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)

“What does “eco” in ecosystem mean?” asks Austin (8)

I will just add a few words myself. Thanks for your input.

I like the idea of an ant’s nest being an example of an ecosystem. The nest is ‘everything’ it’s a home, a place to live and to work from, a creche for baby ants, a food store, a food production place, a protective environment, maybe an ant hospital, and lot’s more. It is an ecosystem.

The word ‘eco’ also combines with ‘logy to form ‘ecology’. This is like the word ‘bio’ combining with ‘logy’ to form ‘biology’.  The word ‘logy’ is a word which originally described lots of learning.

I will stop now. For an eight year old I think everything gets very complicated. I very much like the ant’s nest described as an ecosystem.Maybe you could let me know of other ecosystems?

STOP

Hayley (11) asks “Were unicorns ever real????”

Thanks for the question Hayley. My friends are back from their holiday so I asked them ….this is their answer.

The fact that there are no fossils does not mean that unicorns never existed. If you look at how modern humans evolved (changed) from apes there are a lot of gaps in our understanding, which could be linked to fossils that have not yet been found.

Where fossils have been found we can get lots and lots of information from them especially from the age of the rock in which they are found. This is to do with something called radioactive decay. This allows the fossils to be placed fairly accurately on the ‘evolution table’.

Evolution is the change in the inherited characteristics of  populations of living things over successive generations. Evolutionary processes give rise to diversity at every level of the population. For example a pair of monkeys might give birth to an albino (white) baby. If that baby, when it is older, gives birth to an albino baby, we could call that an evolutionary change which might, in a few thousand years create a whole population of albino monkeys.

I have two immediate thoughts about unicorns. Firstly they are completely made up and secondly they are a brief part of an evolutionary  story that didn’t survive. For example an animal (horse, deer, goat or other animal) was born with one horn by some biological accident, it lived but it’s children were ‘normal’ so the trait ended.

I prefer the mythical, made up model. I would like your thoughts.

 

Will (8) asks “What makes seeds grow?”

 

Will, thank you for your question. Let’s start with some interesting questions. Answers to these might help in answering your question. Firstly is a fruit a seed?  If it is not a seed then what is it for? Does it help the seed grow? How will we know if the seed is growing? What does a seed need to grow? Does it need soil? Do seeds grow when it is cold? Do different seeds grow at different speeds? What do you think? Are there any more questions? Remember questions are what science is all about. By investigating questions you are building knowledge of the world around you.

So, let’s think about how we could investigate some of these questions. Shall we look at just one type of seed, or choose a variety of different seeds to investigate? Maybe looking at one type of seed would help us begin to answer some of the questions. We could then look at another type of seed and compare the results. Maybe one seed would grow faster than the other?

Now we have to think about the conditions for our growing experiment ….. soil/no soil, wet/dry, light/no light, hot/cold. Even for our selected seed this can be very complicated. Can you see why?

The investigation equipment could probably be obtained at home. A empty plastic bottle, with the top cut off, would be a good holder for the seed. Some cotton wool could act as soil. A cupboard and a refrigerator could also help you create the right environment.

Let me know how it went?

Some more questions about the Solar System and Space by Seb, Luke, Luca, Sammy and Bowen

Many thanks for your questions. I told the last group that, 3 days ago I visited the Kennedy Space Centre in Orlando. It was brilliant. I was particularly interested in their idea to visit Mars in the near future. However let us look at the other superb questions and see how many other questions they create….that is what science is about.

Seb asked  “What does Mercury orbit?”

Seb, many thanks for the question. Not long ago, in our history, everybody thought that the Sun orbited the Earth. Why shouldn’t they? You see the Sun rise everyday and move across the sky and then disappears on the opposite horizon. It moves, we don’t.

Or could it be the other way – the Earth moves and the Sun stays in the same place? This was a question that a early scientist Copernicus (1473-1543) thought about and and then Galileo Galilei (1564-1642) confirmed ..it was the Earth that orbited the Sun. With this knowledge other scientists (we call them astronomers) worked out what Mercury orbited. What do you think?

Luke asked  “Do Saturn,Neptune or Venus orbit any planets other than the sun/orbit each other?”

A question I think that is linked to Seb’s. What evidence would you think would show that a planet orbited another planet? Think about the Moon, what does that orbit? Does it orbit the Sun? Supposing it did, what would you observe?  It was Galilei who built a telescope that would enable observations of the planets and therefore provide evidence which would answer the question. Like all science once the hypothesis has been made it can only become an accepted fact after relevant observation and production of evidence.

Luca asked “What is the furthest distance of a spaceship travel?” and “What is space made of?”

Luca, two great questions. For the first question I must admit I have no idea. From my visit to the Space Centre I know that NASA is planning to go to Mars. I see no reason why humankind will not be able, in the future, to leave the Solar System. We can already send satellites and other objects beyond the Solar System.

To your second question, the easy answer is ‘nothing’, other than stars, planets, asteroids, satellites and other bits an pieces. It does however contain what would be called ‘radiation’ of different types, otherwise we would not be able to see stars, the Moon or the Sun. Do you think it could contain anything else?

Interestingly, in Earth orbit, you would not be able to see any stars in space? Any ideas why?

Sammy asked “Can a black hole swallow Earth? If so when could this happen?”

Sammy, what do you think a black hole is? Why do you think it is called a black hole? I think it is something to do with that magical force called gravity. Think about gravity.  What does the gravitational force that an object has, depend upon?  Think about the force that pulls you to the ground. Think about the force that keeps the Earth in orbit around the Sun. Think about the force that holds the Moon in orbit. A black hole is a hole which light has been pulled into it, by a gravitational force. Think about a gravitational force that can pull light into it …….will it be able to swallow the Earth?

