Eli5: how do the pillars of creation just stay the same shape out in space for so long and how did it all accumulate in that area?
In: 7284
The first picture of them was taken in 1995, but we are seeing them as they were 7000 years ago. There’s a theory that they were destroyed 6000 years ago, but we won’t see that for another 1000 years.
Big things seem to move slowly. Have you ever watched a cloud that stays in the shape of a teddy-bear or a dragon’s head, and it doesn’t seem to change shape for a few whole minutes? Winds up high are moving as fast, or faster than our cars, but it still takes a while for them to shift the cloud enough to make it look different.
Now remember that the pillars of creation are clouds in space bigger than whole planets and even solar systems. Even if they were pushed by winds the speed of light, they would take 4-5 YEARS to be entirely smooshed. Any solar winds, gravity, and other forces on them are pushing their parts MUCH slower.
So us watching them for many human lifetimes is like watching that Teddy-bear cloud for just a fraction of a second, just a quick blink of time.
They are changing, the changes are just subtle because the pillars are so huge. The largest one is about 4 light years across and we’ve only been watching them for 27 years. If that longest pillar was a 1,000 pixels long on a digital photo, for it to change by one pixel would be a real-world distance of like 23 million miles.
But, as said, NASA has noticed changes:
[https://astronomy.com/magazine/ask-astro/2015/10/shifting-pillars-of-creation](https://astronomy.com/magazine/ask-astro/2015/10/shifting-pillars-of-creation)
Space is big. Like, very, very big. I mean, you might think it’s a long way down the road to the chemists, but Space is way bigger than that.
– Douglas Adams, paraphrased.m
They’re big. Like, really really big.^1
They’re around 5 light years tall. From a quick back of envelope question, unless I lost a zero somewhere, the clouds could be changing shape at almost 1,000,000 miles an hour and you’d see approx 1% difference in their height.
^1 Well, not big for the galaxy, they’re still a speck against the scale of the galaxy, but big for human experience.
“For so long” Is it really that long “amount of time” though?
The pillars of creation are huge clouds of gas and dust in space. They are held together by gravity, which is the force that pulls things together. The pillars are so big and massive that they can hold themselves together for a very long time. It’s thought that they were formed by the compression of existing material by the shock wave from a nearby supernova. Over time, the pillars will be eroded away by the star’s radiation, and the material within them will be dispersed into space.
The pillars of creation are massive. Even if the clouds were to move at the speed of light we would not notice it unless we were observing it for a long time since the entire structure spans light years in size. We have been observing it for a long time to us, but the first telescope, let alone the first telescope able to clearly image the structure, up until now has been a drop in the ocean of how much time the pillars have had to formate
Everyone keeps saying “space is big” but then uses terms and numbers that you don’t have a frame of reference for. Let’s try this a different way.
Space is big, like, really really big, bigger than that. So incomprehensibly big that if you were to truly grasp the size of it, you would probably change the way you live your life. It is larger than you can possibly imagine, and things in space are *really* far apart.
The fastest thing in the universe is light at 299,792 km/second, it’s so fast that it travels around the Earth 7.5 times in the time it takes to snap your fingers. The closest object to the Earth is the moon, at an average of 384,000 km, it takes light a little over 2.5 seconds to get all the way to the moon and back. It takes 8 minutes for light to go from the Sun to the Earth (we call this 1 Astronomical Unit or AU, it is equal to 149,597,870.7 km). A light year is the distance that light can travel in a straight line for a year, 9,460,730,472,580 km, or 9.4 trillion km.
The Pillars of Creation are 6500-7000 light years away. That’s 61,494,748,071,775,200- 66,225,113,308,065,600 km or 61.4-66.2 quadrillion km. Let’s average and say 63,859,930,689,920,400 km or 63.8 quadrillion km. These numbers are literally too large for the human mind to understand in any real way. So let’s change tact again.
The fastest a human being has ever traveled was during the Apollo 10 mission in 1969 at 39,897 km/hour. Let’s call it 40,000 km/h. We could probably go faster now, but let’s stick with that number for now. If we traveled for that speed the entire way to the Pillars of Creation, it would take over 180 million years to get there.
But what is the fastest we could get there? Let’s ignore the limitations of current technology and pretend that we could go much faster, nearly 100% the speed of light. Well there’s a pretty simple answer, if we went the speed of light, it would take 7000 years (gross oversimplification, let’s not get into time dilation).
Let’s get to your actual question though, why don’t they appear to change? Because they are so massive. And the picture you see all the time is only a small part of the [Eagle Nebula ](https://en.m.wikipedia.org/wiki/File:Eagle_Nebula_4xHubble_WikiSky.jpg). The leftmost pillar is 4 light years long, it’s huge. The Eagle Nebula is a stellar nursery, it’s where stars are born. Stars many times the size of our Sun are created here, and they are so small on this scale that you can barely see them. Stars that would consume our entire solar system. We probably won’t see large changes for 100 years or more.
Edit: forgot to convert units when calculating travel time.
They are big. Really, REALLY, unfathomably big.
If you were to shoot a gun on one side of the Pillars, it would take 1.5 Million years for the bullet to cross them without slowing down.
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