Is space a perfect vacuum?
For a perfect vacuum to occur, space would need to be totally devoid of all matter including energy fluctuations which exist even in empty space.
Asked by: Talhah Loonat, Handforth
A vacuum is defined as a space devoid of all matter. In the Solar System, space contains on average five atoms per 1cm3. Interstellar space, between stars, contains around one atom per 1cm3, while intergalactic space, between galaxies, contains 100 times less. Ultimately, a perfect vacuum isn’t possible because quantum theory dictates that energy fluctuations known as ‘virtual particles’ are constantly popping in and out of existence, even in ‘empty’ space.
Read more:
- How can something explode in the vacuum of space?
- Why doesn’t Earth’s atmosphere vanish into the vacuum of space?
Subscribe to BBC Science Focus Magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun facts.
Authors
Sponsored Deals
Spring Savings!
- 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.
