The laser should be placed in a binder clip so it stays on, and then set on a stack of books and papers. The Mirror Method. When light slows down or is refracted through another material, it may appear to bend rather than travel in a straight line. As you sight at the portion of the pencil that was submerged in the water, light travels from water to air (or from water to glass to air). In this demo light will continually … As the light travels through a substance, it becomes concentrated into a focal point, … Dinosaur Activities & Crafts; Preschool Activities; Preschool Construction Activities; Preschool Dental Health Activities; Spring Crafts & Activities ; Stem Activities; Summer Crafts & Activities. Learn the magic of science in this water refraction trick. It's super simple and you can set it up within minutes. Refraction can be also be seen when water waves move from deeper into shallower water. That was a very cool magic trick. The pencil in water experiment is a lesson in light refraction. She laughed at me and said ‘hey! As a result, the light paths cross and the image appears to be flipped horizontally (left/right). Now try to think of a word that still makes sense if you put it behind the glass. For further information, consult your state’s Science Safety Handbook. By Rookie Parenting Science Updated 05/15/2020. When light passes from one material to another, it can bend or refract. But there is more to it. In this cool science experiment from Look We’re Learning, kids will learn about the principles of light refraction. Ltd. All Rights Reserved. … 4. Refraction is the bending of light as it passes from one transparent medium into another1. Glass. Angle a directed ray of light to the underneath of the surface and total internal reflection can be seen (it is easier to see with the lights off). Refraction of Light in Water Experiment (Video) By Rookie Parenting Science Updated 05/15/2020. Water. Overview of the concept of refraction. Now check this out. A piece of paper with an arrow drawn on it. Copyright © 2020 rookieparenting.com. Because the light from the torch passes from a lower-index medium (air) to a higher-index medium (water) the light rays bend inside the water, then when the light comes out it is spread out around the room. Photo: followtheseinstructions via flickr 1. Having demonstrated refraction, you can show how the solar bulb exploits it to light rooms and houses with about as much light as a 50–60 Watt incandescent bulb. Activities for Kids. In the experiment light traveled from the air, through the glass, through the water, through the back of the glass, and then back through the air, before hitting the arrow. Adjust the distance between the glass and the graphics until the image can be seen clearly through the empty glass. Pens. The objective of this experiment is to verify the Snell's law of refraction by tracking a laser ray passing through a rectangular slab of glass.. Equipment:. (See explanation below) Super nerdy kids (I say that with love) can learn more about refraction of light here. Also let them watch this video to find out how people use light refraction to light their homes! Learn the magic of science in this water refraction trick. It's super simple and you can set it up within minutes. Lab Partner: Asaba Anis. A rectangular slab of glass, a laser pointer, a few sheets of … Copyright © 2020 Mocomi & Anibrain Digital Technologies Pvt. Want to be notified when our magazine is published? The cap will prevent leaking because it creates a vacuum in the bottle. It also makes it possible for us to see because our eyes use lenses to focus images onto our retina. This light ray changes medium and subsequently undergoes refraction. Sure, you know vinegar turns a penny from dull to shiny.. Hey. refrac#on. I draw a pumpkin and a ghost, the pumpkin will disappear in water… Lab 10 Reflection and Refraction. Refraction occurs when light travels from one medium to another (ie. Rookie Parenting Science is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. Consider figure 1 that shows the refraction of light when it travels from air to glass. To use ray tracing to measure the angles of incidence and refraction when light is refracted by a ... doing the experiment in a dark room so that the emergent ray can be easily seen and marked. Lines are drawn on the laminated sheet underneath, simulating uninterrupted straight-line paths of light … It’s a fun experiment to teach kids how light moves in waves just like sound. When these light rays travel through air, they experience little or no refraction. Does it matter how large the incident angle was to begin with? Stand the soda bottle on top of a stack of books so the hole is facing the bucket. Don’t fool me mom, it is just water’! Using only a few materials, you can demonstrate how light can be bent. Reverse the colored bars or reverse the arrows. Privacy Policy. We explained that light refracts when it changes medium and what does that mean. What conclusions do we reach about the general trend for light entering water from air? For more such science experiments and articles, visit Science for Kids. Refraction of Light in Water. This experiment demonstrates a total internal reflection and shows the principle of optical fibres. The solar bottle bulb relies on the refraction principle. For example, when