A Research About Liquids That Produce Invisible Refraction

Holy Family Academy

High School Department

Cutcut, Angeles City

A Research on Liquids that can Produce Invisible Refraction

An Investigatory Project

Presented to:

Mrs. Joyce Ann B. Lapid

In Partial Fulfillment of the Requirements in Science 10

By:

Riveral, Alyzza Francheska Bernice L.

Sison, Josc Enri G.

Dayrit, Michaella

Canlas, Katrina Denise T.

A Research on Liquids that can Produce Invisible Refraction

I. ABSTRACT

The science of invisibility has been one of the most interesting topics in the field of science. There is a question whether it is possible or not. This topic has led the researchers to conduct this experiment. As it is known, people see things because light reflects the object back to our eyes. This then produces an image that we can visually see. Invisibility is possible by using reflection and refraction, also known as the bending of light. Refraction occurs when light enters a new medium, example from air to water. If light passes from air to water then the light bends because it has entered a new medium. Invisibility occurs when light bends the object at the same index as the new medium it passes through.

The researchers tried dipping a Pyrex glass rod which has an index of refraction of 1.47 into a liquid that almost matches or has the same index of refraction. The liquids used were Olive oil which has an index of refraction of 1.47, Sugar Solution which has an index of refraction of 1.4774, Clear Glue that has a 1.46-1.47 index of refraction and lastly, Hair Gel which has an index of refraction of 1.49. Based on the end result, only Olive oil was the most effective to show the effect of invisibility. Therefore the researchers conclude that all liquids tested doesn't exactly exhibit the effect of invisibility even though they have the same or almost the same measure of index of refraction

II. BACKGROUND INFORMATION

It is a known fact that light has a number of unique properties. Light reflects off surfaces and into our eyes, which allows us to see images in mirrors as well as colors. One of the properties exhibited by light is refraction. Refraction is the property of light where it describes the bending of light as it passes from one medium to another. This property can be seen and applied in optical devices, such as microscopes, prescription glasses, and magnifying glasses.

Most people have witnessed the refraction of light when looking at objects submerged in water. The object submerged in water seems larger than it looks when taken out of the water. The amount the light bends is based on the index of refraction of the substances being compared. The index of refraction refers to the angle that is formed between the light and the surface of the object. The index of refraction of a substance is determined by dividing the speed of light in a vacuum by the speed of light through that substance.

Glass objects reflect some of the light that shines on them and bend or refract the light that shines through them which is the reason why these objects are visible to the human eye. If you eliminate reflection from and refraction by a glass object, you can make that object disappear. Someone is able to see a glass object because it both reflects and refracts light. When light traveling through air hits a glass surface at a certain angle, some of the light reflects on it. The rest keeps going through, but it bends or refracts as it moves from the air to the glass.

When light passes from air into glass, it slows down. The change in speed is what causes the light to reflect and refract as it moves from one material to another. Each and every substance has an index of refraction that is linked to the speed of light in the substance. The higher its index of refraction, the slower light travels in it.

The smaller the difference in speed between two clear materials, the less reflection will occur at the boundary and the less refraction will occur for the transmitted light. The speed of light will not change as it enters the object if a transparent object is surrounded by another material that has the same index of refraction.

The researchers have chosen to experiment on four liquids that are easily available. These liquids are clear glue, sugar solution, olive oil, and hair gel. The factors considered were the transparency of the material and an index of refraction close to the index of refraction of the glass (1.47).

First, clear glue, known as solvent-based glue, is a polyvinyl acetate that is a rubbery synthetic polymer having a refractive index of 1.46-1.47 (1.55597). Commonly used as an adhesive, it is usually safe and non-toxic. They go on clear, dry clear and are typically used for extended wear.

Next is the sugar solution. Typically composed of sugar and water, this solution is boiled to achieve the thick consistency of a sugar solution. Sugar have been used a preservative, essential for storing fruits -- pickling method. Sugar solution is now used today for cocktails, lemonades and especially in baking. This dense material is clear and transparent and has a refractive index of 1.4774.

Olive oil is a vegetable oil referred to as the oil obtained from the fruit of olive trees. It is the traditional tree crop of the Mediterranean Basin. Olive oil is commonly known for its use in cosmetics, soaps and its culinary usefulness. Olive oil is a common household liquid characterized by being translucent; having high viscosity because of its thickness it has an Index of Refraction of 1.47.

And lastly, Hair gel is a styling product that acts like hair spray, which makes your hair stay in place throughout the day, but instead of being a pure liquid hair gel is a molasses like substance. Styling gel is made of mostly styling polymers, which are usually based on vinyl monomers such as PVP (Polyvinylpyrrolidone) or VP (Vinyl Pyrolidone). Hair gel is often used on people with thick hairstyles because of its thickness and viscosity. It has an index of refraction of 1.49

III. STATEMENT OF THE PROBLEM

The purpose of the problem is to know how the index of refraction of a liquid affects the visibility of Pyrex glass.

A. General Objective

        The general objective is to dive deeper on how refraction works in the field of optics.

        B. Specific Objectives

        1.  To explore the properties of invisibility

        2.  To show the importance of refraction in allowing an individual to see.        

        C. Hypotheses

        1.  If light would refract on a liquid with the same index of refraction as the glass rod, then the glass rod would appear invisible to the naked eye.