I was tempted to entitle this thread “There is no such thing as gravity” and I hope to come to it later on. But to start with something familiar to everyone, let’s put these three spheres in your favorite spot in space and you tell me what happens.
Will they form a planetary system among themselves and how long will it take? What is different whether they are on orbit or in outer space?
Assuming they are placed motionless with respect to one another, and assuming no other influences, they will fall toward each other,
there will be a series of collisions and rebounds. At each of these, some of the system’s energy will be converted to heat and they will eventually come to rest as a clump.
The question “How long will it take?” depends on their distances from each other. If they are equidistant from each other, the golf ball and the marble will be drawn to the baseball, while moving toward each other much more slowly. If they’re not equidistant from each other, it gets complicated. But given enough time, they’ll wind up in a clump (assuming there’s no outside influence).
Before you “come to that later on,” try this experiment. Stand on a chair. Step directly off the chair. What happens? My bet is that you will rediscover gravity.
Note that, assuming a baseball’s mass is about 0.15kg, and its radius is about 0.05m, the escape velocity of a baseball is about 0.02mm/s. It would be very hard for a person to place the objects motionless to such a precision that the golf ball and marble would not have escape velocity relative to the baseball.
Edit: But also, OP, don’t be coy about why you think there’s no such thing as gravity.
Glad that wasn’t just me. I sense a ‘Gotcha!’. I supect it will be along the lines of gravity being an effect, not a cause
The question is a famous problem in classical mechanics and surprisingly difficult to answer.
Well, sure, but that doesn’t mean the three objects will wait until they’ve worked it all out before doing anything. Or indeed that gravity doesn’t exist.
Interesting the OP gave 3 objects. Assuming a highly idealized initial state: no outside forces, essentially no initial motion, with 2 objects they will circle, collide, bounce, etc., but stay close to each other. With 3, however, it’s possible that one of the smaller mass ones will get ejected from the system and go off on its own. It’s going to take a long, long time however given the weak forces involved and the tiny speeds that can be imparted. (Cf. leahcim’s post.)
What if they vote and they decide 2-1 that gravity doesn’t exist. Majority rules.
Unless you miss the ground.
Earlier this year, I was walking under a crabapple tree and one of the fruits fell on my head. That was the day I discovered crabgravity.
Too bad you didn’t do it every day. You might have to see a doctor.
Well, he wouldn’t be able to, would he?
A baseball, a marble and a golf ball walk into a bar. The bartender says “See ya 'round!”
A baseball, a golf ball and a marble walk into a bar. The bartender says “We don’t serve balls in this bar.” And the balls say “Well, we’re not gonna get hyspherical over it…”
A golf ball, a marble and a baseball walk into a bar. Bartender says “We don’t serve balls in this bar.” And the spheroids reply “YOU sure got a pair, don’t’cha?”
I’ve done it - results as expected. What I’m saying is that maybe gravity is NOT one of the fundamental interactions, but another one misinterpreted…
**A baseball, a golf ball and a marble in space - what happens? **
What does this mean? If you don’t want to be misinterpreted, use your words to tell us what you mean.
I’m going to throw this thought out there, regardless. The universe is remarkable in it equanimity. It doesn’t care if the object is in deep space or sitting on the Earth, the laws all apply, and apply the same way.
They clear off. They’re back five minutes later. Bartender says “I told you we don’t serve balls in this bar!”. They reply “Chill, dude - we’re just looking round”.
A baseball, a marble and a golf ball walk into a seedy bar in space. They look around and say, “we better stick together.”
A baseball, a marble and a golf ball walk into a bar. They quickly realize they don’t have any money, but they order rounds anyway.
A baseball, a marble and a golf ball walk into a bar. The bartender says “Hey, we don’t serve your kind!” The baseball goes over and quietly talks to him. The bartender says, “It’s OK, come in.” Two cubes were watching from the corner. One look at the other and says, “Wow. That’s a sphere of influence.”