Warning: Cannot modify header information - headers already sent by (output started at /home/content/70/7481070/html/appsrc/doyouknow.php:18) in /home/content/70/7481070/html/header.php on line 20

Warning: Cannot modify header information - headers already sent by (output started at /home/content/70/7481070/html/appsrc/doyouknow.php:18) in /home/content/70/7481070/html/header.php on line 21
Do You Know
Questions & Answers on General Knowledge.

Does your pupil opening and closing have anything to do with it focusing on a more distant object?
The size of your pupil does not depend on the distance to an object. It depends only on how bright the scene in front of you is. But the size of your pupil does affect your ability to focus. When it is relatively dark and your pupil is wide open, the whole lens of your eye is involved in light gathering. Focusing becomes very critical and you have very little depth of focus. Moreover, if your lens isn't perfect, you will see things as blurry. But when it is bright out and your pupil is small, you are only using the center portion of your lens and everything is in focus. That's why it is harder to focus at night than during the day. When you squint, you are artificially shrinking the effective diameter of the lens in your eye and increasing your depth of focus. Unfortunately, you are also reducing the amount of light that reaches your eye. If you look through a pinhole in a sheet of paper, you will find everything in focus, although it will appear very dim.
--- >>>
More Questions:
  • Did T-rex really hunt down its prey?
  • What are earthquake zones?
  • What is a shockwave and a sonic boom?
  • How did technology help improve sailing?
  • Which species is known as the crying ape?
  • Do people live in the Arctic?
  • What are sunspots?
  • What is the difference between a porpoise and a dolphin?
  • Could I see the Sun rise and set from space?
  • Why is the skin between my toes sometimes red and itchy?
  • What did the Incas do for a living?
  • How does an ice cube become water?
  • Why is a limited space called “close quarters”?
  • If you throw a dead ball at a baseball, would the baseball not roll as far as if you throw a super ball at it?
  • What causes large electric resistances?
  • Why is a car's rear window put and kept under stress, and what has this to do with polarization?
  • How does electricity get from the generating station to the outlet in my living room?
  • How do clouds exist? If oxygen molecules, which must weight less than water vapor are drawn toward earth, then why aren't the clouds?
  • What is Tornado Alley?
  • Why does purple bend more in a prism than, say, red?
  • What is the alimentary canal?
  • How does air pressure affect the distance a soccer ball can be kicked?
  • Which are the largest and smallest seals in the world?
  • Before you speak into the tape recorder, is the tape non-magnetic because half of the magnets face one way and half the other way?
  • Who discovered Australia?
  • Healthy Teeth
  • Architectural Wonders of the Ancient World
  • Healthy Skin
  • The Beautiful World Heritage Sites
  • Precautions while using Websites
  • Benefits of Durian

  • Amazing Science Images You Must See

    Snow White Penguin Chick

    Not all emperor penguins sport black and white tuxedoes. Scripps reseacher Gerald Kooyman spotted this unique all white emperor chick, dubbed Snowflake, during a penguin survey on the ice shelf of the Ross Sea, Antarctica, in December 1997. Its white feathers blended in so well with the icy background that Kooyman said he almost missed the chick emperor penguin chicks are usually covered in a grayish down coat, with dark tail feathers and dark bills and feet. Scientists dont think Snowflake is an albino, however, as it didnt have the characteristic pink eyes associated with albinism.

    Chourishi Systems