1. ## The Nerdy (science) Thread

Contrary to popular misconception, Lots of Nerdy people also love Comics and Manga. Sometimes they find themselves wincing in pain when certain scientific concepts seem to be disregarded in entertainment literature.

The purpose of this thread is Two-Fold:

1) To discuss and explain scientific concepts in simple day-to-day terms.

2) To provide a forum for folks to discuss and ask questions about any areas of science that they have seen or heard about and would like someone to clarify for them.

Things do not have to be Manga related only.

I do hope that Those of you who have taken advanced science courses in college will lend some time to help with the thread.

This Thread was inspired by the recent episode of Naruto, but I have hopes that it could become an area for discussion of our favorite science topics. Thanks.

2. ## Weight vs Mass... Acceleration vs Momentum

Weight = The Force exerted by an object when that object is inside a gravity field. The Gravity feild is Created by another object since all objects create gravity.

Mass = The Stuff (amount of substance) that Comprises an object.

A Massively huge object would be weightless in outer space because it is not under the influence of any significant Gravity field. Even though it is weightless the Mass of the object is still very important.

Acceleration = The rate of Change in speed of an object when some outside force is exerted on it. It could mean speeding up from a still position and getting moving, it could also mean slowing down from a fast speed to a slower speed (negative acceleration).

Momentum = The Tendency of an object which is in motion, to keep on moving. The amount of Momentum will depend on the objects Mass and its speed.

If an object is already moving, it's Momentum (and Kinetic Energy) is Totally independent of its weight. This means that even if the object's weight was Zero (like in outer space), One would have to apply a lot of force against the object in order to slow it down or stop it.

A good example to think about is say, a Doomsday Asteroid is coming at Earth. The Asteroid is weightless (not being under influence of significant gravity). Now because the asteroid is very Massive, and has a lot of speed (it has Momentum). It will require a huge amount of force to stop it in its tracks.

3. So I take it that simply changing the meteor's weight bugged you too?

4. It bugged most of us seeing as the density changed without any apparent change in the volume of the material. It begs the question of what actually happened to the mass of the meteor since its density changed. For density to reduce at a constant volume, mass has to reduce but given the Law of conservation of matter or mass, mass should be a constant.
Law of conservation of mass: states that the mass of a closed system (in the sense of a completely isolated system) will remain constant over time. This principle is equivalent to the conservation of energy, in the sense when energy or mass is enclosed in a system and none is allowed in or out, its quantity cannot otherwise change (hence, its quantity is "conserved").

The way I see it, it will make more sense if Onoki's jutsu affected the weight of the meteor by creating a field with lesser acceleration due to gravity around the meteor hence reducing its weight and not the mass. Or he could have simply made the volume of the meteor increase at that constant mass. this will mean that the mass of the meteor will be distributed over a larger surface area when it lands on the battlefield. Not that increasing the volume will decrease the overall mass but will increase the mass distribution so when it falls no one feels the whole impact.

5. Originally Posted by jdblaze85
So I take it that simply changing the meteor's weight bugged you too?
Yeah,

The weight change would do nothing to slow the Meteor down, A change of Mass on the other hand would have done something. Unfortunately you can't make mass disappear. You'd have to say convert it to energy.

Think about it like this the Meteor is like a Giant truck , Gravity is like the gas (petrol) pedal pushed down and increasing the speed all the time. If you were to somehow make the weight = Zero, it would be the same as canceling gravity, which in the truck analogy would be like taking your foot off the accelerator. This would mean that the Truck would no longer be speeding up.

All Oonoki would acheive by reducing the weight (cancelling gravity), is to prevent further speed increases on the Meteor. He still has to deal with the incredible Kinetic Energy of the Meteor that is already moving very fast. Even though it is weightless, it is not Massless, therefore it still has Kinetic energy and Momentu (Momentum = Mass x Velocity; Kinetic Energy = 0.5 x Mass x Velocity^2).

What kishi did was to Ignore the kinetic energy and momentum of the Meteor. In the Truck analogy, Oonoki did the Equivalent of Standing in front of a Truck going at 200mph and hoping that the Truck would not flatten him simply because he had stopped the flow of gas (petrol) to the Engine. The Truck will still flatten you even if there is no more accelleration (gravity (or Weight) for the meteor, and gas or petrol for the truck).

This is the science of moving objects. (Kinetics), derived from Newton's Laws of Motion.

6. I really appreciate this thread paulbee. I've always tried to promote intelligence amongst our fellow Mangashare users. I was even thinking of making a thread tailored to personality specifics and how they relate to the media. Never thought anyone would partake, so never got around to making it.

Now I just have one gripe with you.

"I do hope that Those of you who have taken advanced science courses in college will lend some time to help with the thread."

A degree does not equal all knowing. I have no degree and am fully capable in displaying more than those who do have a respective degree. Alas, my specialty is not physics, of which seems to be the hot topic here. No, my specialty dwells in biology, psychology, literature, history, robotics and neurology. I have unique hobbies.

