Nihon University professor and head of Nihon University Animal Medical Center Kazuya Edamura, 49, points to cat photos on a computer screen, which are used to train the AI of “CatsMe!”, an AI-driven smartphone application jointly developed by tech startup Carelogy and researchers at Nihon University that purports to tell when a cat is feeling pain, as he gives a lecture to students on diagnosing pain in cats, at the medical center in Fujisawa, south of Tokyo, Japan on June 11, 2024. (Photo by Issei Kato/Reuters)

A cat receives acupuncture treatment in Shanghai, China on August 21, 2017. Traditional practitioners believe acupuncture of the body can stimulate blood circulation to promote healing and relieve some aches and pains. (Photo by Aly Song/Reuters)

A customer grimaces in pain as she gets a tattoo on her arm at the 21st International Tattoo Convention Berlin on December 3, 2011 in Berlin, Germany. The annual tattoo trade fair runs from December 2–4, 2011. (Photo by Adam Berry/Getty Images)

In this Sunday, August 5, 2018 photo, a dancer winces in pain as she is whipped by a fellow dancer in an adaptation of the Inca warrior dance known as “Kachampa”, during celebrations honoring Our Lady of Copacabana, in Cuzco, Peru. (Photo by Martin Mejia/AP Photo)

A devotee takes a holy bath at the Balaju Baise Dhara (22 water spouts) during the Baishak Asnan festival in Kathmandu April 4, 2015. Devotees believe that the water from these stone spouts, which is collected from the catchment area of the Nagarjun forest behind the spouts, will cure pains and skin diseases. (Photo by Navesh Chitrakar/Reuters)

The Boeing 747-8 Intercontinental airliner, the company's newest and largest passenger plane, takes off for its first test flight at Paine Field Airport March 20, 2011 in Everett, Washington. The new plane features quieter, more fuel efficient engines, more seating and a redesigned interior.

Antonio Banderas attends the photocall for “Pain And Glory (Dolor Y Gloria/Douleur Et Glorie)” during the 72nd annual Cannes Film Festival on May 18, 2019 in Cannes, France. (Photo by Pascal Le Segretain/Getty Images)