Planet Speed

[Emageht Tsoluoy]

I wonder if planetary velocity if governed in part by its density, and drag coefficient...

If planets orbit the gravity well of the sun in the fabric of space like a marble circling a bowling ball on a bedsheet...

i wonder if making something sufficiently small and dense will increase its gravity enough to allow it to travel the fabric of space in a similar manner, ike rolling a marble on it's own trajectory on that same bedsheet.

I imagine something with the density of the earth and the size of an aircraft carrier would be exponentially more nimble and mobile than a planet.

I am probably crazy though.

[nextormento]

There's no drag in empty space.
orbital speed is governed by mass and distance. A black hole the mass of the earth would travel just as fast around the sun.

[Kujako]

Only thing that noticeably effects an object in space once it's in motion is gravity or hitting something. That's ignoring complex things like dark energy...

[Tradewind]

gravity is relative to an object's mass anyway, not its density.

[Nadiru]

And Earth is about as large a planet as you're going to get that can actually leave. Any larger and the planet's gravity well makes it practically impossible to leave the atmosphere using conventional means. Earth is already right on the boundary itself.

[Kujako]

Put another way, gravity is relative to mass. Mass relative to volume givens us density. Weight is the effect of gravity on mass.

[Emageht Tsoluoy]

gravity is relative to an object's mass anyway, not its density.

density... mass... imaderp

also there most certainly is drag in space, on a planetary scale at least.

100-300 tonnes of cosmic dust enter the atmosphere each day.

Just like stationary air hitting a moving vehicle creates drag, stationary dust hitting a moving planet creates drag.
(although the air and dust is not really stationary, just stationary relative to the object moving through it)

[nextormento]

also there most certainly is drag in space, on a planetary scale at least.

Notice I wrote "empty space" to cover for that. The cosmic artifacts we go through are some 20 orders of magnitude smaller than the mass of the planet, or, in other words, negligible.

[Tradewind]

The mass of "space particles" are so insignificant compared to pretty much everything they impact that their effect is pretty much fuck all.

[Emageht Tsoluoy]

Notice I wrote "empty space" to cover for that. The cosmic artifacts we go through are some 20 orders of magnitude smaller than the mass of the planet, or, in other words, negligible.

negligible, but not nonexistent.

When playing around with the sliders of fantasy physics, it would be truly nonexistent, and may have a significantly noticeable impact at that point.

[Pterodactylus]

The mass of "space particles" are so insignificant compared to pretty much everything they impact that their effect is pretty much fuck all.

Millions and millions of dust particles over billions of years? For every action there is an equal and opposite reaction. Thanks Obama.

Just as an FYI:

Satellite observations suggest that 100-300 tonnes of cosmic dust enter the atmosphere each day

[Atrea]

negligible, but not nonexistent.

When playing around with the sliders of fantasy physics, it would be truly nonexistent, and may have a significantly noticeable impact at that point.

Negligible to the point that over the course of several billion years, there has been no real change as a result.

Why are you even arguing, when it's clear you know nothing about astrophysics?

[Arkenaw]

These threads always end up becoming a bunch of people who know nothing about the subject arguing over incorrect facts and assumptions.

[Kujako]

These threads always end up becoming a bunch of people who know nothing about the subject arguing over incorrect facts and assumptions.

Isn't that more or less all of the Internet?

[Emageht Tsoluoy]

Negligible to the point that over the course of several billion years, there has been no real change as a result.

Why are you even arguing, when it's clear you know nothing about astrophysics?

Yes. /10chars