“How, where or when we’re magnets found or made?” asks Sam (11)

Thanks for the question Sam. Magnets and magnetism was first discovered about  9000 years ago. A long time ago. It was found in rocks and called ‘lodestone’. Lodestone is a naturally occurring compound of iron. It is thought that it was magnetised by lightning strikes.

We will make our own magnets by using a slightly weaker form of electricity.  Here are my team.

Firstly let us try to make a magnet (without using lightning)

You will need a battery and a length of wire and some paperclips. The a collection of nails. Try and find as many different nails as you can. Wrap the wire around the nail and sellotape the bare wire ends to the terminals of the battery. See the diagram below. See how many paperclips you can pick up? Are some nails better than others?

DO NOT USE MAINS ELECTRICITY. IT IS VERY DANGEROUS. 

You might have found out that only certain metals can be made into magnets. These metals are called ferromagnetic metals.

Included in this group are the metal iron and the alloys of iron with the metals cobalt, nickel.

It is thought that in these metals (including iron) have some electrons called ‘free electrons’ (not sure what an electron is, then go to Science Master Special – Atoms and Atomic Structure). It is these ‘free electrons’ that are involved in magnetism. In the alloys the  ‘free’ electrons align themselves with the magnetism of the external magnet, making a (for the alloys) a permanent magnet.

Look at the short video I have made below. In the ferromagnetic metal (iron alloy) crystal domains you will see free electrons. In the metal these will be moving freely. As they begin to interact with the external magnetic field, they begin to align themselves, making a permanent magnet.

Liam (10) asks “Why does warm air go up?”

 

Thanks team. You are quite right we have to start at the beginning to really understand why warm air goes up. Let’s start by looking at what is air?

Air is a mixture of small gas particles (called molecules) of nitrogen, oxygen, carbon dioxide and some other gases. The image below could be a picture of what it would look like, if you could see it. What do you notice about it?

The red molecules are the oxygen, the blue the nitrogen and the others water and carbon dioxide. Imagine them moving around (I am trying to make an animation). Because they are moving they have energy.

If we heat the air, we are giving the molecules in it more energy. This makes them move faster and they move further apart.

The ‘thicker’ cold air surrounding the warm air drops into the space under the warm air and doing so pushes up the warm air which rises.

You can see this happening in a beaker of heated water.

Ronan (10) asks “How do stars form?”

Ronan ..this is my thinking about your excellent question.

Yes it is all about Gravity – There was a previous question by Tegan on Gravity. Have a look at it.

It is thought (it is therefore a hypothesis – an unproven idea)  that dust and hydrogen gas from the ‘Big Bang’ was gravitationally attracted to each other.

As the mass of the dust and gas got bigger it’s gravitational pull got bigger and the more dust and gas it attracted.

Eventually  the compact squashed ball of dust and gas started to heat up. It got hotter as it got bigger and eventually the particles of dust and gas began to break up in this hot environment and the hydrogen particles began to come together to make new particles … an atomic FUSION reaction began to occur and the star was born.

Liam Astra asks “Why does Mentos lollies make coke spurt everywhere?”

Liam, thanks for the question. Are you sure that you wanted to talk about Mentos lollies? I couldn’t find any mention of them …..only sweets …so I have focussed on them. 

Let me start my answer by showing you my favourite clip of the Mentos/Diet Coke reaction.

My first question is ….is there anything special about diet coke and the Mint Mentos tablet?

Firstly there is evidence (somebody has done some experiments) that diet coke contains more carbon dioxide gas than ordinary coke. When they make coke they add carbon dioxide gas to it. Lots of gases are absorbed by liquids. Oxygen gas is absorbed by water…..this allows fish to breathe. The manufacturers add carbon dioxide to the coke because it enhances (makes better) the taste of the coke. Carbon dioxide, like oxygen is a safe gas  – it is the gas that you and I breathe out – it is created by our bodies.

Experiment 1.  Add a Mentos to a bottle of Coke and one to a bottle of Diet Coke….is the reaction the same? Make sure that it is a fair experiment (talk with others about how you can make it fair). Make sure that it is a safe (if you have them wear goggles) and a tidy experiment. (think about your parents or teachers)

Experiment 2. Now let’s look at the Mentos tablet. Is the tablet smooth or rough to the touch? Try and find something (maybe an adult can find you a little bit of sandpaper) that will change the surface of one of the Mentos tablets (more rough or more smooth) and drop it into a diet coke bottle. What happens? Do the rough and smooth tablets both give exactly the same ‘spurt’?

You could also carry out this experiment with Fruit and Mint Mentos tablets?

Here are some magnified photographs of the surface of a Mentos tablet.

 

So what have we found out? What has roughness to do with surface area? Why does the dissolved gas decide to come out of solution when it meets the tablet?

Let me know your thoughts in the box below.

Yet more questions on Space and the Solar System from William, Kylan, German, Rob, Aidan, Gavin, Lucas, Jake, Thomas and Kylie.

