"There hear" Rod Sterling.
Please explain this
- Thread starter oldman45
- Start date
"There hear" Rod Sterling.
DeathGrip
US Veteran
Acorn tossing evil tree rats.
Well that explains it.. of course if you really want to prove it..Then the following must be true...
Well that explains it.. of course if you really want to prove it..Then the following must be true...
which simplifies to
If one addstimes this to the EFE, one gets the following equivalent "trace-reversed" form
Reversing the trace again would restore the original EFE. The trace-reversed wheel spinning, with the rock actually peircing the wind shield..
And anyone driving down a gravel road would have a busted windshield.
For sure........
Yep, what he said..............
Well that explains it.. of course if you really want to prove it..Then the following must be true...
which simplifies to
If one addstimes this to the EFE, one gets the following equivalent "trace-reversed" form
Reversing the trace again would restore the original EFE. The trace-reversed wheel spinning, with the rock actually peircing the wind shield..
Yep, what he said..............
handejector
Staff member
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Whur's all ire rock-it siyuntissts and fisisisstes when we need 'em?
Never.
Yes. I was in it.
venomballistics
Member
rock from the tread ... OK Ill buy that once on the basis that one in a million shots do happen ... but twice?
Nah buddy, its something else
Nah buddy, its something else
Beejabbers
US Veteran
Well that explains it.. of course if you really want to prove it..Then the following must be true...
which simplifies to
If one addstimes this to the EFE, one gets the following equivalent "trace-reversed" form
Reversing the trace again would restore the original EFE. The trace-reversed wheel spinning, with the rock actually peircing the wind shield..
That's easy for you to say!
Once, while traveling with my wife on a two lane highway with no other cars in sight, we heard a very loud pop. This pop was so loud that I initially seriously thought someone shot the car. After leaving the area, I pulled over. No one around for miles. On the windshield directly in front of my wife's face was a blackend blast mark. Like you might expect to see if you threw a small firecracker at a window. It wiped off clean with my finger leaving a very small etch in the glass. Not even a crack. Just a dust sized white speck. I was stumped. Anything big enough to make the much noise and leave a carbon ring smudge should have put at least a good sized chip in the windshield.
Later that evening, watching the news, they mentioned the earth was moving through a debris cloud and that for the next few days there would be pretty meteor showers at night.
I could only conclude that a very small very fast and hot flecked of space rock hit us. Either that or there are squirrels or birds armed with firecrackers in Montana.
Later that evening, watching the news, they mentioned the earth was moving through a debris cloud and that for the next few days there would be pretty meteor showers at night.
I could only conclude that a very small very fast and hot flecked of space rock hit us. Either that or there are squirrels or birds armed with firecrackers in Montana.
What was the weather when your windshield was hit? If there were any thunderstorms in the vicinity (even up to 20 miles away), it could have been hail stones. Severe thunderstorms will sometimes "throw" hail many miles from their location - that's one of the reasons (in addition to staying out of airframe-destroying severe turbulence) that we always fly at least 20 miles from strong thunderbumpers. Hail usually is ejected out of the anvil side of the T-storm, which is why one never wants to fly under, or near, the anvil. Just a possibility, and the small impacts with cracks spreading from them sounds just like hail damage to a windshield (we had a pretty good hail storm a few weeks ago, and I have replaced one windshield, need to get a second replaced, as well - one car hit while driving, the other just sitting).
That is possible. While there were not any thunderstorms in the area, there was some unsettled weather on the leading edge of a cold front.
Now we can rule out rocks from my own vehicle. It is not going to be possible. For all the forumla using people, there are missing pieces of needed information such as the weight of the projectiles and the shape. Also being on a concrete roadway and having two hits to the windshield would defy all odds.
Many years ago, mostlikely still mentioned on the internset, a commercial pilot was flying at several thousand feet above ground. Suddenly, the plane's windshield was struck by a large snake. How did the snake get up there? It was suggested a bird dropped it as the plane got too close. Why would a bird be at that altitude and why would a bird have a large snake in it's grasp?
Things happen that cannot be explained.
JohnnieB
US Veteran
Hopefully someone armed with a calculator reviews traffic safety reports because 70mph = 102.6667fps rather than 105fps.
Nitpicking aside, the tread on top of a tire moves forward at the same speed as the tread on the bottom of the tire moves backwards.
Unless the tire is spinning or sliding, the speed the tread on the bottom is moving backwards equals the vehicle's velocity.
Therefore the relative speed between the tread on the bottom of the tire and the road is -Zero- while the relative speed of the tread on top of the tire is twice the vehicle's velocity.
Ergo, a projectile launched forward from the top of the tire will be traveling at twice the vehicle's velocity at the moment of departure.
From that point on it follows a path dictated by gravity, aerodynamics and any barriers obstructing its ballistic arc.
