How to make rainbow
How to make rainbow
How To Make A Rainbow – Simple Science Experiments
How Are Rainbows Formed?
Sunlight or white light is a mixture of all the rainbow colors. The different rainbow colors are essentially mixed together to result in a white color.
You may wonder why when you mix all the different colors of paint together result in black instead of light. That is because light mixing is additive while pigment mixing is subtractive.
When light passes from one medium to another medium of a different density (e.g. from air to water), the light bends. This is known as refraction of light 1 (More light experiments).
How much a light is refracted depends on the wavelength of the light. The shorter the wavelength, the more it bends. Because lights of different colors have different wavelengths, each color is refracted by different amounts.
In nature, a rainbow is formed when sunlight is refracted on entering a droplet of water, reflected inside the back of the droplet and finally refracted again on leaving the droplet.
Seeing A Rainbow
To see a rainbow caused by sunlight, the sunlight needs to come from behind us because rainbows only appear in the part of the sky directly opposite the sun.
Red has the longest wavelength among the visible colors. So it tends to bend the least and the angle between the incident light and our line of sight for red is approximate 42 degrees. As a result, red appears on the top of the rainbow
Violet has the shortest wavelength. It tends to bend the most. To see violet, the angle between the incident light and our line of sight is roughly 40. So violet appears at the bottom of the rainbow.
Why Are Rainbows Arched?
Rainbows are not two dimensional. A rainbow is seen at an angle that is between 40-42 degrees from the incident sunlight. So all the water drops that produce each color in the rainbow lie on a three dimensional cone. Our eyes are at the tip of the cone.
That is why rainbows are arched. The circular shape below the ground is invisible.
Rainbow Experiment
Now are you ready to make some rainbows? Here are 3 easy ways to make your own rainbows at home.
Warning: Adult supervision is vital in experiments involving sunlight. Do not look directly at the sun or at the reflection of sun in a mirror.
1. Rainbow Prism
One of the easiest and most visually stunning ways to see an artificial rainbow is by using a prism. Creating rainbows using a prism is really fun.
How to Make Rainbow Shots
Introduction: How to Make Rainbow Shots
How it works: The different densities of the four liquids used to make these, allow the separate liquids (i.e.: colors) to stack up in the shaker. As the shots are poured out, slight blending occurs between the layers creating the transitional colors like orange and green.
Note: All the shots will not have equal amounts of alcohol, nor will they all taste equally awesome. (ex: the red will be mostly grenadine. Ew.) This is more meant to be an «oohh, aaaahhh» party moment that comes before the really tasty, if less magical, drinks are served.
And the best thing? With just a little practice they’re surprisingly easy to make. So let’s go chase that rainbow!
Step 1: Supplies
Ingredients
Tools
*I used a glass one to make this Instructable more clear, but to maintain the mystery when doing this in front of others, a non-transparent/steel one is best.
Step 2: The Bottom Layer: Grenadine
Set up your 7 shot glasses in a line in front of you. Place your shaker just in front of the line of glasses and put everything else you’ll need within reach.
Measure out 1/2oz. of grenadine and carefully pour it into the bottom of the shaker, being careful not to get it on the sides.
Step 3: Ice Ice Baby
Gently add crushed ice to the shaker until it is 3/4 full.
Step 4: The Middle Layer: Pineapple Juice
Place a big spoon over the ice and SLOWLY pour 6oz. of pineapple juice into the shaker.
Step 5: The Almost Top Layer: Vodka
Leave the big spoon resting atop the ice and pour 1oz. of vodka slowly onto the spoon.
Step 6: The Tip Top Layer: Blue Curacao
IMPORTANT: The blue curaçao is actually the heaviest of all these liquids, so it’s very important to start pouring the shots immediately after adding it to the mix.
Slowly add 3/4oz. blue curaçao to the tip of the spoon only.
Step 7: It’s Pouring
As soon as the blue curaçao’s been added, remove the spoon and place the cocktail strainer into the shaker. Start pouring the shots right away from the side of the shaker your added the blue curaçao to.
I find it helps to count as you pour to try and get the shots even-ish. I counted to four for each pour.
You may have to try 3-4 times to get your pour timing down to avoid having a brown shot instead of yellow. (Especially if you choose to wear the unicorn head while doing it.) But once you get it, you will be able to pull this trick out anytime a party needs a pick-me-up.
Step 8: How to Make Friends and Impress People
Maybe that should have been the title of this ‘ible. : )
Have fun with this one you guys!
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34 Comments
Question 4 years ago on Step 8
Is there a non alcohol substitute for the vodka
Nice, but I would never let this be served at the club I managed. The flavor, and color is varied, but so is the alcohol content. No way of telling how much is in each. Controlled portions are one of the best tools you can use for many reasons, including the safety of your patrons.
