Optical reflections

[cdave]

Big thanks to major_clanger for inviting me to a talk on invisibility at the IET. It was actually about the new materials with interesting optical properties, that don't exist in nature. His write up is worth a read.

I've tried to find some copies of the ray diagrams from the slide show to illustrate the fantastic properties of this stuff (if you made a milk bottle from it, you would see the milk outside the edge of bottle), but couldn't find any online. If I get time, I'll write them up from memory.

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chiller has found what causes the squigly things you see when you look up at clear blue sky.

It reminded me of an odd visual distortion I've noticed a few times.

If you press you palms to your closed eyes, applying a light pressure simulates the retina. When I do this I see sort of yellowy-greenish-purple blobs. It wasn't until I tried to photoshop the image you'll see below that I realised this is the colour of magic and being made up from opposite sides of a colour wheel shouldn't exist e.g. (red+green = white, blue + orange = white, yellow+purple=white, etc).

To get the point, I've noticed that I occasionally, when having a shower in the morning, and I'm scrunching my eyes up to stop soap getting in them, I see an Phosphene that looks a bit like this:


It gets brighter the longer and tighter I screw my eyes up. If I leave them closed long enough I even get afterimages. Never happens at any other time.

Anyone else have any intersting visual distortions?

Being a Friday Afternoon I doubt there's many LJ readers out there, but thought I'd ask just in case

Comments

[fiat-knox.livejournal.com]

I have seen the same transient visual phenomenon against a featureless blue sky. I've also seen a swirling moire pattern on a hot day, when I was on the verge of a heatstroke; and the same kind of visual distortions when I've pressed my eyes gently in the morning.

I also get a visual distortion effect of a red and black flickering when I'm heading into town on the bus, in the sunlight, and the light shines through the trees along the sides of the road at a certain speed. That's not such a pleasant effect. I get a headache by the time I get into town.

[cdave]

Erk. Yeah, lights through trees when moving really fast aren't great. Doesn't give me red flashes though.

Ooh, does remind me of another one though. Sometimes when my green indicator lights areflashing on the dashboard, I see them as blue flashes in my peripheral vision. This is the colour of the highbeam light, so I keep looking down to make sure I'm flashing the driver in front.