A visitor learns about post-operative sewing skills during the "Night of Scientists" event at Charles University in Prague, the Czech Republic, Sept. 27, 2019. More than 60 scientific institutions and universities in the Czech Republic opened to visitors during the event Friday evening. (Photo by Dana Kesnerova/Xinhua)

A student introduces orthopedic surrogates to visitors during the "Night of Scientists" event at Charles University in Prague, the Czech Republic, Sept. 27, 2019. More than 60 scientific institutions and universities in the Czech Republic opened to visitors during the event Friday evening. (Photo by Dana Kesnerova/Xinhua)

A child learns about bone drilling techniques during the "Night of Scientists" event at Charles University in Prague, the Czech Republic, Sept. 27, 2019. More than 60 scientific institutions and universities in the Czech Republic opened to visitors during the event Friday evening. (Photo by Dana Kesnerova/Xinhua)

Children learn about post-operative sewing skills during the "Night of Scientists" event at Charles University in Prague, the Czech Republic, Sept. 27, 2019. More than 60 scientific institutions and universities in the Czech Republic opened to visitors during the event Friday evening. (Photo by Dana Kesnerova/Xinhua)

Visitors learn about the structure of human body during the "Night of Scientists" event at Charles University in Prague, the Czech Republic, Sept. 27, 2019. More than 60 scientific institutions and universities in the Czech Republic opened to visitors during the event Friday evening. (Photo by Dana Kesnerova/Xinhua)