (octohedron)
5.5.5 (dodecahedron)
3.3.3.3.3 (icosahedron)
There can't be any less than 3 polygons per vertex because you get degenerate objects, eg.: 3.3 (a 2D flat triangle)
And most configurations have an upper limit or you get a tiled plane: 4.4.4.4 (4x90degrees=360 - a flat plane)

So there are very clear bounds on the regular solids. Ah what what about interpolation? Has every combination of polygons vs. sides been represented? No! There's one left.

4.4.4.4.4

It is neither degenerate nor a tiled plane. And it does form a closed shape (eventually). But it bends just one platonic solid rule: it's not convex.

Sorry, I'm hijacking this thread.

 

[tribdog]

I haven't had 5 platonic relationships in my life. are you sure you added right?

 

[DaveC426913]

I haven't had 5 platonic relationships in my life. are you sure you added right?

Ba DUM bum!

 

[franznietzsche]

I haven't had 5 platonic relationships in my life. are you sure you added right?

Its ok, I'm sure the lurkers thought it was funny.

Are you campaigning all of a sudden for that ribbon?

 

[Evo]

Aha, tribdog might be eligible if he hangs around long enough.

 

[tribdog]

If you're asking I'm always eligible, baby.