Define transparent internal

User description

For define internal 8 images found by accurate search and more added by similar match. What is certificate transparency. How would you define internal stimuli and external stimuli. Define transparent internal, critical angle and total internal reflection.

304 x 211 8 0
602 x 476 10 0
800 x 450 10 0
377 x 366 3 0
1920 x 1087 3 0
1280 x 720 10 0
1148 x 634 3 0
880 x 440 5 0