What is used in various ways?
Infrared radiation
How many ways is it used?
a lot
What are the general ways it is applied?
industrial, scientific, and medical
What helps you not be noticed at night?
Night-vision devices
What does it use?
active near-infrared illumination
Is the point of visibility exactly known?
no
What is the general range?
between 700 nm and 800 nm,
Where does the eyeball become not as perceptive?
above 700 nm wavelength
Do astronomers use it?
yes
For what?
to penetrate dusty regions of space
Like what?
molecular clouds
Can it be helpful with medical stuff?
yes
How so?
to observe blood flow
How can it help an electricity unit?
detect overheating
How wide can the waves be and still be noticed?
780 nm
When is it hard to notice?
above 700 nm wavelength
How can hard to notice things be fixed?
by indirect illumination
What is brighter than most things when noticed?
Leaves
Can an eyeball be adjusted for this?
yes
What is the outcome of this observation called?
the wood effect