“Why does the sky go green when it hails?” asks Swifty (11)

What a question? Thanks  team for your thoughts. To me it seems to be a unique mixing of the colours from our sunlight. We know that the blue sky is because of the blue part of the spectrum of colour that comes from the white light from the Sun.

Some of the blue part of that spectrum of light is scattered when it hits the molecules of Oxygen and Nitrogen in Earth’s atmosphere. So blue coloured light illuminates the daytime sky. We know that when we see a sunset we can see a red sky in the distance and that is because we are looking at the Sun through a lot more atmosphere than we would do in a normal day. I attach a NASA video that explains this then I will tell you my ideas about a green sky.

My thinking, and that of some others, is that the green sky is linked to the storm clouds (the background image above, was a pause in the hailstorm that the cyclists were experiencing). These were preventing some of the sunlight reaching the viewer who saw a yellow light mixed with the blue sunlight. the mixture of these lights could have caused the green light (a cyano type of light).

Very happy to hear comments and questions. Remember science development is about admitting your ignorance and my thoughts above are just thoughts. You and I need to do some further investigations.

Siobhan (11) asks “Do fish sleep?”

Siobhan. You maybe interested in why all animals (ourselves included) sleep. It is in sleep that we make our memories. Our nervous system and brain work because of fantastic cells called neurons. When we feel something, it is the neurons in the nerve system of our hands that send messages to the brain about what we are feeling. When we sleep it is the neurons in our brain that link up and create the memory of that touching experience.

Thanks for the question. If you have any further questions you can make a comment or ask another question.
(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

“How do your eyes work?” asks Jeff (11)


I have tried to make the image below to show you how it works. The eye is complex and is made of lots of different things. For example it has it’s own sets of muscles which can stretch the lens and allow your eye to move. It is filled with a special fluid that allows light to pass through it and gives the whole eyeball a very ‘squashy’ feeling. It is also connected to the brain by something which we call the optic nerve. The optic nerve transfers the electrical signal created by the image to the brain.

You also have two eyes and one of them is more dominant than the other.

Try this little experiment.
Look at an object in the room and then hold a finger out in front of both of both of your eyes and look at the same object. Then close one eye while looking at the object, then open the closed eye and close the open eye. What happens to the object that you are looking at? For one of your eyes the object that you looked at did not move.That is the dominant eye.

Jeff you can make a comment or ask another question.

(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

Andrew (11) asks “How do you make plasma?”

Andrew, quite an ‘exciting’ question. To find out how we make plasma lets look first at atoms and their structure. My team will do this and then I will come back to talk about plasma.

Andrew. I will be talking about a Neon atom. The Neon atom has 4 protons in its nucleus with 4 electrons orbiting it. Does that give you a clue to my plasma source?

The most familiar plasma sources that you might come across are Neon light tubes and lightning.

Firstly let us look at what plasma is. It is defined as a hot ionised gas which has an equal number of protons and electrons existing in the same space. Lets look at a neon light tube.

In the tube the Neon atoms lose electrons to the positive electrode, the remaining  Neon positively charged atoms (they have lost an electron) are attracted to the negative electrode. Lots of exchanges of electrons take place during this process and this ‘excites’ the electrons and creates the  plasma environment which gives of energy in terms of light.

Really hope that this helps. Please tell me if you do not understand bits of it or ask another question.

(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)


Edited 11/10/2017 Pictorial representation in image changed to ‘drawing’. Text size on image changed.

“How many particles are there in the Earth?” asks Ravindra (11)

Wow what a difficult question. I will ask my friends to try and answer this question.

A ‘particle’ is a tiny bit of something. So Ravinder, well done, you have asked a question that I or my friends cannot answer. Try and ask some more.

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


“What is the difference between speed and velocity” asks Sayed(11)

Absolutely right my friends. The two cars have the same speed but they are going in the opposite direction so their velocities are different.

An interesting example of the difference between
speed and velocity is when you look at an object moving at a certain speed in a circle. The speed is constant BUT the velocity is constantly changing as the object moves around the circle, see V1 and V2. The velocity at 1 is drawn as a line (representing the speed) pointing in the direction V1. This is a ‘vector’.

Sayed – this site is mainly directed at 8-13 yr olds so the answer above is very ‘general’. I have published it because younger readers might be interested in the difference between the two terms …for more information visit this site.




“Why doesn’t America use the metric system?” was Dekekisha’s (11) question.

Dekekisha, what a question.  Something that I have always asked myself when I have been converting Centigrade readings to Fahrenheit so that I could understand the weather. Friends, help me.

It is one of those occasions when I agree with you. As long as we all know and understand the different measurement systems and can confidently convert one to another.

Disagree, then let me know by clicking on the Reply button below. Thank you team.

Marcus(11) asks – ‘How do tsunamis form?’


They seem to have left me to finish off.

You could try to create your own Tsunami. In a tank of water drop a pebble and look at the small waves that are created. Then (in an area where water on the floor is not a problem), drop a brick into the tank and look at what that creates. This movement of water becomes larger when the wave reaches the shallow areas (beaches) of the surrounding area. It gets bigger, faster and more powerful. Look at the excellent video below.