Water droplets of varying sizes reflect different colours Credit: Zarzar Laboratory, Penn State Source: https://www.eurekalert.org/multimedia/pub/194181.php
Pigments, dyes, and the rainbow are one of the many examples of the physical phenomena that create colour. A purple coloured t-shirt appears purple due to scattering and absorption of a certain wavelength of light more than others. The scattering and diffraction of light in a circular droplet forms a spectrum of colours in the atmosphere, which is known as a rainbow. However, an unrecognized mechanism of changing the structural shape of a droplet can also generate hues of colour.
In most cases, oil and water do not go so well together. However, transparent oil droplets have shown that a change in the structural shape of these concave droplets can appear as different colours depending on the viewer’s perspective. Below is a video demonstrating the many hues of colour that appear at different viewing directions.
A group of researchers at Penn State published a paper which explored the origin of these colours by projecting white light into a biphasic (have two phases, water and oil) concave droplet in a petri dish. The light enters the droplet which bounces on the oil-oil interface, and the reflected colours are projected in the shape of a translucent dome, which are the colours you see. They discovered that the curvature of the oil-oil interface in the droplet corresponds to the change in the iridescence. With correct techniques, they were able to manipulate the droplet shape, size, and curvature to produce an image of a blue and green penguin. This research can be of use to a variety of fields from sensors, displays, cosmetics and any colour-changing materials.
A penguin image produced by the reflection of oil in water droplets Credit: Zarzar laboratory, Penn State Source: https://www.eurekalert.org/multimedia/pub/194182.php?from=422099
Observation of this phenomenon applies to droplets on transparent surfaces, and you can easily replicate this at home. A container with hot food and a sealed transparent lid will lock the steam forming droplets which will produce hues of colour.
Ranked lists are widely present in social media content and can be found on most sites due to its effective method of conveying information. Ranked lists are accessible and easily linked in blogs. This can generate tremendous traffic towards the original list and increase its rankings in Google search results.
Top 20 Movies of 2017 Source Flickr: https://tinyurl.com/y2hlq6eb
For example, Billboard magazine publishes a weekly “Hot 100” list, ranking the sales and popularity of songs. Sites like Buzzfeed have grown tremendously due to the usage of ranked lists which accumulate views that lead to higher advertising revenue. The “Three Different Price Points” from Buzzfeed is a viral segment which compares foods and items at different price points, much like a ranked list. Why are ranked lists so popular, and despite the differences in the topic, these continue to be read, shared, and linked?
The science behind ranked list was investigated by researchers who published, The Top-Ten Effect: Consumers’ Subjective Categorization of Ranked Lists. The top-ten effect demonstrated in the study showed that a human’s mental tendency is to use categorical lists and to exaggerate the difference between them. These tendencies are a natural human behaviour in perceiving discrete things. According to the data, a human’s ability to grasp numerous items is limited. Instead, those items are re-coded into categories, or “chunks”. Ranked lists are categorized which then enables the readers to better digest the content presented.
Specifically, evidence has shown humans are more easily able to chunk lists of information that end in zero such as 10, 20, or 30. This supports the evidence for cognitive salience of round numbers which proves why we are more willing to read these ranked lists.
Marketers often use ranked lists as an easy way to introduce products to consumers. Lists are often short and believable, and people can often find different connection points in which makes them feel connected. Readers who feel more connected and comfortable subconsciously are more inclined to read the content.