Reply 4 years ago
My first thought was also to add the alcohol to the individual ingredients. However, that would create a lot of extra work. It could also mess with the layering.
My suggestion would be to advertise it as one drink for one person. Seeing as it only has 1.75oz of alcohol all of the shots combined are about as strong, if not weaker, than the average cocktail.
Reply 7 years ago on Introduction
One possible way to remove the alcohol content difference is to mix the vodka with each ingredient separately first. You would need to have a separate set of bottles just for this though, so that there aren’t any additional steps needed at runtime.
How to Make Rainbows at Home
February 26, 2015 by Sue Lively
This week, Onetime and I had fun exploring some different ways of creating rainbows at home and we’re going to share those with you today.
I’ve also rounded up lots of other fun rainbow activities that you might be inspired to try with your kids.
Amazon Affiliate links have been included for your convenience. Please see Disclosure for more details.
To Make Rainbows – You Will Need:
What Makes a Rainbow?
Before we began our rainbow making adventures, I talked with Onetime a little bit about how sunlight is made up of many colours all put together.
A rainbow appears when the light gets split up into its 7 different colours: red, orange, yellow, green, blue, indigo and violet. Sometimes referred to as “Roy G. Biv”
Usually – the reason the light gets split up is because it is passing through a substance that bends the light. The different coloured wavelengths bend in different amounts.
Red tends to bend the least, so it appears on the top of the rainbow, while violet bends the most and ends up on the bottom – with all the other colours in between.
When we see a rainbow in the sky, it is usually when the sun is behind us and it is shining through millions of tiny raindrops floating in the sky – all of which are bending the light and projecting the rainbow.
(Did you know that sometimes – rainbows appear at night too? Read this post to find out about Moonbows!)
In any case – we don’t need raindrops to make a rainbow. Here are our 5+ different ways to make rainbows of your own INSIDE!
1. Making Rainbows with a Mirror
Let’s start with the easiest! Fill a large bowl or dish halfway with water and prop up a mirror inside it so that part of the mirror is under the water and part is out.
Place the rainbow maker near a sunny window with direct light coming in so that it hits the mirror (early morning or early evening light works best).
Play around with holding a large white piece of paper above the maker to “catch” the rainbow. You might have to move a bit until you find it.
Play around with moving the paper closer to the mirror and then farther away to see how your rainbow changes!
SAFETY NOTE: Just like you should never look directly into the sun, be sure that you do not look directly into the reflection from the mirror. It can damage your eyes. If you are at all concerned about this with your child, instead of using sunlight, try a darkened room with a strong light source instead.
2. Making Rainbows with a Glass of Water
When light goes through a glass of water – it also splits into a rainbow.
To get ready – take a piece of paper and cut a slot into the middle of it. Tape this onto the side of a smooth/clear drinking glass so that the sun’s rays can pass through the opening onto the SURFACE of the water in the glass.
You will need to do this on a very sunny day (or try a darkened room with a strong direct light source.)
Make sure that the glass of water is VERY FULL. Place the glass on a white floor or white piece of paper, making sure the sun’s rays are shining through the slot in your paper and hitting the surface of the water.
You should see a mini-rainbow appear below the glass!
Have your child describe the colours they see and you can talk about rainbows you have seen in the sky and how they are similar or different.
3. Making Rainbows with a Prism
If you’re lucky enough to have a crystal chandelier at home, or a hanging crystal decoration, you may not need to buy a prism. We didn’t – so I picked one up at our local kids’ toy shop.
Basically, all I did was place a large piece of white paper on the floor beside our living room window that lets in lots of direct sunlight in the morning.
Onetime figured out pretty quickly that by moving it around, he could make a rainbow beam appear on the paper. He had lots of fun moving the prism in different ways and exploring how to change the size of the rainbow.
If you happen to have 2 of the standard prisms, you can have the light pass through one prism (which then breaks into a rainbow) and enter the other prism – which then bends it back into white light. Cool huh?
For other prism play ideas, check out Rainbow Prism Busy Bag, and Prism Play and Chalk Art.
4. Making Rainbows with a CD
You can make this really simple and just hold a CD up to some sunlight – or shine a flashlight on one in a darkened room – and you will see a rainbow on the CD.
Or go a little further, and try to catch the reflection of the light on some paper!
The reason why a rainbow appears is because there are tiny ridges in the surface of the CD that are reflecting the light in different directions. To read more about the science behind CD rainbows – check out this post at Exploratorium.
5. Making Other Rainbows
Other ways we didn’t try: misting a hose on a sunny day with the sun behind you, looking for rainbows in bubbles and oil slicks, wearing rainbow glasses (okay maybe that one doesn’t count!)
