Angry Glass :)

Last week's glass was bad. kept making simple mistakes. Anyway, took all that anger out on glass, and ended up with this. Another addition for my collection :)

Paperweight and color vase.

This weekend hillary, the person who got me into glass came to hershey, pa. We met, and gave her the glass pieces I made. Made a paper weight and colored vase for her. Below are pictures. Link to her blog, http://herald-dispatchblogs04.blogspot.com/

Paperweight and vase

Paperweight

My vase

After last week's fiasco were I broke 4 cups, was finally able to get one in the oven. It was supposed to be a cup, but the shape was nice, so ended with vase instead. I like thicker glass because it does more to light then thinner ones. It reflects, bends and adds glow to the piece. Thats one reason I love blenko glass. :D

This week made 2 cups and a vase. Although, only one of them is close enough to be considered good. Others are bad. Btw, was using the sock I turned into heat shield. It worked good. Got just 2 burn marks, one on left hand, and other on upper arm. In gap between where sock ended and shirt began. There was no sock covering those.  :D

First cup.

my first cup.  
now i have the basic techniques, have ot practice this for next 2-3 months. This is supposed to be the first piece so you can look back and say, at least I did not make that. But today, was so bad that could not even save them.

Today tried 4 cups and dropped 3. The one I got into the oven was not even what I wanted. I was aiming for cup, got a vase. 

Whats worse is burnt hand several times, and made a lot of mistakes. Might have been distracted.

Earlier, was walking outside without jacket in AM, and then went to glass where temperature was 90. I think it got worse due to no sleep. 

Just angry.  x-(

Here are pictures of snowman and paperweights made last week

How I got to glassblowing :)

This post does not have math equations in it, its more of 'dear diary' post. I have almost no artistic skills, at least not traditional ones. I like glass blowing, ice skating and love trains. Mainly because one involves high temperature physics/chemistry, next different physics than we (at least I) normally experience, and third involves physics of controlling million ton mass. In short, love playing with fire, ice and heavy objects. This post is about how I got into glassblowing. Have used initials of people for privacy purposes. 

I have been involved in glass for nearly 4 years now. It started with my obsession for trains, but did not want to spend my money on trains, so started trading blenko glass. Through that, came in touch with hillary, and started helping her out with blenkoproject blog, even made a website for them. The other blog listed as mine is actually hillary's. I just have admin rights to it. links below. 

Blog:http://herald-dispatchblogs04.blogspot.com/

Website: www.blenkoproject.org

I wanted to learn glass making, but the closest place I knew was corning. Although, they have short classes, they have them as 7 day crash course, and after that you cant practice. Seemed useless to learn an art that takes more than 10 years of practice to master in 7 days, and not practice. However, read many text books on glass making, high temperature physics, and colored glass. All technical, not artistic. But in glass making, biggest issue most people face is to learn how glass behaves at high temperature. 

Glass melts around 1500 C and if you cool fast below 700 C it cracks. So working range is usually between 800 and 1200 C, and as glass cools, its behavior changes. With in minutes it goes from gravy type of liquid to clear. And glass responds differently to heat and cold. For glass at 1000C, room temperature is cold. In fact, one of the techniques to cool the glass (marving) is to roll hot glass on steel table top (earlier it used to be marble) and make a semi-solid layer on top, so you can mold the glass. Its something like shaping a ballon filled with dense liquid. In fact, the way glass is removed from steel rod is using thermal shock, and not actually cutting it.

In short, was involved with glass for 3 years and was studying glass for 2 years. Was looking for a place to go and blow glass, but all were either too far or too expensive. I did fuse glass in my apartment, but theres only so much you can do in a microwave. About 6 months ago, there was a fire in state college (Waupelani dr), where some apartments got burnt down. And a person (C) was looking to raise money for them, and emailed on psu-community-garden workshop. I wanted to do something, but whom ever I asked was either involved with an organization or wanted to give bible with cash. So asked my friends and people on PSU-PD list serve, and got about 800. When I went to give her money, she told she likes glass. Then I went on my usual monolog, and she told about a place at PSU where people go and blow glass, and told I should check it out. So I did.

