A visitor to the lab once asked Reeko how big space was and the lab tour had to be cancelled. In short, Reeko answered with “really, really, really big” but what he really did was add a bunch of “reallys” to make the point that space was “really big”. There were so many “reallys” that after about 20 minutes, the visitors got anxious (one thought Reeko was having a “spell”) and the entire tour had to be called off for the day. For kids that have visited the lab, this explains why the sign at the entrance says “Be curious – ask any question you want (except for how big space is)”.
Fact is, space is really, really big with about oh, one thousand “reallys” in front of the word “big”. It’s pretty hard to imagine how big it is but we’ll try. If the discussion gets to be too much for you, lock your fingers together, put your hands behind your head, tuck your head between your knees, and begin rocking back and forth.
To understand how big space is, we’ll start off small and by “small” we mean “solar system small” which is actually huge [head spin]. Our solar system by itself is huge. The moon, our closest neighbor, takes astronauts about 3 days to reach with rocket ships. If you were to drive a car to the moon, it would take you about 6 months of continuous driving to get there (no stopping to sleep, no side-trips to McDonalds, and no stopping to pee). Yeah, even the Moon, which often looks so close you could touch it, is a long, long way.
The Sun, that big bright light that we all revolve around, is even further away – about 93 million miles. Driving in a car, it would take us about 176 years to reach. That means if your great, great, great, great, great grandfather had started driving when he received his driver’s license (Reeko understands there were no cars back then but using a horse in this example would make the math much more difficult) he would still be driving today. And just think, our Sun is not the only sun in our neighborhood. There are about 300,000,000,000 “suns” (stars) in our galaxy, the Milky Way. To visit each one – well, now we’re way, way, way into the impossible (for now anyway). To get across our galaxy it would take this many years to reach the end, assuming we drove a car – 1,181,401,000,000,000 years. *Poof* – mind blown…
It should be clear now why beyond this, we start speaking in terms of “speed of light” in order to shrink things down in our heads. The speed of light is 186,000 miles per *second*. Think about that for a second. Travelling at the speed of light you would make about 23 trips around the earth in one second travelling at 670,000,000 miles per hour! If you drove through space at the speed of light for one year, you would reach a distance we call a “light year”. You can travel about 6,000,000,000,000 miles in one light year (or more precisely, 5,878,499,810,000 miles). Using these measurements, we can now say that the Milky Way galaxy is 100,000 light years across – a much easier measurement to understand than 70,000,000,000,000,000 miles across.
If you haven’t fallen out of your chair yet, you’re beginning to understand just how big space is. And thus far, we’ve only talked about *our* galaxy. There are innumerable galaxies out there and some are much bigger than ours. For instance, the “El Gordo” galaxy cluster, which scientists call ACT-CL J0102-4915, contains about 600 galaxies within it and most of those galaxies are much, much bigger than our Milky Way galaxy. Again – it has 600 galaxies in it with most being bigger than our little neighborhood which itself takes about 1,181,401,000,000,000 years to drive a car across!
[Let’s take a short pause here – Reeko is getting dizzy…]
Scientists have found that El Gordo (which is Spanish for “the fat one”) contains the mass of about this many suns: 3,000,000,000,000,000. That’s 3 quadrillion suns. That is mind-boggling large with so many stars it’s admittedly, hard to wrap our head around. To drive a car across the El Gordo galaxy, it would take you this many years of driving to reach the end – 42,325,199,000,000,000,000 years.
Expanding it a bit further, scientists believe there are about 100,000,000,000 (one hundred billion) *galaxies* in the universe and each single galaxy can be much more massive than ours. And finally, remember that space is always expanding so by the time you’ve read each number Reeko spouted in this article, they have already changed and grown even larger. So yes, as Reeko once said, space is really, really, really, really big (with a bunch more “reallys” thrown in there).
Class dismissed. Go take an aspirin.