Hello, yet more interesting questions. Many thanks. It is brilliant that you continue to ask questions. By doing so you maybe think that you are showing your ignorance, and you are. However it is important that you do show your ignorance because that is the way that knowledge and science develop. Scientists are constantly saying “I do not know how that happens” then “I will try to find out why it happens”. My answers to your excellent questions below might therefore not be direct answers but may be directed to helping you to find the answer yourself. You can be the scientist. Here we go …..

William asked “How many stars are there in space not including the Sun and what is the hottest planet in the solar system?”

William, the difficulty I have with this question is what do you mean by Space? Space is endless so for an investigation it is better to start with a smaller known area …such as our Galaxy, the Milky Way. Even then the answer is only an estimate ….about 1000,000,000 (a billion stars) and apparently it has been estimated that there are over 1000,000,000 Galaxies in Space.

Maybe the second part of your question has an easier route to an answer. Initially one might have thought that Mercury would have been hottest – it is the closest planet to the Sun! But I am wrong, Venus is the hottest, because of its atmosphere. Why do you think this is?

Kylan asked “Is Space endless?”

Kylan, the answer to this is YES. To us humans this must be a difficult thing to grasp. We are constantly living within confined areas. To think of something as endless is difficult to comprehend.
Kylan, a great but disturbing question.

German asked “Como se origino el universo?”

German, another difficult question. You are obviously in a group who specialise in asking difficult questions. That is brilliant, because that is what science is about, asking difficult questions. There is evidence that the Universe began some 14.8 billion years ago, the Big Bang. This evidence apparently comes from a something called CMB (Cosmic Microwave Background). I think I will leave it there. I have no doubt that the Big Bang idea will at sometime in the future be challenged. Another thing about science is that scientists are always trying to falsify other scientist’s theories (prove them wrong).

Rob asked “Why no one can go to the Mars?”

We will get there Rob. When I was at the Kennedy Space Centre there was a lot of talk about the proposed trip to Mars. They are even now investigating how astronauts can live in a small self contained environment for a number of years. We have got to the Moon, which is 384,000 km away, for Mars we will have to a travel a minimum distance of 54,600,000 km. Why do I say ‘minimum’ distance for the Mars trip and not the same for the Moon trip?

I think it may happen in your lifetime.

Aidan asks “Why doesn’t NASA use a Saturn V rocket to go to Mars?”

They have a Saturn V rocket at the Kennedy Space Centre. It is massive. However they will need a more powerful (notice I don’t say bigger) rocket to launch a Mars probe which includes astronauts. The living module will have to be a good deal bigger than that used to get to the Moon and back.What do you think will be necessary for the astronauts survival?

An image of the engines of the Saturn 5 rocket  at the Kennedy Space Centre

 

Gavin asked “How does the Solar System work?”

Gavin, great question. I have already answered a similar question in a previous post. This was my answer to Rishi:

I immediately think of why does it work in the way it does? The centre of the Solar System is the Sun. The Sun is one of a group of stellar objects called stars. Our star was named, by somebody, in the past, as the Sun. Our star (the Sun) seemed to have attracted to it some massive lumps of matter/material which we call planets (planets are the biggest ‘lumps’ , the smaller ‘lumps’ are called asteroids and meteorites.

What has given the Sun the ability to attract these ‘lumps’?

You then have the amazing thing that these lumps move around the Sun. They are attracted to the Sun but do not fall into it. They rotate around it, why do they do that? . Or does the Sun rotate around them?

Lucas asks “How big is our solar system and do humans know if there are other solar systems?”

Lucas, NASA has a project called Keppler that is looking at other planetary systems. Below is an image of the space telescope that is doing this work. Note that our planetary system is the only one called the Solar System. All others are called planetary systems. The Kepler telescope has identified a number of other planetary systems and some of them are very strange. One system has two stars. Quite a few have Earth like planets. I wonder what it would be like living on a planet with two stars?

Jake asks “Will Mercury crash into the Sun in a million years?”

Jake, it is unlikely that Mercury will crash into the Sun. It is thought that as the Sun gets older, it is now about 4 million years old, it will begin to expand  and eventually destroy Mercury and Venus and the Earth. It is reckoned that this is likely to occur in 4.5 million years time.

Thomas asks “How does the Sun create radiation?”

Thomas, how many types of radiation do you know about? There is visible light radiation,  ultraviolet light radiation, and infrared radiation.  However, there is another type of radiation which produces all of these types of radiation.

The Sun’s radiation is created by a nuclear fusion reaction in its core. This nuclear reaction produces very high energy gamma radiation which, as it passes from the inside of the Sun to the outside, is converted to the other types of radiation listed above.

Kylie asks “Why does Saturn have rings?”

Great question Kylie. Saturn is one of the largest planets in our Solar System. It therefore has a great gravitational attractive force. It has 60 Moons! It is thought that the rings have been created by this gravitational force attracting lots of the bits and pieces that each year enter our Solar System. Bits and pieces like asteroids and meteorites. Gravity is an important feature of our Solar System. Have you any questions about Gravity? I would like to hear them.

