A light cone is a term in physics used to describe the structure of spacetime. It refers to the geometric shape formed by the range of light signals spreading out from an event in spacetime. In four-dimensional spacetime, we usually replace the time dimension t with the z-axis in three-dimensional space. Taking the point where the event happens (x0, y0, t0) as the origin, its mathematical expression defines the spatial range using the product of the speed of light c and time t (ct) as the radius.

Math estimation is a method of quickly figuring out results through approximate calculations instead of getting the exact answer. It's mainly used to quickly judge situations or solve problems where precise calculation isn’t necessary.

A public key is a type of key in asymmetric key encryption algorithms. It comes with a unique pair of a public key and a private key. The public key can be shared openly and is used to encrypt data or verify digital signatures, while the private key is kept secret by the user and is used for decryption or signing.

In math class, when solving a quadratic equation, you can directly plug the coefficients into the quadratic formula to get the result. This method is called the formula method and is where many people first encounter formulas. But the meaning of a formula goes far beyond that; it's a universal tool for expressing patterns and simplifying calculations across different fields. Whether in scientific computations or everyday office work, you can see formulas in action.

The metric system, also known as the meter system, is an internationally used measurement system based on decimal units and is also the foundation of the modern International System of Units (SI).

"Probability levels" usually refer to the qualitative or quantitative grading of how likely an event is to happen in risk assessment, reliability engineering, or safety analysis (commonly from levels 1–5 or A–E), but the exact divisions vary by industry/standard, and there's no unified global standard.

The degree of height; the distance from the ground or a reference point up to somewhere; the distance from the bottom to the top of an object.

It's a number used to show how likely something is to happen. For a random event A, its probability is denoted as P(A).

A fraction line is the horizontal line drawn between the numerator and the denominator. Sometimes, this line can also appear as a slash '/', with the numerator on the left and the denominator on the right.

Analyzing data usually refers to using statistical methods to organize, study, and summarize a large amount of collected data, extracting useful information and forming conclusions to help with business or operational decisions. In English, it's commonly called Data Analysis or Analyze Data.