This is a list of lost inventions - technologies whose original capabilities cannot be recreated in the same form anymore. It does not include theoretical inventions.
It is unknown whether these inventions truly existed, had all of their described properties, or were truly novel.
- Archimedes' heat ray, a device that Archimedes is purported to have used to burn attacking Roman ships during the siege of Syracuse.[1]
- Claw of Archimedes, purportedly a sort of crane used to drop an attacking Roman ship partly down in to the water during the siege of Syracuse.[3]
- Polybolos, an ancient Greek repeating ballista.[4] A MythBusters episode built and tested a replica, concluding that it plausibly could have existed. However, the replica machine was prone to breakdowns.[5]
- Roman flexible glass, whose inventor was reportedly beheaded so that gold and silver would not be devalued.[6]
- Mithridate, said to have functioned as a panaceaic antidote.[1]
- Sloot Digital Coding System, reported to have been able to store a complete digital movie file in 8 kilobytes of data.[7]
- Stradivarius stringed instruments, considered some of the finest instruments ever made. Theories explaining their purported quality include denser wood unique to the time period due to solar activity, treatment with other materials like calcium and aluminum which have been found in a 2016 shaving, and technique.[1] However, blind experiments have never conclusively found a difference between the sound of Stradivari's violins and other high-quality violins.[8]
- Starlite is an intumescent material said to withstand enormous amounts of heat.[6]
- Zhang's seismoscope, also known as hòufēng dìdòngyí, an ancient Chinese seismometer. Multiple modern recreations have been created, but it is debated whether they are mechanical replicas.[9] Hong-sen Yan claims that they do not reach the seismoscope's historically reported level of accuracy and range.[10]
These technologies can be recreated, but are sometimes claimed to be lost.
Farrokh, Kaveh; Maksymiuk, Katarzyna; Garcia, Javier Sanchez (2018). The Siege of Amida (359 CE). Archeobooks. pp. 44–45. ISBN 978-83-7051-887-5. Miller, Roman; Perrin, Pat; Coleman, Wim (2015). 10 Lost Inventions that Might Have Changed the World as we Know it. pp. 20–23.