Amazing shot

[cantunamunch]

At the moment the bullet leaves the rifle that’s true. Are the relevant timeframes the same? What about air movement and friction at time+?

Even ignoring air movement and friction, there is a geometry problem.

Unless you're shooting due east or due west, the Earth moves a different amount at the target than at the shooter.

 

[Seldomski]

The bullet has momentum given to it by the turning of the earth while it's in the gun. It doesn't loose the momentum just because it leaves the barrel. The gun is rotating with the earth and has no force working on it that is different from the bullet since the gun's momentum is continuous, as is the bullet's. And the air is also rotating with the earth, so it does not put any extra force onto the bullet relative to its momentum other than that created by weather. This is a non-issue. Other things must be in play, but not the rotation of the earth.

Another way to say it is that the earth, the gun, the bullet, and the air all are rotating together.

The rotation of the earth does factor in, but it's a much smaller correction factor than the wind/aero forces. You can think of it as though the target and the rifle are moving at different speeds (assuming there is some north/south offset in the target vs the shooter).

Unless you're shooting due east or due west, the Earth moves a different amount at the target than at the shooter.

Beat me to it.

Edit:
Some numbers -- if they were shooting at 43 deg N latitude and shot due north 4.4 miles:
Earth rotation at rifle - 794.4 mph; at target - 793.7 mph. In 25 seconds of flight time, the relative displacement is ~25 feet. 25 ft over a distance of 4.4 miles is a pretty small adjustment.

 

[crgildart]

My dad and grandfather were artillery dudes.. Dad did guidance systems.. grandfather artillery commander of 12th Armored Division.. They'd totally geek out on this..

My question is how many tries did it take? A sniper only gets one or two shots before the target starts moving and evading the sights.. If they did it in less than 10 tries I'd be really REALLY shocked. If they spent all day tweaking and adjusting until they found the target... still impressive but not miraculous..

 

[Posaune]

The rotation of the earth does factor in, but it's a much smaller correction factor than the wind/aero forces. You can think of it as though the target and the rifle are moving at different speeds (assuming there is some north/south offset in the target vs the shooter). But 4 miles is not a lot of distance.

After my last post I was thinking about this. If shooting north to south (in the northern hemisphere) the target would move a teeny bit faster, and shooting the opposite direction it would move slower. If you shoot directly east or west, then the effect is null.

 

[James]

What about the moon’s gravity?

Also, on some scale, is air really moving in sync with the earth?

Also, if shooting directly north/south, isn’t the angular velocity the same, so it cancels out? Or is it the air friction/time influence?

Meh, the British actually rejected it for being inaccurate AF - and the still-visible-in-the-80s bomb damage to my grandmother's neighborhood proves their point. I mean she was 5km from the stupid shipyard and further from the then-railroad.

Hah. Yeah the pickle barrel quote is so off. The sight is flying the plane, the instrument is very fragile, has gone from 60F to -10F, what could possibly go wrong? Plus, at some point, taking flak or fighters, I’d think the commander just yells to drop the damn bombs.

A $billion in 1940’s money was spent on production of it though.

 

[Seldomski]

My dad and grandfather were artillery dudes.. Dad did guidance systems.. grandfather artillery commander of 12th Armored Division.. They'd totally geek out on this..

My question is how many tries did it take? A sniper only gets one or two shots before the target starts moving and evading the sights.. If they did it in less than 10 tries I'd be really REALLY shocked. If they spent all day tweaking and adjusting until they found the target... still impressive but not miraculous..

Article says they hit it on the 69th shot and then decided to call it a day. Pretty lame IMHO to just quit then - I'd want to hit it a few more times personally. Quitting may indicate that the scatter they were seeing in shots was so bad that they considered it a miracle at that point.

 

[Seldomski]

Also, on some scale, is air really moving in sync with the earth?

This is why hurricanes rotate different directions between hemispheres.

 

[cantunamunch]

Article says they hit it on the 69th shot and then decided to call it a day. Pretty lame IMHO to just quit then - I'd want to hit it a few more times personally. Quitting may indicate that the scatter they were seeing in shots was so bad that they considered it a miracle at that point.

69 repeats of breath control, trigger pull finesse control and processing of correction variables sounds absolutely exhausting.

