Collins's Law

[DaveC426913]

I have coined a new term: Collins' Law.

It is a variant/update of Cunningham's Law.

Collins's Law: The best way to encourage engagement on social media is not to post an interesting and well-designed problem; it is to post an interesting but ambiguously-defined problem and let the internet bicker over it.

 

[DaveC426913]

An example:

"A few people have mentioned the Coriolis Effect and the Eötvös Effect as reasons the eastbound and westbound cannonballs might stay in the air for different times.
They're not wrong that these effects exist, but they don't change the answer to the question as it is normally presented.
The Coriolis Effect is caused by Earth's rotation. It can cause long-range projectiles to drift sideways relative to the ground. This is important for artillery, missiles, and weather systems.
The Eötvös Effect is also caused by Earth's rotation. An object moving east is moving slightly faster around Earth's axis than an object moving west. This produces a tiny change in effective gravity:
* Eastbound objects experience slightly less effective gravity.
* Westbound objects experience slightly more effective gravity.
In the real world, that means an eastbound projectile could remain airborne a tiny bit longer than a westbound projectile.
However, introductory physics problems usually assume:
* Constant gravity
* A non-rotating Earth
* No air resistance
Under those standard assumptions, east and west are simply horizontal directions. Both projectiles have the same vertical launch velocity and experience the same downward acceleration.
Therefore, the correct answer to the textbook problem is still:
B) The same time
The Coriolis and Eötvös effects are real-world refinements, but they are not part of the simplified model the question is testing."

"As they ask for which stays in the air longer not which will travel the furthest, and as a shooter I know that a bullet shot parallel to the earths surface will strike the ground at the same time as one dropped from the end of the barrel, I wonder if the speed difference caused by the effects you mention will make any difference as to time of flight. A very interesting question."

"If you don't take into account the rotating earth, then it's a ridiculous question. You've removed the distinction between East and West! If the question talks about East and West, you must assume that the only relevant issue concerning East vs West is in play."

"The vertical part of their launch vector is identical. They rise and fall at the same rate. Assuming the same altitude at launch and landing, the landing is simultaneous. Answer "B"."

 

[wrobel]

In the Russian segment of the internet, a question that is, in fact, painfully simple has been sparking heated debates for about eight years: can a propeller aircraft take off from a moving treadmill?

Initially, this question was raised on a student forum of a military aviation school. Since then, it has become a source of endless, often absurd, controversy—frequently escalating into toxic arguments, community-wide scandals, and even mass bans across various forums

 

[DaveC426913]

In the Russian segment of the internet, a question that is, in fact, painfully simple has been sparking heated debates for about eight years: can a propeller aircraft take off from a moving treadmill?

Initially, this question was raised on a student forum of a military aviation school. Since then, it has become a source of endless, often absurd, controversy—frequently escalating into toxic arguments, community-wide scandals, and even mass bans across various forums

View attachment 372644

It makes the rounds of Facebook regularly.

The answer of, course, is: depends on how long the conveyor belt is.
(This is rarely specified in the problem, and probably leads to some of the confusion.)

 

[Hornbein]

In the Russian segment of the internet, a question that is, in fact, painfully simple has been sparking heated debates for about eight years: can a propeller aircraft take off from a moving treadmill?

Initially, this question was raised on a student forum of a military aviation school. Since then, it has become a source of endless, often absurd, controversy—frequently escalating into toxic arguments, community-wide scandals, and even mass bans across various forums

View attachment 372644

That does seem an example of Collins' Law.