1. Tools for Observation

3. Human Eye
CORNEA - The transparent front part of the eye that covers the iris, pupil, and anterior chamber. The cornea is an essential part of the focusing in your eye.
PUPIL - The variable-sized, black circular or slit shaped opening in the center of the iris that regulates the amount of light that enters the eye.
LENS - A transparent, biconvex (lentil-shaped) structure in the eye that, along with the cornea, helps to reflect light to be focused on the retina.
RETINA -
A thin layer of neural cells that lines the back of the eyeball. It is comparable to the film in a camera
OPTIC NERVE - The nerve that transmits visual information from the retina to the brain.
Source:

4. The retina
Rods detect light and dark
A cones detects either Red, Blue, or green
Cones concentrated at the center
Rods at outside of eye

5. Cone sensitivity

6. Ha, Ha! Visible Spectrum of Light!!!

7. Humans have developed tools to see things better….
Galilean Telescope

8. Camera

9. Space Telescopes
Hubble Space Telescope (HST)

10. Trapezium (Orion nebula): Hubble Space Telescope

11. Telescope, Cassini: Moon

12. Yellow filter, digital camera, 6’’ telescope: Sun

13. Mars as seen by HST

14. Star forming region in the Large Magellanic Cloud (LMC) from HST

15. Film camera, 800mm lens: Comet Swan

16. HST, M31 (Andromeda galaxy)

17. Bullet Nebula (HST Chandra X ray)
Is this a “true color” image?
Why was this image taken as an “X ray” photo?