We plan on waiting for a warm spring day to try these out! For even more ideas and tips – check out this Rainbow Making WikiHow.
More Rainbow Activities
Experience colour mixing and crazy sensory fun with Rainbow Goop
Build a Fine-Motor Rainbow to work on fine-motor skills and to create a beautiful craft.
Make Milky Rainbows with ingredients from your kitchen.
Try making our St. Patrick’s Day Shamrock Math Bin for a fun search for gold and counting fun under the rainbow.
Other Rainbow Ideas
Picture Books for Learning About Rainbows
To find some excellent children’s books to learn more about rainbows – click on the picture below!
Hope you found some fun rainbow learning activities for your kids today. We certainly learned a lot and had a few very colourful days at home with these activities!
To find even more fun and educational activities as well as positive parenting tips, follow me on Facebook, and Pinterest.
How to Make a Rainbow Night-light
Introduction: How to Make a Rainbow Night-light
Rainbows are pretty amazing things. Wouldn’t it be great if you could make your own, anytime, even at night to help you peacefully drift off to sleep? I think so! Follow along if you’d like to make your own rainbow night-light!
First off, if you’re interested in how a rainbow is formed and why white light separates when it passes through a prism check out one or both of these videos below.
It’s okay to be smart
While we aren’t going to rely on rain for our rainbow (or more accurately our spectral projection), A diffraction grating will work well in it’s place. A diffraction grating is a set of many small prisms packed into a small space. These, similar to water droplets, can split white light into all the colours in our visual spectrum. An example of a diffraction grating you can find around your house is a DVD or CD. So we’ll be using one of these to help make our rainbow. I found DVDs seem to give a better image, so I’ll be using one in this Instructable.
Supplies
The great thing with this project is that you probably have everything you need laying around your house. And it can be completed in 15 to 30 minutes!
Here’s what you’ll need to follow along with the build.
1. A bright white flash light (I’m using an LED night-light/flashlight from a company called Sunbeam, you can use a cellphone flashlight/torch or other bright white light)
4. Some card-stock (I’m using a cereal box)
5. A pair of tweezers
6. A pair of scissors and/or a utility knife
7. Four paperclips
8. Isopropyl alcohol or some soapy water and paper-towel
9. A stack of books or CD cases about 5cm tall.
11. A protractor
14. A wooden skewer (longer than your box is wide) OR eight neodymium magnets (I’m using rectangular ones 2x5x10mm)
Step 1: Prep the Housing
The first thing you’ll want to do is remove the plastic lining on the top of your tissue box. This will give us a cleaner looking rainbow. Then make the opening wider by cutting to the top edges of the box.
Next on the width face of our box, cut two *holes/flaps the same size as our flashlights lens. One hole/flap should be centred at the top, and the other centred at the bottom.
* You can see in the pictures I cut holes, but if I were to do it again, I’d make flaps, so I could keep one closed while using the other
Step 2: Prep DVD
The DVD can be used as is, but by separating the 2 layers, we’ll get a more vivid rainbow.
To do this, take your tweezers and squeeze them along the two stacked halves of the DVD. Doing so will create a small separation between the two pieces. Now carefully pull the shiny side away from the clear side.
We’ll be using the shiny side. If there is purple adhesive left on the shiny part, you can clean it with the Isopropal Alcohol or soapy water and paper towel. Don’t over do the cleaning or you could start to take off the reflective surface like I did. Despite this, I can still get good rainbows.
Step 3: DVD Angle Adjustment
Option A: Magnetic adjustments (pictures 1-3 of this steps images)
I prefer this setup because it’s easy to make quick adjustments.
Along the outer perimeter of the DVD, take two magnets and stick them together with the disc between them, making DVD-magnet sandwich (picture 1). Do the same with two more magnets across the DVD, 180 degrees from the first two magnets (picture 2)
Put the DVD into the tissue box and lay it flat on the bottom, shiny side up. Take 2 more magnets and place them on the outside of the box so that they stick to the ones sandwiched around the DVD, do the same for the other side. You should now be able to adjust the DVD and have it stay in place.(picture 3)
Option B: Wooden skewer adjustments (pictures 4-8 of this steps images)
I get that if you are making this with a young child you might not want to use magnets. This setup isn’t as flexible to modify things on the fly, but it still works well. We’ll make a flap that the DVD will rest on, and secure its angle with the wooden skewer.
With a utility knife, cut along both bottom length edge of your box from 4cm to 15cm (from your light source side). then cut straight across the bottom of the box at 15cm(picture 4). You should now have a tab that your DVD can rest on.You can tape your DVD in place (shiny side up) to make sure it doesn’t slide down (picture 5).
Next, use a protractor to measure a 25 degree incline for your DVD flap (you can choose a different angle, but I wouldn’t go beyond 40 degrees) (picture 6). Do this on both sides of your box then poke two holes at these points and thread the skewer through the opening behind the flap that the DVD is resting on (pictures 7&8).
