Hugo (7) asked – “Is the world magnetic?”

Hugo, a great question. I think the world is magnetic but I am not sure how we can find out if it is. Let me ask my friends. They should be able to give me an answer in a few hours time. I think it is something to do with compasses.

Hugo, I think you will need some equipment ……. a small bar magnet and a square of polystyrene or woo. This will mean that you can float the magnet on some water.

 

Clara (7) asked – How are all sorts of jewels made?

Clara, thank you for your question. I will ask you a question “What do you think jewels are made of?”  this would help in deciding how jewels are made.

Are jewels made from hard or soft things? Are jewels made of metal or some other material?

Wow…I used the word “material”. What do you think that means?

Material is a word to describe what things are made of. We recognise a material by its properties. Is it hard, soft, bendy, runny, smelly, strong, brittle?

I asked a friend about your question. Here are her thoughts.

Thanks for that.

Clara, it might be difficult for you to examine the properties of the diamond. It is made from a material that is very, very hard. Maybe you could investigate its hardness ….how do you think you could do that?

Is the diamond held in a metal. There are lots of different metals all of which have different properties. Can you find some metals that are different from the metal that the diamond might be held in.

Let me know in the comment box below.

Jaydeep (7) asked “Why do sponges absorb more hot water than cold water?””

Thanks team. I agree with you I don’t have an answer to Jaydeeps question. I think the best I can do is try to carry out an experiment to test the observation that you have made.

I would need a sponge (natural or manufactured), a fixed amount of water and a way of drying the sponge. If we are going to do a fair test the sponge must be the same for both the hot water and the cold water test. It also must be in the same condition (preferably dry). I would also need to be aware that you should weigh the water, the weight of hot and cold water must be the same. As water is heated the volume gets bigger.

Jaydeep …maybe you could also try the experiment above and see whether a sponge does absorb more hot water than cold water. You could let me know the result by telling me your result in the comment box below.

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Unknown (age 7) asked – “Why is the sky blue?”

Hello unknown. I would not normally answer questions to an unknown questioner, but, as it it such an interesting question I asked my friends for some comments.

You are right. Where does the colour come from? It was in 1671 that the famous scientist, Newton, discovered that white light was a mixture of different coloured lights. He did this by passing white light (the light from the Sun) through a glass prism. Look at what he got……….

Later it was found that some of the blue light in the Sun’s light had difficulty passing through the Earth’s atmosphere. this blue light was scattered as it passed through the atmosphere therefore giving the sky a blue colour.

Some of the blue light still got through and appears as part of the white light in the prism experiment and also in the rainbow. In the rainbow the drops of rainwater act as small prisms.

Hope this makes sense. if you want to give your name please let me know in the comment box.

(amended 21/9/18 – raindrops as prisms added)

Jaydeep (7) asks “Why do sponges absorb more hot water than cold water?”

Jaydeep. An interesting question, which I need to think about. I suspect it might be a question of ‘testing’. How did you arrive at the question? Did it include elements of ‘fair testing’? I shall start by passing it over to my friends.

Thanks team. Yes, I agree, science knowledge is based upon fair testing. Jaydeep’s question suggest that he has evidence that sponges absorb more hot water than cold. It is and interesting thought BUT is it true? That’s what a scientist would ask.

What do I think? My initial thought is that as water gets hot it expands, so…., the sponge might absorb less water. From another viewpoint it might be argued that the hot water ‘warms up’ the sponge and causes the sponge to expand, thus absorbing more water. Another argument might be that because both the water and the sponge expand when they get hot …..things cancel out.

The important point is that if the original investigation was not fair all the arguments about Why are meaningless.

Jaydeep ….do a fair test`and then ask the question. Many thanks for an interesting input.

“Why do spiders make webs and what are they made of?” asks Emily (7)

 

Thanks Team and thank you Emily. My first thoughts are about catching a spider and trying to keep it at home or somewhere else or finding a spider in the wild so that you can see it making, or looking after its web. I am however reluctant to suggest both catching a spider or keeping it in an indoors.