I emailed them, and they asked to shadow artists for 6 months, and said after that they will decide if they will teach me or not. I think this is their way to weed out people who are not willing to put in time or effort. I went there for a month, and then sent a thank you note to C. She got excited and wanted to learn too, so she started shadowing too. Yesterday was first time we got to work on our own. It wasnt easy. My mind is usually restless, and is filled with random thoughts. Sometimes, even I dont know what am talking, and thinking. But when I shadowed people, or was working with glass, it was blank. In fact, I dont even notice other people talking to me. How are you supposed to learn in a class something, when that something puts you in a trans. 

Any way, after many mishaps, made 2 snow men and 1 paper weight. I burnt my hand in the process, but not while making. After making the first snowman, got excited, and dropped my arm on hot steel rod. Thankfully, it was after making the glass. The rod was red hot when I started making.  She did the same too, made 2 snow men and 1 paper weight part. Not the hand burn part. Any way, it was fun. And because of shadowing, it was easy to pick up. The pieces are annealing now. Will get them soon, and then there will be another dear diary post. Not this long, mostly pics. :)

Just felt like deriving Rodrigues' rotation formula

Woke up again at 11, and unable to fall asleep. My sleep cycle is following Mr Murphy, most active and alert when am supposed to be sleeping. Was reading something online, and came across wikipedia's post on Rodrigues' rotation formula, and saw that they derived in a juvenile manner, using 11th grade math (http://en.wikipedia.org/wiki/Rodrigues'_rotation_formula#Derivation). So just felt like derived it in slightly more elegant manner, and am here. Will add figures that go with this later. Dont have scanner, nor pencil, paper or patience to draw lines now. Until then, use your imagination. :)

Let v be the vector to be rotated by angle $\theta$ about axis k.

Component of v along k,
$v_k = (v \cdot k) k$
Component perpendicular to k
$v_{\perp} = v - (v \cdot k) k$
After rotation by $\theta$,
Component perpendicular to k, along $v_{\perp}$
$v_{\perp} = |v_{\perp}| cos(\theta) \hat{v}_{\perp} =  \frac{ \left( v - (v \cdot k) k \right)}{\left| v - (v \cdot k) k \right|} cos(\theta) $

$v_{\perp} = |v_{\perp}| cos(\theta) \hat{v}_{\perp} =  \left| v - (v \cdot k) k \right| cos(\theta) \frac{ \left( v - (v \cdot k) k \right)}{\left| v - (v \cdot k) k \right|}  $

$v_{\perp} =  \left( v - (v \cdot k) k \right) cos(\theta)  $

Component perpendicular to k and $v_{\perp}$
$v_{\perp,2} = |v_{\perp,2}| sin(\theta) \hat{v}_{\perp,2} = \left| v - (v \cdot k) k \right| sin(\theta)  \frac{ k  \times  \left( v - (v \cdot k)  \right) } {\left| k  \times  \left( v - (v \cdot k) k \right|}     $
as k is unit vector,
$ \left| k  \times  \left( v - (v \cdot k) k \right| = \left|   \left( v - (v \cdot k)   k \right| $
So
$v_{\perp,2} =  \left( v - (v \cdot k) k \right) sin(\theta)  $
also,
$k  \times  \left( v - (v \cdot k)  \right)  = k  \times  v$.

Now rotated vector is,

$v_{rot} = v_k + v_{\perp} + v_{\perp,2}$
$ v_{rot} = (v_k \cdot k) k + \left( v - (v \cdot k) k \right) cos(\theta) +  ( k  \times  v) sin(\theta)  $
Simplifying
$ v_{rot} = v cos(\theta) +  (v \cdot k) k  ( 1 -  cos(\theta)) + ( k  \times  v) sin(\theta)   $