So with how often this picture, or ones with the same effective meaning, get passed around social media, I’m sure you’ve seen something like it before.
Well, I’ve got some good news for dreamers and star-wishers: This is a gross exaggeration that comes from laymen talking about science-y things while suffering from a condition known as “being a laymen”.
Yes, these stars are an astronomically long ways off. Such a long way, in fact, that the closest known star to earth (other than the sun, obviously) is roughly 25,277,549,200,000 miles away. That would be 25.277 trillion miles – and again, that’s the closest star to earth.
So you’d think that would mean it’s going to take a heck of a long time, like maybe a few million years, for the light to get here, right? Sure…if you don’t understand just how fast light moves.
That 25.277 trillion miles? That’s roughly 4.3 light years. (Light year – the distance that light travels in one earth year) Yup. When you look at that star, the light hitting your eyes left that star around the time this year’s graduating class was enjoying their Labor Day weekend…of their 8th grade year.
The night those same high school seniors walk the stage, there will be light from 26 stars hitting the earth that started it’s journey after they began the 1st grade.
So 26 stars are really close, astronomically speaking. So what? There’s countless stars up there. What’s the likelihood that you’re going to wish on one of those 26 stars? Good question, but it’s not about those 26 stars. Those 26 are just to make it clear how fast light really travels.
There are 88 constellations in modern astronomy, comprised of a few thousand stars total. Of those, about 98% are less than 2500 lightyears away. When you look up at the constellations tonight, the light hitting your eyes began it’s journey after the death of Confucius in 479 BCE, or something more meaningful to westerners, after the creation of the Roman Republic in 509 BCE. (Hey, I said more meaningful, not significantly more meaningful)
The brightest stars in the sky? (read: the ones most noticeable and most likely to be wished upon)
The bulk of them are less than 500 light-years away. Looking at a list of the 500 brightest stars, there are only a handful that are outside 1500 light years away, so for the most likely stars to be chosen for wishing upon (since they’re the most likely to be the “first star I see tonight”) nearly all of them the light left the star in question more recently than the fall of the Western Roman Empire in 476 CE.
Now, the specific collection of stars I’ve talked about are still a really – really – small portion of the stars in the night sky, even if they are the brightest, most noticeable, and most likely stars to be wished upon. The thing is, though, that the Milky Way (The galaxy we float in) is only about 120,000 light years across at it’s widest, and astronomers give a rough estimate of 300 Billion stars just inside the milky way. Stars in other galaxies are so far away that they can’t be seen, individually, by the naked eye. At the distances even the closest neighboring galaxies are are, you’re seeing the entire galaxy as a single point of light and merely thinking it is a star because you can’t tell the difference – if you can see them at all.
So go ahead. Wish upon a star. Chances are, it’s still around. Now, do remember, though, that it’s going to take a heck of a long time to get there.
It takes a sound wave roughly 880,991 years to travel just 1 light-year. The closest star? Your wish will take about 3,788,261 years and 4 months to reach it. That 4 months, afterall, makes all the difference.
Yup. So chances are the star you’re wishing upon is still there, meaning you’re not too late.
However, you might want to grab a few Snickers bars, because you’re going to be waiting a while…
…and now I find myself wondering how hard it could be to hi-jack a semi full of candy bars.