
Cutting a Klein Bottle in Half [video] - DHJSH
https://www.youtube.com/watch?v=I3ZlhxaT_Ko
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JshWright
I love Cliff Stoll so much... I hope one day to be as passionate about
_something_ as he seems to be about everything...

If you haven't read The Cuckoo's Egg, I'd highly recommend it. It details his
experience tracking down one of the first "hackers" back in the 80's, when he
was a sysadmin for Lawrence Berkeley National Laboratory.

~~~
sp332
There's a one-hour long NOVA episode about that story.
[https://www.youtube.com/watch?v=EcKxaq1FTac](https://www.youtube.com/watch?v=EcKxaq1FTac)

~~~
saboot
I'm only three minutes in and I'm already loving this. Thanks for sharing

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hgibbs
Funny story. I saw this video yesterday morning, about an hour before my
topology exam. One of the questions involved calculating the Euler poincare
characteristic of a 3 fold sum of RP2. Unfortunately, I had forgotten the
formula for the case of m-fold sums of RP2 but I knew that it was linear in m
and that the Euler poincare characteristic of RP2 was 1. Luckily, I remembered
a Klein bottle is homeomorphic to the 2-fold sum of RP2. Having seen this
video and knowing the cell complex structure of a mobius band ended up being
enough for me to derive the answer.

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copperx
I want to be like you when I grow up.

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hgibbs
I had a really bad day. Cheers man you have no idea how much that means to me.

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HCIdivision17
Just because there has to be an obligatory link to his phenomenal website:

[http://www.kleinbottle.com/](http://www.kleinbottle.com/)

Cliff Stoll has to be one of the most genuine and wonderful mad engineers out
there. His work is just one gem of brilliant hackery after another.

~~~
dbarlett
I highly recommend ordering one. The checkout process, packaging, and invoice
are almost as good as the bottle itself.

~~~
jws
And remember the inventory is stored in the crawl space under his house and he
uses tiny robots he built himself to go in and pull the inventory out.

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lifeformed
Is a cut glass edge not sharp? It was hard to watch him run his finger along
the edge like that.

~~~
Natsu
That depends on whether it has been seamed or has edgework. It's incredibly
sharp if nothing has been done to it, enough so that merely touching glass
edges can cause cuts. Glass is normally seamed before tempering, but that
doesn't leave it perfectly smooth either. I've gotten glass splinters from it,
along with finding edges that didn't get seamed well, though most sharp edges
will break in the tempering furnace (this is why you seam glass prior to
tempering). Glass splinters are as horrible as you might imagine and can take
weeks to work themselves out, as well as being ridiculously hard to see.

So yeah, I don't recommend the practice if you're not sure, but it may be okay
for glass that has had edgework done as this glass gets polished smooth,
whereas tempered glass is probably okay, but not always safe.

EDIT: Looks like it's blown glass. No, that's not very safe.

~~~
DHJSH
I expected his finger to be bleeding after he picked it up. I'm wondering if
it's just a property of the diamond saw, or he likes to live dangerously.

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DannyBee
Having a cut a _ton_ of stuff with diamond saws, the edge they leave is very
abraded, and rarely sharp.

This is not surprising, since it's basically like cutting it with 60-180 grit
sandpaper

~~~
Natsu
You're probably right that the edge isn't so sharp, though I note that his
finger was higher above it than it looked, but I wouldn't underestimate glass
splinters.

Those really suck.

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newman314
You should also watch the related video about how he stores Klein bottles
under his house. It's fascinating.

[https://www.youtube.com/watch?v=-k3mVnRlQLU](https://www.youtube.com/watch?v=-k3mVnRlQLU)

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te
If someone does a remake of Back to the Future, Doc Brown should have a
robotically-operated klein bottle warehouse under his house.

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jbpetersen
Cliff is a wonderful, wonderful human being. He once did a series of free
physics classes for middle schoolers in his garage. Learned how to measure the
speed of light from him.

~~~
copperx
He emits light?

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tbabb
Sometimes I wonder what future, more evolved humans will be like. What traits
will be emphasized?

I hope they look like this guy. Insatiably curious, extremely intelligent,
endlessly productive, and effusively happy.

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jlebar
I bought a small klein bottle from him some time ago, and it was worth it just
for the papers it came with. Hours of laughter... So good.

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gloves
Never seen this guy before, but I love him! So enthusiastic.

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ubersync
How did I not know about Cliff Stoll until today?

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baldfat
Watch the video that is an hour long about him catching a hacker in the early
1980s

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ubersync
I already did. It is awesome. This guy has so much energy.

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Magi604
I want a diamond saw.