To the discussion at hand, you seem to be strained on the fact that the meteor was stopped in midair by something less than a hundredth of its size simply by changing its weight. Riddle me this Batman, where did the meteor even come from?

7. Originally Posted by xioaxioa
I really appreciate this thread paulbee. I've always tried to promote intelligence amongst our fellow Mangashare users. I was even thinking of making a thread tailored to personality specifics and how they relate to the media. Never thought anyone would partake, so never got around to making it.

Now I just have one gripe with you.

"I do hope that Those of you who have taken advanced science courses in college will lend some time to help with the thread."

A degree does not equal all knowing. I have no degree and am fully capable in displaying more than those who do have a respective degree. Alas, my specialty is not physics, of which seems to be the hot topic here. No, my specialty dwells in biology, psychology, literature, history, robotics and neurology. I have unique hobbies.

To the discussion at hand, you seem to be strained on the fact that the meteor was stopped in midair by something less than a hundredth of its size simply by changing its weight. Riddle me this Batman, where did the meteor even come from?
The Meteor was summoned, summoning in Narutoverse is a Space-Time jutsu which is akin to teleportation. These at least are concepts which fit well into science fiction/fantasy norms. Basically it's all fictional science that doesn't contradict Real science.

The Tsuchikage's explanation contradicts real science, hence it is problematic. If kishi had stuck to fiction, it wouldn't have been a problem.

On the matter of college degree holders, I agree with you and I should have asked anyone with a firm grasp of science whether college grads or otherwise.

8. Originally Posted by paulbee
The Meteor was summoned, summoning in Narutoverse is a Space-Time jutsu which is akin to teleportation. These at least are concepts which fit well into science fiction/fantasy norms. Basically it's all fictional science that doesn't contradict Real science.
Actually it does. You say it's akin to teleportation, yet where is Madara or any and all space time jutsus, (excluding Madara transporting himself and others), teleporting from? We never see huge chunks, (or even smaller chunks), of earth missing when people travel the land, so it's not really necessary teleportation.

The Tsuchikage's explanation contradicts real science, hence it is problematic. If kishi had stuck to fiction, it wouldn't have been a problem.
Like stated above, it's really not the only thing that like most manga/ comic/ television basically blends imagination with science, thereby contradicting real science, so I don't get the particular notice to this time?

Originally Posted by Don.D.Bulky
It bugged most of us seeing as the density changed without any apparent change in the volume of the material. It begs the question of what actually happened to the mass of the meteor since its density changed. For density to reduce at a constant volume, mass has to reduce but given the Law of conservation of matter or mass, mass should be a constant.
Law of conservation of mass: states that the mass of a closed system (in the sense of a completely isolated system) will remain constant over time. This principle is equivalent to the conservation of energy, in the sense when energy or mass is enclosed in a system and none is allowed in or out, its quantity cannot otherwise change (hence, its quantity is "conserved").

The way I see it, it will make more sense if Onoki's jutsu affected the weight of the meteor by creating a field with lesser acceleration due to gravity around the meteor hence reducing its weight and not the mass. Or he could have simply made the volume of the meteor increase at that constant mass. this will mean that the mass of the meteor will be distributed over a larger surface area when it lands on the battlefield. Not that increasing the volume will decrease the overall mass but will increase the mass distribution so when it falls no one feels the whole impact.
Think you're missing something with that 1st paragraph there. How would you really tell from a manga drawing if the "volume" of the "the enormous drawn meteor" material changed? Therein lies the problem. Density can also be explained as "cohesion". If all Onoki's jutsu does is loosen cohesion between each, or some, or more of basically each individual molecule from each other, than it makes better sense. Like with Gaara earlier, he made it easier for the sand/ earth to be lifted, if he breaks the bond/ cohesion between some/all/ or most of them in whatever area he chooses. This would also help explain why the 1st meteor broke the way it did, when struck by the 2nd meteor, since the majority of what it should have done was just push the other meteor, unless Gaara's sand shield was that good...

Originally Posted by paulbee
Yeah,

The weight change would do nothing to slow the Meteor down, A change of Mass on the other hand would have done something. Unfortunately you can't make mass disappear. You'd have to say convert it to energy.

Think about it like this the Meteor is like a Giant truck , Gravity is like the gas (petrol) pedal pushed down and increasing the speed all the time. If you were to somehow make the weight = Zero, it would be the same as canceling gravity, which in the truck analogy would be like taking your foot off the accelerator. This would mean that the Truck would no longer be speeding up.

All Oonoki would acheive by reducing the weight (cancelling gravity), is to prevent further speed increases on the Meteor. He still has to deal with the incredible Kinetic Energy of the Meteor that is already moving very fast. Even though it is weightless, it is not Massless, therefore it still has Kinetic energy and Momentu (Momentum = Mass x Velocity; Kinetic Energy = 0.5 x Mass x Velocity^2).

