Topic 2 Flashcards
Name some developments and impacts of modern telescopes
Greater magnification
Recording observation using photos
Can be made with greater precision
They can detect other parts of the
electromagnetic spectrum
What are some signs of alien life?
Liquid Water
Oxygen in the atmosphere from photosynthesis and plants
Living organisms release waste. If one of these chemical changes is detected it could mean life.
What is the life cycle of a star?
- A nebula (Gas(Mostly Hydrogen)) the dust and gas is pulled together by its gravity and it turns from GPT to K energy making it hotter.
2.Eventually the gas gets hot enough for the nuclei of the hydrogen atoms to fuse together and turn into helium. this releases lots and energy and star begins to shine. - After about 10 billion years the star will have used up most of its fuel, and will turn into a red giant.
- Eventually the fuel runs out and gravity pulls the materials together to form a white dwarf which cools off into a black dwarf.
Some big starts may go into a supernova and is the mass remaining is less than four times the mass of the star it will turn into a neutron star. Otherwise it forms a black hole.
What are the two main theories about the universe?
The big bang - The entire universe started out as a single particle about 13.5 million years ago. The universe expanded from this point and is still expanding
Steady state - The universe has always been there. It is expanding and new matter is being created as it is expanding
What is Red Shift?
When something moves it compresses the waves in front of it and expand the waves behind it. This can be seen in the light waves that it gives off. If something is moving towards us we see it as slightly blue. If something is moving away from us it is on the red side of the spectrum. We can use this to see if objects in the universe are moving closer or away from us.
What is Infrasound?
Sounds and frequencies lower than 20Hz are called infrasound
What is Infrasound used for?
Infrasound travels further than sounds with higher frequencies. Therefore some animals such as elephants use infrasound for communication
Meteors burn up in the atmosphere and release infrasound which scientists can detect
Volcano’s do this as well
What is Ultrasound?
Sounds with frequencies higher than 20,000Hz are called Ultrasound
What is Ultrasound used for?
Animals - Communication
Sonar
Ultrasound scans
What is a P wave?
P waves are longitudinal waves, P waves travel faster than S waves
What are S waves?
S waves are transverse waves, S waves are slower than P waves
Name the different levels of the Earth?
Crust
Mantle
Core
How do earthquakes happen?
Tectonic plates move due the convection waves underneath the plates.
There are no gaps between the plates so they slide together, forces build up so the plate breaks
The sudden movement of the plate causes earthquakes
