Ella (10) asks “Was there ever any life form on Venus?”

Many thanks for the question Ella. At the present time there is no evidence that there has been any form of life on the planet Venus. Venus is quite close to the Sun, it is the second planet. Because of it’s closeness to the Sun it is a very hot planet.

It would be brilliant if we did find evidence of life on the other planets of our solar system. It would be evidence that at one time life on Earth was not alone in our Universe. If that was the case we could assume that life could exist on other planets in our Universe.

The planet that is closest to the Earth is Mars. At one stage during its existence Mars had a lot of water on its surface. As life on our Earth originated in it’s oceans any life on Mars might have started in its oceans.

I’ll let my friends continue the conversation.

There are plans to build a new Space Station that will allow humans to go to Mars. Meanwhile there are several mechanical ‘rover’ devices on the surface of Mars which at this very moment are looking for evidence wether life, did once, exist on Mars.

“Will the world ever end?” asks Caroline (10)

Caroline. let us look at the possibilities that the team have suggested.

Yes we are destroying our world. Climate change will in the next hundreds of years will  probably make the Earth unlivable for humans. There might be some animals that will survive so life will survive even if we do not.

There are other things that could destroy our world. An asteroid strike killed the dinosaurs and if there is another strike it could kill humanity. It is reckoned that the Sun is about midway through it’s life. It will at some time begin to die BUT this will not happen for billions of years. When it does die the Earth (our planet) will also die.

Unknown (age 7) asked – “Why is the sky blue?”

Hello unknown. I would not normally answer questions to an unknown questioner, but, as it it such an interesting question I asked my friends for some comments.

You are right. Where does the colour come from? It was in 1671 that the famous scientist, Newton, discovered that white light was a mixture of different coloured lights. He did this by passing white light (the light from the Sun) through a glass prism. Look at what he got……….

Later it was found that some of the blue light in the Sun’s light had difficulty passing through the Earth’s atmosphere. this blue light was scattered as it passed through the atmosphere therefore giving the sky a blue colour.

Some of the blue light still got through and appears as part of the white light in the prism experiment and also in the rainbow. In the rainbow the drops of rainwater act as small prisms.

Hope this makes sense. if you want to give your name please let me know in the comment box.

(amended 21/9/18 – raindrops as prisms added)

“Questions about the Universe” by Lewis Jordan Sexton (13)

Questions about the Universe??????

Lewis, thank you very much for your thoughts and the questions in your own mind that you are thinking about. Wow.

I’m tempted to tell you a story about a question that my wife asked to her mother when she was about your age. “Mother what is the Universe and what was the big bang?” Her mother’s reply was “They are very big questions, I think your time is better spent making sure that this planet we are living on lasts as long as possible, rather than worrying about the Universe”

For readers who are interested here is the what Lewis submitted. Lewis, if you would like me to remove it send a request in the comment box below.

My thinking is that we have no idea, at the moment, whether any of the the thoughts put forward by various scientists are valid. It seems to me to be a classic case of a set of developing scientific ideas as the tools and thoughts of the the scientists develop.

For example notable scientists like Newton and Einstein developed ideas relating to your thoughts  which were effectively disproved. This is in fact the way that all scientific arguments progress. For example ……When Albert Einstein was formulating his ground-breaking theory of gravity in the early 20th Century, at a time when astronomers only really knew of the existence of our own galaxy, he used the simplifying assumption that the universe has the same properties in all its parts, and that it looks roughly the same in every direction wherever, in the Universe, an observer happens to be located. Like Sir Isaac Newton two hundred years before him, he assumed an infinite, static or “steady state” Universe, with its stars suspended  motionless in a vast void.

One of the driving forces behind the development of science thinking is to disprove earlier scientific thinking. It is called falsification.

It was a philosopher,Karl Popper who said you can only have a scientific theory if it can be proved to be false. This is what has happened to the scientific theories of Einstein and Newton. Some of their ideas/theories on gravity and the nature of the Universe have been successfully disproved. New theories by Hubble (the telescope scientist) disproved the stable Universe idea’s of Newton and Einstein. This led to new scientific ideas of an expanding (rather than a stationary static state)  Universe …which could be false? To illustrate how scientist are challenging Hubble’s ideas it is now known that the Universe is expanding at an accelerating  rate than rather than a steady rate …….the mystery continues. 

Have a look at this website The Physics of the Universe.

I shall continue thinking and possibly updating.

Thanks again for your thoughts.

 

 

 

Destiny (10) asks “Did/are unicorns real?”

