How have scientists calculated the universe's total number of galaxies?
The huge clusters of stars known as galaxies are found throughout the cosmos.
How many galaxies exist, though?
They appear to be impossible to count.
One issue with sheer numbers is that it takes a while to tally up the numbers until they reach the billions.
The limitations of our tools are another issue.
Fig 1: The Galaxies( References: Astronomy Trek.com)
A telescope must have a big aperture (the diameter of the main mirror or lens) and be placed above the atmosphere to prevent distortion from Earth's atmosphere in order to obtain the best view. The Hubble extreme Deep Field (XDF), an image created by integrating 10 years' worth of images from the Hubble Space Telescope, is possibly the most striking illustration of this reality. According to NASA, the telescope made repeated trips to a tiny area of the sky for a total of 50 days. The XDF region is roughly the size of the head of a pin if you extended your thumb out to cover the moon. The XDF is the deepest image of the cosmos ever obtained since it showed hundreds of galaxies, both local and extremely far away, by gathering feeble light over many hours of observation. Therefore, if that one little region includes thousands of galaxies, consider how many additional galaxies may be discovered in other places.
Fig 2: The Hubble telescope(references: Salon.com)
While estimates from various specialists vary, according to astronomer Mario Livio of the Space Telescope Science Institute in Baltimore, Maryland, a reasonable range is between 100 billion and 200 billion galaxies. The Astrophysical Journal predicts that the James Webb Space Telescope will provide much more details about the early galaxies in the cosmos.
Livio asserts that the Hubble Space Telescope has been effective in measuring and counting galaxies. The primary mirror of the telescope, which was launched in 1990, initially had a distortion that was fixed in 1993 during a shuttle visit. Up to the final shuttle flight there in May 2009, Hubble also experienced a number of upgrades and maintenance visits(opens in new tab).
Fig 3: The James webb Telescope (references: newscientist.com)
The process for calculating the galaxy population is the same regardless of the equipment. You select the area of the sky that the telescope captured (in this case, Hubble). The number of galaxies in the cosmos may then be calculated using the ratio of the little portion of sky to the entire universe.
This is supposing that the cosmos is homogeneous and that there is no significant cosmic variation, according to Livio. "We have solid grounds for thinking that's the case. The cosmological principle is that.
The general relativity theory of Albert Einstein is where the idea first appeared. According to Einstein, gravity distorts space and time. Several scientists, including Einstein, attempted to comprehend how gravity influenced the entire cosmos after gaining this insight.
More about science:
More about universe:
Tags:
Universe