Why does negative attract positive

He does a great job at explaining things in an honest way with no or very little mathematics. The argument I went through above is covered in some capacity in just about every textbook on quantum field theory, but a particularly clear exposition along these lines with the math included is in Zee's Quantum Field Theory in a Nutshell. This is where I would recommend starting if you want to honestly learn this stuff, maths and all, but this is an advanced physics textbook despite being written in a wonderful, very accessible style so you need probably at least two years of an undergraduate physics major and a concerted effort to make headway in it.

Because careful physicists have made an innumerable number of observations and have found that this is what nature does. There is a long history of observations before any theory could be solidified. Classical electromagnetic theory modeled the behavior of charges very well , with Maxwell's equations. They show how, when positive and negative charges exist in nature they can be modelled with accurate mathematical solutions of the equations and one could think that your "why" would be answered by " because they fulfill Maxwell's equations".

Then quantum mechanics came as a revolutionary mathematical theory to describe phenomena measured in the microcosm, including charged elementary particles, and a theory was developed as explained in Michael Brown's answer above, which again models extremely well the behavior of charged particles, and your "why" can be answered by "because they fulfill quantum electrodynamical equations".

You must perceive then that the "why opposite charges attract" with the answer "because that is what we have observed" becomes "because we have modeled mathematically the observations successfully". Then the question becomes why this mathematical model, and the answer is "because it describes the observations", circular. I am pointing out that "why" questions can not be answered with physics.

Physics can be successfully modeled mathematically with postulates and using the model one can show how the behavior of positive and negative charges under all sorts of experimental conditions can be predicted accurately, but not "why" they exist. The why gets the answer "because that is what we have observed nature to do".

Well the mutual repulsion of like particles, such as electrons for example is commonly explained as being due to "exchange particles" that mediate the four standard forces of the standard model. For the Electro-magnetic force Coulomb between like charges electrons the exchange particle is the Photon. Two electrons in the vicinity of each other "exchange" a photon with each other back and forth that results in the mutual repulsion.

Imagine two ice skaters facing each other on smooth ice. Suppose they toss a 12 bowling ball, back and forth to each other; well maybe a "medicine" ball would be safer.

The result of "exchanging" the ball back and forth, is that the reaction from tossing the ball to the other, results in both skaters moving away from each other. The farther apart they get, the more difficult it is for them to exchange the ball, and the repulsive force between them drops.

Each of the four forces of nature has its exchange particle; the photon, being the one that mediates the EM force. I'll let the OP dig out what the other three are. It's all about the energy, in the sense that everything is positive or negative energy. Opposite charges attract each other in order to complement the lack or surplus of energy. Sign up to join this community.

The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Ask Question. Asked 8 years, 1 month ago. Active 2 years, 4 months ago. Viewed k times.

Improve this question. Volker Siegel 3, 1 1 gold badge 21 21 silver badges 55 55 bronze badges. Muhammad Umer Muhammad Umer 2, 6 6 gold badges 19 19 silver badges 22 22 bronze badges. You can find arbitrarily large sets of charges that are repulsive in all possible pairing, but you can not find a similar set of more than two charges that are attractive in all possible pairing.

That implies that the sets of mutually repulsive charges are all the same, while mutually attractive charges are distinct. Add a comment. Active Oldest Votes. Improve this answer. JMac Because of the towards each other nature of the mutual interaction, the force is described as being attractive.

The interaction between two like-charged objects is repulsive. The interaction between two oppositely charged objects is attractive. What type of interaction is observed between a charged object and a neutral object? The answer is quite surprising to many students of physics. Any charged object - whether positively charged or negatively charged - will have an attractive interaction with a neutral object.

Positively charged objects and neutral objects attract each other; and negatively charged objects and neutral objects attract each other. This third interaction between charged and neutral objects is often demonstrated by physics teachers or experienced by students in physics lab activities. For instance, if a charged balloon is held above neutral bits of paper, the force of attraction for the paper bits will be strong enough to overwhelm the downward force of gravity and raise the bits of paper off the table.

If a charged plastic tube is held above some bits of paper, the tube will exert an attractive influence upon the paper to raise it off the table. And to the bewilderment of many, a charged rubber balloon can be attracted to a wooden cabinet with enough force that it sticks to the cabinet. Any charged object - plastic, rubber, or aluminum - will exert an attractive force upon a neutral object.

And in accordance with Newton's law of action-reaction , the neutral object attracts the charged object. Because charged objects interact with their surroundings, an observed interaction provides possible evidence that an object is charged. Suppose that you enter the physics classroom and observe two balloons suspended from the ceiling. Rather than hanging straight down vertically, the balloons are hanging at an angle, exhibiting a repulsive interaction as shown at the right. The only way that two objects can repel each other is if they are both charged with the same type of charge.

Thus, the repulsion of the balloons provides conclusive evidence that both balloons are charged and charged with the same type of charge. One could not conclude that the balloons are both positively charged or both negatively charged. Additional information or further testing would be required to make a conclusion about the type of excess charge present upon the balloons. Nonetheless, one can be convinced that both balloons possess an excess charge - either positive or negative.

Now let's contrast the observation of repulsion with that of attraction. Suppose that you now enter the physics classroom and observe two balloons suspended from the ceiling and exhibiting an attractive interaction as shown at the right. There are two underlying reasons for two objects attracting each other. One balloon could be neutral and the other balloon charged or both balloons could be charged with the opposite type of charge. Thus, your only conclusion could be that at least one of the balloons is charged.

The other balloon is either neutral or charged with the opposite type of charge. You cannot draw a conclusion about which one of the balloons is charged or what type of charge positive or negative the charged balloon possesses.

Additional information or further testing would be required to make these conclusions. For example, if you could take each balloon and individually bring them near some neutral bits of paper, you could test to see if each individual balloon is charged or neutral.

If a balloon were charged, then it would exhibit an attractive interaction with the neutral paper bits. On the other hand, an uncharged balloon would not interact at all with neutral paper bits. The above thought experiments illustrate the conclusive nature of a repulsive interaction. When objects repel each other, one can be certain that both objects are charged.

On the other had, the observation of an attractive interaction leads to limited conclusions. At best, one can conclude that at least one of the objects is charged. We'll conclude this part of Lesson 1 by asking the question "How can a charged object and a neutral object attract? Where did this third charge interaction come from? In all likelihood, most of us have only heard of two types of charge interactions opposites attract and likes repel ; and both of these charge interactions are fundamental interactions.

The third statement - any charged object and a neutral object will attract each other - is simply an observable fact that can be explained by the two fundamental charge interactions.

The explanation of this third charge interaction will be saved for the last page of Lesson 1. Draw a picture showing the relative location of the electrons on each. Hand out a mixed pile of salt and pepper and challenge students to separate the two. Salt is heavier than pepper, so holding a charged balloon over the pile will result in the pepper flying up and sticking to the balloon.

If you move closer to the pile, the salt will eventually fly up too, so move slowly to get the best separation! Extend the water activity by investigating more variables. Does the temperature of the water affect how much it bends? Does a bigger balloon make the water bend more?

How does the strength of the stream flow affect how much it bends? Create a mini race between two groups by challenging them to move their pop can from a starting line to a finish line first. The distance to travel should be about 30 cm i. Students rub a balloon against a sweater and visualize the movement of electrons as they bring the charged balloon to a neutral wall.

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