Question

at which speed light runs
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Answer 1

670,616,629 miles per hour

Answer 2

• The universal physical constant c, or the speed of light in vacuum, is fundamental in many fields of physics. Its precise number is 299792458 metres per second (about 300000 kilometres per second, or 186000 miles per second).  
• It's precise because a metre is defined as the length of light's passage in vacuum during a time span of 1299792458 seconds, as agreed upon by international agreement.
• c is the highest limit for the speed at which ordinary matter, energy, or any signal conveying information may move across space, according to special relativity.