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The Amazing Telescope | Astronomy History Of The Telescope- Two Small Pieces of Glass


hey wait up hey wait up I can’t see okay wait for your eyes get used to the
dark and it’s so dark in here because you
wrote it from the bright lights of the city into the dark apart the pupils in
your eyes are slowly opening up right now let more lighting just wait you’ll
be able to see well enough soon is that why i always have they got so
they can see at night yeah the larger the pupil more light and
let sin and that’s why they can hunt at night the telescope we’re gonna look
through works the same way the bigger the mirror or lens the more like the
telescope captures last year in a telescope that was big enough that i got
see galaxies it was really cool hi guys i am so glad you could come i
was looking for you and see you brought your big telescope this year yes I do no way that thing is Hugh and
it sure doesn’t look like the telescope science classroom school the eyepieces
at the back where’s yours it’s at the top that’s why
we need the Latics click-through rate that’s right this is a reflecting
telescope which means the light is gathered on a mirror at the back of the
telescope and reflected to the front of the telescope where it hits another
mirror and the light is reflected again into the eyepiece the telescope your
teacher has is called a refractor that uses lenses instead of mirrors together
and focus the light which is better the reflector or the roof rack it depends on
what you want to observe with your telescope but the general rule is the
bigger the mirror or lens the more light the telescope will gather and the
brighter and more resolved the object you are looking at will be resolved well to resolve an object means that you
can see detail when you look through the telescope from our school you can see
jupiter and it’s four moons but when you look through this telescope you can see
the band of clouds on Jupiter so the better the resolving power or resolution
the better the view right right you have a great memory how could I forget I will always remember seeing Saturn’s
rings for the first time and the spiral arms of that galaxy showed me last year can I look through your telescope
absolutely the whole reason I brought it here how is that really super and what are
those stars lined up on either sat those are the four Galilean moons IO
Callisto Europa and Ganymede why are they call Galilean moons an italian
mathematician and Galileo in 1610 was the first man to see them with a
telescope in fact it’s believed that Galileo was the first use a telescope to
view the heavens he was surely the first to record his observations Galileo
invented the telescope nope can you tell the story of that
Dutch guy sure but let me tell your friend what it was like before there
were telescopes prior to the invention of the telescope everyone believed that
the earth was the center of the universe and at the Sun Moon and planets orbit
around it yeah yeah then in 1543 Nicolaus Copernicus
proposed a different model with the Sun not the earth at the center this was a radical idea but he had no
evidence to prove it nearly 65 years later in 1608 a dutchman
named Hans slipper hey took two small pieces of glass and fix them in a tube
creating a spyglass a few months later Galileo read accounts
of it and built his own on a clear evening in January 1610 he
pointed toward Jupiter the telescope’s narrow field of view made it difficult
for him to find Jupiter but when he did he saw three stars next to the planet
one to the right and two more on the left he watched these points of light over
several nights noting how they changed their position he determined that they
were moons orbiting Jupiter not the earth this became the first observational
evidence that the heavens work differently than what people had
imagined up to then Copernicus theory that we orbited the
Sun was eventually proven using Galileo’s new window on the universe the
telescope and he saw more than just Jupiter’s
moons his telescope magnified enough for him to recognize that there are
mountains on the moon spots on the Sun and that Venus goes through phases like
our moon he also saw that the Milky Way was made
up of thousands of stars now would you like to look at Saturn
sure ok give me a minute ok take a look Wow is that real it’s real Galileo see Saturn in his telescope yes
but he only saw an oblong point of light because his telescope like the
resolution to see the Rings he described it as a planet with ears the dutch
astronomer Christiaan howkins using a 23 foot long refracting telescope revealed
that Saturn is a ringed planet and discovered its largest moon Titan was
his telescope as big as this one it was quite a bit longer but the aperture of
the lens was just a few inches in diameter why was his longer it has something to
do with how light focuses through the lens something about color and
aberration that’s right when you view a bright star
planet through a simple refractor you see a colored ring of blue and yellow
around its edges by increasing the focal length the telescope or making it longer
the less aberration you get but i only see a ring around chatter and it’s not
blue or yellow that’s because her telescope is not a
refractor it’s a reflector shortly after happens made his long refractors a man
named Sir Isaac Newton did some experiments and figured out that the
color operations were produced when the light passed through the lenses so he
found a way to use a mirror to focus the light just like a lens but without the
color aberrations now you want to see some real color sure ok I’ll . the telescope over here
to a pretty sight Albireo a and B a binary star system
which means these two stars appear extremely close in fact with your on ADA
dies it appears as a single star in the sky I see two stars but they’re not the same
color one is blue and one is gold that’s because each stars of a different
temperature i learned that last year when you look at a candle flame see go
from blue near the wick almost ready at the top each color relates to the
temperature of the flame at the . the top of the flame red part is hot but the
