Today's random IMG is...!

[Ovarku]

[Aramek]

Me leaving work every Friday:

[Ovarku]

[Aramek]

[Minty]

Hahhhh. Seriously laughed out loud at that. Nice one Mekky.

[bananabuddy]

I'm addicted to this show.

[Aramek]

There's a several hundred post thread on SA arguing over this picture:



It has been one of the more hilarious reads in a long time.

The answer is clearly B, by the way.

[bananabuddy]

I'm gonna have to disagree.
I say A.

[Aramek]

Motion is relative, A only happens if there's a sudden force acting on the cube as it leaves the portal to stop it.

Portals conserve momentum.
1- replace cube by cylinder for easier viewing;
2- replace end portal with wall portal instead of 45 degrees.

This is what scenario A would look like from the exit portal:


This is what scenario B would look like from the exit portal:


Which one looks right(er) to you?

A only exists if there's a sudden force acting on the cube to stop the velocity as it exits Blue. The portal is imparting velocity without acceleration. Once the cube is through, its velocity doesn't just stop, and the momentum created by it clearly having the exit velocity carries it past the portal.

[Aramek]

[bananabuddy]

Jun 29, 2012 13:44:02 GMT -5 Aramek said:

Motion is relative, A only happens if there's a sudden force acting on the cube as it leaves the portal to stop it.

Portals conserve momentum.
1- replace cube by cylinder for easier viewing;
2- replace end portal with wall portal instead of 45 degrees.

This is what scenario A would look like from the exit portal:


This is what scenario B would look like from the exit portal:


Which one looks right(er) to you?

A only exists if there's a sudden force acting on the cube to stop the velocity as it exits Blue. The portal is imparting velocity without acceleration. Once the cube is through, its velocity doesn't just stop, and the momentum created by it clearly having the exit velocity carries it past the portal.

B "looks right" because we are accustomed to seeing objects pushed through a hole; there is velocity, and because there is velocity, there is momentum.
Until the cube is engulfed into the portal, it is sitting on a platform, it is static, and, therefore, is without velocity. Until the cube is engulfed into the portal, it has no momentum.
Until the cube is completely transported through the portal, gravity keeps that cube on the platform. You aren't pushing a cube through a portal, you are dropping a portal onto a cube, the cube stays static.

[Aramek]

"Static" is relative, when you realize we're on a giant sphere hurtling through space at hundreds of thousands of miles per hour.


The image should suffice as an example and TLDR for this post. Though to understand it more thoroughly you may need to at least skim the post's later sections.
One thing should be noted which also may add to this example. Consider the observer. He is motionless in space. The crate moving toward him through his view through the portal. If OP's type "A"-physics were to be in effect, a physical paradox would occur in which nothing has acted upon the relative motion of the crate as it passed the gate, yet it simply ceased it's motion (relative to the observer). This can't happen, neither in imaginary nor real physics.


Ultimately, A-style physics from the OP's diagram make absolutely NO sense even within the most basic rules of how the portals work. It MUST be "B". Let me explain. The argument is that the motion of the portal doesn't translate to motion of the object, but this is already false. It very well does, every single time you use one. Motion is not a simple concept of "speed" it also includes heading. As such, a simple example should show why "B" is the only valid application of physics to this given what we already DO know to work.

You have two portals. Both facing north. You walk at 2m/s towards the first portal and you cross through, exiting the other portal at 2m/s. The portal's have changed your motion to a stationary observer outside both portals, which works exactly as B suggests. As you enter the entrance portal you are moving due south at 2m/s as you exit the other portal you are now headed north at 2m/s, you've just changed your state of motion by 4 meters per second. I'm going to say that these portals would have a unique quality multiple relative states. The either portal, used as an entrance, is linked to the exit portal in a straight line to the exit portal's point in space. The straight line is outside of our dimensional concept of "relative". Since heading is part of motion the heading (and thus speed) of the exit portal is relative only to the space that exists after crossing the line of the entrance portal, not to that which is on the other side of the portal, the relative state of the external "straight line" would be that of heading and motion of the entrance or exit portals in relation to that which is external to the portal you are exiting relative to that which is external to the portal you entered. Motion and heading must transfer, since they do when the motion is by the object crossing the boundry, it must cross through this "straight line" into two linked relative states.

