From a biased perspective, Physics is a beautiful branch of science. However, from a less biased perspective, it is also incredibly interconnected. Ranging from formulas being applied to countless scenarios, occasionally using formulas from multiple sections, to two seemingly unrelated concepts having a correlation, there are many surprises all over the Physics world. Speaking as a high schooler with a little experience into the university Physics, the further you explore into classical Physics, the greater you appreciate how the world actually makes sense. Welcome to part 1 of this interconnection of Physics exploration, where we begin with three of the fascinating connections.
1. Scalar and Vector Quantities
Beginning with the simple connections, scalars provide a numerical magnitude (ex: 5m/s) and vectors provide both magnitude and direction (ex: 5m/s @ east). Because vectors also include direction, there may be scenarios where some vectors cancel (ex: 5m/s @ east + 10m/s @ west = 5m/s @ west. Recall that west and east are in opposite directions so 5m/s @ east cancels with 5m/s @ west).
However, this characteristic does not exist for scalars; instead, you simply add their values (ex: 5m/s + 10m/s = 15m/s). Sometimes, the direction does not matter (ex: 5m/s @ east + 5m/s @ east = 10. Similarly, 5 + 5 = 10. Both magnitudes are the same.)
Scalars and Vectors are the fundamental building blocks into the Physics world, and they both clearly relate to one another in any scenario that involves numbers. In practice, if a bird flies at a speed of 5m/s, it is a scalar quantity. If the bird flies at a speed of 5m/s @ east, it is a vector quantity because it includes that direction. The only difference between the two is that vectors concern direction, whereas scalars do not.
2. Micro and Macro Views
Micro means “small” and macro means “large” . Therefore, in Physics, microscopic levels typically refer to sizes similar to the atom, and macroscopic levels to the vastness of the universe. Here, it becomes harder to connect Physics ideas together. It requires practical use and some imagination, however, to actually see these correlations.
Think about gas particles, oxygen, for example, and consider how that microscopic thing contributes to the Earth, a relatively macroscopic thing. An important thing to note is that the laws of Physics are the same for both microscopic particles and macroscopic particles. Yet, these two states, which don’t necessarily directly interact with one another, make up the entire universe!
A more thorough example would be the device that you are holding to read these words. Electrons, a subatomic particle, are moving around in your device and creating electricity, leading to the power that your device uses!
3. Gravity and Electricity
As a quick overview, gravity forces attraction between two masses (i.e. things that weigh something), and electricity is the interaction between charges. Referring to what was mentioned earlier, finding this connection also requires some imagination!
Inside Earth, gravity is all around us. Because everyone and everything weighs something, we all experience an attraction to the center of Earth. It is the reason why we fall back down after jumping, let alone why we do not just float. No matter how light or heavy you are, we will always feel an attraction to Earth’s core. On the other hand, the fundamental idea for electricity is the idea that like charges repel (electrons repel from one another) and unlike charges attract (electrons are attracted to protons).
Notice how both gravity and electricity causes attraction. The only major difference between the two are that electricity can cause repellent interactions and that they both concern either mass or charge. In addition, those that are familiar with Physics may have noticed the parallelism between the formulas for their forces (Gravity formula / Electricity formula). Both formulas concern with the distance between charges/masses, and includes a universal constant. In fact, both universal constants are found using a torsion balance and seeing how each force affected a string’s rotation.
Part 2 Coming Soon!
With that, part 1 is over. So far, we have explored the connections between scalar and vector quantities, microscopic and macroscopic interactions, and the parallelism between gravity and electricity. Recognize that after each connection, it requires more and more imagination, as well as application, to discover the next one. Hopefully, this first out of two blog posts not only reminds you that the laws of Physics are consistent, but consistent to the point where these surprising connections emerge!
