“I know I can see myself in a mirror but why cannot I see myself in other things?” asks Isabella (8)

Many thanks team. I have some ideas about investigations that you could do at home. People say that light travels in straight lines. How can we test this idea. Firstly we need a source of light. How about a torch. 

Now we know that a torch sends out light in all directions but how do we know if it is travelling in a straight line? Think……..

Now lets ‘capture a little bit of the light from the torch. Let’s use a piece of card with a hole in it and see if we can make the light from the torch go through the hole.

Now what do we have to do to show that, the little beam of light coming through the hole is travelling in a straight line?
Supposing we had another piece of card with a hole in it in exactly the same spot do you think you could arrange it so that the little beam of light goes through the hole in the new piece of card?

Do the same for a third piece of card arranging it so the little beam goes through it’s hole. Now draw a line between the torch and the third hole. What do you notice?

Now lets quickly look at your question about not seeing reflections in materials that are not mirrors.

Reflections are wonderful things and they happen, or do not happen because light travels in straight lines. A reflection occurs when a beam of light bounces off a surface. You could set up your torch and card above to make a reflection, using a mirror or something flat and shiny.

Now do the same for a different type of surface.try it with a piece of material. What happens? Try with all sorts of flat surfaces – shiny metal (use flat aluminum foil and then crinkle it), cardboard, paper, plastic, water, leather……..
What do you notice? Maybe reflection requires a flat shiny surface? Think about the results.

“Is a shadow a reflection?” asks Jack (7)

Thank you team. Some excellent observations. You noticed that the shadow had no detail on it, no colour, no lines, no images of seeds in the fruit. It was just black. On a dark night, under street lights look at your shadow. Other than your shape what detail does it have? It changes now and again, but why?

Now the reflection? If you look into a mirror what do you see? Is it like your shadow? How different is it?

Look at the two images of the fruit. The first image of the the fruit is the ‘real’ image. What about the image just below it (on the shiny surface)? Is it the real image? How did it get there?

Think about this – where did it come from? Now think about your image in a mirror, where did that come from?

You can create you own image of a reflection and a shadow. Get a mirror and a small screen. Put the object on the mirror and the screen behind it and use a torch to shine on the object.

Jack, this a great question. Lot’s to think about. Do you want to ask another question? Then click on the Reply button below.

 

Beatriz (7) asks “What happens to the the light at night?”

How do we tackle this question Beatriz? Lets tackle it by looking at light being used.

Let us see if we can make light move around a table. For this experiment you will need 3 plastic mirrors some plasticine and a torch. Light can be ‘bounced off’ an object so can it be bounced off mirrors?

So your task is to bounce the light from the torch around the four sides of the table. Think about what you did to make it happen.

Also let us look at shadows. Collect a variety of objects, a torch and a screen (maybe mounted in some way). Shine the torch at the object, what do you see on the screen.

Why do you think the shadow is formed? Can you change the shape of the shadow? Can you get more than one shadow?

Any reader can ask another question or leave a Comment in the Leave a Reply box below

Science Master Special – Energy

Thanks team. I would like to add a few things.

Firstly the list of different types of energy is not complete. If you can think of some more then ‘Leave a reply’ in the box below.

Secondly it is interesting how the energy conversions can take place. For example a microphone converts sound energy into electrical energy and a loudspeaker does the reverse process, it converts electrical energy into sound energy. Can you think of other examples?

Any reader can leave a Comment in the Leave a Reply box below

Soham (10) ask “Why is the sky blue”

Soham, I have tried with my friends to answer this question previously. Have a look at my a previous answer.

Think about it and if there is something that you are unsure of ask another question. Sometimes other questions help. They  help all of us to understand some of the strange aspects of our lives.

Soham(10) asks – “Why do Chameleons change their colour and how ?”

chameleon

Thanks team, some good answers. On most occasions it is suggested that a Chameleon changes colour for defensive purposes.  It seems that they can do this by changing the tension in their skin. Not something that we can do very easily. For the Chameleon, part of the skin is a compound that can be stretched and it is this compound that changes the light colours that are absorbed by the skin and those that are reflected. Thus the colour change.

Reflection of light of things depends on the material and the light that is falling on it. Suppose green light was shone on a red object in a dark room. Would you see it? Sometimes you can also notice that changing the temperature of a material changes the way it reflects light. Running a hot iron over a red material changes the ‘redness’ of the material because of the effect of the heat on the compound that the red dye is made of. Some experiments that you might try (with the help of an adult).

Why is the sky blue in the day and black in the night? asks Lamar (12)

Lamar – a brilliant question. I will ask my friends to think about it.

blue-sky

Lamar. I hope that you have had the opportunity of passing ‘white light’ through a prism and see the fantastic ‘spectrum’ of coloured light that results. If not then try ‘creating’ white light by using torches and  coloured cellophane (blue, red, green) on each torch and shining them at a white piece of cardboard. Let me know what happens.

Things then get a little difficult. You have to think of the Sun’s white light reaching the atmosphere of the Earth. The two major components of the atmosphere are nitrogen and oxygen. The structure of the molecules of these two components makes them very receptive to the blue part of the white light from the Sun. The air molecules absorb this blue part and then re-emit it in all directions. This is a process called ‘scattering’. Thus the blue sky. The rest of the (white minus some blue) sunlight passes onwards.

At night the Sun is shining on another part of the Earth, so no white light is falling on your part of the Earth. No light ….blackness.

Lamar . An interesting question, a complex answer. Feel free to ask another question.

Abdur’s question on shadows

Abdur asked the following excellent question –
“If light was pointing downwards and you put an object in front of it, would the shadow still be big like when the shadow is pointing sideward?”

I asked one of my team to look at the problem.

Shadows

Enjoy this short video on shadows. Then tackle my questions.


Why is my friend keeping at least 5 things the same in her investigation?  What are they? What is this type of test called? Why does it have this special name?

Sorry lots of questions. That is what science is all about.
If you want to answer these questions write in the ‘Leave a Reply’ area below. If you have a further question ask it by clicking on the ‘Ask a Question”

Fatima asked. How does light work?

A great question Fatima. I asked my friends to do a little research.

new what is energy

 

I think I would like to add a few words.  What can light do to other things?  If you have any problems look at the video. Answer in the Reply Box below. There is also another question …How many types of Energy are there? One of my friends came up with the magic number of 9. Can you match that or even give a higher number? Remember my friends explanation of what energy is and try to see how many forms of energy you can find.

Do you want to ask a further Question? Click on the button below.