The speed of light in vacuum (c), equal to 299,792,458 meters per second or 186,282 miles per second. In the real world this is only applicable to actual lasers/maser based technology and is typically invisible to the naked eye without some sort of computer-assistance. Due to physics, the attempt to move at the speed of light say, within the atmosphere of the Earth, would cause irreparable environmental and atmospheric catastrophes; firestorms, hurricane like forces, sheering the Earth's crust, etc... (in fiction however this is rarely ever a problem and such shouldn't be used as an argument against a character supposedly moving at the speed of light). According to relativity, nothing with mass can reach the speed of light.

Real World:

- Mass-less photons
- Lasers
- Certain types of radiation


- J-Giel's Stand: Hanged Man from JJBA
Giorno Giovanna's Stand: Gold Experience
- Turbolasers and certain weapon technologies from Star Wars
- First time 7th Sense users from Saint Seiya
Kizaru when using the Pika Pika no Mi's techniques
Gold Key Solar

Note: Someone mentions more examples.

See also:

- Hypersonic
- Massively Hypersonic
- Relativistic
- Speed of Sound
- Supersonic
- Sub-Relativistic