Meteor nearly hits sky diver. Film at 11.

tcmtech

Joined Nov 4, 2013
2,867
You instantly create enough drag to slow down your horizontal speed, that's why jumpers are more afraid of hitting the plane they just jumped out of then hitting the ground.
Exactly! That initial deceleration is pretty hard which is why jumpers try to have the plane going as slow as possible when they take that first step.

The decrease in velocity in going horizontal is almost as quick as the increase in velocity as you drop vertically. After the first 10 or so seconds your horizontal travel is largely determined by the relative wind speeds and has little bearing relating to what direction or speed the plane was going.

I don't jump either but I had a college class with someone who did and he gave a super presentation on skydiving for one of our assignments. :cool:
 

GopherT

Joined Nov 23, 2012
8,009
I suspect insurance companies would rule it an Act of God if it had hit him.
Insurance doesn't normally cover skydiving. Imagine everything went right for the dive but he gets hit by a meteor and insurance doesn't cover it.

For the other arguments, read the two links I posted. They cover a lot of the vector issues and how difficult, dangerous dropping a rock at a skydiver would be and, since it is falling about 2x or 3x faster. The diver fell far enough so he could pull his cord which means the plane would have had to circle back and drop it over the diver.

The other think is that all factors about the meteoroid are correct - cleaved surface from fragmentation, dark scorch marks on the un-cleaved surfaces from entry, no gaps or unexplainably sharp focus of some objects to indicate photoshopping. Velocity is correct, ... It is really an interesting read.
 

Sensacell

Joined Jun 19, 2012
3,432
I think it's fake.

Would it not have absorbed so much thermal energy as it decelerates through the atmosphere to be incandescent or at least outgassing (smoking) like crazy?

All the images and video I have seen from meteors are more fiery and dramatic.
 

THE_RB

Joined Feb 11, 2008
5,438
Agreed. There's a lot of good reasons to suggest it's fake.

tcmtech said:
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BTW the plane is not right above them. When you jump your relative motion and vector from the aircraft quickly changes from horizontal to vertical but the plane direction and velocity stays the same horizontal and going away because is still in powered flight thus after the first few seconds it is now nowhere near being above you.

Didn't anyone pay attention in physics class?
It's close enough to "above" them to allow the prank. If it's deliberate then they can deliberately circle back or throw the meteor out backwards etc. Skydiving planes have a low airspeed.

I paid attention in "Skeptics class". ;)
 

GopherT

Joined Nov 23, 2012
8,009
Agreed. There's a lot of good reasons to suggest it's fake.



It's close enough to "above" them to allow the prank. If it's deliberate then they can deliberately circle back or throw the meteor out backwards etc. Skydiving planes have a low airspeed.

I paid attention in "Skeptics class". ;)
If throwing a rock out of a plane, directed to within a few meters of a skydiver, was the key feature of a prank, then they are very stupid people with a very cleaver idea.

It is also a strange prank to get scientists involved for 18 months to diagnose and convince the photographer that the black object was a meteoroid before the video was released to the public.
 

Thread Starter

ErnieM

Joined Apr 24, 2011
8,377
This case is actually from my country Norway. Now it seams like the most plausible is a earth rock that somehow has gotten into the parachute during packing. This was also a solution that many suggested during the debate here in Norway. A researcher from NASA has looked into this problem. And here is what he say about the earth stone theory https://www.facebook.com/Philtill/posts/10203622350143366?stream_ref=10

Philip Metzger on The Facebook said:
It's late and I've done far too much work on this Norwegian skydiver rock problem. Here is my conclusion: the ballistics are consistent with it being a small piece of gravel that came out of his parachute pack and flew past at close distance. The ballistics are also consistent with it being a large meteorite that flew past at about 12 to 18 meters distance. It could be either one, but IMO not anything in between. Based on the odds of parachute packing debris (common) versus meteorite personal flybys (extremely rare), and based on the timing (right after he opened his parachute), I vote for the parachute debris as the more likely. My three plots are below. The first one shows how the measured and predicted velocity agree only at the two different distances mentioned above. The second assumes it was parachute debris, and shows the velocity of the debris as a function of time after being released from his pack. the third shows the separation between the skydiver and the debris as a function of time. Note that the debris passes the skydiver at 12 seconds after the debris was released, which is the same amount of time in the video from when the drogue chute was opened until the debris passed the skydiver. Other variations are possible by adjusting the unknowns, but the point is this: we can't rule out debris. Everything can be seen as consistent (in the ballistics) with it being a small piece of gravel about 3.3 cm in diameter that flies by at about 30 m/s absolute or 10 m/s relative to the skydiver. Maybe the optics of focus or other factors can rule out debris, but for now the fact that ballistics are consistent with debris makes me lean more to believing it is just debris.
SO... the analysis says either a piece of gravel from the shoot up close OR a meteor back a ways... Occam's razor calls it as gravel.
 

GopherT

Joined Nov 23, 2012
8,009
This case is actually from my country Norway. Now it seams like the most plausible is a earth rock that somehow has gotten into the parachute during packing. This was also a solution that many suggested during the debate here in Norway. A researcher from NASA has looked into this problem. And here is what he say about the earth stone theory https://www.facebook.com/Philtill/posts/10203622350143366?stream_ref=10

Ok, simpler solution is usually right. Rock-in-parachute seems more plausible than meteoroid and more likely (based on participants actions) than a prank where a rock is dropped from an airplane.
 
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