Half-life
Half-life is a measure of the time taken for a quantity to reduce to a half its initial value. The term is found in the medical and nuclear sciences and is expressed by the formula t by 1/2 or t1/2.
In particular it is used to describe the speed at which unstable atoms become less stable through decay, releasing radioactivity in the process, or conversely, how long atoms remain stable.
In medical science the same measure is used to describe the biological life span of drugs and other chemicals in the human body.
It is also more generally used to describe any type of exponential or non-exponential decay.
The converse of half-life (when considering exponential growth) is doubling time.
[edit] Related articles on Designing Buildings
- Chernobyl New Safe Confinement.
- Generation nuclear.
- Methane and other gasses from the ground.
- Nuclear power.
- Planning and managing Hinkley Point C.
- Radon protection for new domestic extensions and conservatories with solid concrete ground floors (GG 73 revised).
- Radon: Guidance on protective measures for new buildings BR 211
- Radon protection for new dwellings GG 74.
- Radon protection for new large buildings GG 75.
- Radon.
- Radon: Guidance on protective measures for new buildings BR 211.
- Types of radioactive material (Radionuclides)
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
Recognition, influence and growth
SocEnv identifies three strategic pillars in new strategy to 2045.
Discover the future of roofing, cladding and insulation.
New guidance for professional practice, cultural change and regulation in social housing.
The heritage of nuclear and conventional power stations.
New measures to stop people being ripped off
Government to protect families from cowboy builders and aggressive bailiffs.
New Futurebuild showcase brings an innovation-first approach.
National Planning Policy Framework
Understanding the 2026 changes.
ECA's public affairs priorities
Member consultation opens to shape priorities for 2027 to 2030.
Dutyholder responsibilities from 1 July 2026.
Where performance meets practice
The Building Envelope Stage at UKCW Birmingham.
CIAT publishes briefing on planning reforms.
Leaders in Learning for Practice Network
Call for conservation leaders in learning to register interest in new network.