Do you know any material that can stop bullets and knives? A material thatis 5-8 times stronger than steel yet lightweight and durable, which does not melt and canwithstand temperatures up to 450 degrees Celsius to -196 degree Celsius?

Yes, the material you're referring to is Kevlar. Kevlar is a heat-resistant and strong synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, this high-strength material was first commercially used in the early 1970s as a replacement for steel in racing tires.

Kevlar has many applications, ranging from bicycle tires and racing sails to body armor because of its high tensile strength-to-weight ratio; by this measure, it is 5 times stronger than steel. It is also used to make modern drumheads that withstand high impact. When used as a woven material, it is suitable for mooring lines and other underwater applications.

Kevlar is a well-known component of personal armor such as combat helmets, ballistic face masks, and ballistic vests. Other military uses include bulletproof facemasks used by sentries and spall liners used to protect the crews of armored vehicles.

In addition to these uses, Kevlar is also used in cryogenics for its low thermal conductivity and high strength relative to other materials for suspension lines. It is also used in the construction of body panels for high-performance cars.

However, it's important to note that while Kevlar is incredibly strong, it's not completely impervious to damage. It can still be damaged or degraded by long-term exposure to ultraviolet light or certain chemicals.