A recent study has confirmed Einstein’s theory of relativity by detecting time dilation effects in quasars.
Key points
- Astronomers watched the distant universe running in slow motion, marking the first time that the weird effect predicted by Einstein more than a century ago has been observed in the early cosmos.
- The scientists found that events appeared to unfold five times slower when the universe was a mere 1bn years old. These celestial objects, powered by supermassive black holes, exhibit fluctuations in their emitted light.
- According to Einstein’s theory of general relativity, astronomers should see ancient cosmic events happen more slowly than modern ones. The effect, known as time dilation.
- It is driven by the expansion of the universe, as laid out in the scientist’s fundamental exposition of gravity in 1915.
- One consequence of the expanding universe is that light is stretched as it travels across the cosmos, making the wavelength longer. It is called the Doppler effect.
- The effect causes ancient galaxies to appear redder than they are, or redshifted.
- But time is also stretched: if a distant object flashes once every second, the expansion of the universe ensures that more than one second elapses between the flashes by the time they reach Earth.
- The time dilation effect in quasars is a testament to the expanding nature of our universe, affirming our understanding of the Big Bang theory.