blue part is really hot right again Newton was involved with figuring that
out as well remember the light passing through the
glass lens that created color aberrations well Newton past light
through a prism and figured out the colors of the rainbow correspondent with
different temperatures the blue portion of the rainbow or spectrum is warmer
than the red so not only did Newton figure out how to build a telescope
using a mirror as allen’s removing collar operations he also started the study of light
called spectroscopy these unique discoveries are utilized on telescopes
all over the world every night even on the 10-meter mirror telescopes in la
palma and Hawaii 10 meters that’s like over 30 feet what’s it like with either one of them
astronomers don’t look through telescopes that big they use devices
called detectors detectors take the focus life and your image it into a
digital photograph or great the light up into a spectrum now a photograph can
tell you a lot about an object but a spectrum can reveal the unseen see when
astronomers studying spectrum from a start they can deduce a lot of
information about it by comparing the observed spectrum to
those created in a lab they can tell how hot it is they detect what elements are in the
Stars upper layers they can also observe the Stars apparent motion by how much
the spectrum is shifted have you ever heard a siren from a police car
ambulance change its pitch as it drove by sure what you heard was something
called the dr effect with the sound wave was compressed as it came towards you
and then stretched as it went away the same effect can be seen inspector of
stars that are in motion coming toward your going away from the observer this
effect can also be used to observe motion and galaxies galaxies don’t we
live in a galaxy yes it is called the Milky Way but did
you know that we only known it for less than a hundred years why did it take so long for us to figure
that out before the 20th century astronomers thought the universe
consisted of a flat disk of stars with the earth and the solar system residing
in the center an astronomer named Carolyn Herschel even made a map of this
disk because telescopes of the day didn’t have the resolving power to see
individual stars in other galaxies they thought the patches of light which they
called spiral nebulae were part of this immense disk it wasn’t until the hundred inch
telescope a top mount wilson was built the astronomer see individual stars in
the discs of the spiral nebulae why an astronomer named edwin hubble use
this telescope to observe a special type of star called Cepheid variables and was
not only able to determine that spiral nebula or individual galaxies that he
called Island universes but they were extremely far away look here this is the
closest major galaxy 2 r’s it’s called the Andromeda galaxy didn’t publish also determine that the
universe was expanding yes he did the expansion that he observed and later
observations of cosmic background radiation in the nineteen sixties
confirmed the model that the universe was created in a big bang is that why
they named the Hubble Space Telescope after him that’s right when nasa launched the
Hubble Space Telescope they knew that the telescope would reveal a universe
unseen by land based telescopes of the day see how the stars twinkle yeah our
atmosphere causes that and regardless of how big you make a
telescope the limiting factor in what a telescope can see is the air between it
and space so when they put a telescope in space astronomers knew that they were in for
some surprises the Hubble Space Telescope revealed the formation of
stars and planets the Magnificent remnants of stellar death it has shown us that the universe is
dynamic and not stagnant but what it really showed us is that the early
universe was different than the one we live in today but what do you mean the
early universe isn’t it all the same how can we see the early universe if we
rolled great question see that star over there that’s Vega it’s about 26
light-years away that means that the light which that
start generates takes 26 years to travel to us so we see it as was 26 years ago
now that start over there is called denim and it is 3600 light-years away so that’s the way it looked 3,600 years
ago that’s correct and how old is the light
from the Andromeda galaxy over 2 million years so telescopes are not only optical
instruments they can be used as time machines and the Hubble Space Telescope
look back over 13 and a half billion years when it took an image called ultra
deep field this image revealed a very different universe than we live in today it shows small young galaxies colliding
and merging to form larger galaxies which led to the galaxies that surround
us today so now that we have telescopes in space astronomers don’t need telescopes on
earth anymore right that might have been true if they hadn’t
developed a process called adaptive optics astronomers and engineers can now
measure the distortions caused by the atmosphere in real-time and subtract
them out before the light from an object reaches the focal plane of the telescope because of this technology large
aperture telescopes that operate around the world can now rival the resolution
of the Hubble Space Telescope yeah yeah even larger land based telescopes the
size of football fields are planned to be constructed in the next 10 years and
will look even further back into time yeah what do you think they will see i’m not
sure but i want to be the first astronomers use that telescope good for
you astronomy is filled with puzzles and
unsolved mysteries the recent discovery that the universe is accelerating in its
expansion is one that will need lots of observations to figure out what drives
it dark matter and the physics that hold galaxies together is another one but the
one that excites me the most is that we are close to having the power to observe
earth-like planets around other stars and should be able to detect life on
those planets who knows maybe you will be as famous as
Galileo is today because of two small pieces of glass that he turned to the
heavens launching humanity and the ultimate voyage of discovery yeah yeah yeah yeah yeah

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