In some countries spiders can be dangerous so please do not interfere with it until an adult has identified it and  said that it is OK to collect it, or observe it closely.  If, with an adults permission, you can keep a spider then a large plastic aquarium would probably provide a good home for it.

A spider’s web is made of a type of silk, so ask an adult if they could find some silk for you to investigate. Maybe you could use it to make a web and see how strong it is?

If you do keep a spider, at home, or in the classroom you will have to decide how you will feed it. That will be an interesting investigation.

Look at this video of a garden spider building its web. In the first part of the video everything is slowed down. In the second part of the video things are at the real speed of web building.

Mason (7) asks “Why is water wet?”

Thanks team. Let us start with a investigation. Let us look at the way water interacts with different materials.

 

Let us now look at the properties of water drops. Firstly let me define ‘cohesion’ and ‘adhesion’. The term ‘hesion’ means  … to stick. Cohesion is is the attraction and sticking together of the same things while adhesion is the attraction and sticking together of different things.

Look at the image of the water drop below. Each water particle is attracted to the other water particles around it , this is cohesion. Now add a different surface and the water particles are attracted to that rather than each other, this is adhesion. When adhesion occurs we get the spreading of the water drop and wetting,  providing the adhesive forces are greater than the cohesive forces.

So what about your investigation? Is there any evidence of cohesion or adhesion?

Here is a thought. it has been suggested that water is ‘wet’ because you can feel it’s wetness.

Maybe another little experiment.

You could let me know by clicking on the ‘Reply’ box below.

Some questions on Gold from Chantelle (7), Shelby(9) and Mary(9)

Chantelle asked “Why is gold so hard to find?”

Shelby asked “Why is gold so heavy and hard to pick up ?”

Mary asked “Why is gold so expensive?”

Chantelle, Shelby and Mary some great questions , thank you. But are they science questions? Lets look at what a science question is.

science question is a question that may lead to an idea and help us in answering (or figuring out) the reason for some observation.

For example ‘Why is gold so heavy?” …so firstly let us look at what gold is. Gold is a solid –  Is it a rock? Is it wood? Is it plastic? Is it a metal? ……it seems to fit into the group called metals (it’s cold to the touch, it’s solid, it can be scratched, it’s shiny, it’s heavy) it’s a metal. So Shelby’s second question is a good science question.

Is it heavier than other metals?  It doesn’t seem to be heavier than other metals but how do I test this?  Fair tests are important in science investigations. Being fair I compared my gold with with metals of comparable size? It is heavier, why? Maybe the bits which make up the gold are heavier than the bits that make up other metals?

Chantelle. I think gold is quite easy to find compared to other metals. Lots of other metals, iron, silver, copper and aluminium exist as minerals  so they are quite difficult to find. What is a mineral? Look at the following page.

Science Master

 

Liam (7) asks “What causes an earthquake?”

Thanks team. When the Earth cooled down the crust was formed over the whole planet.

However, after the crust was formed there was still a lot of activity in the molten core of the Earth. This caused cracks in the crust and it is these cracks which are the cause of Earthquakes. Scientists have investigated the cracks and created a map of where they are.

You can see these in the maps below.

The lines indicate the cracks on either side of our Earth. The spaces within these cracks are called  ‘plates’. These plates are constantly moving (very, very very slowly).

Any idea what is making them move?

Some plates are moving away from the plates next to them BUT that means they are also pushing up to other plates on the surface. It is this movement that causes the earthquake.

Where do you think the earthquake happens …is it in the middle or outside of a plate? Where is your country?

I have created two jigsaws of the Earth images above. Print them, stick them on some cardboard, and cut them out and make your own world of ‘plates’ and try moving them.

Link to Jigsaw 2

Link to Jigsaw 1

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