“Why do metals always feel cold when I touch them?” asks Chen (8)

My question is, are the metals colder or warmer than the things around them? We need to test this question. So how?

We need find out if other materials behave in the same way.  We therefore need to test it with other materials, for example, wood, plastic, china and glass.

To make the test fair (an important part of my experiment) we need to make sure that all of the materials are at the same temperature at the start of the experiment. We can test this by taping a thermometer to the materials, leaving it there for a period of time (maybe 5 minutes) before touching each of them. Do they feel hot or cold? Do they feel like they are at the same temperature that you are.

What did you find out? If the metal, or other material did feel colder, or warmer, than the others then why?  Let me know what you think by filling in the Reply box below and post your comment or ask another Question . Anybody can do this.

Ethan (8) asked “How can you hear things?”

 

Ethan. There are some other small experiments I would like you to try.

Find a ticking clock and a box that you can put it in.  Listen to the ticking with the lid on and the lid off. could you hear the ticking when the lid was on?  Now with the lid on get a cardboard tube (maybe one from a tube of kitchen roll) , put one end of the tube on the box lid and the other end over your ear. Listen. Is the sound of the ticking louder when you use the tube? Move your ear away from the tube. What happens to the ticking?

Ethan, lots of questions from me to you.  Maybe the experiments have created some more questions. Any reader can ask a question or leave a Comment in the Leave a Reply box below

Also see Clara’s question on sound.

“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

Miwah (7) asked ” I hit a drum and it produced a banging sound. How did it do that?”

Miwah, what a great question. It really needs some thoughts from my team.

 

So Miwah what are your thoughts? What happens to the rice when the sound  occurs?

Is there anything around the rice? If there is will that behave in the same way?

Think, ask questions, see if there are links. That is what science is all about.

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

Frozen Eggs – a comment from Eizen

Eizen made the following fascinating comment.

‘Hello I did something with a snow and an egg. So 2 days ago I was really bored so I decided to go outside at my backyard and put a full non-cooked egg in a snow, I covered the egg with the snow.. Then 2 days later I went back and took the egg, then I took the shell off then it was like a boiled egg but it was raw when I put in the snow then I cut the egg and the yolk looks exactly like a boiled egg… So I’m curious how that happens?
Sincerely, Eizen’

What an interesting discovery, so of course I checked it out. Not having any snow where I live I did the next best thing and popped a fresh egg into the freezer. Left it there for 2 hrs and then took it out. The first thing that I noticed was that the shell was cracked. What do you think that indicated? I then removed the shell, and it did look like a white boiled egg and the yolk looked exactly the same as the yolk of a boiled egg – just as Eizen had observed.

So let’s look at the structure of an egg.

The Albumen is 90% water and 10% proteins and fats. It is however a homogenous mixture (Do you know what homogeneous means?). As the egg freezes the water/ice particles expand and push away the fat and protein particles so the Albumen begins to reflect the colour of the fat and protein colours instead of the transparent water particles … it turns white.

There is the potential for lots of further investigations here to test the thoughts suggested above. At what point in the freezing does the Albumen turn white? Why does the egg cracking occur?

Interesting addition (15/03/17)

I have just read about the ‘skin or membrane’ that covers the Albumen, it’s a form of Collagen, the stuff that keeps our joints together. A little experiment ….put an unboiled egg into a beaker of vinegar …..the vinegar will slowly dissolve the eggshell ….. you will then be able to investigate how strong the Collagen is.

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

Ujala asked questions about where Science came from.

Many thanks for the question Ujala. I hope my friends answers satisfy your curiosity. Interestingly although ‘Natural Philosophy’ and ‘Science’ were names that evolved 2500 years ago there is evidence that ancient civilizations practiced ‘science’ more than 4000 years ago in Africa where they used measurements to create maps of plots of land by the Nile – Geometry is a scientific tool.

Any reader can ask another 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)

“What is the difference between speed and velocity” asks Sayed(11)

Absolutely right my friends. The two cars have the same speed but they are going in the opposite direction so their velocities are different.

An interesting example of the difference between
speed and velocity is when you look at an object moving at a certain speed in a circle. The speed is constant BUT the velocity is constantly changing as the object moves around the circle, see V1 and V2. The velocity at 1 is drawn as a line (representing the speed) pointing in the direction V1. This is a ‘vector’.

Sayed – this site is mainly directed at 8-13 yr olds so the answer above is very ‘general’. I have published it because younger readers might be interested in the difference between the two terms …for more information visit this site.

 

 

 

Elizabeth (9) asks “How does sand form in a desert?”

I agree we need to do an investigation.  The suggestion is that the desert sand might have come from the soil. Let’s see if we can find sand in the soil around us. Before we do this lets think about soil, the soil in your garden. What do you think it is made of? Maybe it is just made of soil? Maybe it is made of a mixture of things? Let’s investigate these questions.

Collect some soil. Get a plastic transparent beaker or a jar with a lid. Put a couple of small spoonfuls of your soil into the container. Add enough water so that it is half full. Cover and shake for about 20 seconds. Put it down and wait for about fifteen minutes. Now look at it and make notes on what you see. Repeat with another sample and another beaker or container (investigations always need to be checked).

Has your experiment resulted in layers of stuff in the beaker? Maybe a bit like the layers in the image below.

If it has then think about why you have layers? What has formed the first layer and why? Was it because it was the lightest or heaviest ‘stuff ‘ in the jar (soil)? Is the second layer made up of ‘stuff’ that is lighter or heavier?

The bottom layer is ‘sand’ …..the heaviest ‘stuff’ that makes up soil. The other layers are ‘silt’ and ‘clay’. Look at the diagram that my friends have given you the sand particles are the biggest.

Now to deserts. In very arid (dry) conditions the soil dries out. The wind basically blows away the smallest particles of clay and silt leaving the largest so a desert of sand is formed.

Elizabeth … thank you for your question.