If the galaxy were reduced to the size of an electron, how big would the universe be?

At present, the universe that humans can observe is only a part of the universe, that is, the observable universe. Although the size of the observable universe has been explored by scientists, the size of the entire universe is still a mystery due to the age of the universe, the speed of light, and the expansion of the universe, among other factors.

So, today, we are going to explore not the size of the universe, but how big the observable universe can be when it shrinks to the size of an electron in the Milky Way.

How big is the Milky Way

The galaxy in which our home planet, Earth, is located in the Milky Way, which is about 10 billion years old, that is, it was born 3.8 billion years after the Big Bang.

In addition to planets like Earth, there are also a huge number of stars in the Milky Way galaxy, which, according to statistics, has between 100 billion and 400 billion stars.

So, how big is the Milky Way galaxy when it can hold so many planets?

According to scientific data, the diameter of the Milky Way is about 100,000 light years in terms of volume, and the length of 1 light year is 9.46 trillion kilometers, so the diameter of the Milky Way is more than 946 trillion kilometers.

This data is already far beyond normal human perception. To visualize the size of the Milky Way, we can give an example.

In the galaxy, the solar system is not far from the center of the galaxy, about 25,000 to 28,000 light years.

If we drive a flying car with a speed of 120Km/h from the Earth in the solar system, then we have to travel about 26,000 light years to reach the center of the Milky Way.

Based on a life span of 100 years per capital, this means that it will take our 23.4 billionth generation of descendants to reach the center of the galaxy from the time of departure.

How big is the observable universe

The observable universe, also known as the Hubble volume, is a sphere of space centered on the observer.

What we call the observable universe is a spherical space centered on Earth, and if we stand on Mars for observation, then this observable universe is centered on an observer on Mars.

As of today, scientists estimate that the observable universe has a radius of 46.5 billion light-years and a diameter of 93 billion light-years.

And the Milky Way is only a tiny 100,000 light-years.

What needs to be known is that the expansion of the universe has never and will never stop from the birth of the universe until now, or until the future and that the expansion of the universe is far faster than the speed of light.

In the 1920s, scientists already discovered that the universe was expanding by measuring the distances of galaxies and by the phenomenon of Redshift.

Since the 1990s, scientists have further discovered that our universe is not only expanding but also expanding at the speed of superficiality.

The 93 billion light-year diameter part of the universe detected by humans today is also caused by the FLT expansion of cosmic space. This expansion of the universe will not only lead to the increasing distance of celestial bodies in space but also the increasing volume of the universe.

In other words, the universe has been increasing in size, and what we can observe now is only a small sphere with the Earth as the center and a diameter of 93 billion light years, which is very small in front of the universe.

Therefore, mankind still has a long way to go in exploring the universe.

When the galaxy shrinks to an electron

We now know the size of the Milky Way and the observable universe. To understand the difference in a more general way, let us make a hypothesis: when the Milky Way is reduced to the size of an electron, how big will the observable universe be if it is reduced in the same proportion?

An electron is an elementary particle that makes up an atom, and everything on Earth is made up of atoms.

The atom can be divided into a nucleus and an electron outside the nucleus, where the nucleus consists of a neutron and a proton, and the nucleus accounts for more than 99% of the mass of the atom.

According to scientific experiments, the rest mass of an electron is 9.1 x 10^(-31) kilograms, which is only 1/1842 of the mass of a proton, enough to see that the electron is very tiny.

And the electron is not only very small in mass, but also volume.

However, the size of an elementary particle like the electron cannot be measured by conventional methods, so scientists initially used a more roundabout means to measure its size.

They first fired a large number of electrons toward the target electron, and then measured the size of the space occupied by the target electron by observing the scattering of these emitted electrons.

Accordingly, the scientists concluded that the diameter of the electrons is no larger than 10^(-15)m.

It should be noted that there is "not greater than" and not "equal to", that is, the diameter of the electron may be smaller than this value, here we may take the maximum diameter of the electron, which is 10 ^ (-15) meters.

Knowing the volume of the electron, it can be calculated that when the Milky Way shrinks to an electron-like size, it is equivalent to shrinking the Milky Way by a factor of about 9.46 x 10^35.

The diameter of the observable universe is known to be 93 billion light years, so after shrinking it by the same ratio of 9.46 x 10^35 times, its diameter would be approximately 9.3 x 10^(-10) meters, which is roughly 0.93 manometers.

The diameter of an atom is 10^(-10) m, which means that an atom is roughly 0.1 manometers large, which means that when shrinking the galaxy to the size of an electron, the universe is roughly the size of about 9-10 atoms.

Speaking of manometers, you may have heard of nanotechnology, but you may not have a clear idea of the size of a manometer.

To put it simply, take the smallest atom, the hydrogen atom, for example, when 4 hydrogen atoms are lined up in a row, the length of this queue is 1 manometer.

Thus, when the galaxy shrinks to the size of an electron, the observable universe is not yet 1 manometer in diameter, less than the size of the diameter of four hydrogen atoms.

Conclusion

People always like to look up at the stars and lament the vastness of the universe, but compared to the universe, which can be hundreds of millions of light years, how can everything around us not have its vast universe? Just like the most basic atom, there is also a universe of tiny particles in it.

Therefore, we do not need to feel as small as dust because of the vastness of the universe, in fact, in the eyes of some matter, we are not a huge universe.