What kishi did was to Ignore the kinetic energy and momentum of the Meteor. In the Truck analogy, Oonoki did the Equivalent of Standing in front of a Truck going at 200mph and hoping that the Truck would not flatten him simply because he had stopped the flow of gas (petrol) to the Engine. The Truck will still flatten you even if there is no more accelleration (gravity (or Weight) for the meteor, and gas or petrol for the truck).

This is the science of moving objects. (Kinetics), derived from Newton's Laws of Motion.
Which continues my point from ^. But also think you guys are forgetting a very important factor. We don't know exactly what Gaara's sand did to further stop the meteor. The clever thing about having Gaara's sand there is that it fulfills both roles. It can be hard when it needs to but it can be soft as well, as well as possesisng some fluidity to do or be both at the same time. meaning if widespread enough, it can absorb the majority of the initial impact with the softer sand, yet still be hard enough, and heavy / solid/ stable enough that it still can hold the meteor after impact without collapsing. Like I said the biggest question mark here isn't just what Onoki did, but also what exact effect did his have on the situation as opposed to what effect did Gaara's have seperate from his, and or together with his.

9. @Scaredluffy

1) I assumed the Meteor was teleported from outer space, the asteroid belt if you like, but I really think that this is really irrelevant. The fact that I don't know where the stuff is being beamed from does not preclude the possibility of the beaming.

2) So what if the Tsukikage in this instant is not the only instant in manga of fiction contradicting science. If you see other blatant ones you want to mention in this thread please go ahead and do so. However you should also state what laws of science were being violated when you do so.

In this particular instant It is stated or implied that the Tsuchikage is going to slow down the Meteor by reducing its weight. That statement is scientifically false. It really has nothing to do with imagination, its just plain false.

3) I actually hope that someday we'll be able to cancel gravity, either by manipulating gravitons, or erecting warp fields around objects, this is good and acceptable science fiction.

What I do find objectionable scietificaly is that Tsuchikage flies directly into the path of a massive meteor traveling at incredible speeds, and that he is not immediately pulverized by it, and yet no effort was made to excuse this other than that he can reduce the weight. A good old fashioned Force Field would have worked quite nicely.

I'll conclude by saying that the Great thing about great Sci-Fi, is that every effort is made to adhere to known laws of Physics, and where they are being apparently violated, some plausible explanation is found. This is what made StarTrek such a successful sci-fi franchise in its day.

One last thing Scareluffy....don't forget that this is a thread for Nerds. Not every one will see or get the point of it, that's understandable and okay.

10. Originally Posted by SCarred Luffy Lvl:Z
Think you're missing something with that 1st paragraph there. How would you really tell from a manga drawing if the "volume" of the "the enormous drawn meteor" material changed? Therein lies the problem. Density can also be explained as "cohesion". If all Onoki's jutsu does is loosen cohesion between each, or some, or more of basically each individual molecule from each other, than it makes better sense. Like with Gaara earlier, he made it easier for the sand/ earth to be lifted, if he breaks the bond/ cohesion between some/all/ or most of them in whatever area he chooses. This would also help explain why the 1st meteor broke the way it did, when struck by the 2nd meteor, since the majority of what it should have done was just push the other meteor, unless Gaara's sand shield was that good...

Which continues my point from ^. But also think you guys are forgetting a very important factor. We don't know exactly what Gaara's sand did to further stop the meteor. The clever thing about having Gaara's sand there is that it fulfills both roles. It can be hard when it needs to but it can be soft as well, as well as possesisng some fluidity to do or be both at the same time. meaning if widespread enough, it can absorb the majority of the initial impact with the softer sand, yet still be hard enough, and heavy / solid/ stable enough that it still can hold the meteor after impact without collapsing. Like I said the biggest question mark here isn't just what Onoki did, but also what exact effect did his have on the situation as opposed to what effect did Gaara's have seperate from his, and or together with his.
No it does not make much sense. Reducing the cohesion between the individual molecules of the meteor will mean an increase in porousity which is inversely proportional to density. From this analogy, since we know a reduction in cohesion doesn't necessarily reduce the mass of the meteor we can conclude that it increases the volume. This was not the case when Onoki used his jutsu so what you are saying isn't plausible. It goes to show that for most solid apart from water, when the cohesion between its molecules are forced to become loose they usually turn to liquids with a higher volume at that same mass and further turn to gases with even higher volumes.
In the meteor's case, further loosening of the cohesion between its molecules will make it more porous (eventually dust) meaning a higher volume. A higher volume or surface area means also that it will be more affected by air resistance when it falls (retardation). Your cohesion theory is right if you are using it to explain my point. In other words you can't use this theory to prove that at constant mass density ca reduce without an increase in volume
Also I know the meteor didn't increase in volume since Oda specifically told us that Onoki reduced the mass of the rock. He never mentioned anything about the volume so I know it remained the same.
Garaa helping slow down the meteor was a good point. I missed that. It can show why the meteor lost some momentum. Also the second meteor colliding with the first will also reduce the initial momentum of the second meteor considerably.

Edit: Water is the only substance with an anomalous behaviour when it expands in its solid state and shrink in volume in the liquid state.

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