Recently, hard to say exactly when since the online version of PC Magazine doesn’t put dates on their stories but recently, John Dvorak put out a piece called Our Modern World—Weirder by the Minute. In it he listed several things that he thought someone from 1920 might find "odd" if they were sucked into the here and now.
What has John been putting in his wheaties? Most of the things he thinks the person from 1920 would find odd would actually be incomprehensible. Most of the details would be "odd" to someone from 1980.
Something strange happened on the way to making a two-channel hologram Saturday…
I made a master hologram of a sand-dollar yesterday morning which came out nice and bright and clean and Susan suggested a two-channel, front and back of the same subject. Being in the groove I set about doing just that.
I exposed the left half of the plate, put the plate in my drying box while flipping the subject, got the plate back out and switched the mask so that the left half of the plate was covered and the right clear. Exposed, developed and found that the right channel was bright and clear and the left look dim and ugly. Examining the final bleached hologram lead me to believe that the plate had moved during the first exposure, mostly because I couldn’t find any other cause.
This could also have been called optic destroying with collodion. You’ll see why in a bit.
Based on my first three attempts, I wouldn’t recommend bothering to use collodion with cheap mirrors.
Collodion is used for a number of applications, such as cleaning optics used in astronomy. It was recently mentioned on the Holography forum as a way to clean our precious mirrors and lenses.
Here’s the first mirror with a tape dam at an angle which attempts to show all the crud on the mirror. It’s not excessively dirty like you might get with optics used in astronomy but it’s dirty enough that it’s interfering with my reference beam light. The mirror is used to steer the light coming out of my spatial filter up to my collimating mirror and needs to be as clean as possible. Note that this was a cheap $1 mirror I bought at a local electronics shop.
It’s disappointing that Steve Pavlina has gone off his polyphasic sleep clycle. I was (not very seriously) thinking about trying the same thing but had reservations that matched his eventual reasons for quitting. Continue reading Polyphasic sleep
Being a bad blogger I haven’t been blogging enough about what I’ve been doing. I’ve been too busy doing it. To rectify that a bit, here’s a summary of what I’ve been up to holographically. Continue reading What have I been doing?
Parts I and II are part of my original blogging back before I started using blog software.
This is a continuation of the some of the discussion from this thread.
I’ve done a ton of testing over the last few days, changing air in my inner tubes, swapping lasers and optics, moving my big laser off the table, wandering around the house doing various housely things and recording what happens to the fringes in an interferometer.