Sammy …something I didn’t know. It is thought that all galaxies have a black hole. Even our Milky Way galaxy has its own black hole.

A NASA photograph of a black hole. There is one…its a dot in the middle of the bright circle in the middle of the picture.

Bowen asked “Why do humans still think that there are resources on the moon? I think there are none.

A interesting question Bowen which I would like to challenge. Why do you think there are none? My thinking is that the Moon seems to be made of rocks and rocks are sources of all sorts of things. A lot of rocks contain silicon, what do we use silicon for? A lot of rocks (moon rocks included) contain aluminum which is used in a variety of ways, the rocks also contain hidden oxygen, a lot of rocks exist in the form of oxides (iron oxide is an example). Probably the biggest resource that the Moon has  is a low gravity. Any ideas why that is so important? Let me know.

“I have a question about Hermann’s tortoises” says Christopher (10)

Many thanks team. The Western Hermann’s tortoise has evolved in the warmer parts of Europe while the Eastern Hermann’s tortoise has evolved in the colder parts of Europe where the ice age lasted longer. The Eastern tortoise is bigger than the Western one and it has been determined that it probably evolved faster than the Western tortoise. They can be distinguished by their carapace and plastron patterns. The images below are from Chris Leone
The Plastron

The Carapace

Maybe, Christopher you could tell me how long tortoises live? All you need to do is tell me in the Reply box below.?

Many thanks to
Chris Leone for his images
Changes to title, images  and added information on tortoises (21/11/17)

Laura G (10) asked “Is it possible to collect condensation to water a garden?”

Laura, have you ever on a warm day noticed faint water droppings on leaves of some of your plants. Where has this water come from? It might have come from the leaf itself or alternatively it might have come from the atmosphere. The atmosphere/air around us can hold an immense amount of water in its vapour form. For example a parcel of 1 cubic meter of air at 30 degrees centigrade could contain 28g ( or 28 cc) of water. There is therefore a good chance that those drips on the leaf came from the atmosphere.

The fog fence provides a surface that is colder* than the air around it and therefore a place where water vapour can condense and the water collected. The water can then be used for irrigation of plant life AND the plant life itself generates it’s own water vapour so it is possible to use a fog fence , in a desert like area to collect water, feed it to plants and begin the process of creating a self sustaining green environment.

I am happy for suggested revisions to the above arguments.

*Sorry Laura,I have given you a completely wrong bit of information. It is very unlikely that the fence would be at a different temperature from the air around us. So how does it aid condensation?  It’s made of metal. What do you feel when you touch a metal object that has been lying around on your table?.

See a previous question that may give you a clue.

It feels cold. Why? It should be at the same temperature as the rest of the objects on the table. It feels cold because metal is a good conductor of heat and as your fingers are quite warm it conducts the heat away from them and they feel cold. Maybe the metal in the fence is conducting heat away from the water vapour and because it loses heat it changes from the vapour form to the liquid form …..condensation.

Para added 15/10/17

link added  15/01/18

“If all living things were in one food chain, what would be at the top?” asks Chelsea and Ashli (10)

Thanks team. I found a nice little revision site on food chains that you might like to try, find it at Food Chain Game.

Now to your question. Firstly it might be a little difficult putting all living things into one food chain. Secondly do you think it would be humans?  Ecologists (They are scientists who specialise in studying the living environment) rank species by their diets using a metric*  called the trophic level scale. Plants, which produce their own food, are given a rank of 1. Herbivores, which eat only plants, are ranked 2. The fiercest of meat-loving predators, such as killer whales, are rated at 5.5. Humans are rated at 2.5 which is the same level as a pig.

If you want to make a comment please use the box below or you could ask another question.

* metric as a noun means a standard scale of measurement so you could call a temperature scale a metric or any other standard scale of measurement a metric.

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

(updated 13/9/17 -changed metric to measurement)
(updated 15/9/17 – ‘measurement’ back to ‘metric’ after realising it was the correct word in the context in which it was presented, added addendum explaining it’s use as a noun)

“Why do volcanoes erupt?” asks Silas and Zakk (10)

 

Thank you Silas and Zakk for your question. My team are correct it’s all about pressure. All volcanoes have a thin ‘lid’ of solid rock which which is solidified magma. Underneath the lid is lots of molten magma which is heated by the Earth’s central core.

Things can happen to this magma. Some of it could cool, and solidify. You could also get convection currents like you do in any hot liquid. These can increase the pressure (push) on the volcano lid, break it and the pressure is released like the liquid in a bottle of fizzy drink.

Want to make a comment, please make it in the box below. Not sure about something …ask another question.
(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

(revised 13/9/17  Magna misspelling and added support text)

Donna (7) asks “Where do clouds come from?”

Donna, many thanks for the question. Before trying to answer it I thought I would ask my team a question.

Donna, what do you think about the puddles question? Think about how you would answer it and then go to my answer to a previous question.

Now to your question. Firstly I have created a little animation to show how the puddle disappear. You have to imagine that the shapes are water particles (molecules is the proper word). In the puddle they are all moving around. Most of them like being with the other particles BUT some are just moving around a little bit too fast and manage to escape from the puddle. When the Sun begins to warm the puddle it makes more water particles move around faster and more escape. This goes on until the puddle disappears.

 

The water particles are very small and are are lifted by the air up into the sky. High above the ground the air is quite cold so the water particles ‘slow down’. When they are moving ever so slowly if they meet another water particle they join up with each other and form droplets of water. This is how a cloud begins to form.

At home look at the steam from a kettle, BE VERY CAREFUL AND CONSULT AN ADULT.  At the exit of the kettle spout you can see nothing, BUT just above this the hot water particles begin to cool down and slow down and reform clouds of water.

(revised 21/4/17)