A small object is placed at the center of a large evacuated hollow spherical container. Assume that the container is maintained at \( 0 \, \text{K} \). At time \( t = 0 \), the temperature of the object is \( 200 \, \text{K} \). The temperature of the object becomes \( 100 \, \text{K} \) at \( t = t_1 \), and \( 50 \, \text{K} \) at \( t = t_2 \). Assume the object and the container to be ideal black bodies. The heat capacity of the object does not depend on temperature. The ratio \( (t_2 / t_1) \) is ____.
