Light years

Astronomical distances are sometimes measured in light-years (the distance that light would travel in one Earth year, roughly 9.46×1012 kilometres or about 5.88×1012 miles). Because light travels at a large but finite speed, it takes time for light to cover large distances. Thus, the light from distant objects in the universe was emitted from them long ago: in effect, an observer at a large distance sees their distant past. Light from the sun takes around eight and one-third minutes to reach the earth. If the light from the sun were to cease we would not know about it on Earth for several minutes. Even if an observer close to the sun were to communicate this information to Earth, there would be no way for the communication to warn Earth without violating causality.

This record-breaking GRB was observed by the Swift observatory (launched into Earth orbit in 2004) which surveys the sky for GRBs. Using its Burst Alert Telescope (BAT), the initiation of an event can be relayed to Earth within 20 seconds. Once located, the spacecraft turns all its instruments toward the burst to measure the spectrum of light emitted from the afterglow. This observatory is being used to understand how GRBs are initiated and how the hot gas and dust surrounding the event evolves.

Originally posted by albertfothergill
Time and speed or even distance dont exist in astrological terms! Maybe this is a help.

It notes that by being able to measure time and space, ancient human managed to leave the caves, build urban settlements, and organize his life. As for modern human, the measurement of time and space represents a continuous challenges for his development and progress, it says.

Note on Cosmic Distances
In astronomy, distances are measured in units of light years, where one light year is the distance that light travels in a year—10 trillion kilometers. For historical reasons having to do with measuring distances to nearby stars, professional astronomers use the unit of parsecs, with one parsec being equal to 3.26 light years.

Astronomers compute the distance to remote galaxies (ones that are more than about 20 million light years away) with Hubble's law. According to Hubble's law, the universe is expanding in such a way that distant galaxies are receding from one another with a speed which is proportional to their distance. The recession causes the radiation from a galaxy to shift to longer wavelengths—the red shift. From a measurement of the red shift and the constant of proportionality, called Hubble's constant, astronomers can determine the distance to a galaxy.

One of the central problems of modern astronomy is to accurately determine Hubble's constant, which is a measure of the rate of expansion of the universe. At present it is known to an accuracy of about 20 percent, so we usually modify distances by saying "about 100 million light years," for example. We assume throughout the Photo Album a value of the Hubble constant that corresponds to a recession velocity of 600 kilometers per second for a source at a distance of 30 million light years or 10 million parsecs (H0 = 60 km/s/Mpc).