Seeing in Monochrome

Doreen Chin

Hypothesis

Hypothesis: If held under a blacklight for a period of time, transparent liquids will show up as a “glowing” stain because of phosphor, which in this case, causes the object to glow, often with a illuminate blue or purple color.


Variables

Independent: The type of liquid being tested per trial


Dependent: The amount of liquid per trial


Constant: The UV light and black cloth


Experimental Group: All liquids listed for testing


Control: The cooldown factor (amount of time between trials)

Research

Ultraviolet light, or UV light, by some, has shorter light waves than visible light. Ultraviolet light isn’t invisible to everyone. Some insects, such as bumblebees and wasps can see them, although they still remain unseen to the naked human eye. Although Ultraviolet light comes from the sun and high amount of it are harmful is looked at for too long, UV rays are found in black lights. Black lights are used for decoration via parties, amusement parks and haunted houses, often in the form of a small light bulb or lamps. One may recognize black lights when stepping into a lazer tag arena, more specifically, when all of your white clothing starts to illuminate a blueish- purplish glow. This is is because the light bulbs that give off blacklight actually producing UV light, as opposed to UVB light, which is much more harmful.


The chemical that is causing all of your white colored objects to “glow in the dark” is called a phosphor. Phosphors are substances that cause the effect of object “glowing in the dark” by emitting visible light when coming in contact with any sort of radiation. The phosphors then convert the energy that is found in a black light through the form of UV radiation into visible light, which in this case, causes the object to glow, often with a illuminate blue or purple color.


Ultraviolet radiation, which comes with Ultraviolet light, is a portion of the electromagnetic spectrum that has the one of the shortest wave length out of all the lights present. This sort of radiation is caused by continuous high temperature surfaces, such as the Sun, and when atomic molecules discharge as a discrete spectrum of wavelengths. However, most of the radiation caused by this process is then absorbed by the Earth’s atmosphere, or rather, the oxygen that is found present in it. This then forms the Ozone layer. Of all the ultra violet radiation that if left after this process is in the form of UVA radiation, or sun rays.


When the Ozone layer weakens and becomes thin, gradually more and more UVB radiation will enter Earth’s atmosphere and begin to have a negative effect on planet Earth’s organisms. For example, the UVB rays that enter the Earth’s ocean will gradually begin to kill off plankton and other microorganisms that other species need in order to survive and thrive. However, UVB isn’t the only culprit in this crime scene. UVA radiation, along with its “partner in crime”, UVB rays, cause damage to our skin when it’s unprotected for an extended amount of time. When tanning, you don’t really think about all the damage that’s being done to your skin, only of the gorgeous bronze skin that you’ll end up with afterwards. That’s not the case. Yes, you may have the “picture perfect” skin tone that you’ve always dreamt of, but overexpose to either one of the two rays can damage the skin and make you look years old. UVA rays cause your skin to look years older than it really is and UVB rays burn the skin itself. So, you may have wrinkly aging skin, but at least you have that gorgeous bronze tan that will make all your neighbors jealous, right? As long as you don’t mind getting skin cancer.



Although UV rays have the one of the shortest wavelengths out of all those found on the Electromagnetic spectrum, it’s easier to think that the shorter the wavelength, the more powerful the radiation is. UV rays have a wavelength of around 320 to 400 nm, or 320 to 400 nanometers. UV radiation, as stated before, can affect our planet in 2 different ways, harming it and helping it. There’s no inbetween. When the wavelength of UV rays reaches up to 290 to 320 nanometers, it’s known as UV-A, which plays a helpful role in forming Vitamin D in our skins. However, it also helps form sunburns and causes eyes to gain cataracts, or, simply put, vision loss. When the wavelength fall shorter on the scale, say around 290 to 320 nanometers, it will fall into the UV-B portion on the electromagnetic spectrum. UV-B causes damage to the molecular portion of the human body, all the way down to the basic human blocks of all human life, deoxyribonucleic acid, or DNA, for short. The DNA absorbs the given UV-B radiation, which then causes said DNA to alter the shape of it’s molecules in one of several different ways. Because of this, enzymes will no longer be able to “read” the DNA code that is imprinted in the cell, and as a result, the cell may die.


