Techy Tuesdays This weeks theme Fun at the fair! Miss Law’s Science activities at home Optical illusions can be found within funhouses and sometimes is used as part of sign designs at the fair. Here are some optical illusions you can have a look at yourself and with your family Are the horizontal lines sloping or straight? Are the circles moving in the image? Is the image spinning? https://www.optics4kids.org/illusions https://sciencebob.com/see-some-optical-illusions/ Bokeh effect photography Step 1 Set up your camera on a tripod or flat surface and set your camera's aperture to the widest setting, preferably f/1.8 or f/1.4 Step 2 Set up your fairy lights. Try to spread the lights evenly across the background you plan to use. Step 3 Set up your subject. Bokeh turns out better if you place the subject at least four to five feet in front of the lights. Step 4 If you are not using a fixed lens, zoom your lens in all the way. Step 5 Focus on your subject. Try to stay close to the subject, because if you are too away from it, your bokeh will suffer and appear smaller. Step 7 Release your camera's shutter, and voila! You have produced a photo with artificial bokeh obtained from simple fairy lights. https://photography.tutsplus.com/tutorials/quick-tip-creating-artificial-bokeh-in-your-own-home--photo-5773 Toffee Apples You will need:- •4 apples, Granny Smiths work well •200g caster sugar, golden if possible •½ tsp vinegar •2 tbsp golden syrup Place the apples in a large bowl, then carefully pour over some boiling water. This will remove the waxy coating and help the caramel to stick. Dry thoroughly and twist off any stalks. Push a wooden skewer or lolly stick into the stalk end of each apple. Lay out a sheet of baking parchment and place the apples on this, close to your stovetop. Tip the sugar into a pan along with 100ml water and set over a medium heat. Cook for 5 mins until the sugar dissolves, then stir in the vinegar and syrup. Set a sugar thermometer in the pan and boil to 150C or 'hard crack' stage. If you don’t have a thermometer you can test the toffee by pouring a little into a bowl of cold water. It should harden instantly and, when removed, be brittle and easy to break. If you can still squish the toffee, continue to boil it. Working quickly and carefully, dip and twist each apple in the hot toffee until covered, let any excess drip away, then place on the baking parchment to harden. You may have to heat the toffee a little if the temperature drops and it starts to feel thick and viscous. Leave the toffee to cool before eating. Enjoy Stored in a dry place for up to 2 days. Make a ring toss game What do I need? •Kitchen Roll Middles •2 Squares of Cardboard •PVA Glue •A Retractable Knife/Stanley Knife •Pencil •2 Different Sized Plates •Decorations How to make it Start off by cutting 4 lines, roughly 3cm, on one end of each Kitchen Roll Middle and folding them out. Apply glue to the bottom of the flaps and set them out on one of the sheets of cardboard in whatever pattern you like. Make sure you give the glue plenty of time to dry, at least an hour. While the glue is drying, take the other sheet of cardboard and draw on the hoops using the 2 different sized plates. Once these have been drawn, very carefully use the retractable knife to cut them out. You may want to ask an adult to help. You can decorate these using ribbons, tape, paper or anything else you can think of. Once the glue has dried, it’s time to decorate. Make sure to put scores on each pole. Mr Wing’s weekly wordsearch Fairground anagram RETLER SKTELER Outdoors with Mrs Ogburn It’s not magic that keeps people in roller coaster cars that travel in looping, spiraling paths – it’s physics. Try this experiment to see how centripetal force and inertia keep people inside cars even when traveling upside down. What You Need: Small plastic bucket Water Sturdy string Outdoor place that is OK to get wet What You Do: Tie the string securely around the handle of a plastic bucket. Use a plastic bucket rather than metal so it is not heavy. Pour a glass full of water into the bucket. (Again, don’t add too much water so it is not too heavy.) Hold the string so that the bucket is about level with your knees. Adjust length of string as needed. Spin the bucket of water over your head in a vertical (up and down) direction. Make sure you spin the bucket fast enough so it stays in a circular path. Does the water spill out? What Happened: It seems as if the water in the bucket is defying gravity, but is it really? No. Gravity – the force pulling down on everything – is still at work even when the bucket and water are above your head. The water’s inertia wants to keep the water traveling in a straight path, but gravity is acting on the water, causing it to fall in a downward path that will eventually hit the earth. However, while the water is falling, the bucket is falling with it, catching the water. What keeps the bucket and water moving in a nice circular path that doesn’t get wet or messy is the string. The string acts as the centripetal force that pulls the bucket and water into the center and keeps them from following their paths of inertia, giving the illusion that centrifugal force is pulling the water away from the center. But be careful. In order for the bucket to keep falling with the water, the bucket must travel fast enough to keep up with the water. If you spin the bucket too slowly, the water will fall out YOU WILL NEED - 2 empty toilet roll tubes - 2 small elastic bands (if they are too “strong” they will destroy your launcher) - 1 pencil - Adhesive tape - Cotton wool or cotton wool ball - Single hole punch or something sharp to make a hole. Take care, you may need to ask for help with this. 1. Use your scissors to cut one of the toilet paper tubes in half lengthwise. 2. Squeeze the roll so that it becomes narrower, about half the original diameter, then tape it to hold in place. 3. Use your scissors or your hole punch to punch two holes in the skinny tube. Make the holes opposite one another, half an inch away from the end, so that you can poke your pencil all the way through the tube. 4.Carefully push your pencil through the holes. 1. On your second toilet paper tube, cut two slits into one end of the tube, about 7mm long and 15mm apart. Cut two more slits on the same end of the tube, directly across from the first two. 2. Carefully loop one rubber band through the slits on one side, so that it hangs from the cardboard piece in the middle. Put a piece of tape over the slits to reinforce the cardboard tab. Do the same on the other side. 3. When you are finished, the tube should have a rubber band hanging from each side. 4. Holding the rubber band tube so that the rubber bands are at the top, slide the narrower tube into the wider one, with the pencil end at the bottom. 1. Carefully loop each rubber band end around the pencil. 2. Hold your launcher so that the pencil is at the bottom. Place a cotton wool ball on the top, so that it rests inside the narrower tube. 3. Pull back on the pencil so that the inner tube extends 5cms out the back of the Try launching your “missiles” into empty boxes or launcher. Carefully aim your cotton wool wastepaper baskets. ball—away from people! How accurate are you from different distances? 4. Release the pencil and watch your Challenge your brothers and sisters, (or others cotton wool ball fly! within your household). Something to think about Scrumptious Science: Making Ice Cream in a Bag No fun fair would be complete without ice cream. There are no funfairs at the moment but you can still have all the fun by making your own ice cream. You may have seen lorries spreading salt on the road in the winter. Why is this? The salt lowers the temperature at which water freezes, so the ice will melt even when the temperature is below the normal freezing point of water. When a freezing point is lowered, such as by adding salt to water, the process is called freezing-point depres- sion. In this activity you'll make your own ice cream in a bag. You will need: A large bag of ice Salt Milk – we used chocolate milk A tablespoon sugar and a teaspoon of vanilla essence – optional 2 Ziploc bags Tea towel What to do: Pour a cup of milk into a ziploc bag. Add the sugar and vanilla essence (or just use flavoured milk). Make sure the bag is properly sealed. Half fill a bigger ziploc bag with ice and add a good amount of salt. Put the milk bag into the ice bag and give it a good shake. Keep the milk in contact with the ice as much as possible.