Nearly transparent clear glass
* Clear glass absorbs heat and reradiates it outdoors.
* Clear glass is also less reflective than opaque glass from a camo perspective
  - more widely collected than colored glass
* Clear glass is the glazing material of choice by most professionals
  - most easily contaminated by other colors
  - used on the back and face
  - magnifies the sun and intensifies the heat
  - nearly transparent material

Nebula
* All nebulae contain the necessary components of a star.
* Many nebulae are the birth place of stars
  - have young stars forming at the same time
* Most nebulae are capable of producing stars
  - of vast size, even millions of light years in diameter
* Most nebulas absorb light
  - consist of gases
  - contain dust
  - emit light
  - have mass
* Some nebulae are regions of gas and dust in space where new stars are born
  - glowing gases and dust which have been puffed off by dying stars
  - small and dense, others can be dozens or hundreds of light years across
  - the remains of stars that have exploded
  - form stars and some are formed by stars
  - give birth to new stars, and dying stars expel nebulae
* Some nebulas contain gas vapour
* Some nebulas reflect blue light
* are clouds of gas or dust in space, far outside our solar system
  - formulations
  - gases that are floating in space
  - heavenly bodies
* are located in space
  - universes
  - spots
  - symptoms
  - the raw materials from when stars form
  - where stars are created
* exist within other galaxies as well as in our own Milky Way galaxy.

### nebula:

Dark nebula
* Most dark nebulas absorb light.
* e are big blobs of gas or dust in outer space
  - clouds of dust which are simply blocking the light from whatever is behind
  - just that - dark
  - propably the least observed objects
  - the only nebulae dense and cool enough to allow stars to form
  - follow the same notation except that the lines are dashed

### nebula:

Planetary nebula
* Some planetary nebulas are a thousand times larger than our solar system.
  * e are very special objects because they can help make more stars. When a star dies, the metals that were in the core of the star are sent to other places in the universe. The only place that these metals form are in stars. This is called nucleosynthesis.
* are big, bright clouds of gas and dust that puff out from an exploding, dying sun
  - remnants comprised of illuminated material that surrounds white dwarfs
  - the biggest carbon-producing objects in the sky
* e appear through the telescope as small disks with well-defined boundaries.
* e are another type of emission nebulae
  - astronomical objects made up primarily of gaseous materials
  - ball-like clouds of dust and gases that surround certain stars
  - easy to find in other galaxies
  - huge clouds of glowing gas that certain kinds of stars emit near death
  - important sources of the gas in the interstellar medium
  - large luminous shells of material ejected from dying stars
  - of the emission type
  - shells of gas thrown out by some stars near the end of their lives
* e are the end stage of the evolution of stars such as our sun
  - perfect test particles
* e are very bright, and readily discovered out to large distances
  - evolve from gas and dusty clouds surrounding red giant stars
  - have nothing to do with planets
  - indicate relative brightness of the central star, brightness of halo and more
  - provide another measure of abundances in the Milky Way and other galaxies
  - seem to mark the transition of a medium mass star from red giant to white dwarf