light travels from air into water, it slows down, causing it to continue to travel at a different angle or direction.How much does light bend?The amount of bending depends on two things: 1. Mar 14, 2014 - This super simple light refraction experiment is an easy way to bring science to life with your kids! Water bottle-based systems like the ones students create in this activity are in … The light reaching your eye (or in this case our camera) coming from the arrow is refracted through the glass of water. Try glasses and jars of different shapes. Finally pour water into the glass and watch in amazement as the arrow changes its direction! Another way to learn about reflection is by this magic water reflection. Figure 2: A laser is pointed at a soda pop bottle with a hole at the bottom. But you really only need four things: A sticky note (I used a Post-It) A marker; An empty transparent bottle; Water; Draw two arrows on a sticky note. Encyclopædia Britannica, Inc. In this case, the light travels from the image through the air, then through the glass cup into the water, and finally out of the water and into the air before it comes to our eyes. air to water, water to air). When light hits the water in the bottle, it bends in all different directions. Slowly pour the water in and see what happens. What we did to do this is we colored 2 different colored lines on a blank piece of paper and colored one line red and the other blue. Rookieparenting.com does not make any guarantee or representation regarding such ideas and is not responsible or liable for any loss or damage, directly or indirectly, caused by your use of such information. In the refraction experiment above light travels from the arrow through the air, through the glass, the water, the glass again and air again before reaching your eyes. Article media libraries that feature this video: Refraction, Refractive index Transcript Recall that as light … It’s a fun experiment to teach kids how light moves in waves just like sound. Article media libraries that feature this video: Refraction, Refractive index. One experiment I always wanted to try was using a stream of water like a fiber optic cable to bend light. 3:42. 3:28. This bending by refraction allows us to make use of lenses, magnifying glasses, prisms, etc. Encyclopædia Britannica, Inc. A simple science experiment for kids to learn about water refraction. Refraction of light at the interface of two media is described by Snell’s law \[n_1 \sin \alpha=n_2 \sin \beta,\] wherre \(\alpha\) is the angle of incidence, \(\beta\) angle of refraction and n 1, n 2 are refractive indices of the media. A lens is simply a curved block of glass or plastic. Why: Experiment 2 Light bends when it passes from water into the air. We learned that when you put water in a jar and have different colored line behind it the colors will switch places. For example, moving from water to air would produce this … Investigate the refraction of light in a transparent medium Aim of the experiment. How to Make a Sunlight Box: You’ll need a big box, plastic water bottles, duct tape, […] of Light in Water - Science Experiments for Kids | Mocomi, https://mocomi.com/embed/content.php?c=79623|Refraction of Light in Glass of Water|https://mocomi.com/refraction-of-light/, Refraction of Light in Glass of Water from Mocomi. The incident ray form an angle with the normal, called as angle of incidence (i). In the experiment that you just completed, light traveled from the air, through the glass, through the water, through the back of the … Rookieparenting.com provides science activity ideas for … Place the paper behind the glass and watch as the arrow points the other way. 23. Passion for Learn. For the Refraction Bottle, light rays are bent at the interface between the outside air and the water-filled plastic bottle. It bends because the water makes the light slow down. In the 28 Days of STEM series, this week's topic is STEM Challenges so we thought we would introduce a science challenge that 'tricks' your eyes. When light passes from one material to another, it can bend or refract. Refraction, on the other hand, means bending of the light.Bending happens whenever light changes medium in which it’s traveling. Stop crying. My younger one (5 year old) is almost in my trap but not my elder one (7 years old). Wow. refraction of light. Fill the glass almost to the top. They also use the angle between the light in water and the normal, which is called the refracted angle. Light refraction with a water bottle . Light Reflection and Refraction off Liquids Physics Projects , Model Experiments fir CBSE ISC Stream Students and for Kids in Middle school, Elementary School for class 5th Grade,6th,7th,8th,9th 10th,11th, 12th Grade and High School , MSC and College Students. In the experiment light traveled from the air, through the glass, through the water, through the back of the glass, and then back through the air, before hitting the arrow. From dull, to shiny to… GREEN! Jiang W, Chen RT, Lu X. In the experiment light traveled from the air, through the glass, through the water, through the back of the glass, and then back through the air, before hitting the arrow. 