Destiny, thanks for this second question. Interestingly it has connections to your previous question about evolution.

I asked my friends about unicorns.

The fact that there are no fossils does not mean that unicorns never existed. If you look at how modern humans evolved from apes there are a lot of gaps in our understanding, which could be linked to fossils that have not yet been found.

Where fossils have been found we can get lots and lots of information from them especially from the age of the rock in which they are found. This is to do with something called radioactive decay. This allows the fossils to be placed fairly accurately on the ‘evolution table’.

I have two immediate thoughts about unicorns. Firstly they are completely made up and secondly they are a brief part of an evolutionary story that didn’t survive. For example an animal (horse, deer, goat or other animal) was born with one horn by some biological accident, it lived but it’s children were ‘normal’ so the trait ended.

I prefer the mythical, made up model. I would like your thoughts.

“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)

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.

What does a dead star turn into? asks Liam (9)

Liam. Science is an interesting area of knowledge. It is recognised that it originates from an area of study called Philosophy. Philosophy (an Ancient Greek term) is about asking questions and for Science it is about asking questions about the physical and biological world. We ask the question and try to find the answers. For your question the answers are not easily found.

To try to answer your question, we have to know a little bit about the Sun. We know that in it’s centre there is an atomic reaction going on. It is not the type of atomic reaction we have in our Atomic Power Stations where we have an atomic ‘fission’ reaction occuring.

‘Fission’ means splitting something into two or more parts. The animation below shows a small atomic particle called a ‘neutron’  hitting a much bigger particle called an ‘atom’ . It splits forming more neutrons that hit other atoms, which break and form more neutrons………and on and on. This is a fission reaction and a lot of energy is released.

In the Sun the opposite is happening. Instead of fission we have fusion , the joining up of particles (Hydrogen atoms) to give Helium which creates lots and lots of energy. See the diagram below.

.

Why would the Sun die? The main reason is that it runs out of Hydrogen. So what will happen then?  Firstly the Sun will get brighter. This will happen because of the helium that is produced. It will be pulled into the centre and begin to burn, adding more light and heat to the Sun’s radiation. Then as the hydrogen gets less and less the Sun will get cooler but at the same time begin to expand. It will become a Red Giant.

It is reckoned that it will expand so much that it will consume the Earth……that will happen in about 4 billion years time, however life on Earth will no longer exist in 1 billion years. This is because of the brightening of the Sun and the rising temperature of The Earth’s atmosphere, all the oceans will disappear and plant life will not be able to survive.

 

 

 

Viper Astra (9) asks “What makes earthquakes happen?”

Viper, to answer your question it might be useful if we go back to the beginning. By the beginning I mean 4.6 billion years ago when the planet was first formed. Then it was a ball of molten lava. (1 billion is 1,000,000,000 or one thousand, million)

Over the next billion years the planet cooled and bits of crust formed on its surface. We call these bits of crust tectonic plates (the word ‘tectonic’ comes from the ancient Greek word for ‘building’ ……the crust is ‘building a surface’). These bits of crust got bigger, sometimes sunk into the molten sea they were floating on, but slowly covered the Earth.

Because they floated, the ‘plates’ of crust would have constantly experienced the movement of the molten ‘sea’ below them, so they moved and bumped into each other, and they are still doing that today. It is the movement and the, bumping into each other that causes earthquakes.

Watch this short video. It explains the different types of earthquake that can occur.

Thanks for the question Viper. Not sure about something then ask another question.

What natural phenomenon made the Mariana Trench? asks Sabine (9)

The Mariana Trench ….. I have been thinking about this and I think, worked out a way of explaining the answer to your question.

Firstly

Our planet, the Earth, is an interesting planet. It has a solid surface (we call the crust) that surrounds a molten (liquid) inside, called the mantle. Like a boat on water the surface floats on the molten liquid interior. Look at the image below:

Many millions of years ago the planet was just a hot molten sphere. Slowly the crust began to form. It didn’t all form at the same time so it became a little like a cracked egg shell with each bit floating and moving on the molten mantle. These pieces were the tectonic plates. The image below shows you the present positions of the tectonic plates.

You might be able to see what tectonic plate you are living on.

These plates are constantly moving (very, very slowly). When they bump into each other they can cause lots of problems, like earthquakes. The Philippine Plate and the Pacific Plate bumped into each other many millions of years ago  and this made the Philippine Plate sink below the bigger Pacific Plate …. and the result the Mariana Trench. See the diagram below.

Where is the Mariana Trench?

I hope this makes sense Sabine. Feel free to ask another question.