It has been established that too much of UV radiation can and will cause harm to your skin, but it large amounts of it will actually proves to be lethal to insect, specifically, flies. What do you think those fancy bug zappers are made of? The bulb that emits a faint blue glow off its surface is made of black light, which in return, gives off radiation. UV radiation will damage a person skin and give it a burn, but will literally fry an insect’s body. Besides murdering pesky household insects, black light has been used in some government cases to depict counterfeit dollar bills from their real counterparts. Legit paper bills have a watermark on them which is easily noticeable when you hold the piece of paper up to a source of lighting. A very faint outline of the respective presidents face will appear and that will weed out the frauds from the legitimate bills.

Materials

  • UV (black) light

  • White colored candle

  • Vinegar

  • Water

  • Bleach

  • Corn Syrup

  • Lemon Juice

  • Black cloth

Procedure

  1. Lay out all the materials in order

  2. Place a tbsp of liquid onto the black clock and wait for it to soak in

  3. Turn on UV light and shine over the black cloth

  4. After testing, turn off the light and wait for cooldown

  5. Repeat steps 2 through 4 for each testable liquid

  6. Record the final observations of the experiment.

Observations and Data

  1. The white candle seemed to be the one that glowed the brightest. This may have been because liquid wax is incapable of actually soaking into the cloth provided.

  2. Because the light itself is black, there has to be a cooldown time of at least 2 minutes before continuing with another test. This is because black absorbs heat faster than any color. To eliminate the risk of burning oneself or causing the cloth to heat up, a cooldown period has been set at the end of every trial for safety precautions.

  3. Pictures are impossible due to holding the camera up at an awkward angle, balancing the cloth with (possibly) still liquid substances and keeping the liquid from touching the bulb.

Calculations

No formulas were used, but time intervals were.


Each liquid was allowed 10 seconds to “soak” into the cloth, before being shoved under a blacklight. This time might not have enough for all the liquid to actually absorb into the cloth, as the results with only 10 seconds of “soaking time’ were rather sporadic. The hypothesis tested, “If held under a blacklight for a period of time, transparent liquids will show up as a “glowing” stain because of phosphor, which in this case, causes the object to glow, often with a illuminate blue or purple color,” was proven incorrect, as not all liquids have phosphors in them. True, there might be some exceptions to this, such as lemon juice, which doesn’t actually contain any phosphor, but instead has Vitamin A, which happens to glow under Ultraviolet light. A common misconception about this experiment is that, if you’ve played laser tag, or at least stepped foot into a laser tag arena, then you would know that your lighter colored clothing, such as white, peach, and pink, all seemed to turn a shade of light blue or violet. This information is then carried over to the experiment, only to be proven wrong when certain liquids, such as water or vinegar, are put to play. The purpose of this experiment was achieved, but the results were completed unexpected.


Analysis

Claim

  • Since none of the transparent liquids appeared to glow under UV light, it proves that there aren’t any phosphor found in the liquids.

Evidence

Due to the lack of phosphor found in transparent liquid, those types of tested liquids weren’t able to glow properly when subjected to UV blacklight. Phosphors are commonly found in liquid object that would normally glow under dimly lighted circumstances, an example would be the liquid found inside bright colored highlighters. If the transparent liquids lack these phosphors, the chances of them showing up under UV light, without any additional outside forces, would be close to impossible. However, the lemon juice and melted white candle wax both showed up under the blacklight.

