Physics HL
5
Chapters
329
Notes
Theme A - Space, Time & Motion
Theme B - The Particulate Nature Of Matter
Theme C - Wave Behaviour
Theme D - Fields
Theme E - Nuclear & Quantum Physics
Physics HL
Theme C - Wave Behaviour
Radar & Doppler Effect: Unveiling Astronomical Secrets
620 words
4 mins read
Last edited on 5th Nov 2024
Table of content
RADAR - what's that about? 📡
- Stands for Radio Detection And Ranging.
- Used for detecting and measuring moving and stationary objects.
- Usually uses microwave wavelengths or a bit longer ones.
- Cool Uses of Radar
- Avoiding collisions in air and sea.
- Detecting weird underground stuff.
- Weather forecasting (Yes! Know if it’s shorts or jacket weather tomorrow!)
- Police speed traps (Caught ya! 🚓)
- Measuring the speed of rain clouds, ocean currents, and even turbulence.
Doppler effect & stars 🌌
- Remember Doppler? He thought about why binary stars change color.
- Modern astronomers use Doppler shift to guess the speeds of galaxies and stars.
- But how do we see these shifts?
- Earth’s lab sources are stationary, so no shift.
- But celestial bodies are moving! So, we see shifts in their spectrum.
- A redshift means the body is moving away.
- A blueshift? It's coming closer!
- Fun Fact: Not all redshifts are due to motion! Some are due to gravity or the universe expanding. Mind blown, right?
Astrophysics - not just gazing at stars! 🔭
- It's all about understanding celestial objects.
- These space detectives use scientific methods.
- They need big telescopes to gather data because space is, well, big.
- Sometimes they share this data in databases, like the NASA Extragalactic Database.
- Example: The Abell catalogue of galactic clusters. (Think of it as the Instagram of space but with a lot of tags!)
Using the doppler effect for speed 🌔
- Doesn’t just work for sound. Can be used for light and radio waves too.
- Like when a police speed gun catches speeding cars.
- Or when docs measure the speed of blood in arteries using microwaves.
- A double shift occurs when a moving object reflects a signal: original shift + reflection shift = double shift! This gives the relative speed.
- Ever wondered about the Moon's speed? Use radio waves and see the shift.
Unlock the Full Content! 
Dive deeper and gain exclusive access to premium files of Physics HL. Subscribe now and get closer to that 45 🌟
Physics HL
Theme C - Wave Behaviour
Radar & Doppler Effect: Unveiling Astronomical Secrets
620 words
4 mins read
Last edited on 5th Nov 2024
Table of content
RADAR - what's that about? 📡
- Stands for Radio Detection And Ranging.
- Used for detecting and measuring moving and stationary objects.
- Usually uses microwave wavelengths or a bit longer ones.
- Cool Uses of Radar
- Avoiding collisions in air and sea.
- Detecting weird underground stuff.
- Weather forecasting (Yes! Know if it’s shorts or jacket weather tomorrow!)
- Police speed traps (Caught ya! 🚓)
- Measuring the speed of rain clouds, ocean currents, and even turbulence.
Doppler effect & stars 🌌
- Remember Doppler? He thought about why binary stars change color.
- Modern astronomers use Doppler shift to guess the speeds of galaxies and stars.
- But how do we see these shifts?
- Earth’s lab sources are stationary, so no shift.
- But celestial bodies are moving! So, we see shifts in their spectrum.
- A redshift means the body is moving away.
- A blueshift? It's coming closer!
- Fun Fact: Not all redshifts are due to motion! Some are due to gravity or the universe expanding. Mind blown, right?
Astrophysics - not just gazing at stars! 🔭
- It's all about understanding celestial objects.
- These space detectives use scientific methods.
- They need big telescopes to gather data because space is, well, big.
- Sometimes they share this data in databases, like the NASA Extragalactic Database.
- Example: The Abell catalogue of galactic clusters. (Think of it as the Instagram of space but with a lot of tags!)
Using the doppler effect for speed 🌔
- Doesn’t just work for sound. Can be used for light and radio waves too.
- Like when a police speed gun catches speeding cars.
- Or when docs measure the speed of blood in arteries using microwaves.
- A double shift occurs when a moving object reflects a signal: original shift + reflection shift = double shift! This gives the relative speed.
- Ever wondered about the Moon's speed? Use radio waves and see the shift.
Unlock the Full Content!
Dive deeper and gain exclusive access to premium files of Physics HL. Subscribe now and get closer to that 45 🌟
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