# What would happen if we travelled at the speed of light?

My youngest child is seven; he is a boy of many questions. Lately he has turned his attention to speed, specifically the speed of light, and what would happen if you travelled that fast.

The first question came at bed time (why is it always bed time??). He wanted to know what would happen if he travelled at the speed of light and would it change time. I answered as best I could (while trying to back out the door and turn off the light) and left it at that but the question has resurfaced and I know this little guy will not let it rest until he is sure he has full understanding of the answer. So, to satisfy my own son’s curiosity, and in case anyone else out there wanted to know… here is a quick low down on high speed.

Firstly, the speed of light is a staggering 299,792,458 metres per second (or approximately 299 792 kilometres per second). Albert Einstein may not have calculated this, but he was the one that recognised it as the fasted thing in our Universe, a cosmic speed limit.

This is the speed of light in a vacuum and is commonly denoted as c. Light travelling at different speeds depending on what it is travelling through, so for light to travel through anything other than a vacuum, it will travel a little slower. For example, light travels about 90,000 m/s slower in air (that’s about 0.03% slower).

In water light travels at 75% the speed it would in a vacuum.

## It’s all relative

Einstein’s work on this cosmic speed limit led him to develop a little theory, calling it the Theory of Relativity.

Einstein’s Theory of Relativity…

E = mc2

E stands for energy, m is the mass of the object and c is the speed of light. But it still looks pretty confusing, right? Keeping it simple, this equation says two interesting things…

1. it ties mass and energy together
2. it says that nothing with mass can travel as fast as, or faster than the speed of light

You might like a refresher on what mass is… mass is basically a measure of how much matter (atoms) something is made up of, or how densely packed those atoms are. We usually talk about mass in terms of weight (kilograms) but when we do so, we are typically saying how much it weighs here on Earth.

## Close, but not close enough

Light is made up things called photons and they have no mass. Everything else we can think of in our everyday lives does have mass.

Applying Einstein’s Theory of Relativity, the closer an object (with mass) gets to the speed of light, the more energy is required to keep it moving, until eventually the object would have an infinite mass and require and infinite amount of energy to move it… and that’s just not possible.

So nothing with mass, including us, or a big rocket, can move faster than the speed of light.

The fastest speed of a manned spacecraft to date was achieved by the Apollo 10 lunar module, on May 26, 1969 when it reached speeds of 39,897 km/h (about 11 km/s) before re-entering the Earth’s atmosphere.

Where does time come into all this? Well, you might remember that the c in E=mc2 is a unit with distance and time in it, so time is part of the equation too.

What happens to time when we start to travel at close to the speed of light? The answer to that depends on where you are standing, in other words, it depends on where you are observing from.

Let’s take an example, and remember, this is all hypothetical… you are in a rocket travelling through space and you manage to travel at speeds approaching the speed of light. So for you, time slows down and you reach your destination in a relatively short space of time. You arrive, do whatever it is you went there to do and then head back to Earth (again at speeds close to the speed of light).

The main thing you would notice when you get back home is how old everyone is! People who were the same age as you when you left would be a lot older than you when you come back. Remember, as Einstein said, it’s all relative! It depends on where you are observing from; if you are on Earth then time continues as normal. But if you head off into space and travel at speeds that slow down time, then a little time for you will equal a lot of time back on Earth.

Scientists like to call this the twin paradox; if you took a set of identical twins and sent one travelling off in space at speeds close to the speed of light and left the other here on Earth, when the first twin returned from his cosmic travels he would be younger than his twin who remained on Earth.

In summary… we can’t actually travel at the speed of light, but if we could travel close to the speed of light then yes, time would slow down (for us anyway) but by the time we got back to Earth, everyone else would have aged more than us!

What did my son think of my explanation? I read this post to him last night and broke some of the theories down into seven year-old sized chunks of information and he was happy enough with the answer, he especially liked the twin paradox 🙂

Then he added some theories of his own… I’m not sure what Einstein would make of these but this guy certainly has some interesting ideas; Have a listen to a seven year-old’s theories on what else would happen if you travelled close to the speed of sound!

`Image sources: Rocket, time and light images were sourced on Pixabay.com`

# The science of imagination – is it more important than knowledge?

Is imagination more important than knowledge?

Albert Einstein certainly thought so…

“I’m enough of an artist to draw freely on my imagination, which I think is more important than knowledge. Knowledge is limited. Imagination encircles the world.”

I have looked at imagination at work in life and it never ceases to amaze me. When I see my children share the knowledge they have learned I encourage and applaud with pride but when I see their imagination shine through I really stand back in awe… it is theirs, it is unique and it is truly amazing!

So yes, I do believe imagination is more important than knowledge, but I also think that if you combine both you are really tapping into life’s power. What does science have to say about it?

What is imagination?

