Null point: in physics null point in a field is the point where the field quantity is zero as the result of 2 or more opposing quantities completely cancelling each other.Let us look at few situations where null point arises: null point can arise in patterns of microphones, antennas and wheatstone ... More on vedantu.com

In general relativity, the path that light (or anything else that moves at the speed of light) takes through space is called a null line. In principle, a light ray will follow that path forever. Now, intuitively we think that if light doesn't run into anything, it should keep getting farther and farther away. That is, that its path through space goes out to infinity. But in general relativity this doesn't have to be true. It might instead get closer and closer to a point, never quite reaching it. That point is said to be at null infinity. In summary, null infinity is all the places where, even if you moved at the speed of light, you would never be able to reach. More on reddit.com

The term "null point" can have different meanings depending on the context in which it is used. Here are a few common interpretations: Physics: In physics, the null point refers to a location or condition where a certain physical property or effect becomes zero or null. More on askiitians.com

"Null" means it has zero length. That sounds weird, I know. Unless the vector is itself completely zero, how can it have no length? It has to do with the fact that you can define new concepts of length that allow this. This kind of definition of length is useful when you're talking about objects moving through space and time. Your velocity through spacetime is a vector which contains how quickly you're moving through both space and time. It turns out that if you calculate the length squared of this velocity vector, your speed through space contributes a plus sign and your speed through time contributes a minus sign. (Some people prefer to write things with space contributing a minus sign and time contributing a plus. This sign convention doesn't matter for physics but is the source of much dorky debate among physicists, but the point is that they have different signs.) So if your speed through space and speed through time exactly cancel each other out, then the length of the velocity vector is zero. This turns out to be the case for a particle traveling at the speed of light. This is a lot of math. What does it mean physically? The person you talked to might not have gotten it exactly right. The length of your velocity vector turns out to be related to the time you measure with a clock you're carrying. The fact that for light (and other things travelling at the speed of light, i.e., other massless particles) this length is zero means that time doesn't tick for such a particle. There's nothing mysterious about this, actually. One of the fundamental tenets of relativity is that everyone, no matter what their speed is, measures light travelling at the speed of light. But you also (by definition) always measure yourself to be at rest. So if you're moving at the speed of light, do you measure yourself to be at rest or travelling at the speed of light? The resolution to this paradox is that an observer travelling at the speed of light simply doesn't have a well-defined frame of reference which they can use to make measurements. More on reddit.com