A large problem here is that it is wholly imaginary and hard to think in the way that it requires. But just consider that the motion of point plays a big part in the motion of that which exit's it. It seems a lot of the "object at rest" argument ignores some of Newton's laws when considering this function of the portals. The whole statement about "object at rest" is "An object at rest stays at rest or of uniform motion in a straight line, unless compelled to change that state by external forces acted upon it."

So if we consider the aspects of the object using the portals' heading and motion, You'll see it can't be anything but "B" since the motion of the portal translates into motion of a point in space and is thus modified relative to the exit "space" and it's relative motion from as observed from the entrance portal of the space that the exit enters.

Another example that further clarifies what I'm saying is that of the observer, no need to enter the portals to see it as necessary to function as "B". Looking through one portal which is facing north with an exit portal also facing north, you'll find that your line of sight is modified in heading. You are looking north, while looking south. Since we know this to be the case, then we know that not only heading but speed to will be effected by the portal in reference to the space you'll be entering. An object's OWN motion is shifted from one space to the other without loss, as it is considered a straight line, whether a portal is in motion or not. When a portal is in motion, the straight line is warped from your point of observance and the relative state of motion (rest+the motion of the object). If a straight line from your relative "rest" is in motion relative to everything else. Only to those observing it outside of your relative state will see that your straight line is not actually straight. A single case which makes this very clear. Consider the OP's diagram without any platforms and only a piston and portals and a block in front of the orange portal, simply floating in space. This makes it very easy to visualize. If you are the block, you'll observe, relative to you, that the orange portal is in motion. However, if you move from that position and are now looking through the blue portal, you will be absolutely unable to determine if the block is moving or if the portal is moving towards the block, since it is only the expected lack of motion of the surroundings moving that implies that the portal is moving in your head.

[bananabuddy]

Jun 29, 2012 14:57:48 GMT -5 Aramek said:

"Static" is relative, when you realize we're on a giant sphere hurtling through space at hundreds of thousands of miles per hour.

That's besides the point. This experiment is taking place on the earth. For this experiment to make any sense coherently, we must approach it with laws relative to the experiment.

The image should suffice as an example and TLDR for this post. Though to understand it more thoroughly you may need to at least skim the post's later sections.
One thing should be noted which also may add to this example. Consider the observer. He is motionless in space. The crate moving toward him through his view through the portal. If OP's type "A"-physics were to be in effect, a physical paradox would occur in which nothing has acted upon the relative motion of the crate as it passed the gate, yet it simply ceased it's motion (relative to the observer). This can't happen, neither in imaginary nor real physics.

You assume that the space the observer occupies and the space he observes through the portal are one in the same. At least, that's what I think you're saying. I could be wrong.
What the observer is doing is looking through a window into a space where the laws of physics are relative to that space. The space the observer occupies and the space he observes are separate spaces. If the space he observes and the space he occupies are one in the same, then it is to say that, if both portals were to be planted on the ground, the observer would fall towards the ceiling, were he to enter one of those portals.
It doesn't matter what the cube is doing, relative to what the observer sees. Relative to the space that the cube occupies, it is still static. Again, until it fully enters the portal. And that part, I will look into later on in this post.

Ultimately, A-style physics from the OP's diagram make absolutely NO sense even within the most basic rules of how the portals work. It MUST be "B". Let me explain. The argument is that the motion of the portal doesn't translate to motion of the object, but this is already false. It very well does, every single time you use one. Motion is not a simple concept of "speed" it also includes heading. As such, a simple example should show why "B" is the only valid application of physics to this given what we already DO know to work.