Step 4: Limiting Light
We now need to make two sliding sheets to block out any stray white light that would overpower our rainbow.
To do this, cut out two pieces of cardstock (cereal box), each large enough to cover the tissue box top opening. Bend one piece to about 60 degrees 5cm from the edge (for a cleaner look, you can score it using a utility knife and a ruler).
Step 5: Making Rainbows!
Great, now you’re ready to start making some rainbows!!
Light position
To make straight line rainbows you’ll want to position your light through the bottom hole/flap we made in step one.
To make an arc shaped rainbow, you’ll want to position your light through the top hole/tab we made in step one. To do this, you’ll need to stack something underneath the flashlight.
Adjusting card-stock sliders
To best adjust the card-stock sliders, first slide one along the top of the box lengthwise until you start to see a rainbow. Keep sliding until you see colour start to fade from the rainbow. Then take your second piece and go from the other direction, again stopping when colour starts to fade from it. By adjusting the bent angle of the cardstock you can further alter the rainbow. You’ll know when you’re in a good position when you can’t see any bright white light on the wall or ceiling. Once they are in a good spot, you can hold them in place with your paper clips.
Wall or Ceiling
If you’re using your cellphone, turn the box 90 degrees and rest your cellphone on top of it where the light can travel through the holes you made. This will put the rainbow on the wall as opposed to the ceiling.
Step 6: Going Further
(i) Even more rainbows!
You can create even more effects, by moving your flashlight around freehand over top the tissue box. I’ve included some images I took when I was doing this. See what other shapes you can make!
(ii) Getting in focus.
Take a magnifying glass and hold it between the wall and your rainbow, move the magnifying glass until you can see which part of the DVD your rainbow is coming from!
(iii) Editing the rainbow
If we put a piece of transparent coloured plastic over the light source or over the tissue box opening,We can limit the amount of colours in our rainbow. You can also do this with a bit of food colouring and water in a clear glass. Try a few colours and guess which colours will or won’t be shown in the projected rainbow. This is pretty much how a spectrometer works! By looking at a rainbow spectrum through a material and seeing how it affects the that spectrum, we can find out what exactly we’re looking at.
6 Incredibly Easy Rainbow Science Experiments
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No rainbow in the sky today? No problem. Just pick one (or all) of these easy kid-friendly science experiments with your rainbow-making know-how. From reflection (mirror) to refraction (water glass) to learning about density, we’ve found six science experiments to make or learn from the rainbow. Scroll down for the details.
1. The Mirror Method
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. When you shine your flashlight (or position your glass so the sun comes in) you are bending the light waves, each one of the waves at slightly different angles resulting in the different colors of the rainbow. This is the same basic principle that occurs when water and sunlight create a rainbow in the sky. Reflection is the light bouncing off of the mirrored surface.
You will need:
A small mirror (like a compact mirror)
A glass of water (big enough to hold the mirror)
A piece of white paper or a white wall
1. Put the mirror in the glass of water.
2. Turn off the lights and draw the curtains. Make sure the room is totally dark.
3. Shine the flashlight on the mirror and check out the cool mini-rainbows that appear above the mirror. Put your hand behind the glass for extra fun.
2. The Garden Hose Technique
Lesson: Refraction, as above. This time, instead of using a mirror to reflect the light, you are going to basically mimic the natural formation of a rainbow by causing the water to hit the light in a fine mist.
You will need:
A spray bottle or a hose
1. Put the hose on mist or grab your mister and spray it into an area of your yard/house/garden that has natural sunlight hitting it.
2. Let the kids ooh and ahh over your rainbow-making skills, then let each of them take a turn.
3. Water Density Rainbow
Lesson: By adding more or less sugar to each water solution you are creating different density levels. When you add coloring to the glasses you will be able to see which solution is the heaviest. Add the colors in rainbow order to impress the kids. Visit Steve Spangler Science to get the complete how-to.
Five glasses or plastic cups (clear)
4. The Glass o’ Water Approach
Lesson: The most simple form of light bending, this lesson in the light waves is similar to #1 above.
You will need:
A glass of water
A piece of paper
1. Put the glass of water in the sunlight.
2. Put the paper next to it.
3. Let the sunlight stream through the water and create a rainbow on the paper.
5. Advanced Glass o’ Water Approach:
You will need:
A glass of water
A piece of paper
1. Put the glass of water on a table or windowsill where there is sunlight.
2. Put the piece of paper on the floor where the sunlight hits, in the line of the glass.
3. Spray the window with warm water where the sun is coming through, and so it lines up with the paper.
4. Move the glass and paper around until you see a neat little rainbow on the paper.