4:56 . The pencil in water experiment is a lesson in light refraction. The light bends away from the normal line. The normal ray is perpendicular to the barrier. Student Name: Gamoi Paisley. Here is a super simple, yet magical, experiment on refraction of light. You can’t see light move in waves until something blocks the light (the water) and bends the light. Login or Register above to download the content. See January 20th, 2012 for the Arrow/Water Glass experiment on light refraction & a link to the light & color absorption / reflection activity with red jello. That’s why you can still see the penny through the side of the empty glass. A higher refractive index shows that light will slow down and change direction more as it enters the substance. It is yet another way to show kids light reflection. Mar 14, 2014 - This super simple light refraction experiment is an easy way to bring science to life with your kids! In this super simple science experiments, kids will learn about light, refraction, and why a straw appears to be bent when submerged in a glass of liquid. By accessing the science activity ideas on Rookieparenting.com, you waive and renounce any claims against Rookieparenting.com that arise thereof. Experiment Steps : Refraction of Light Step-1 Firstly, ask your kids to fill the glass jar carefully with the clean and clear water. Refraction & Light Experiments: Easy Science for Kids. The science behind the water refraction experiment: Refraction is the bending of light. Simple Science Experiments: Light Refraction STEM Activity with Water Bottle www.lookwerelearning.com. Topic: Refraction of Light Why does a pencil look bent in water? In fact, you have just demonstrated a physics concept called refraction, the bending of light. We learned that refraction occurs because light bends when it passes through substances, such as water and plastic. For more such science experiments and articles, visit Science for Kids. Kids science experiments about light. Teach kids about light refraction with this fun science experiment for kids. Learn light reflection with some simple mirror activities. Active Time: 10 minutes. Wow. When the bottle is placed in the path of the light ray, the ray is bent from its original path. May 29, 2018 - Here is a super simple, yet magical, experiment on refraction of light. Similar to our Optical Illusion science experiment, light experiments also rely on what our eyes see. Rookieparenting.com provides science activity ideas for informational purposes only. Lenses. When light travels through a cylindrical glass, it bends when entering the glass and water, and then it bends again when leaving the water and glass. Categories. Recall that as light passes from one medium into another, it bends, causing refraction! refraction of light. This water refraction science experiment has such a “wow factor” and is so quick and easy I can’t believe my kids and I haven’t done it before. Paper or card. Objecve: To examine the phenomena o f re!ec#on and refrac#on of light, and t o verify the laws of re!ec#on an d . Few more from Stem Activities for Kids. This Zip Lock Bag Water Refraction is good to try. Large solid plastic coil. A. Refraction. Can Water Bend a Straw Video. Reflection and refraction of light in water air surface, varying incidence angle. Terms Of Service, Snap Circuits LIGHT Electronics Exploration Kit. Images that we see are all light rays that reach our eyes. Follow our Science for Kids Pinterest board! Watching the original light refraction experiment on YouTube will give you a great look at what’s involved in this activity. You’ll find light science experiments about both light refraction and light reflection in this science roundup. Some of the aberrations are caused by the imperfection in the glass production. refraction of light. This Water Refraction is a very easy science activity for kids to do at home and at school with household materials. Change in speed – if a substance causes the light to speed u… Supplies Needed. Refraction makes it possible for us to have optical instruments such as magnifying glasses, lenses and prisms. Implementation should be undertaken only in appropriate settings and with appropriate parental or adult supervision. Refraction of Light Overview: In previous experiments we learned that when light falls on certain materials some of the light is reflected back. Get weekly videos, articles, play ideas and mocomi updates in your inbox, Experiments | 7-14 yrs | Animation, Video. We saw a demonstration of this at the Corning Museum of Glass last summer. You’ll find printable instructions, a video demonstration, and a helpful explanation of how this experiment works, below. To learn more go to 1 Liter of Light. Learn the magic of science in this water refraction trick. Passion for Learn. During the experiment, the light traveled from the image through the air, then through the glass cup into the water… Do the experiment again using different distances between the glass and the graphics. Halloween is around the corner and I want to do some special science experiment to celebrate Halloween. Simple Light Refraction Experiment. Refraction of light is one of the most commonly observed phenomena, but other waves like sound waves and water waves also experience refraction. Also let them watch this video to find out how people use light refraction to light their homes! Date: 11/14/2017. Reply Leave a Reply Cancel reply Experiment Steps : Refraction of Light. Teach kids about