Bottom line:
Can a stone be thrown off a front tire, hit the road, bounce up and be hit by the vehicle's windshield? Yes!
Is it likely to happen? It depends on wheelwell design, ground clearance, road surface and other factors, but to have it happen twice in a few miles would most likely be unlikely.
If it ever happens to me, I'll buy a lottery ticket since I just used up all my bad luck for the day.
Nitpicking aside, the tread on top of a tire moves forward at the same speed as the tread on the bottom of the tire moves backwards.
Unless the tire is spinning or sliding, the speed the tread on the bottom is moving backwards equals the vehicle's velocity.
Therefore the relative speed between the tread on the bottom of the tire and the road is -Zero- while the relative speed of the tread on top of the tire is twice the vehicle's velocity.
Ergo, a projectile launched forward from the top of the tire will be traveling at twice the vehicle's velocity at the moment of departure.
From that point on it follows a path dictated by gravity, aerodynamics and any barriers obstructing its ballistic arc.
Bottom line:
Can a stone be thrown off a front tire, hit the road, bounce up and be hit by the vehicle's windshield? Yes!
Is it likely to happen? It depends on wheelwell design, ground clearance, road surface and other factors, but to have it happen twice in a few miles would most likely be unlikely.
If it ever happens to me, I'll buy a lottery ticket since I just used up all my bad luck for the day.
Babalooie
US Veteran
Cosmic debris, no doubt about it.
ohiobuckeye
Member
Brings to mind a question sometimes debated....If you are traveling at the speed of light and turn on the headlights, would they light the path ahead of you?...
Brings to mind a question sometimes debated....If you are traveling at the speed of light and turn on the headlights, would they light the path ahead of you?...
If you're on a path you already have more problems than figuring that out presents
Write this down:
ONLY go the speed of light out in space!
I'm going to go with the space junk scenario.
That or meteorites.
Once - Maybe some nut shooting at cars, but twice, miles apart........... Ya got a lot of nuts that don't like cops out your way?
roscoguy
Member
Something about this bothered me & stuck in my little brain...
The thing is: something falling from the tire would be going 70mph, but something thrown by centripetal force from an object will have it's own initial velocity +/- the velocity of the throwing object - depending on their relative directions. A month or 2 ago there was a really good show about light (starring Neil Degrasse Tyson, IIRC) that explained that light was the only exception to this & actually even gave examples wherein somebody threw an object forward or reverse from a moving vehicle. Light travels at the same speed regardless of the velocity of whatever it emanated from. (So the answer to ohiobuckeye's question would be "No. You'd just have to drive very carefully! )I know this is kind of counter-intuitive but Neil has never lied to me before...
Another proof if this: look inside your wheel-wells after driving on a wet/muddy road. There will be water/mud splatter all around the tire - not just behind it. So it is possible for a rock to briefly travel faster that your vehicle. Then it would just have to be thrown at the correct angle to bounce up to the same height as your windshield. At that point, it could actually stop (relative to the road) & you'd still hit it @ 70mph. It seems unlikely that a car would have either the ground clearance or enough room in the wheel-well for this to happen, but looking at a pickup, I believe that it could (but rarely would).Edit: I should have read all of the posts added while I was wasting my morning thinking about this. Then I could have just given JohnnieB a +1.
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Aubie
Member
Well, tires do throw rocks forward. Appears most of you have never ridden a motorcycle. I have and my windshield has been hit several times and so have I over the years while riding bikes.
Therefore it is possible your tire could have picked up a small rock, threw it forward and it bounced up and you ran into it.
Therefore it is possible your tire could have picked up a small rock, threw it forward and it bounced up and you ran into it.
truckemup97
Member
Brings to mind a question sometimes debated....If you are traveling at the speed of light and turn on the headlights, would they light the path ahead of you?...
You try it first and let me know.
nicky4968
Member
Growing up surrounded by gravel roads, I can tell you that rocks do go forward, bounce, and you run into them. Most of them don't clear the bumper. Usually not large rocks, but small ones without much mass. I don't believe the rock is "thrown" from the tread, however. They best I can do is offer the analogy of a watermelon seed being squeezed between your finger and thumb.
Well, tires do throw rocks forward. Appears most of you have never ridden a motorcycle. I have and my windshield has been hit several times and so have I over the years while riding bikes.
Therefore it is possible your tire could have picked up a small rock, threw it forward and it bounced up and you ran into it.
Nope, not possible. Even if the premise that a rock was tossed forward and at a faster rate than the truck is moving, it would had to have gone over six feet high after clearing over five foot of hood. I drive a large one ton dually that is set up to hold all the cameras, measuring equipment, cones, computers and machinery needed at a accident or crime site. It has large tires so I can get across medians, curbs and such. The windshield is about six foot off the ground where the items hit. With about 400,000 miles on it, not even a headlight or lens cover has been broken by a rock.
