“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.

(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)

“What was the first plant that ever grew on Earth?” asks Mahdiyat (8)

So what now? Thanks team, some good answers.

It would be great if we could do some small investigations using Moss.

1.Firstly let us confirm that the moss has no stems or flowers.

2. Secondly a more long term experiment. Try ‘planting’ your moss on a rock. Before planting look closely at the surface of the rock. compare the surface 6 months after planting (and not disturbing the Moss).

Now a story ……..

The moss was the Earth’s first plant and it took over the world. It damaged the rocks it settled on and it took all of the Carbon Dioxide out of the atmosphere. This made the Earth very very cold (the first ice age). The coldness killed most of the moss and as the Carbon Dioxide built up again it allowed other plants to share the Earth with it.

 

“Why does my banana skin go brown when I peel it off? asked Gina (10)

Gina, it seems to be something about the ‘breaking’ of the skin of the fruit, which lets  in oxygen and allows it to react with some of the fruits chemicals.

We could test that idea. One way to test it might be to try and stop the ‘breaking’ of the skin of the banana. Can you think of a way of removing the skin without breaking or damaging it?

We could also test the role of oxygen. Any ideas how? If you have an idea why not try it  by comparing the speed of ‘browning’ for your oxygen and ‘no oxygen’ banana skin?

Remember to try and make the tests as fair as possible. Think about what that may mean. Remember a fair test means only changing one thing at a time while you try and keep all other things constant.

Let me know how you got on by Leaving a Reply in the box below.

Preethikha (13) asked a question about planting corn seeds in clay.

Preethikha you asked your question on behalf of your friend  Johan who appeared to be having trouble in growing his corn seeds in clay. I asked my friends about this and these were the ideas that they arrived at. 

The roots of the corn plant are very complex like most plants and they NEED oxygen . Clay is an important soil, it is full of nutrients which are important in providing the growing plant with food , HOWEVER  it is very different from most of the soils that we meet in our gardens.

Soils are composed of three types of particles: sand, silt, and clay.

The size of the particles varies, with clay having the smallest size and sand the largest.Smaller sized particles pack more closely together and slow the flow of water through the soil.The composition of a soil can affect the permeability (flow) of water through it.

There is the possibility that your friends corn seeds produce roots which are then ‘drowned’ in the surrounding clay soil. Investigate your friends soil and compare it to other soils in your neighbourhood. My next question for you is how would you go about investigating it ?

 

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)

A question “How does the world work”

Some time ago a well known scientist (James Lovelock) suggested that the Earth (our planet) was special. He claimed that the Earth itself was a living thing and had control over its environment. He gave the Earth the name Gaia (a Greek name for the goddess of the Earth) and suggested that the planet’s objective was to support life on it, at all cost.

It has been argued, by those who support this idea, that there is a lot of evidence from investigating the Earth’s history over the last 3 billion years, that suggest the idea is valid. Below are some of those arguments. What do you think?


Note
The Gaia idea is something called an hypothesis (an idea). It has yet to be proven. If proven it can then be called a theory.

 

Ruby (8) asked “What type of chemical is in capsicum that hurts when police put it in eyes?”

Yes, a great question Ruby. There is this temptation to relate Capsaicin to Black Pepper, however this is not true. The black pepper seeds are from a plant in the vine family of plants. The Capsicum family is the home of the chillies and the chemical Capsaicin which is a chemical in the alkaloid family. Capsaicin is not only used in pepper sprays it also has some curative properties, for example it is an effective pain killer.

I think it is very interesting that certain chemicals, particularly those derived from plants can be used for destructive purposes and for curing purposes. Just a thought.

Niamh (10) asks “How do scientists know what the weather is going to be like in the future?

Niamh, that is a question that I have asked several times over the last 20 years ….. and the answers have changed. I asked my team about their thoughts.

Niamh, the weather forecasts were initially based upon previously recorded weather patterns. Records of the what happen to the weather go back to the 19th century  and the weather experts of today look for patterns in past weather to predict what is going to happen in the future.

All the past patterns have now been computerised so part of the role of the forecasters is to get the computers to analyse the patterns and then make suggested predictions.

Nowadays the weather experts ( they are called meteorologists) also have satellite images  to help them predict the weather. They also use other sensors like weather balloons which record air pressure and temperature at different levels in their location.

Niamh, for the distant future it is very difficult to predict what the weather will be like. The weather is one of those magnificently independent variables that we still cannot control.

Niamh if you or any other reader would like to make a comment please go to the Leave a Reply box below. Or ask another question.

“Am I living?” asked Cloe (7).

Many thanks team. You are right there was a question about clouds  and if they were living. Think about what living means for you and for other things that might be living.

Do you think that plants, rocks, clouds, germs, the air, birds, trees and you are living?  You might not think that a tomato is living BUT does it contain seeds? Think about seeds and what happens to these non-moving, non-growing things. Are they living? So put them in some water and give them some soil, what happens?

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

Why do we have droughts? asks Lisa (10)

It is a difficult question to answer. There are a lot of possible things that could cause a drought, however one of the most interesting is the effect of atmospheric pressure.

If you listen to weather forecasts you would have heard of a low and high pressure areas. You might have also noticed a pattern. When the weather forecast talks about low pressure it is normally accompanied by rain while high pressure is accompanied by sunny periods and dryness. Dryness over a long period of time could mean the loss of a lot of ground water and therefore create a drought. You get long periods of high pressure over deserts,

So why does this happen?

When you have high pressure dry air descends from the colder air higher in the atmosphere (cold air is more dense and heavier than warm air. In low pressure the movement of the air is in the opposite direction with the warmer, ground level air rising carrying with it water vapour which eventually forms clouds as it gets colder.

Lisa, there are some difficult ideas here. Think about them and then ask another question.That’s the way science works.


Revised (03/02/17)