• Little Fact: Gravity between two humans? Almost non-existent! 🕺💃
• Two big rocks, each weighing 1000 tonnes? Their gravitational pull is just about one newton when they're cuddling.
• For us to really feel the force of gravity, one of the masses needs to be the size of, say, Earth! 🌍

• Gravitational force is the shyest and weakest among the fundamental forces.
• We gauge its strength using the concept of a tiny "test mass".

Real-World Analogy: Think of measuring the spiciness of a dish. You wouldn’t eat the whole dish at once (unless you're really brave! 🌶️). Instead, you’d try a tiny bite.

• This test mass has to be tiny; otherwise, it's like throwing a basketball in a pond and hoping the ripples won't affect your measurements. 🏀💦

• Remember how we talked about the test mass? The force it experiences due to gravity is F.
• So, g = \(\frac Fm\)​ where m is the size of this test mass.
• Units? Nkg^-1.
• Bonus: Gravitational field strength isn’t just about how strong the force is, but also where it points! Hence, it’s a vector. ➡️

TL;DR: The gravitational field strength at a point is like asking, "Hey, if I put a tiny test mass here, what force would it feel and in which direction?"