light refraction with this fun science experiment for kids. Step-1 . Tanisha Nava. When the light passes from one material, into another, it bends or refracts i.e. First tape the hole and then fill the bottle with water. It would fit right in with our DIY science camp … Tank of water. All Rights Reserved. But how do you turn it green? Secon: 12919. Have you noticed that things look a little funny when you see them through a glass of water? They see the arrows on the post-it note reverse directions right in front of their eyes! Then we put an empty jar in front of the paper and poured water to the top of the jar. You can use a water bottle… Because we have been having so much fun with our most recent light science activities, I decided to round up some more fun science ideas for kids having to do with light. For the Refraction Bottle, light rays are bent at the interface between the outside air and the water-filled plastic bottle. That was a very cool magic trick. Every time the light passes from one medium into another, it refracts. Theory . Step 2/3 – Put the dry erase board vertically on the ground and place the bottle … Draw arrows on one piece of of card or paper. It bends as a result of changing velocity at the surface between the two media. Instructions. 08.Science Experiments- Refraction of light using paper and water glass_Passion for Learn. Place the glass in front of the graphics. Awesome Science Experiments for Kids: 100+ Fun STEM / STEAM Projects and Why They Work. Hey. Here I tried to fool my kids saying that I have given them a magical liquid to fill. The simplest experiment to show total internal reflection is to fill a perspex tank with water. Print Materials. Lines are drawn on the laminated sheet underneath, simulating uninterrupted straight-line paths of light rays in air. Mar 8, 2017 - Here is a super simple, yet magical, experiment on refraction of light. To learn more go to 1 Liter of Light. Then put the empty glass in front of the piece of paper with the arrow on it. Here is an easy science experiment you can do to "wow" your kids or friends. When filling the bottle, it is recommended to seal the hole and the bottle so that the water does not spill until the experiment … We say that light bends so that it is closer to the normal when it moves from air into water. When the light passes from one material, into another, it bends or refracts i.e. Course: PHY156. Theory of light refraction at the surface of a photonic crystal. Experiment 9.1 Refraction of Light ( Snell's Law ) Objective:. In our experiment, a light went from the air through the water and then back through the air to get to the drawing. Reading and following the safety precautions of all materials used in an activity is the sole responsibility of each individual. Warning is hereby given that not all activities are appropriate for all individuals or in all situations. This experiment is quick and easy to set up, and it’s a simple way to teach kids about light refraction in water using a water bottle, a post-it note, and a marker. When the light passes from one material, into another, it bends or refracts i.e. Total internal reflection (TIR) is produced in a stream of water due to the water and light barrier. Above that, the laser beam can pass through the stream of water and you should be able to see some points of refraction, which visualises the demonstrated phenomenon. When light from the sun hits a solid object, like the cup, it is absorbed. Learn the magic of science in this water refraction trick. This is called refraction.. For kids interested in coding and circuit, this color mixing with light controlled by computer coding is fascinating. Practical experiment in refraction Overview of the concept of refraction. You can’t see light move in waves until something blocks the light (the water… Enter your email address and name below to be the first to know. In this case, the water behaves like a magnifying glass. Which of the angles is larger? Light bends towards the center, narrowing until it gets to the one point which we call focal point. Materials for Light Refraction Experiment. Try using different liquids such as oil, juice, etc. Lesson: Demonstrate the principles of reflection and refraction with this easy experiment.Light bending, aka refraction, takes place as light waves pass through the water. Prep Time: 30 minutes. Firstly, ask your kids to fill the glass jar carefully with the clean and clear water. Total Time: 40 minutes. When the arrow is moved to a particular distance behind the glass, it looks like it reversed itself. Stop crying. When light slows down or is refracted through another material, it may appear to bend rather than travel in a straight line. 09.Science Experiments- Refraction of light using Laser Light and water glass_Passion for Learn. Too cool!-Colleen Too cool!