The internet produces physics-shaped content faster than any teacher can grade it. After fifteen years of students sending me links, I’ve sorted the material into a handful of recurring shapes. Learn the shapes and you can triage a video in under a minute. The shapes repeat because the incentives repeat: a good physics video takes a week of calculation, and a bad one takes an afternoon of enthusiasm.
The recurring character is the garage inventor with a machine that produces more energy than it consumes. The camera loves these. The wiring in the base is always a tangle, which is convenient, because a tangle hides a battery. A variant runs on magnets arranged just so, which is how you know nobody in the video has read a force diagram.
The usual suspects
Perpetual motion machines fail the same way every time: energy leaves the system somewhere the camera doesn’t point. A machine powering a 1000 W heater “forever” delivers 24 kWh a day, which is 8.6 × 10⁷ J, and the inventor never says where it enters. Magnets don’t supply it, since a magnet returning to its starting position has done no net work.
Second shape: the word “quantum” doing the job of an equation. Quantum mechanics is a specific mathematical theory with a track record of correct predictions. If a claim about healing water or a frequency bracelet cites “quantum resonance” and no numbers, it’s borrowing the word’s prestige and skipping the word’s content.
Third shape: relativity as a slogan. “Everything is relative” is usually a request to stop checking. In physics, relativity means specific statements about measurements in different reference states, most famously that the speed of light is the same for all of them. It constrains claims tightly.
Fourth shape: the single unrepeatable demonstration. A guy in a workshop does an experiment once, on camera, with a result that would overturn a well-tested law. Real experiments come with error bars, repeated trials, and an apparatus description. If the video has a dramatic soundtrack instead of those, grade accordingly.
Resonance gets abused often enough to count as its own subgenre. The Tacoma Narrows bridge failure appears in hundreds of videos as proof that any vibration destroys anything. The bridge twisted in a wind-driven aerodynamic flutter, which is related to resonance the way a car crash is related to parking. The video’s lesson is real physics with the mechanism swapped out.
Another shape lives in headlines rather than videos: the experiment that “changes everything”, reported before the paper exists. Ask for the paper. If one turns up, read the units in the abstract before you read the claims in the press release. If none exists, the story has already done all the physics it plans to do.
Four questions that do the grading
Where does the energy enter, and where does it go? Most fake machines fail this question alone. What are the units? A claim expressed only in adjectives has told you nothing measurable. Can I compute the number myself with high-school physics? For the magnet motor, I did, and 8.6 × 10⁷ J a day appeared out of nowhere. What does the claimant lose if they’re wrong? People who are right accept tests and bets. People who are selling something decline both, politely, and upload another video.
I grade these videos the way I grade homework: units first, enthusiasm second. Two minutes with a calculator disqualifies most of the genre, which leaves you the good stuff, where the physics is real and the numbers hold up.