seedlings, need help

hey!

my speed queens have cracked and i put them in those cubes made of a spongy looking soil (don't know the name).
the root has reached the bottom of the cube and is growing down there (like in the pic). can the root be exposed to light (it's a 250W HPS)?
i'm expecting the leaves to come out tonight and i want them to have some light as soon as possible but i'm afraid of stressing the plant by exposing the roots to the light.

what can i do?

just get a styrofoam cup poke one small hole in the center and a few surrounding the bottom of the cup (for drainage). fill it with chemical free soil gently place your puck in the cup so that the top of your puck is level with the top of your cup then fill in the empty space with dirt and water till you see it coming out the bottom. when you want to transplant simply cut gently the bottom of your cup about 1-3 inches from the bottom and place it in your new pot. the existing styrofoam cup will not harm the growth of the plant.

. . . .and no the root, as a seedling, should not be exposed to light or dry air. whn it gets bigger the roots will simply die off if exposed to light. as a baby it would most likely kill it.

thanks a lot man will do