Cold fusion
Hypothesized room-temperature nuclear reaction, controversial since 1989.
Wikipedia / Wikimedia Commons
Cold fusion is a hypothesized type of nuclear reaction that would occur at or near room temperature, contrasting with the high-temperature fusion known in stars, hydrogen bombs, and prototype reactors. It gained widespread attention in 1989 when electrochemists Martin Fleischmann and Stanley Pons reported anomalous heat and nuclear byproducts from a tabletop electrolysis experiment using heavy water and a palladium electrode, though subsequent replication failures and methodological criticisms led most scientists to dismiss the claims as pathological science.
- field
- Nuclear chemistry / Electrochemistry
- known_for
- Claim of cold fusion in 1989
- key_figures
- Martin Fleischmann, Stanley Pons
- year_of_announcement
- 1989
- status
- Hypothesized; not accepted by mainstream science
Lore & Background
The most famous cold fusion claims were made by Stanley Pons and Martin Fleischmann in 1989. They hypothesized that the high compression ratio and mobility of deuterium within palladium metal using electrolysis might result in nuclear fusion. Their experiments used a palladium cathode and heavy water in a calorimeter; after weeks of electrolysis, some cells showed sudden temperature rises to about 50 °C without changes in input power, producing excess heat they attributed to nuclear processes. They also reported measuring small amounts of neutrons and tritium, byproducts of deuterium fusion.
Reader's Guide
The Fleischmann–Pons announcement in 1989 drew wide media attention and raised hopes of cheap, abundant energy. However, many scientists failed to replicate the results, several positive replications were retracted, and methodological flaws were identified. By late 1989, most scientists considered cold fusion claims dead, and it gained a reputation as pathological science. The U.S. Department of Energy reviewed the evidence in 1989 and again in 2004, concluding that the reported excess heat did not provide convincing evidence of a useful energy source and declining to fund cold fusion research. A small community continues to investigate under alternative names like low-energy nuclear reactions (LENR) or condensed matter nuclear science (CMNS), but articles are rarely published in peer-reviewed mainstream journals.
Did You Know?
- The term 'cold fusion' was used as early as 1956 in a New York Times article about muon-catalyzed fusion.
- In the late 1920s, Friedrich Paneth and Kurt Peters originally reported transforming hydrogen into helium with palladium, but later retracted due to background helium from air.
- Swedish scientist John Tandberg applied for a patent in 1927 for fusing hydrogen into helium in an electrolytic cell with palladium electrodes, but it was denied.
- A Google-funded failed replication attempt was published in a 2019 issue of Nature.
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