Sunday, 23 December 2012

Why can't humans breathe underwater?

When we go swimming, we hold our breath under the water. It is just a habit that we all do but why can't we breathe? Water has oxygen in it as it is H2O so surely it could go round our bodies like air. Also, water is just another state of air and the molecules are a bit further apart. But apparently this makes a big difference on what we can and can't breathe.

Water is made of hydrogen and oxygen gas. The reason that we can't breathe water is is because the oxygen is bonded together with 2 atoms of hydrogen and the oxygen is then useless to our lungs in this form. Also, humans can't breathe underwater because our lungs don't have enough surface area to absorb enough oxygen from water as there is not that much in it. The lining of our lungs, also is adapted to handle air rather than water. However, scientists have done experiments where they make humans breathe other liquids like fluorocarbons. Fluorocarbons can dissolve enough oxygen so that we can breathe.

That's all for today and see you next week! I hope you enjoyed this post and please comment! Also, if you have any questions that you would like me to answer, go to the top of the main page and click on the tab that says 'questions that you want me to answer'. You can comment on this page and I may answer your question in my next post! Thank you!

Friday, 14 December 2012

Are chickens really related to dinosaurs?

I've heard that chickens are related to dinosaurs but I don't really understand how that is possible! They look COMPLETELY different! First of all, chickens have feathers and have beaks and also, chickens are much smaller! I have done some research on why scientists believe that they are related and here is what I've found:

Scientists believe that birds evolve from dinosaurs because of the architecture of the bones. Also, extracts of  T. rex's bones reacted with antibodies to chicken collagen which is a further suggesting the presence of birdlike protein in dinosaur bones.

Scientists still don't know if this theory is correct as it is very difficult to discover.  Dinosaurs, as you all know, are extinct which means that scientists can't do any tests on them to see if they are correct.

 I think that it may be possible for this to be true but it must have happened over billions of years. As we evolved from monkeys, chickens could have evolved from dinosaurs. If you look at the picture above, you can see how dinosaurs began to look like chickens. Although it is a bit odd for it to shrink in size, you can see the resemblance between the pictures.

Please comment on this post and put any questions that you would like me to answer on the special page that I made! (Look at the top of the main page and click on the tab that says 'questions that you want me to answer')

Thank you and see you next week!

Wednesday, 5 December 2012

Why do clouds change colour?

Have you noticed that clouds change colour over time? They start off as white and fluffy and then turn to heavy, dull, grey clouds. Isn't it strange?! There are a few different ideas on this and here are some of them!


Some people say that the heavier the cloud is, the darker it gets. This may be because the sun can't get through the heaviest clouds so makes them darker. After evaporation occurs, water drops form around dust and when they get heavy enough, it rains! This happens everywhere around the world but a lot more often in some places *cough*England*cough*.

Other people say that clouds look grey when we are directly underneath them. This might be because the sunlight doesn't shine directly on the bottom of clouds, but through the top of the clouds. 

The sunlight has to travel a very long way to get to our eyes. As the light travels through a thick cloud, the light will get scattered and reflected off things so when the light eventually reaches us, it will look different.

If all the colours in the spectrum are there (red, orange, yellow, green, blue, indigo, violet) then the colour of the light is white. If none of the colours of the spectrum are there, the colour is black. This may also be why clouds look different colours. It just depends what colours can get through the clouds!