Is this possible?

[betagold]

So, I'm looking at This Comic, and I start to wonder if this is actually possible. I figure this is the smartest place on the entire forum, so I ask, is this possible?

 

[Transfinite]

I don't have the slightest clue about the science behind the comic, but if it's true then the effect would have to be so miniscule as to be unmeasurable.

 

[Rayne]

I'll have to admit right now that I'm not much of a fan of rotational kinematics, but I'll give it a shot... Through interpretive folk art. muh ha ha.

Ok since I'm too lazy to explain the math behind it and that it would be too difficult to format it the way I want any way, let's just say it works. If I made a mistake, feel free to point it out. I'll make corrections at a later date, but from the top of my head, this is my best explanation.

However before we begin there are a few things that need to be addressed. Momentum sort of acts on it's own, with a mass and some external force getting it started. This addition of force is applied through torque. Applied torque works best in closed systems which we'll see worked out in examples below.

Counterclockwise.. I'm not sure why Randall went with that. I suppose it doesn't matter too much from where you're located.

Now if you were to start spinning right now, realistically you'd die of exhaustion before you made any sort of noticeable advancements in the earth's rotational spin. Even if you could do it your entire life, you just couldn't put that much necessary torque to spin the axis in the opposite direction.

Now let's look at the earth.

My extremely crude version of the earth.

The earth rotates 23.5^o counter clockwise on it's axis.

Now let's assume it's just you and the earth.

If you were start to spin from your current location (defaulting to the US. Sorry rest of the world.) You'd notice you're not exactly aligned with the core. The core's momentum is roughly parallel with the x,y plane.

You can spin and spin, but from where you are, you'd simply influence a new spin, not reverse direction.

If you're going for the full tango, you'd want to be positioned a top one of the poles and do your rotation there.

Also, there's another issue. The only bit of contact you have with the ground is through friction. The small moments of force you add to the ground are so minute, it'd be better to twist a giant screw in the earth and crank it in the oppisite direction of the planet. Of course to do something on that magnatuide, you'd need a really long crank made out of a material that can withstand the shear of the internal bending moment.

Other than that, gravitational force would be the only other effective means of reducing and reversing the spin. However, your mass alone is much too small to influence the mass of the entire planet. Shoot, we're millions of miles away from the Sun, and that thing can swing this billions ton thing of rock for a loop every year.

It's not like we can bully our planet around by sheer force.
Of course as the old saying goes, 'why don't you pick on someone your own size?'

Of course our own moon, at being about a fiftieth of the earth's mass, can heavily influence our rotation as well as a few of our surface features.

Adding the moon to the equation, while rotating, you'd now have to work against the gravitational force applied by the moon. It's small, but it'd counteract nearly any effort you tried to place into spinning the earth backwards.

I'm sure you're aware that the tides are caused by the gravitation pull of the moon.

Well it's also true that the gravitational effect the moon has on our water may be true for what internally happens as well and that one day we may become tidally locked with the moon's orbit. In other words, millions of years from now one of our days will be exactly one lunar orbit around the earth.

The origins of the relationship between the moon and earth is uncertain, but being locked by gravity, the earth's rotation, its very momentum, must be shared with our neighbor since momentum is conserved. The eventual slow down process is just equilibrium at work.

As for you spinning in circles. Just watch where you puke, k?

If Megagargomon from Digimon Tamers can force a vortex to reverse by rotation and overcome an angular velocity faster than the speed of light, then sure, then by that logic, a baby can handle this. [/terrible sarcasm + reference]

 

[Habunake]

Seems like alot of physics to use a simple pick up line.

:X

 

[betagold]

I was thinking more along the lines of having hundreds of thousands of people do this all at the same time, a la Global Orgasm Day...okay, maybe that wasn't the best analogy, but it works. Maybe on the longest day of the year, or some such thing, to give a few extra minutes of daylight.

 

[Rayne]

Except ... many more people doing it doesn't really help. It would take the efforts of a single combined mass rotating in a coordinated fashion to create a more efficient reversal.

There was a 'world jump day' two years ago, with a premise to knock the earth into a longer orbit. But that wouldn't work because by being a part of the same system, both you and the earth push each other away equally and then gravity pulls the both of you back to the same point so I believe there is no net distance that you and the earth moved. Plus, it's not like everyone could have landed at the same time anyway. The only changes would be small seismic tremors, caused by people shifting rock, but that doesn't really change anything.

Kinda like this scenario here.

 

[Drybones|ROOTBEER|]

Its not true. The earth itself must spin slower, not only one person.