Imagination is creativity in action. It can be using our brain and our senses to create an image within our mind.

Imagination draws on our experiences and knowledge of the world around us and combines them with the complete unknown to make something new.

It allows us to explore beyond the constraints of our environment and our reality, into a world of dreams, where creativity and invention are at their strongest.

How does it work?

Science has long held that the complex nature of imagination must involve more than one area of the brain. The idea and the proof have been hard to amalgamate but recent studies using advancements in the monitoring of complex neural interactions within the brain provide new evidence for this theory. The findings from this study suggest that imagination uses a large portion of the human brain, creating an interconnecting network of activity across many different areas.

Imagination really does light up our brains!

Is imagination unique to humans?

It would appear that imagination (at least in its complete form) is a uniquely human experience. It has allowed us to modify and develop our surroundings and to create and invent new ideas, new structures, new technologies. Imagination also allows us the very human emotion of empathy as we can literally imagine another person’s life experience without ever having actually experienced any of it.

In the words of JK Rowling…

“Imagination is not only the uniquely human capacity to envision that which is not, and, therefore, the foundation of all invention and innovation. In its arguably most transformative and revelatory capacity, it is the power that enables us to empathize with humans whose experiences we have never shared.”

The evolution of imagination

Our early ancestors, the hominids showed basic levels of imagination in their tool making abilities, cooperative hunting skills and social interaction and colonization. It would appear that their level of imagination was limited though, perhaps with respect to their brain size and their compartmentalized thinking.

As modern humans evolved scientists have reported an increase in brain size, advances in technical skills and creativity and a development in social complexities. Farming, sophisticated tool making, complex language development, the performance of rituals and the development of art and crafting all required a complex development of thought and mental interaction… Imagination!

A more developed neural network within the brain, connecting the different areas of brain function, must have had some part to play in all this. The majority of these changes evolved between 500,000 and 200,000 years ago, to the eventual emergence of the modern human.

The importance of imagination in our development and learning

As a parent this is the part that I am most interested in. What part does imagination play in my children’s development?

Science has shown that imagination stimulates brain function and activity. It literally expands the mind as it encourages connections between so many areas within the brain.

Both neurologists and psychologists agree that play in early childhood is necessary for children to develop at a normal rate and to reach their full potential.

Imagination and play have been shown to increase brain development and growth in children. At a neurological level imagination can increase the number of neural connections within the brain, linking different regions. These links need repeated stimulation and activation to be maintained.

Imagination is an activity that used the whole brain rather than isolated, individual sections.

Use of the whole brain in this way increases a child’s problem solving abilities, emotional development and social interactions.

Early childhood (between the ages of three and six) is usually when children are most actively involved in their imagination. Through pretend play children create their own imaginary world, allowing them to develop and learn from the new experiences they explore.

When children start school there is often a shift in how they play, moving towards games with more social interaction and rules. These games still engage the children in creative play, often with a more cognitive imaginative thought process.

Imagination is a vital learning tool within the classroom. Children will learn and remember more powerfully when imagination is included. Imagination will create more neural links within the brain, engage more regions within the mind and it will bring the subject to life!

This holds true for all subjects not just the ones we consider more creative. I have always loved maths, for example, and I remember from a young age that each number took on a personality for me. This probably increased my enjoyment of the subject and certainly would have increased my memory and ability.

As children grow it is important therefore that their imagination is constantly stimulated and encouraged. As they enter their teenage years imagination will allow better social interaction and social awareness as it encourages a better sensitivity to the needs and feelings of those around us.

Imagination can also decrease stress levels as it encourages problem solving and the possibility of positive outcomes and solutions.

A powerful imagination is a wonderful skill to have and a very important one to nurture throughout all stages of life. To really reach our full potential I believe imagination and play should be as important in our daily lives as love, nutrition and health.

How can we encourage imagination within our children?

We all have imagination within us, that is what makes us human. We do not need to instil it within our children but perhaps we can encourage and assist what is already there. Starting from a young age we can encourage pretend play, imaginative fantasies and the belief in some things unknown.

An imaginary friend can be encouraged rather than feared. Dress up clothes are a great facility for a child’s imagination. There are many simple toys that can assist a child in a wonderful make believe world. It is also a wonderful reinforcement for children to see their parents actively involved in the imaginary worlds that they create.

# Thought for the day – imagination!

This is one of my favourite quotes …

“I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.”

….it always makes me think of my daughter, she has the most amazing imagination I have ever come across; when she was very young she told me I was not her real mum and one day she would have to leave me and go back to her real family!  Apparently she is a fairy princess and when the wicked witch attacked their kingdom her parents changed her into a baby in my tummy to keep her safe!

I see her imagination as a wonderful gift and feel humbled and nervous about the responsibility of keeping it nurtured and alive while she grows!

…just a thought!