Yet snowdrops are family in another genuine sense. I was reminded of this by Prof Robert Fosbury, a distinguished astrophysicist who researches the impacts of light upon eukaryotic life, which is essentially you and every other complex organism on Earth. We’re all deeply familiar with the idea that visible light drives photosynthesis, in turn making life possible at all. But Fosbury has discovered that light we cannot see, in the infrared spectrum – which can penetrate exposed surfaces and reach every cell in our bodies – is also crucially important.