Light & Optics 1-2 Flashcards
1
Q
What did Archimedes do?
A
- Archimedes (yes, the guy
with the screw) created an
invention to burn boats - Used a series of mirrors
and lenses - Would focus light on boats
in the Syracuse Harbour
2
Q
What did Euclid do?
A
- Another Greek mathematician
- Shining a light on a flat mirror
- Suggested light travels in
straight lines - Discovery:
–The angle of the incoming
beam is equal to the angle of
the reflected beam
3
Q
What is ptolemy?
A
- Described the bend of light going
from air to glass. - A principle we now know as
refraction (more on that later
in the unit)
4
Q
What was the correlations between Newton and light?
A
- Very interested in rainbows and
light - Shone white light through a prism
–It separated into the colours of
the rainbow - Passed the rainbow through a
second prism
–Colours combined and the light
was white
5
Q
What is the speed of light and how was it determined?
A
- Early scientists knew light travelled, just not how fast
- Mirrors were placed on two different mountains and
sensitive timing devices were used - Beam of light was sent from one mirror to the
other - By dividing distance by time speed of light was
determined as 299 798 km/s.
6
Q
What are the (4) basic properties of light?
A
- Light travels in straight lines.
- Light can be reflected.
- Light can bend.
- Light is a form of energy.
7
Q
What is an optical device?
A
- Any device that
uses light - It could be a
mirror (simple)
or the Hubble
telescope
(complex)
8
Q
When were microscopes made?
A
- First microscope is believed
to have been built in 1595
Hans and Zacharias Jansen of
the Netherlands - Very simple design, but led to
great discoveries
9
Q
Who was Antonie Van Leeuwenhoek?
A
- Dutch amateur scientist
- Experimented with a simple
microscope - Looked at things like pond water,
blood and his own tooth plaque - He saw small moving organisms
which he called “little animalcules”, a
shock to the scientific community!
10
Q
What is microbiology?
A
The study of micro organisms
11
Q
How do microscopes work?
A
- Combine the power of at least
two lenses so you can see great
detail - Two lenses are: Eyepiece and
objective - Light shines through the
specimen and a large image is
produced by looking through the
eyepiece
12
Q
When were telescopes made?
A
- Early astronomers used a
single lens to get a better
look at the stars - The telescope
revolutionized astronomy - First telescope: 17th century
Netherlands
13
Q
Who was Galileo Galilei?
A
- Heard about the telescope and
made his own in a day- it wasn’t
great, but it did the job - Began developing better higher
power telescopes - Amazing astronomical discoveries
- Telescopes have two characteristics:
– Magnify
– Collect light
14
Q
What is a refracting telescope?
A
- Have two lenses, one at each
end of a long tube - Larger objective lens collects
light, focuses light on the eye
piece - In turn you see the image larger
than with an unaided eye
15
Q
What is a reflecting telescope?
A
- Use a large circular mirror
- Mirror is curved so it collects
light extremely well - Another mirror directs the
light to the eyepiece
16
Q
What are binoculars?
A
- Just two short
refracting telescopes! - Not as powerful as
telescopes - More convenient
because they’re smaller
