Every Friday Dr. Chris Smith, popularly known as The Naked Scientist, satisfies your curiosity about the world you live in and helps you to find out more about the weird and wonderful laws of nature and the intricacies of the human body.
The Naked Scientist says science taken from about 2500 years ago has been brought into the present era to solve our battery problems.
Those early engineers realised that they could reduce the effort needed to make things move by stringing together a system of ropes running around wheels. Now modern-day chemical engineers have achieved a similar feat at the molecular level to build better batteries, explains the Naked Scientist.
Scientists in Korea have built batteries with internal molecular pulleys that can distribute stresses and stop silicon shattering. Writing in Science, Sunghuan Choi and his colleagues used long string-like molecules called polyethylene glycols - which operated as the "ropes", and threaded onto them rings made from sugar molecules known as cyclodextrins; these were the pulleys.— Dr Chris Smith, Naked Scientist
And a question about plants...
I have a pot plant in my house. The plant hasn't shed or grown a single leaf in five months. Do plants go through a prolonged stage of hibernation? It's not growing but it is not dying either.— Tshiamo, caller
The Naked Scientist says some plants never shed their leaves because they are evergreen species, while others are deciduous because they go through cycles.
He says if house plants are not kept in an ideal condition then they are prone to thinking that it is winter or a non-growing season leading to a reduced metabolism of the plant. Another reason could be that this particular plant is a slow growing species says the Naked Scientist.
And weighing in on that dreaded scale...
Why do I weigh more in the morning before I've taken a bath and much less after my bath?— Karen, caller
The scales aren't calibrated well, explains the Naked Scientist. He adds that if you sweat during a hot bath, you're likely to lose 300 ml of fluid you - added to which if you go to the loo you are likely to relieve your body of at least 300 ml of fluid.
Listen to the Naked Scientist here: