In part 2 of my MRI series, I discuss how an external magnetic field affects the magnetic moment of the hydrogen nucleus. In particular, how it aligns and precession. Both are explained at length in a non technical fashion
One of my students asked me to quickly review a bone scan with an X-ray image. Here is a quick video I produced
CAT or CT scans are used to achieve high resolution images inside the body. But how do they work? Watch the video to find out
Reviews how an A brightness (B) scan is produced in the context of ultrasound/sonograms
Reviews how an A amplitude (A) scan is produced in the context of ultrasound/sonograms
An intro to ultrasound (sonograms) and the underlying factor (acoustic impedance) that determines how an image is formed.
Want to know how the eye focuses or accommodates? This video goes through the physics of accommodation, how the eye adjusts in order to produce a sharp image on the retina. It also covers long and short sightedness and how to fix them.
In this video I cover the difference between the two lens types and how they produce virtual images.
In this video, I go through refraction using the excellent animation from pHET (http://phet.colorado.edu) I discuss the basics of refraction as well as Snell’s Law.
This video covers how crystals are used to create and receive high frequency sound. Apart from their use in small speakers, they are especially useful in their used of transducers for ultrasound imaging.
How do you make a current carrying wire into an electromagnet? This video explains the physics of the solenoid, covering both the shape and size of the magnetic field it generates
What is an electric field? How do you draw them diagrammatically? Watch the video as I explain fields around – single charges – multiple charges – plates
A follow up of my first video on circuits, this video explores the mathematics. of circuits, with the use of Ohm’s Law to determine resistance, voltage and current, in both series and parallel circuits.
In this video I discuss AC motors, in particular, synchronous motors. I then lead on to the physics behind induction motors
I run through a basic explanation, without involving quantum physics, to explain why the magnet levitates
How do two bits of semiconductor make a diode? In this video, I show you what happens when you put two semiconductors together and how that is able to convert AC to DC
This is an addendum to my Michelson Morley Experiment video It explains the maths behind why they thought the light paths would arrive at different times
In part 4 of my 5 part series I discuss how an image is formed from the result of relaxation. I also discuss T1 and T2 weighting and how that proves the image.
In my final part of a 5 part series on MRI, I discuss how the MRI machine uses gradient coils to determine the location of precessing hydrogen atoms. I also do a brief review of all 5 parts
In part 3 of my MRI series, I discuss how an radio frequency alters the aligned precessing nuclei through the process of resonance Both are explained at length in a non technical fashion