PHYSICS🚀 Flashcards
(54 cards)
What are the two types of telescopes?
Refracting and reflecting.
How does a reflecting telescope work?
A reflecting telescope works by the light entering the telescope, and reflecting off a concave, or curved mirror, onto a flat mirror, that reflects the lights off onto the eyepiece lens, creating an image.
How does a refracting telescope work?
They work by travelling through the objective lens, which reverse the image to be the correct way round, creating an image where the lines converge, known as the focal point, into our eyes.
Name a similarity and difference between the two telescopes.
They observe distant objects in space, but refraction only can use light to work, reflection can use any electromagnetic radiation.
Is the Hubble Space Telescope a reflecting or refracting telescope?
Reflection
Compare the Hubble Space Telescope and the Kepler Space Observatory.
Similarities:
* Observes space.
Differences:
* hst takes pictures, kepler detects changes in intensity, figuring out the size.
* HST observes the Solar System, Kepler observes exoplanets that might support life.
* HST is a decorative, picture based purpose, Kepler is scientific focused.
Why does a refracting telescope need two lenses?
To make the image parallel again after it has been converged.
What is the current model of the Solar System, and which two men developed it?
Heliocentric; Capernicus and Galileo
What is the heliocentric model?
- The Sun is at the centre of the Solar System.
- The Earth is the third planet from the Sun, and orbits it.
- Moons orbit their planet, not the sun.
Why was the heliocentric model developed?
Because of the observation of retrograde, why would planets go backwards if they orbited a stationary Earth? Also, Galileo using his telescope to observe moons orbiting Jupiter, which didn’t match with the geocentric model.
What used to be the model of the Solar System, and who developed it?
Geocentric; Plato, Aristotle and Ptolemy
What was the geocentric model?
Earth was at the centre of the Solar System, completely stationary, everything orbited it, the six planets
What was another problem with the geocentric model, in addition to retrograde motion?
In the 17th century, Galileo observed with his telescope four stars apparently orbiting Jupiter. They were the 4 moons, Io, Callisto, Europa, and Ganymede. This completely disproved the old model as everything should be orbiting the Earth.
Compare the two models of the Solar System.
Similarity:
Moon orbited the Earth
Difference:
Object at the centre, everything orbiting said object.
Why does retrograde motion happen?
Planets move at different speeds, so orbits can be closer and further apart. This means planets get closer and further away, appearing that they move backwards.
What did Indians originally think the Earth was?
Flat
What did Thai people think the Earth was suspended by?
The Earth was held up by a turtle.
How long ago was the Big Bang?
13.7 billion years.
How many minutes after the Big Bang were the first elements, hydrogen and helium formed?
3
How long did it take for the universe to cool down?
400,000 years
How old is the oldest star?
13.2 billion years old.
How long ago was the Sun formed, along with the rest of the Solar System?
4.6 billion years.
Why could atoms not be formed at the beginning of the Big Bang?
It was far too hot.
What is the widely recognised theory about the creation of the Universe?
The Big Bang Theory
