Calcium chloride – polarized light with compensator

Calcium chloride is used to give fireworks their orange colour, a de-icer, in heating pads and in water treatment. Not only is is hygroscopic, absorbing water from the air, but is has deliquescence, meaning it absorbs so much water as to form an aqueous solution. When I tried to make standard glass slides with glass…

Polarized light foldscopy

I finally got myself a polarizing film. By this I can now polarize the light falling on the sample by placing the film between the light source and the sample and further by placing another film between the lens and the eye/camera I can block the same polarized light so that only light whose polarization…

Aspirin Crystals Under Polarized Light

I have always been interested in polarized light and wondered if the foldscope could be made to incorporate it. Knowing nothing about optics, I was pretty sure that the viewing situation would be too compressed for this to work…but I still wanted to try. I purchased two plastic, linear polarizing sheets from Edmonds Optics.  I…

Maple Syrup with Polarizing lenses

As winter approaches, the Maples’ leaves change colors. In a few months, as it begins to warm, the tree produces a sweet sap which is boiled down to Maple syrup, over 100litres of sap are boiled to make 1 litre of the sweet syrup. After sitting out for a few days, it dries. Here is…

Psyllium husk (Ispaghula)

Psyllium husk is used to increase dietary fibre. Met analyses show it is of benefit for irritable bowel syndrome and decreasing LDL cholesterol. It is also of benefit in improving blood sugar control in type 2 diabetes mellitus.. Here are some images showing psyllium husk with polarized light, plane polarized light and a short video…

Potash

Here is Potash with polarized light and you can see the birefringent KNO3.

Cellulose Insulation

Cellulose is treated with boric acid to make household insulation.  Here is a picture with plane polarized light.

Raw Honey (Unpasteurized)

Raw Honey plane polarized light.  You can see some of the crystalline structure of the sugars here.  

Xylitol

This 5-carbon sugar used as a sugar substitute. Though found naturally in a number of foods, and a product of our normal metabolism, industrially it may be produced from wood and wood products. Here are two images with plane polarized and polarized light.

Wasp nest

Often seen as pests, wasps have an important role in pollination (especially figs) and can be used for biocontrol. Social wasps make their paper-like nests out of broken down pieces of wood and other material. Here I have the images of a nest with plane and cross-polarized light.

Raw Honey – polarizing light clip

Raw Honey often contains pollen and tiny bits of beeswax. I think the structure at about 4 o’clock maybe wax, but am not sure if I can say so confidently. As you watch the clip under polarized light, you can see the sugar (primarily glucose and fructose) crystals shimmering. Ambient room temperature is quite high…

Calcium chloride – polarized

This salt is used to give fireworks their orange colour, as a de-icer, desssicant and in heating pads. Not only is it hygroscopic, taking water from the atmosphere, but it is also deliquescent — absorbing so much water from the atmosphere as to form an aqueous solution. I made this slide with a glass slide…

Minerals with Cross-Polarized Light

Using some minerals samples that we had lying around at work and low budget tools (my fingernail to scrape off pieces of the minerals), I looked at crystal structures with a cross-polarized light Foldscope (see this post for instructions). First, some muscovite mica which forms in very thin sheets and has high birefringence (which is what…

Experiments with Cross Polarization and Fibers

In the published papers, it’s clear that a variety of flavors of the Foldscope are being developed to allow for specialized lighting or contrast-enhancement. Some will require additional components, but one in particular seems accessible and easy to adapt the “vanilla” brightfield Foldscope. Polarized light microscopy is attainable by introducing two, perpendicularly oriented polarizing filters…

Fruit fly and wing

On the iPod, the light module can be too bright to get some images. I took two LCD (liquid crystal display) polarized filters from a broken handheld game I took apart and inserted them between the light module and slide (one filter rotated 90 degrees to the other) this reduced the light from the light…

Learning by watching: Explorations at the cellular scale and beyond

Learning by watching: Explorations at the cellular scale and beyond (Aprendiendo al observar: Exploraciones en la escala celular y mas alla) Last week the inaugural version of Clubes de Ciencia Colombia event took place in Bogota and Medellin. The idea behind this program is to bring graduate students in the US back to Colombia to…