Finding ways to put the size of the universe into perspective is something of a fool’s errand. Humanity’s place in it is so infinitesimal that coming up with a meaningful comparison would undoubtedly overstate the importance of people. That doesn’t mean, however, that such comparisons are worthless. Having reminders of how small you are in the universe helps give some meaning to Earth’s place in the bigger picture, even if that picture is so big that Earth might as well not be in it.
When dealing with the types of enormous numbers that define the universe, it’s easy to get lost in the abstract. Even the value of common numbers, like 1,000,000, have little actual meaning. Putting it into perspective and noting that 1,000,000 seconds is equal to 11.5 days makes it easier to grasp the value of that number. Here are some examples of that on an even larger scale.
Measurements on Earth refer strictly to the physical distance between two objects. A town that is one mile away is located 5,280 feet from the observer. But in outer space, distances are so large that units of measurement take into account time. The most common unit is a light year, which is equal to the distance that light, the fastest known quantity in the universe, travels in one year.
This is equal to approximately 5.88 trillion miles. The second-closest star to Earth, Alpha Centauri, is 4.4 light years away. In other words, to make life easier for themselves, astronomers had to find a way to condense six trillion miles into shorthand.
One doesn’t have to travel very far to realize just how insignificant Earth is. Jupiter, the largest planet in the solar system, has a volume of 1,300 times the size of Earth. There’s a storm on Jupiter, known as the Great Red Spot, that is itself 2-3 times bigger than Earth.
Yet, Jupiter is nothing compared to the sun, which is more than 1,000,000 times larger than Earth and makes up between 99.8 and 99.9% of all of the mass of the solar system. Every morning, when the sun comes up, is a reminder of the scale of the universe.
On a particularly clear night in a place with very little light pollution, it might look like the sky is filled with tens, maybe hundreds, of thousands of stars. It’s more like 2,000. For the impact the night sky has had on human culture, it can be disappointing to find out that there are fewer than 10,000 stars the naked eye can see from Earth. Only half of them can potentially be seen at one time, and that’s under the most ideal of conditions.
Conservatively, the Milky Way galaxy as a whole has about 100 billion stars, and it could have as many as 400 billion. That’s up to 399,999,980,000 stars that can’t be seen from Earth.
When dealing with such astronomically large numbers, it’s not feasible to manually count every single galaxy, and even estimates are difficult to obtain. Which is why, until the end of 2016, astronomers believed there were about 100-200 billion galaxies in the universe. Not only were they wrong, they were off by a factor of ten.
New discoveries put the new total at about 2 trillion galaxies (and this could one day seem laughably small), or 285 galaxies for every single human being on Earth.