Reasoning

The reason the lemon juice showed up under the light, while the other liquids, save for candle wax, didn't is because the juice itself contains high amounts of vitamin C, and some amounts of vitamin A, the latter which shows up under Ultraviolet light. One might think that since the amount of Vitamin C drastically overwhelms the amount of Vitamin A in the lemon juice, that it wouldn't show up under the light at all. That’s not true. If there’s any source of Vitamin A or B in a substance, it will most likely glow, unless an outside force it added to the mixture in an effort to tamper with the properties. The reason that the white candle wax glowed when subjected to blacklight is fairly simple. The wax color is white, and that was all that was needed in order to make it glow. When you stick a sheet of white paper, or any object that’s white underneath a black light, it will glow, or at least become visible in a shade of purple or blue. In this case, the white wax didn't exactly “glow”, but instead became visible in a shade of violet light. The reason that white paper has such different results than that of white candle wax is because of it’s fluorescence compounds, which helps the paper appear to be more “white” and brighter. Now, when bleach was tested, the original theory was that it would glow under the UV light, but that theory was proven wrong. As a side experiment, solid laundry detergent was tested under a blacklight, only to glow when bleach did not. This is because the tested bleach didn't have any whitening attributes. This particular trial may be up to debate because different brands of bleach may lead to different results.

Conclusion

Although at first glance, anyone would’ve thought water, or any clear liquefied substance would’ve glowed under the rays of UV light, but that theory has been proven incorrect. In order for anything, whether it be in liquid state, or a solid object, to glow, it must have phosphors, or some form of white surface. The hypothesis tested, “If held under a blacklight for a period of time, transparent liquids will show up as a “glowing” stain because of phosphor, which in this case, causes the object to glow, often with a illuminate blue or purple color,” was proven incorrect, as not all liquids have phosphors in them. True, there might be some exceptions to this, such as lemon juice, which doesn’t actually contain any phosphor, but instead has Vitamin A, which happens to glow under Ultraviolet light. A common misconception about this experiment is that, if you’ve played laser tag, or at least stepped foot into a laser tag arena, then you would know that your lighter colored clothing, such as white, peach, and pink, all seemed to turn a shade of light blue or violet. This information is then carried over to the experiment, only to be proven wrong when certain liquids, such as water or vinegar, are put to play. The purpose of this experiment was achieved, but the results were completed unexpected.

Errors

For this experiment, lots of things could have gone wrong, as well as factors which could ultimately change how the results were shaped. Most of these wrongs revolve around which type of liquid was used, and which brand. Since each brand is unique in its own way, the ingredients used to make the solution may have decided the the trial’s outcome. For example, if the experiment had used tonic water instead of regular spring water, the results for that individual trial would’ve been a “yes” for water, because tonic water does appear as a glowing stain under UV light. Another mistake was the brand of bleach that had been used. Under normal circumstances, bleach may contain chemicals that cause clothing to whiten, also known as whitening. Whitening is found in most, if not all, laundry detergents and is known to glow under blacklight. If 2 types of bleach were used, one with whitening and one without, the experiment would have 2 different results. The results as a whole could change via other opinions, as there are no set materials for this experiment.

Application

This experiment applies to real life through the process of testing common household liquids that may or may not have phosphor. Although the trials tested and the data received from those trials can only tell so much, it is clear that most, save for a few, transparent liquids don’t react in any way to UV light. However, there are some specific liquids, namely ones that come from your own body, that have not been tested in this experiment, as the tester had no means of obtaining said liquids. This information can be applied to daily life as a mean of identifying what liquid stained a piece of cloth without, hopefully, using any of your unneeded senses.

Improvement

As stated before, this experiment only covers a very small variety of the many testable liquids that can be found anywhere. A way to expand upon this idea would be to find more liquids and test them the same way as the previous trials, or to research specific liquids and test for any reaction. Design wise, this trial doesn’t have any comparative data, save for the cooldown time of the UV light, which was mainly enforced to exercise caution, as well as eliminate the chances of getting badly burned.

Did you really read all that? I'm impressed. Here, have a cute cat.