You have two portals. Both facing north. You walk at 2m/s towards the first portal and you cross through, exiting the other portal at 2m/s. The portal's have changed your motion to a stationary observer outside both portals, which works exactly as B suggests. As you enter the entrance portal you are moving due south at 2m/s as you exit the other portal you are now headed north at 2m/s, you've just changed your state of motion by 4 meters per second. I'm going to say that these portals would have a unique quality multiple relative states. The either portal, used as an entrance, is linked to the exit portal in a straight line to the exit portal's point in space. The straight line is outside of our dimensional concept of "relative". Since heading is part of motion the heading (and thus speed) of the exit portal is relative only to the space that exists after crossing the line of the entrance portal, not to that which is on the other side of the portal, the relative state of the external "straight line" would be that of heading and motion of the entrance or exit portals in relation to that which is external to the portal you are exiting relative to that which is external to the portal you entered. Motion and heading must transfer, since they do when the motion is by the object crossing the boundry, it must cross through this "straight line" into two linked relative states.

A large problem here is that it is wholly imaginary and hard to think in the way that it requires. But just consider that the motion of point plays a big part in the motion of that which exit's it. It seems a lot of the "object at rest" argument ignores some of Newton's laws when considering this function of the portals. The whole statement about "object at rest" is "An object at rest stays at rest or of uniform motion in a straight line, unless compelled to change that state by external forces acted upon it."

So if we consider the aspects of the object using the portals' heading and motion, You'll see it can't be anything but "B" since the motion of the portal translates into motion of a point in space and is thus modified relative to the exit "space" and it's relative motion from as observed from the entrance portal of the space that the exit enters.

Another example that further clarifies what I'm saying is that of the observer, no need to enter the portals to see it as necessary to function as "B". Looking through one portal which is facing north with an exit portal also facing north, you'll find that your line of sight is modified in heading. You are looking north, while looking south. Since we know this to be the case, then we know that not only heading but speed to will be effected by the portal in reference to the space you'll be entering. An object's OWN motion is shifted from one space to the other without loss, as it is considered a straight line, whether a portal is in motion or not. When a portal is in motion, the straight line is warped from your point of observance and the relative state of motion (rest+the motion of the object). If a straight line from your relative "rest" is in motion relative to everything else. Only to those observing it outside of your relative state will see that your straight line is not actually straight. A single case which makes this very clear. Consider the OP's diagram without any platforms and only a piston and portals and a block in front of the orange portal, simply floating in space. This makes it very easy to visualize. If you are the block, you'll observe, relative to you, that the orange portal is in motion. However, if you move from that position and are now looking through the blue portal, you will be absolutely unable to determine if the block is moving or if the portal is moving towards the block, since it is only the expected lack of motion of the surroundings moving that implies that the portal is moving in your head.

I skimmed, as you've suggested, so forgive me if I've missed something.

Allow me to reply with an image.



Like it? I made it myself. MSPaint. Anyways...
Let's assume that there is a box. Let's assume that there exists another dimension in this box. Let us also assume that, despite adhering to the laws of gravity on the outside (let's call the space the box is occupying "Dimension I"), the inside remains relative to its own space, where the only real force working (for the purposes of this experiment) is gravity, again, relative to it's own space. Let's call this Dimension II.

Let's drop this box over our little cube. What happens to the cube?
Should it hit the top of the box? If so, what force is in action? There is a bit of velocity the moment the cube enters into Dimension II, sure, but to say that it hits the top of the box is to say that the laws of physics in Dimension I are to be ignored; until it fully enters Dimension II, the cube adheres to the respective laws of physics of both dimensions. The moment the cube enters the portal, there are 2 forces at work: gravity in Dimension I and gravity in Dimension II. Even then, gravity is pulling the cube down from Dimension I and to the right in Dimension II (relative to Dimension I).

[Aramek]

Yours is a little different since both portals are moving identically to each other, which actually makes it easier. It depends on the speed it enters/exits the Dimension 2 portal, but the moment it does indeed the different gravity would act upon it. But it would still have its momentum. So it would fall to the right, per the gravity diagram, wile still moving up, from its momentum. Whether it hits the wall or not depends on how big the room is, and the momentum of the cube.

Sand cats are hella cute.

[Aramek]