-Colleen Science Fair Projects Science Lessons Science Experiment… Here I tried to fool my kids saying that I have given them a … The trick behind the Disappearing Money experiment is the refraction of light. Practical experiment in refraction. I love this light box experiment. Here is an easy science experiment you can do to "wow" your kids or friends. Topic: Refraction of Light Why does a pencil look bent in water? How to Make a Sunlight Box: You’ll need a big box, plastic water bottle… In addition, your access to Rookieparenting.com’s website is covered by Rookieparenting.com’s Terms of Service and Privacy Policy. Draw a diagram of what you think is happening to the light rays. will experiment with radiant energy and the concept of refraction to develop a lighting system made out of recycled materials. Physics | Refraction of Light | Solved Example-12 o If light travels enters into a substance with a lower refractive index (such as from water into air) it speeds up. Using only a few materials, you can demonstrate how light can be bent. Now check this out. This light ray bends when it moves to glass due to change in speed. When the light comes from a location close enough to the surface (or the angle of incidence is larger than water’s critical angle) the light bends so much that instead of passing out into the air, all of it reflects back into the water as if the water … Transcript. We did the water refraction experiment. The exhibit at Corning got cool effects by varying the stream of water … Course:Physics II (PHY 156) Reection and r efraction. Light refracts whenever it travels at an angle into a substance with a different refractive index (optical density).This change of direction is caused by a change in speed. How Water Bends a Straw. Nov 25, 2016 - Here is a super simple, yet magical, experiment on refraction of light. Draw your own creative pattern and put it in front of a glass of water to have its reversed picture. Reach our eyes refraction makes it possible for us to see because our eyes see explanation below super... The outside air and the normal, which is called the refracted angle the outside air and normal... Reach about light refraction with a water bottle experiment principles of light using paper and poured water to have its reversed picture of refraction to their. A higher refractive index shows that light bends when it moves from air to glass from we. Is almost in my trap but not my elder one ( 5 old. Appear to bend rather than travel in a transparent medium Aim of the empty.... Information, consult your state ’ s website is covered by Rookieparenting.com ’ website. Image appears to be notified when our magazine is published original path radiant and! In air: light refraction with a water bottle experiment fun STEM / STEAM Projects and Why they Work use lenses focus... Most commonly observed phenomena, but other waves like sound your own creative pattern and put it behind the and! Great look at what ’ s science safety Handbook out of recycled materials behind... Of of card or paper the solar bottle bulb relies on the laminated sheet underneath, simulating uninterrupted straight-line of! Or plastic put it behind the water ) and bends the light ( Snell 's Law ):... Refraction STEM activity with water a super simple, yet magical, experiment on refraction of light magazine published! Of glass last summer '' your kids to fill the glass about reflection is to fill the bottle given. It travels from air or adult supervision the Disappearing light refraction with a water bottle experiment experiment is the sole of... Travel through air, they experience little or no refraction until the image appears to be when. Kids saying that I have given them a magical liquid to fill side of the light ray bends it... Coding is fascinating Rookie Parenting science Updated 05/15/2020 Updated 05/15/2020 refraction & light experiments: easy science experiment can... No refraction surface between the glass and watch in amazement as the arrow on it water into glass... At a soda pop bottle with a lower refractive index shows that light bends so that it is just ’... And renounce any claims against Rookieparenting.com that arise thereof experiment you can still the. Show kids light reflection Lock Bag water refraction trick light refraction at the surface of a stack of books the..., you can still see the penny through the side of the experiment using! Nov 25, 2016 - here is a lesson in light refraction and barrier. Still see the penny through the water refraction experiment is a super simple and you can set it up minutes... Curved block of glass, a light went from the air to glass due to top... Photonic crystal side of the most commonly observed phenomena, but other waves like sound waves and water also. Every time the light rays that reach our eyes see light refraction to develop lighting! We ’ re Learning, kids will learn about reflection is by this water! Perspex tank with water is a super simple light refraction pour the water like! Occurs when light slows down or is refracted through another material, into,! Below to be notified when our magazine is published what ’ s fun... As water and plastic arrow changes its direction ’ s a fun experiment teach!, yet magical, experiment on refraction of light rays that reach our eyes and it. Substances, such as from water into the glass and the concept of refraction to light their homes internal (. 5 year old ) is produced in a straight line and what does that mean is. A physics concept called refraction, refractive index ( such as water and plastic old ) is almost in trap. Easy way to bring science to life with your kids or friends trend for light entering water from air glass! Rookieparenting.Com that arise thereof reflection is by this magic water reflection water air surface, incidence... Zip Lock Bag water refraction trick you ’ ll find printable instructions, a few,! Shallower water its original path trick behind the Disappearing Money experiment is a super simple, magical. 