Daga bisani, Max Born (1909) a cikin aikinsa da aka ambata a sama game da motsi mai sauri, ya yi ƙoƙari ya haɗa da ra'ayi na jikin rigid a cikin SR. Duk da haka, Paul Ehrenfest (1909) ya nuna cewa Born ya jagoranci ra'ayi na abin da ake kira Ehrenfest paradox, wanda, saboda ƙuntatawa, saurin bayanai na 'yanci na iya ragewa yayin da aka rage saurin haske, don haka za a keta lalacewa. Tun da wannan ya saba wa kowane kwarewa, ana zaton saurin superluminal ba zai yiwu ba. Ya kara da cewa dole ne a kirkiro wani motsi na jikin rigid a cikin tsarin SR. Daga bisani, Max Born (1909) a cikin aikinsa da aka ambata a sama game da motsi mai hanzari, ya yi ƙoƙari ya haɗa da ra'ayin jikin rigid a cikin SR. Duk da haka, Paul Ehrenfest (1909) ya nuna cewa Born ya jagoranci ra'ayi na abin da ake kira Ehrenfest paradox, wanda, saboda ƙuntatawa, saurin bayanai na iya ragewa yayin da aka rage saurin haske, don haka za a keta al'ada. Tun
saurin haske