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I was inspired by a diagram tweeted by University of Massachusetts Physics Professor, Robert Fisher @fisherastro that lead to referencing a video called Episode 31: Voltage, Energy And Force - The Mechanical Universe. 8 yrs ago - https://twitter.com/fisherastro/status/1256414640399147009 https://twitter.com/ClaireCSmith/status/1255013738727518210
- I had a conditional offer to study an #Electrical #Engineering degree by a lecturer who had read some of my short essays on my website & asked what level I had studied physics & maths at (was O level for both). I didn't take up the offer as it wasn't the right time to study-
- but knew that at some point I would reference it in some way & that it was a good opportunity & to take the gesture with me for the rest of my life. On the continuation of this theme, I decided to write a little about it here. Referencing Episode 31: Voltage, Energy And Force -
- 'The Mechanical #Universe', we are taught about the fundamental areas in #physics covering #electrical potential. At 1st, it's common to assume the term #energy as a static entity but this e.g. shows it’s the conversion that surprises the learner, not just the value of each -
- component on its own as at 1st, elementary terms are learnt as individual parts, like voltage, energy & force but later it’s vital to introduce the maths for a rate of change, written dy over dx, to include first & second order, change as time & a function of the derivative -
- My book ‘A First Course in #Calculus’ by Serge Lang, shows an e.g. as the function y = x2. Back to the video, we are introduced by Caltech Professor, David Goodstein & taught the principles of electrical forces. Prof Goodstein asks students if a machine developing a voltage -
- of a hundred thousand volts & using a bank of 100 Leyden jars to store #energy in (as 2000 joules of energy) is impressive but he answers that it’s not & in fact about only 1 half of 1 food calorie. A joule is a unit of energy of work & 1 newton of force over a distance of 1 -
- meter, or as kinetic energy of a 1 kilogram mass moving at 1 meter per second & thought in that way, makes it sounds much less impressive, but what matters is the fact that the students has learnt how to think about why - that’s impressive. Voltage or electric potential is a -
- measure of the potential energy of an electric charge. Prof Goodstein asks what’s important about #electricity & says point electrical charges are in a vacuum with positive & negative charges that attract or repel each other, with force that varies #inversely with the square -
- of the distance between them. He later says, in order to understand electricity we must 1st understand #matter but matter is electrical in nature, but in order to understand matter, we must 1st understand electricity! The e.g. for electric potential in the vid uses elevation -
- as a good analogy, whereby moving up the incline of #potential is hard work & the steeper it is, the harder it is to climb & if the potential isn’t changing, there is no work at all. It uses contours of constant #electric potential & says the electric field is a #negative -
- #derivative of the potential. After grasping force on a charged conductor & the #equation for flux as a magnetic field multiplied by the perpendicular area that it covers, the next area is to jump a bit & move on to electric #charges at rest, flux density & electric flux to -
- force on a charged conductor & the #equation for flux potential lines on a parallel plate capacitor about flux lines & equi-potentials that are almost square (but not!). In my 2nd fav #science book, Electromagnetism for #Engineers by P Hammond (1975), pg 56, section 3.10, ref -
- Figure. 3.21, ‘Field near the edge of a parallel-plate capacitor’, but just before the equation, P Hammond writes:
“The picture looks very complicated, but with a little practice one can make fee-hand #sketches which are quite accurate”. Wow, I love it! From my slightly more -
“The picture looks very complicated, but with a little practice one can make fee-hand #sketches which are quite accurate”. Wow, I love it! From my slightly more -
- detailed book, ‘Electronics Made Simple’ by Henry Jacobowitz, we learn that #Electronics is about what goes on inside circuit diagrams. Some e.g. - transistors & #semiconductors & current flow across P-N junction with forward bias. Later, oscillators & frequency amplifiers. -
- This important hardware makes up most of the TV’s (it did in 1962 when the book was 1st written!) we use today, including radar & navigational aids etc. 1 principle of learning is that in order to grasp difficult concepts, the #learner (or #student) has to work against their -
- preconceptions that easily flow, much like current in electricity, as this is how they are taught in a prescriptive way & they think this is the only way to learn. In this instance, the world of #physics is about the study of energy that can be easily grasped, but as learning -
- pushes against those preconceptions, much like the e.g. in the video illustrated by computer graphics pioneer Jim Blinn, showing incline of potential as hard work, & the steeper it is, the harder it is to climb, & if the potential isn’t changing there is no work at all & as -
- a push of voltage in 'The Mechanical Universe' is to learning, physics does tend to get trickier & although is more work compared to other subjects, the byproduct is a wider & more qualitative grasp of science.
That's electrifying!
2 pics from my 'The Wonder Book of Science'
That's electrifying!
2 pics from my 'The Wonder Book of Science'
Decided to watch BBC's Shock and Awe, The Story of #Electricity (again) with science hunk @jimalkhalili 1 of my fav science presenters on #BBC4 (when it had proper science & good programmes - the ones we had to run back home in order to especially watch on TV, in the olden days)