(Speaking as a sometime-archer with zero precision firearms experience)

 

[cantunamunch]

What about the moon’s gravity?

What about the Earth's gravity? I mean it's different next to mountains, ore deposits and weird places like Hudson Bay.

 

[Lorenzzo]

Even ignoring air movement and friction, there is a geometry problem.

Unless you're shooting due east or due west, the Earth moves a different amount at the target than at the shooter.

I take into account the CE when watering trees with hose/nozzle from a distance. Water is scarce (because people need lawns in deserts). And we're weeks from snow.

 

[dbostedo]

What about the Earth's gravity? I mean it's different next to mountains, ore deposits and weird places like Hudson Bay.

NASA Scientific Visualization Studio | Untitled

Satellite measurements offer scientists a new view of our planet. Warm colors (red, orange, yellow) represent areas with strong gravity. Cool colors (green, blue) represent areas with weak gravity. Mountain ranges, such as the Himalayas, have a high concentration of mass, and therefore have a...

nasaviz.gsfc.nasa.gov

Gravity maps based on local density differences and altitude!

 

[Andy Mink]

It always drops away from the plane it was at when it left the barrel cuz gravity works.

I'd like to know the angle at which the bullet impacted the target. Coming down from 2500' it must have hit at a pretty steep angle.

 

[Posaune]

I'd like to know the angle at which the bullet impacted the target. Coming down from 2500' it must have hit at a pretty steep angle.

This reminds me of a shot I witnessed that is similar in amazement. When I was working at a summer camp during high school we had staff orientation at every program station. I worked on the beach so I went to orientation one day at the archery range. The head guy there was a bit of a blowhard and liked to brag about how great of a shot he was. None of us really believed him. At the orientation he pointed out a target down range a way (don't recall how far) and he told us he would put the arrow through the bulls eye. OK, he's good, right? Well, he proceeded to point the arrow what looked like straight up into the air and let go. We all ducked into the shed so we wouldn't get an arrow through the head and waited. It seemed like it took forever but when the arrow came down it went directly through the middle of the bulls eye at an almost vertical angle. This was his first and only shot like this while we were there. I still have a hard time believing it even though I was there. The best shot I've ever seen. Maybe he wasn't such a blowhard after all.

 

[johnnyvw]

Article says they hit it on the 69th shot and then decided to call it a day. Pretty lame IMHO to just quit then - I'd want to hit it a few more times personally. Quitting may indicate that the scatter they were seeing in shots was so bad that they considered it a miracle at that point.

Barrels like that have a life of maybe 400-500 rounds, so once they accomplished what they set out to do, no point in continuing. At a mile, they would probably be hitting more consistantly. I've shot out to just over 1000 yards...it ain't easy LOL

 

[scott43]

What about the Earth's gravity? I mean it's different next to mountains, ore deposits and weird places like Hudson Bay.

Always buy your groceries on top of the hill...

Wait, Hudson Bay is weird??

 

[scott43]

69 repeats of breath control, trigger pull finesse control and processing of correction variables sounds absolutely exhausting.

(Speaking as a sometime-archer with zero precision firearms experience)

Wonder if they used some kind of mechanical pull to eliminate the human wiggling about..

 

[BS Slarver]

MODS - This thread needs to be moved to the ski school for deeper discussion on movement analysis on trajectory and rotation

 

[Andy Mink]

MODS - This thread needs to be moved to the ski school for deeper discussion on movement analysis on trajectory and rotation

I always account for the curvature of the Earth when railing a carve!

 

[crgildart]

Article says they hit it on the 69th shot and then decided to call it a day. Pretty lame IMHO to just quit then - I'd want to hit it a few more times personally. Quitting may indicate that the scatter they were seeing in shots was so bad that they considered it a miracle at that point.

So it was just one LUCKY shot then...

 

[mdf]

NASA Scientific Visualization Studio | Untitled

Satellite measurements offer scientists a new view of our planet. Warm colors (red, orange, yellow) represent areas with strong gravity. Cool colors (green, blue) represent areas with weak gravity. Mountain ranges, such as the Himalayas, have a high concentration of mass, and therefore have a...

nasaviz.gsfc.nasa.gov

Gravity maps based on local density differences and altitude!

View attachment 179366

That's a great visualization.