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#91

Science / Re: The Smith Hat and Light

Last post by Dark Lightning - September 16, 2026, 02:06:44 AM

I saw that this morning. Very cool!

#92

Science / The Smith Hat and Light

Last post by Recusant - September 15, 2026, 11:05:19 PM

Certainly we've had threads that have least mentioned Penrose tiling and related ideas. I'm pretty sure there's at least one devoted solely to that topic, but a few stabs with the site search didn't bring anything up that seemed to fit the bill.

Thus a new thread it born.    I think this is just really cool. A "Smith hat" is a 13-sided polygon that fits the bill: a single shape that can cover a surface without ever repeating. Somebody came up with the idea of shining light through a transparent surface covered by the Smith hat shape. . .

"The shape behind the Einstein problem just revealed strange new physics" | ScienceDaily

Researchers from the Institute of Industrial Science, The University of Tokyo experimentally demonstrate unique optical behavior from a long-sought aperiodic pattern. Credit: Institute of Industrial Science, The University of Tokyo

In a study published in Nature Communications, researchers from the Institute of Industrial Science, The University of Tokyo, and collaborating institutions built optical structures inspired by the "Smith hat." This unusual shape is known for solving the so-called Einstein problem in mathematics. When the team illuminated the structures with laser light, they observed diffraction effects unlike those seen in conventional quasicrystals.

The Einstein problem asks whether a single tile shape, known as a "monotile," can cover an entire surface without creating a repeating pattern.

Familiar tilings such as checkerboards and honeycombs repeat in a regular way. An aperiodic monotile, by contrast, can fill a surface without ever settling into a repeating arrangement.

[. . .]

"What is especially fascinating about the hat tile is that, although the resulting pattern appears irregular at first glance, it is actually constructed from the honeycomb lattice," says lead author Yuto Moritake. "We wanted to see whether this unique shape could also produce any unexpected physical phenomena."

To test that possibility, the researchers created nanoscale versions of the pattern on silicon nitride films using electron beam lithography.

When laser light was directed at the structures, the resulting diffraction patterns formed distinctive pinwheel-like shapes. These patterns directly revealed the chiral character of the aperiodic structure.

Chirality refers to a form of handedness in which a structure and its mirror image cannot be perfectly matched. In this case, the unusual arrangement of the monotile pattern caused the light itself to display a chiral response.

"We found that the diffraction patterns themselves become chiral because the structure lacks mirror symmetry," explains senior author Masaya Notomi. "This kind of optical response is fundamentally different from that observed in conventional quasicrystalline materials."

[Continues . . .]

#93

Religion / Re: Evangelists

Last post by billy rubin - September 15, 2026, 03:18:41 PM

when did england become a country of peace that abjures fighting?

#94

Religion / Re: Evangelists

Last post by zorkan - September 15, 2026, 12:57:41 PM

Meanwhile at Speakers' Corner in Hyde Park London lies proof of religious peace after 90 seconds.

https://www.youtube.com/watch?v=0dS3CCM1XOU

Proof of bullshit, too.

https://www.youtube.com/watch?v=pEoMKmTqsMM

#95

Religion / Re: Evangelists

Last post by Dark Lightning - September 13, 2026, 11:40:41 PM

   That kind of sang froid is something I don't have. It was a Waldorf school, and I didn't want to terrorize the students. At least beyond a little math. Please don't judge, I just needed the money. I modified my previous post. It should have read ..."thought came to me..." I missed to the word "came".

#96

Religion / Re: Evangelists

Last post by billy rubin - September 13, 2026, 11:30:22 PM

i am truly sorry that you had to let that opportunity slip by. those are the moments that make life worth living.

my father once worked with an operations geologist in oklahoma.

operations geologists drive hundreds of miles with no sleep. AMHIK

anyway, the guy fell asleep and ran the car off the road. it hit the ditch, flipped, and skidded on its roof into a gas station and stopped by the pumps.

the attendant ran out,

my god! my god! are you okay??

and the geologist, upside down, had the presence of mind to look him in the eye and say,

fill 'er up!

#97

Religion / Re: Evangelists

Last post by Dark Lightning - September 13, 2026, 04:41:36 PM

Heh, when I was teaching a math class many years ago, one of the students blurted, "Why are you doing this to us?". I told one of the other teachers that the thought  came to me of saying, "I've come for your souls. Give them to me now!", in that James Earl Jones voice. Of course, I didn't say that to the class. The other teacher was amused.

#98

Religion / Re: Evangelists

Last post by billy rubin - September 13, 2026, 01:49:08 PM

a friend of mine in school once told me about his response to college campus performative evangelizing. he put on a black cloak, iirc, and stood next to them evangelizing for satan as an alternative.

i was not there but i imagine the entertainment value alone would have been high.

#99

Religion / Re: Evangelists

Last post by Dark Lightning - September 12, 2026, 06:02:51 PM

Man, that's annoying. I don't see any of that around here. Probably if I went into Los Angeles, or something.

#100

Religion / Re: Evangelists

Last post by zorkan - September 12, 2026, 03:55:14 PM

Saturday 12th September:
Just been walking through the centre of Coventry, a place where ordinary people love to shop but now dominated by loud and aggressive evangelists.
Groups of christians making an unbearable noise shouting over each other, then a guy shouting over them with a microphone. Also a muslim and JW presence.
People of this city deserve far better. It's supposed to be 'City of peace and reconciliation', or so it says when you enter it.

https://www.youtube.com/shorts/LBbw-tLJvu8

https://www.facebook.com/groups/341102676017302/posts/10089879251139547/

https://www.facebook.com/coventrycityofpeace/
No, stay away until this menace is stopped.
Until then: There is no hell, only Coventry.