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Red_Apocalypse_Horse
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Name: Crosby
Country: Australia
Birthday: 10/27/1985
Gender: Male
Interests: Reading blogs, blogging, cycling, computer gaming, ice skating, listening to music, playing my instruments, eating, sleeping
Expertise: Chemistry, physics, maths, nanotechnology
Occupation: Student
Industry: Education/Research
Message: message meEmail: email me
Website: visit my website
MSN: darkmutant@hotmail.com
Member Since:
8/7/2004
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| This week, a bunch of (year 11 equivalent) kids from Jurong Junior College came to our physics school. They're attached to the research groups here for a week. I'm part of this program and takes care of 5 kids along with another colleague. We organised experiments for them to do:
- Fun with liquid nitrogen
- Latent heat of fusion (freezing)
- Coke + Mentos experiment
- Build a simple giant hard drive (encode 2 letters on it with 10 bar magnets)
- Lenz's law
- Chaotic pendulum
The whole of this week has been occupied with taking care of the JCC kids. And...
...according to NaT, I'm like the male version of a mother hen taking care of the kids...
>.< | | |
| Today, my devotions is based on Isaiah 55:8. It's one of those verses quoted many times; hence taken for granted most of the time. This verse was one such one. I have always thought that this was how the verse went:
"My thoughts are not your thoughts, nor are My ways your ways."
I was quite taken aback when I read the verse in the Bible and this is what it actually read:
"My thoughts are not your thoughts, nor are your ways My ways."
Can you spot the difference? The order in which "my" and "your" appear in the later half of the verse makes a big difference in the meaning. How so?
The first statement (which is NOT what the Bible says) is quite passive in that it's simple God describing his ways, with no active human involvement. The second statement (the true statement) requires the reader to respond to it.
If our ways are not in line with God's will, then we need to actively do something about it to get it back in-line.
This was a good lesson for me. I realize now that I shouldn't presuppose how a verse sounds like if I have only heard it from a secondary source; I need to check it up myself carefully, because my ear and/or mind might have registered it differently than what's actually in the Bible. | | |
| To my dear sister Carrie,
~Happy 21st birthday~
I know that many times, I haven't been a good brother that I'm supposed to be. I hope you can look past my flaws. Even though I don't show it much, I am proud to have a precious sister like you, and also proud of the lovely lady that you have grown up to become. (Just bear with the conflicts we get by having to share one bathroom and toilet in the family)
I express myself better in written word rather than spoken words, so this blog post is dedicated for you. You have my full blessings as your older brother in this important day of your life, turning 21. May God also bless you and direct your path in your life.
Your brother, Crosby | | |
| In case you're wondering, no this isn't about some accident involving a guy's limbs being chopped off by an industrial-grade steel-cutting laser. This is about my epic struggle with setting up the laser optics in our lab properly.
Day 1 (Wednesday)
Bob wasn't convinced that the MOKE data for the Co-CuMn multilayer films were reliable. So he asked me to really probe the MOKE using a known permalloy sample to check for artefacts.
So it was the standard procedure of doing MOKE... mount up the sample, align the laser and then turning on the oscilloscope and electromagnet...
But there was no hysteresis loop!
Checked everything to the best of my knowledged and couldn't find anything visibly wrong with the experimental setup. Called in "reinforcement"; Rhet to help determine the cause of this anomaly. Checked that the coil is actually producing a magnetic field using a magnetometer. Checked the wiring, but nothing seems to be physically wrong with the setup.
However, this wasn't the first time the MOKE failed to produce a hysteresis loop; I've encountered this similar problem in the past before as well and have never been able to pinpoint its cause. I simply attributed it to the gremlin.
Battle result of the day; the laser triumphed over man.
Day 2 (Thursday)
After sitting on the problem for a while, I was reminded of something:
The laser probably does not produce ellipse.
And so the battle begins again, this time man carries more ammunition against laser. It was time consuming, because every time I rotated the laser, the allignment changes and I need to reallign the entire optical steup (which is quite straight forward but painstaking). After much tug-of-war, I finally got everything right... and could produce a hysteresis loop! The battle seems to be won, but it's not ideal;
One of the beam splitters now had to be rotated 180 degrees to compensate, and the result was that I needed an extra mirror to redirect the path of the laser coming out that direction and in doing so, crossed path with the incoming laser beam; interference resulted. In theory, it shouldn't affect the MOKE, but I shouldn't build on an assumption. Eventhough I got it up and working, I need to re-setup everything to an ideal state.
The battle is not fully won; the enemy was routed from the battlefield, but not eliminated.
By logic, if I rotated the laser and the beam spiltter both 180 degrees, it should turn it back into the ideal state. I did so, but was then faced with another type of problem; significant 50 Hz noise from the mains AC supply had somehow crept into the signal and is appearing on the oscilloscope!
Argh! The joys of experimental physics. I would like to continue to wrestle with this gremlin all night if I have to; I don't like to leave a challenged smirking back at me like that. But unfortunately, I had to tuition a year 11 kid, so I had to leave the "battlefield".
Day 3 (Friday)
The lines are drawn. It is now or never, because the Jurong kids will be visiting next week, and I will need to get the system working in perfect condition to demonstrate a hysteresis loop to them. It is a must win situation against the laser gremlin.
Time to head down to the lab / battlefield now... | | |
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