Unknown (7) asked “What is carbon dioxide?”

Firstly….my apologies…I lost your name.I can remember the question but not the name.

 

I asked my team to try to answer this important question

We all produce Carbon Dioxide when we breathe …..it is however not as much as when the things burnt above produce. As you get older you will learn about how Carbon Dioxide affects the weather on our planet. You will also begin to see why all plants and trees are important in controlling the amount of carbon dioxide in our atmosphere.

Many thanks for asking your question.

Dhanashree (13) asks “Why is sound a longitudinal wave?”

Dhanashree, thank you for the question. I asked my team about the question and they arrived at the following answer….which I was not happy with …….

There are two types of ways in which waves manage to travel ……. Longitudinal and Transverse. I can see the way the waves they develop BUT need time to think about how to explain them. Longitudinal waves travel along straight lines away from the source …  I am trying to understand how the particles associated with the travelling disturbance (sound) travel in each of these ways.

How do the particles of air (in longitudinal movement) make further particles of air move in the same way…if they are doing forward and back vibrations? The vibrating air particles (or particles of any gas) must be moving forwards as well as moving back and …thus moving the wave forward.

So …to answer your question …..sound is created by things vibrating, the drum skin vibrates, up and down when it is hit…….the air above the drum skin follows this vibration, and the air next to the vibrating air , starts to vibrate and so on. This is your longitudinal vibration.

With Transverse vibrations the particles move up and down. Like waves …which stay in the same place.  More thinking about this later.

Taj (13) asks ” “What makes some metals more reactive than others?”

Many thanks for that introduction to Taj’s question. the images for the three metals show the electrons in ‘shells’ around the core metal atom.  Taj, you may be interested to know that the electron was discovered in 1897 by Thomson and the arrangement of electrons in shells around the nucleus by Neils Bohr in the 1920’s ….only 100 years ago.

Look at the ‘shells’ …the first one near the nucleus of all the metal atoms contains 2 electrons, the second shell  contains 8 electrons, the third shell contains 18 electrons , the fourth shell contains 32 electrons (which are subdivided into three levels).

It is the outermost shell that is the important one when it comes to chemical activity. If the shell is full (has its load of electrons) the atom is unreactive (noble gases). If the shell is not full …the atom is reactive and the reactivity seems to be linked to how empty the outermost shell is and how close the shell is to the atomic nucleus.

Think about these rules when you look again at the sodium, copper and gold atoms.

Thanks for the question.

 

Oliver (10) asks “Is it possible for any life form on Earth to survive the conditions of outer space?

Oliver, many thanks for the question.

I think it would be very difficult to survive the conditions of outer space. Think about it, no air, very cold temperatures, no water …………but. Think about it ….if anything was to survive in outer space ….. What size would it be, small  or large?  Would it have a thick or thin skin? Would it need lots of oxygen or very little to survive? Would it need lots of food or very little?

….meet the Tardigradum

It is less than 7mm long and has 8 legs

It can survive the pressure of living in deep water trenches and temperatures of over 150 degrees centigrade.

It has been known to survive without water for 30 years.

It has also been shown that it can survive, without protection in outer space.

Amasidda (?) asked “Give one reason to prove that light is form of energy”

 

Then Amasidda you might be able to answer the question yourself.  Think about what all forms of energy – electric (electricity), light, heat (thermal), movement (kinetic), nuclear, chemical, sound, gravitational, can do. Can they all in some way do work? Can they all be converted from one from one form of energy to another?

What do you think ‘work’ is? Let me know in the comment box below.

How we can take care of the world? asks Luisa (9)

Luisa, an important question. Thank you for asking it. There are obviously some very important things that every human in our world should think about. Let me present you with three of my thoughts. I will let my team present them…….

During the 5 billion years that life has survived on our world a lot of different animals, insects or plants have come to dominate life on our world and not survived.  One of the early plants that became dominant was a type  of moss. It grew so much that it poisoned the atmosphere with all the oxygen that it produced. Dinosaurs were destroyed when our world (the Earth) was hit by an asteroid, it created so much dust that the plant life they eat stopped growing.

Life survives but in a different forms. We should be careful because we might be the next form of life to disappear. 

“How does speed affect the energy of motion during a collision?” asked Damián Muñoz (9)

Thank you for your question Damian. I asked my friends about it and they had the following thoughts.


Sorry Damian it doesn’t really answer the question you asked. They have just presented you with more questions.
Let’s look at what they said.

Firstly energy is about work. The Energy or Work associated with a moving car is its movement. This type of energy is called Kinetic Energy. We could change the car’s Kinetic Energy by making the slope steeper (move the slope up a rung). It will make it go faster.

How do we measure the energy it is gaining as it moves faster and faster down the slope? Yes it does go faster while it is on the slope (we say that it is accelerating). Remember it starts with no energy at all (not moving). When it reaches the bottom of the slope it is going at its fastest speed.

We could measure the energy by seeing how long it takes to stop moving when it reaches the bottom of the slope. Try it. Make sure the test is fair. Fairness is very important in science investigations.

Alternatively you could involve it in a collision at the bottom of the slope…..say some cardboard or paper and see how far the car can push the shape it collides with. That would be another way to measure the ‘work’ that the moving car could do.

Damian, think about it. Experiment, and let me know how you got on.

Science Master

“Is time travel possible ?” asks Lachie (9)

Thanks for the question Lachie . My friend is correct, Albert Einstein thought that time travel would be possible because of something he called relativity. It seems to be about the time it takes to move through a given distance (space) and the speed of light. The faster you go the slower the time that has past. That is a very, very difficult idea to understand. Even I find it difficult ….. but lets try and give you an example

Suppose you could move through space at or around or about 186,000 miles per second, which is the speed at which light travels?

Say you were 9 years old when you left Earth in a spacecraft traveling at about the speed of light (which is much faster than we can achieve now), and celebrated only five birthdays during your space voyage. When you get home at the age of 14, you would find that all your classmates were 59 years old, retired, and enjoying their grandchildren! Because time passed more slowly for you, you will have experienced only five years of life, while your classmates will have experienced a full 50 years.

So, if your journey began today in 2018, it would have taken you only 5 years to travel to the year 2068, whereas it would have taken all of your friends 50 years. In a sense, this means you have been time traveling.

According to Einstein’s ideas you can only move forward in time you cannot move backwards. However we do not at the present time have any vehicle that could reach the speed of light so if you want to travel in time you might have to wait a little while.
(revised 23rd May 2018)

What happens to your eyes when you die? asks Olivia (12)

You did suggest Olivia that the eyeball might explode when a person died.  This is very unlikely. Look at the eye image below and try to identify the muscles in the eye. they will be attached to the two things that are constantly changing in the eye.

There are muscles attached to the lens and the iris.

When you die, your muscles relax. This causes the iris muscle contracts when this happens the eye is said to dilate ….like the image below

This is probably what your eye would look like  when you are asleep. Thanks for the question.