r/nextfuckinglevel • u/InsaneMocktail • 13h ago
This is how much earth rotates in two hours.
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u/Goldglove528 13h ago
I've seen so many timelapses of the Milky Way and star trails, but never like this. Very cool perspective!
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u/JPJackPott 5h ago
We must be close to being able to do this shot with drones that counter the earths rotation. Obvious challenges are you need very long exposures (stability) for Astro, and over 3 hours your timelapse would finish 3000 miles away from where you started. But give it a few yearsā¦
Edit: I am dumb. That would require a drone that could do Mach 1 while taking photos. Maybe this would be better achieved from multiple static cameras like bullet time
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u/MeowMasterFIex 12h ago
Since the video doesn't actually say it: 30.08 degrees.
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u/Pimpinabox 2h ago
Which would have been pretty easy for anyone to figure out themselves, though this visualization is really neat. Since circles are 360 degrees around and this rotated 2 hours out of a 24 hour day, you can take 360/12=30 and viola.
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u/MeowMasterFIex 2h ago
Close, but no cigar.
24 hours is how long a Solar day is and that only applies to the Earth's relation to the sun.
Since we're looking at stars, we have to use something called a Sidereal day which is 23 hours, 56 minutes and 4 seconds.
Since the duration is slightly shorter, the amount of rotation is slightly higher: 30.08 degrees.
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u/amoghzie 13h ago
How is camera stabilisedĀ
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u/_sounak 13h ago
It's a normal timelapse, the videographer changed the ancor point to be the sky instead. Think it as if you are using a drill machine but you are holding the bit with pliers so the body of the drill machine moves instead
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u/4everLost82 11h ago
It would actually be amazing if we could get a drone to fly at the speed of Earth's rotation (opposite, obviously) so that not only could we see the curve, but how much of the earth goes by that fixed point in the given time frame. Basically what a satellite sees, but from about 200-2,000 feet in the air so that we can actually grasp how fast we are spinning.
I hope I explained that right, I've had a couple of beers lol.
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u/BHMusic 10h ago
You wonāt see curve at 2000 ft.
The earth would move by at half the speed of the hour hand of your clock.
You would have to make it a time lapse over a long period to really see the spin as we are spinning very very slowly.
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u/4everLost82 10h ago
I think what I'm trying to get at is being able to see that speed of the earths spin from ground level...basically go 25k mph or whatever it is.
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u/BHMusic 10h ago edited 10h ago
At the equator, the spin is roughly 1000 miles per hour (1600 km/hr), slower as you move toward the poles. The earth isnāt spinning nearly as fast as you think it is ;)
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u/4everLost82 10h ago
Ahhh...I knew I was off by a lot and would be corrected. Cunningham's Law applied for the win! Thanks internet friend!
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u/2BeTheFlow 12h ago
would assume this is done via software pixel tracking. So in laymens terms: Press button in Adobe Premiere/After Effects, select Pixelarea, done* (maybe tweak some sliders and values, done).
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u/germansnowman 6h ago
No, this is in hardware: The camera is mounted on an equatorial mount. It rotates at the same speed as the Earth and counteracts its motion relative to the stars. You need to align it with the rotation axis of Earth; in other words, point it at the celestial pole (close to Polaris on the northern hemisphere).
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u/Cullyism 1h ago
In other words, the rotation of the camera was already calculated and fixed beforehand?
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u/AugustOfChaos 13h ago
With a tripod.
Joking aside, the camera is almost certainly still the entire time. The still galaxy is edited in post by focusing on one point of reference in the sky.
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u/Mr_Evil_Dr_Porkchop 12h ago
Could also have been on an equatorial mount
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u/germansnowman 6h ago
It is. You can see it in the beginning, just after the overlayed text disappears. The angle of the camera (slight tilt to the left) matches that of the video at that point.
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u/4everLost82 11h ago
THIS is why the internet should exist! Amazing work OP. Flat Earthers, whatcha got now?
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u/m3m0m2 12h ago
Was this recorded near the North pole? The axis of rotation seems almost perpendicular to the ground. Very clear sky.
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u/PaleInSanora 11h ago
You see the church do a slight bob up and down to show the additional polar wobble.
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u/SirFoomy 11h ago
First I thought it rotates 30 degrees in two hours. I was not prepared to see that in a video.
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u/D_M-ack 11h ago
How does this work?? How does the camera mount keep from rotating with the earth?
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u/Rad_Habits 7h ago
There are devices called "star trackers" which allow the camera to follow a fixed point in the night sky.
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u/Dreadnoughttwat 8h ago
I donāt know if I got this right. But I think the shot itself is wider and this cropped version moves and rotates along the wider shot. Staying locked on the visible galaxy to demonstrate the earth rotating.
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u/germansnowman 6h ago
No, this is in hardware: The camera is mounted on an equatorial mount. It rotates at the same speed as the Earth and counteracts its motion relative to the stars. You need to align it with the rotation axis of Earth; in other words, point it at the celestial pole (close to Polaris on the northern hemisphere).
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u/NevrEndr 5h ago
I tripped on mushrooms and watched the tide roll in from the ranparts. Pretty cool place
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u/ANOREXORCIST- 4h ago
I wonder if thatās the pulling I feel when Iām drunk and got the āspinsā.
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u/CoolCong2019 3h ago
Hold on, isn't this a little too much? Like if this thing rotates proportianally to earth them shouldn't it take a day for it to spin once? Because if that's the case this looks too fast for 2 hours
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u/peter-bone 2h ago
It's 1 12th of a day, so it should rotate the same amount as the hour hand on a clock does in 1 hour. It looks about right to me. Remember we're only seeing a small portion of the sky.
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u/2BeTheFlow 13h ago
Normal people: wooow cool
Flatearther: didnt you know, its fake?