Our expanding universe is a captivating cosmic phenomenon that continues to unfold in the vastness of space. Galaxies throughout the cosmos are in a state of expansion, distancing themselves from one another as space itself expands between them. From our vantage point on Earth, nearly every galaxy beyond our Local Cluster is gradually moving away and it appears the farther away the galaxy, the faster the rate at which it expands. Scientists call the source of this acceleration and movement dark energy, however, they still aren’t completely sure how dark energy works. While these cosmic shifts are invisible to the naked eye, astronomers utilize Doppler shifts to measure them and the rate at which they are expanding accurately.
More specifically, researchers use the wavelength of light to determine whether an object is approaching or receding from Earth. A shorter wavelength, denoted as a “blue shift,” signifies the object is moving towards Earth. Conversely, a longer wavelength, identified as a “redshift,” indicates the object is moving away from Earth. Moreover, the greater the speed of the object in its trajectory, the more drastic the shift in wavelength becomes.
Furthermore, this observational technique has allowed scientists and astronomers to estimate that our universe is approximately 14 billion years old. It is exciting to think how different our universe will look in the billions of years to come.
Sources: Photo, Dark Energy, Doppler Shift
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