Why don't birds get electrocuted while perching on power lines?
Try 3 issues of BBC Science Focus Magazine for £5!
It's all in the difference between voltage and voltage difference.
Asked by: Ahmed Hussain, London
It's not voltages per se that kill, but voltage differences, which are needed for electricity to flow. If a bird lands on a single power line at, say 35,000 volts, the lack of a voltage difference keeps it safe. If it extends its wings and touches another power line at a different voltage, though, it will be electrocuted. That's why electricity companies put plenty of space between cables.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.
Robert is a science writer and visiting professor of science at Aston University.
- Try your first 6 issues for just £9.99 when you subscribe to BBC Science Focus Magazine.
- Risk - free offer! Cancel at any time when you subscribe via Direct Debit.
- FREE UK delivery.
- Stay up to date with the latest developments in the worlds of science and technology.