Today’s questions about space are a little bit less about standing on the ground looking up, and a bit more about getting into space ourselves. The answers are brought to you by AC, who is not an astronaut, despite wanting to be one until about year 10, when she realised she was going to be too short. (Who knew there were height limits on rockets?). Also, Australia STILL doesn’t have a space program, which she finds really annoying…
Welcome to Ask a Scientist, where we answer your most pressing science questions! Today, we are joined by Senior Postdoc Dr Hendrik Falk, who works in Discovery Technology at the Cancer Therapeutics CRC.
Do you have any significant proof that there is life beyond Earth? – Corbin, 12
Scientists are still researching this, for instance a type of molecule thought the be produced by living cells was discovered recently in the Venus’ atmosphere (https://www.nature.com/articles/d41586-020-02785-5) But it turned out there are more questions about what the measurement really means – good proof of life anywhere else but Earth is still a dream. Maybe you’ll find it one day?
What is the universe made of? – Victoria, 10
All made from the same stuff as earth and our surrounding solar system, just loads more of it, and a lot of empty space in between!
I would like to know if the end of space has ever been seen. – Vinh, 11
Nobody knows if it is even visible, it is also too far away and moving further away all the time. There’s a pretty cool video about the expanding universe that you can look at here.
Who invented the moon? – Dylan, 9
Who invented Earth? Both don’t need humans, they were already there before us.
How can there not be any gravity in space but more on earth? – Vihaan
There is a little gravity in space. On board the International Space Station they call it microgravity, but it is not noticeable because the space station is falling around the Earth all the time. Only beyond the last planets of the solar system there would be not gravity observed.
In the future will there be another planet that we can live on? – Ryan, 8
Doesn’t seem likely with the knowledge and resources we have today. Can you imagine sending your family, house, garden, sports club and whatever to a place as far away as Mars and setting everyone up there to live safe and happy? Further imagine this for your friends, the friends of your friends, and so on to all people in Australia? That will be a big ask…
Dr Hendrik Falk’s work covers the first steps in creating a new treatment for cancer patients. In drug discovery, scientists identify and refine molecules that modulate a specific function of cancer cells or the rest of the body, for instance to boost the immune system to better fight cancer. This work builds on the innovative findings of other researchers, and it is the exchange with other scientists that he enjoys the most.
Sharing his knowledge with students is a great way to nurture their interest in the world!
Today’s answers to your burning questions come from Lahiru Gangoda and Catherine McLean.
Why can’t you hear in space? – Maggie, 9
Everything in the universe is made of atoms, tiny particles that are too small to see. These atoms can stick together to make molecules, such as water or salt or carbon dioxide.
Sound travels through the vibration of molecules in a medium (such as air or water), and the closer together the molecules are, the faster it can travel. This is why sound travels faster underwater, and it’s also why tin can telephones can work – the molecules that make up a piece of string are packed very closely together and so they can vibrate and transmit sound very efficiently!
But space is a vacuum with no molecules. So, there is no medium for the sound waves to travel through, and so you cannot hear any sounds in space. – Lahiru Gangoda and Catherine McLean
Why is the moon so bright at night? – Abi, 10
Every planet and moon in our solar system reflects the Sun’s light. During the day, the sun illuminates the earth’s atmosphere. Looking into the sky during daytime you will see it is not dark, making it hard to see the moon in the sky. The moon only seems bright in the night sky because it is so close to the earth and because your surroundings are so dark at night. – Lahiru Gangoda
How big is Jupiter? – James I, 11
Jupiter is more than 300 times bigger than Earth. If Earth were the size of a grape, Jupiter would be the size of a basketball. – Lahiru Gangoda
Why is the sun hot? – Natalie, 8 and Dre, 8
The sun is basically a giant nuclear reactor at the centre of our solar system. The sun creates its energy by nuclear fusion. This brings us back to atoms again! The centre of any atom is called a nucleus – which is where the word nuclear comes from.
The sun takes hydrogen atoms and subjects them to intense pressure and heat, until their nuclei stick together, or ‘fuse’, to create a new sort of atom – helium. During this process, a huge amount of energy is released, and this provides the light and heat for all life on earth. – Lahiru Gangoda and Catherine McLean
How does ice melt in summer? – Giovanni, 8
Remember our molecules from Maggie’s question? Well, how closely individual molecules stick together determines their texture or state. When you put water in the freezer, this slows the molecules down until they stick together, forming solid ice (salt does this already at room temperature!).
Ice melts during the summer when heat energy from the sun is absorbed by the ice surface. The heat energy causes the water molecules to move faster, breaking the bonds between molecules to form liquid water.
And if you heat the water right up to boiling point, the molecules will move faster and faster again until they break away from each other entirely and become steam – a gas. – Lahiru Gangoda and Catherine McLean
Dr Lahiru Gangoda is a cancer researcher and a member of Team WEHI. Her research is on finding better ways to treat skin cancer. Don’t forget wear your sun screen! You can read more about Lahiru here.
Catherine McLean is the captain of Team WEHI, and not a scientist at all! She did, however, study Genetic Counselling, as the only Arts graduate in the course, and this left her with a passion for science communication. You don’t need to be a scientist to be interested in science!
Welcome to Ask a Scientist, where we answer your most pressing science questions! Today, we are joined by PhD student Lizzie Lieschke and Senior Postdoc Dr Hendrik Falk, to answer two questions about green and growing things.
My question for the scientist is how many trees are there left in the world today? – Harriet, 8
This is a tricky question to answer as it would take too long to count every single one, and people keep chopping down trees, but also planting new ones.
Because we can’t count them all, this means we have to use models to estimate the number. We can use satellite images to see how much area of the world is covered in trees. Then we send people to count trees in a small area. We can then use maths to calculate how many trees there would be if all the world had the same number as the small are. When a group of people did this, they said there were 3 trillion trees in the world! – Lizzie Lieschke
This link has a video that shows you how the trees are distributed across the world.
If the plant goes out of the space, how will it grow? – Harriet, 8
Are you asking about plants growing too big for the space they are in, or about growing plants in space?
If you want to know about plants outgrowing their space, you could try that in an experiment. Take a plant and restrict its space and see what happens.
What I expect to happen depends on what the plant is missing. Typically plants try to grow towards unoccupied spaces. If the plant is missing light, it will try to grow towards any remaining light spot. On the other hand, if is lacking water or nutrients it may die before it can grow roots long enough to find a new water source.
As for growing plants in space, scientists have grown plants on the International Space Station, so the plants don’t need gravity – but you still need to provide air (carbon dioxide), water, salts, warmth! – Hendrik Falk
This link has a video about growing plants on the International Space Station!
Lizzie Lieschke is a PhD student and scientist studying why people get sick with cancer. She is researching how one of our genes protects our normal cells from becoming cancer. She hopes that by gaining more knowledge into how this gene works, we can make our current treatments for cancer more effective.
Lizzie has always had a passion for learning about the natural world. In Grade 1, her teacher suggested she should become a palaeontologist, and when she came back from a holiday, her sister told her she needed to take more photos of people than of rocks! At university Lizzie had a hard time deciding on which science she liked best, so she tried to do them all, by taking subjects in biology (animal, human and plant), geology, climate science, and chemistry. However, when she had the opportunity to work in a cancer research lab over the summer, she found this was what she was meant to be doing. She loves how as a scientist you are constantly learning, and that what we do aims to benefit others.
Dr Hendrik Falk’s work covers the first steps in creating a new treatment for cancer patients. In drug discovery, scientists identify and refine molecules that modulate a specific function of cancer cells or the rest of the body, for instance to boost the immune system to better fight cancer. This work builds on the innovative findings of other researchers, and it is the exchange with other scientists that he enjoys the most.
Sharing his knowledge with students is a great way to nurture their interest in the world!
Team WEHI Relay for Life 