With billions of stars, outer space should be bright. However, why did the opposite happen; pasted dark black space bintang twinkling?
Some might think space is black because of the lack of light in this interplanetary and intergalactic space, but this is not the case.
“You might think that because there are billions of stars in our galaxy, billions of galaxies in the universe and other things, like planets, that reflect light, and when we look up at the sky at night, the sky gets very bright,” said Tenley Hutchinson. —Smith, a graduate student in astronomy and astrophysics at the University of California, Santa Cruz (UCSC), was quoted as saying Live Science.
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“But instead, it was really dark,” he added.
Hutchinson-Smith called this contradiction what is known as the Olbers paradox in physics and astronomy. This phenomenon is related to the theory of space-time expansion, which states that our universe is expanding faster than the speed of light.
According to this theory, light from distant galaxies might stretch and turn into infrared waves, microwaves and radio waves, which the human eye cannot detect. Then because they are not detected, they appear dark or black when viewed with the naked eye.
Similarly, Miranda Apfel, graduate student in astronomy and astrophysics at UCSC, said “Stars emit light in all colors, even colors invisible to the human eye, such as ultraviolet or infrared”.
“If we could see microwaves, all space would glow.” he added.
According to Apfel, cosmic microwaves still fill the entire interplanetary and intergalactic space, just as light energy from the Big Bang was scattered by protons and electrons that existed at the beginning of the universe.
Another reason interstellar and interplanetary space appears dark is because it is an almost perfect vacuum.
Keep in mind, Earth’s sky is blue because the molecules that make up the atmosphere, such as nitrogen and oxygen, scatter many of the components of visible light with blue and purple wavelengths from the Sun. These waves spread in all directions, including our eyes.
However, in the absence of matter, light travels in a straight line from its source to the receiver. Then because outer space is an almost perfect vacuum, meaning it has very few or even almost nothing in the space between stars and planets that scatters light into our eyes.
However, a study in 2021 in The Astrophysical Journal suggests space may not be as black as scientists think.
Through NASA’s New Horizons mission to Pluto and the Kuiper Belt, researchers can see space without interference from light from Earth or the Sun. The team filtered the images taken by the spacecraft and subtracted all light from stars present in the Milky Way and several other galaxies, as well as any light that might be leaking into the camera.
As a result, space is still twice as bright as scientists thought.
(lom/lth)
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