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.

“How does a magnet become a magnet?” asks Ava (11)

A brilliant question Ava. I asked my team for their thoughts.

Yes team you are quite right there are some limitations to magnet making. The main one is that only certain metals can be made into magnets. These metals are called ferromagnetic metals.

Included in this group are the metal iron and the alloys of iron with the metals cobalt, nickel and some other rare earth elements .

It is thought that in these metals (including iron) have some electrons called ‘free electrons’ (not sure what an electron is, then go to Science Master Special – Atoms and Atomic Structure). It is these ‘free electrons’ that are involved in magnetism. In the alloys the  ‘free’ electrons align themselves with the magnetism of the external magnet, making a (for the alloys) a permanent magnet. For iron alone the magnetism is only temporary and you can test this in the experiment below.

 

Look at the short video I have made below. In the ferromagnetic metal (iron alloy) crystal domains you will see free electrons. In the metal these will be moving freely. As they begin to interact with the external magnetic field, they begin to align themselves, making a permanent magnet.

 

 

 

 

 

 

 

 

 

 

 

Tegan (10) asks “How does gravity work?”

Tegan, a very interesting question. This question was asked some time ago and this is what my team said.

In the 17th Century Newton and another scientist called Hooke did some great observations and experiments on falling objects and proposed that gravity was an attraction between any two masses AND the attraction was dependant on the size of the masses involved.

For example you are attracted by the Earth and the Earth is attracted by you BUT your attraction is so much smaller than that of the Earth it does not affect the motion of the Earth. The attraction between you and the Earth is also dependant upon how far away you are from the Earth. The Moon is attracted by the Earth and the Earth is attracted by the Moon. They are both big bodies so gravity does affect the way they move with respect to each other and this dictates how the Moon orbits the Earth.

Some scientists including Einstein have put forward ideas on how gravity operates but even these are being challenged. There a lots of things which are still unanswered. The questions just have to be asked. Thank you for asking it.

revised 15/01/08 …experiment added.

Hello (13) asks “How do tectonic plates work and influence earthquakes?”

Quite right my friend it’s all about convection. Warm water, air, oil, or any liquid/gas stuff  will move upwards (rise) when it is heated. Why. Think about it.

Lets think of an experiment (this is a science blog) where we can test this idea and then move on to the question that Hello asked.

The experiment

You will need a beaker of water, some pencil lead, 3  A batteries, two leads with attached crocodile clips and some food colouring and a dropper

Connect the pencil lead to the batteries using the leads. As the electricity passes through the pencil lead, the pencil lead will heat up. Drop the attached lead into the water. Look carefully at the water, what is happening. If you put a small screen behind the beaker of water and shine a torch on the water you will be able to get a better view of what is happening to the water.

OR

Drop a small amount of food colouring into the water.

Hopefully what you will see are convection currents that have been created by the water close to the lead  warming up and beginning to rise. The next question is WHY.

Warning. Do not use mains electricity. It could be very dangerous and kill you.

Why does the water rise?

When the water particles(molecules) come into close contact with the heated pencil lead they gain kinetic energy (see Science Master Special Energy), they move faster. The water molecules spread out so that in any given space there are less water molecules (less dense). This means that gravity comes into action and the colder water can begin to move into the space where the warm water was. The warmer water ‘floats’ on top of the cold water. The cold water then gets warm and and more cold water moves in and the original warm water floats up higher in the beaker. As the warm water rises it gets colder and more dense and eventually will join the column of cold water that is moving (by gravity) downwards toward the hot pencil lead. Wow…..I hope you can see the picture

The movement of the tectonic plates is caused by convection currents and it is this movement that can cause earthquakes. Hopefully when you watch the excellent video below you will see the links.

Hello. If you would like to question anything, please 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)

Science Master Special A Push-Pull Meter

Many years ago I and my class made a Push-Pull Meters with dowel rod and a cotton reels and had great fun with them, measuring all sorts of pushes and pulls.OK we could have used conventional force meters, the school had enough of them for class use, however making one yourself and then using it seems to make a big difference in understanding.

A recent question made me look for my plans – no chance. Search the internet – no luck. My team were of no help so I therefore decided to do the obvious thing, make one myself.

These are the drawings of my endeavours. The equipment list is cotton reel (wooden would be nice but if it’s plastic ok), a length of dowel rod with a diameter which will allow it to pass through the central hole of the cotton reel, an elastic band (probably 4 cm long but have a set of them for experimentation), a paperclip which is opened up to make a hook, some drawing pins or sellotape …….and I think thats it.

Once constructed the next task it to calibrate it. If you have access to a set of weights, great. you can create a little bag which will hold them, hang it on the hook and away you go. A 1kg mass will apply a 1 Newton force on the elastic band. This is where the choice of the elastic band is important – a thin band is obviously much more sensitive than a thick band. On the other hand, why not make up your own scale of push a pulls – a five marble/ 3 marble/1 marble push or pull. Below are the images that I created for my answer to the 10 yr olds question.