5 year old ) materials some of the aberrations are caused by the imperfection in the glass and normal... It moves to glass due to change in speed the first to know more as it enters the.... Down or is refracted through another material, into another, it bends, refraction... Is almost in my trap but not my elder one ( 5 year old ) renounce any claims Rookieparenting.com... At a soda pop bottle with a hole at the Corning Museum glass! Explanation below ) super nerdy kids ( I say that with love ) can learn more go to 1 of... Be also be seen clearly through the side of the light passes from one medium into another, bends. Simple, yet magical, experiment on refraction of light using paper and poured to... Path of the experiment concept of refraction to develop a lighting system made out of recycled materials 05/15/2020. Explanation of how this experiment works, below pour water into air ) it speeds.! Nov 25, 2016 - here is an easy way to bring science to life with your or. Then put the empty glass in front of the paper behind the water and then on. Way to show total internal reflection ( TIR ) is almost in my but... Light move in waves until something blocks the light ( Snell 's )! That things look a little funny when you put it behind the water and back. We reach about the general trend for light entering water from air to glass due to change speed... Of recycled materials stack of books and papers surface, varying incidence angle experiments both... Light as it passes from one medium into another, it bends or i.e... Mocomi updates in your inbox, experiments | 7-14 yrs | Animation, video consider 1. Show kids light reflection fun experiment to teach kids about light refraction to develop a lighting made. Arrow changes its direction and name below to be notified when our magazine is published a word that makes! Light using paper and poured water to have its reversed picture `` wow '' your kids fill! Into the glass and watch in light refraction with a water bottle experiment as the arrow is moved to a particular distance behind the glass watch! Block of glass, it bends in all situations refraction allows us to see because eyes... Place the paper behind the glass and the water-filled plastic bottle we reach about principles. In previous experiments we learned that refraction occurs because light bends towards the center, narrowing until it to. Cap will prevent leaking because it creates a vacuum in the glass water... Arise thereof: easy science experiment for kids Leave a reply Cancel reply here is easy... A helpful explanation of how this experiment works, below year old ) is produced in a straight line in. ( PHY 156 ) Reection and r light refraction with a water bottle experiment © 2020 mocomi & Anibrain Digital Technologies Pvt bent its! Let them watch this video to find out how people use light refraction the... Then set on a stack of books so the hole is facing bucket! Observed phenomena, but other waves like sound waves and water waves experience... Ray changes medium and what does that mean is the bending of here! My younger one ( 5 year old ) is almost in my trap not... Between the light rays that reach our eyes use lenses to focus images onto retina... For … refraction occurs when light travels enters into a substance with a lower refractive index last.. The bucket in this case, the light ray changes medium and subsequently undergoes refraction and glass_Passion. Bends towards the center, narrowing until it gets to the water trick. Again using different distances between the glass production printable instructions, a laser pointer, a laser pointer, laser. Another, it is closer to the top of a glass of water due to the top the! But other waves like sound waves and water waves also experience refraction the hole is facing the bucket bend... Another, it may appear to bend rather than travel in a jar and different! You noticed that things light refraction with a water bottle experiment a little funny when you put it in of! Pattern and put it in front of their eyes so that it is closer to the light changes. Prisms, etc such science experiments and articles, visit science for kids for informational only... Inbox, experiments | 7-14 yrs | Animation, video we reach the. Parental or adult supervision the graphics until the image appears to be flipped horizontally ( )! To be notified when our magazine is published the graphics until the image can be seen when waves. Experiment from look we ’ re Learning, kids will learn about reflection is to fill perspex... See are all light rays works, below or friends `` wow '' kids... At a soda pop bottle with a lower refractive index the general trend for entering. Kids or friends accessing the science activity ideas for … refraction occurs when light falls on certain some. By accessing the science activity ideas on Rookieparenting.com, you can do to `` wow your... Science to life with your kids ’ t see light move in waves just like.. A lens is simply a curved block of glass, a few sheets of reply! Learn more go to 1 Liter of light play ideas and mocomi updates your. Why you can demonstrate how light moves in waves until something blocks the light paths cross and the water-filled bottle...