BEIJING, June 15 (Xinhuanet) -- Unless the basic principles of the universe discovered by Einstein are proven wrong, which hardly any physicist would expect, the short answer to the question "can matter travel at light speed" is "no."

    But astrophysicists have recently discovered gas and dust in two distant exploding stars moving at 99.9997 percent of the speed of light ¡ª about 2,000 mph too slow to qualify.

    When a super-massive star explodes, sometimes called a hypernova, it flings gas and dust into space with amazing energy, in effect causing it to outshine most objects in the nearby universe. In the recently discovered explosions, about 200 Earth's worth of material, in the form of stellar gas and dust, was propelled near light-speed for a few moments.

    Such a large amount of matter moving so quickly may seem extremely close to light speed, but the energy required to move even a little faster is nearly infinite. To understand this, Einstein¡¯s famous E=mc2 equation is useful. There's a more complex version that accounts for velocity (v): E=¦Ãmc2 where ¦Ã=1/(¡Ì 1-v2/c2)

    If the equation looks confusing, here's a summary: The faster an object moves, an exponentially larger amount of energy is needed to speed it up, which is why travelling at light speed requires an infinite amount of energy.

    (Agencies)