9-4; Through the Basket from Below

[Camron Rust]

Originally Posted by Snaqwells

In math, a cylinder continues indefinitely.
In basketball, it basically extends to the ceiling. On an outdoor court, it would extend indefinitely upwards.

Which still means the ball can't go above the cylinder.

[BillyMac]

Originally Posted by Snaqwells

In math, a cylinder continues indefinitely.

It does? Don't you mean a right cylinder?

A cylinder is one of the most basic curvilinear geometric shapes, the surface formed by the points at a fixed distance from a given straight line, the axis of the cylinder. The solid enclosed by this surface and by two planes perpendicular to the axis is called a cylinder. In common usage, a cylinder is taken to mean a finite section of a right circular cylinder with its ends closed to form two circular surfaces.

[bob jenkins]

Originally Posted by BillyMac

It does? Don't you mean a right cylinder?

No, he doesn't. The "right" means that the "ends" of the finite section are perpendicular (at a "right angle") to the "sides".

In theory, a cylinder is analogous to a line -- it has no end points. As the rest of the quote shows, in practice, it's used as being analogous to a line segment.


IIRC (I don't have the books with me) the rule on "passing through" doesn't mention the cylinder. The only rule that does has to do with BI (and it uses a pharase like "the cylinder, the bottom end of which is the rim." So, rather than JohnnyRingo asking, "the ball needs to leave the cylinder?," he should have asked, "the entire ball needs to enter the cylinder?"

[BillyMac]

Originally Posted by bob jenkins

The "right" means that the "ends" of the finite section are perpendicular (at a "right angle") to the "sides". In theory, a cylinder is analogous to a line, it has no end points. As the rest of the quote shows, in practice, it's used as being analogous to a line segment.

Thanks. I got it mixed up. This is what threw me: "A cylinder is taken to mean a finite section of a right circular cylinder with its ends closed to form two circular surfaces", from Wikepedia. How can one look at a finite section of something that is already finite? The definition implies that the right cylinder is infinite. Either I misunderstood the definition, or the definition is poorly written. I didn't follow my own rule here: It's alright to use Wikepedia for your first source, but don't use it as your only source.

In summary: A cylinder has no "top", or "bottom" (the circular planes), so the "sides" go on infinitely, the center being a line. A right cylinder has a "top", and a "bottom", perpendicular to the "sides", is therefore finite, the center being a line segment, and volume, and surface area, can be defined, and measured.

Our basketball cylinder, as described in basketball interference, has a bottom, the ring, but has no top, theoretically, the center being a ray, so it's not a true cylinder. Is is a right cylinder, with only a "bottom", and no "top"?

[Johnny Ringo]

Would you say that the ball, if going upward from underneath the basket, clears the ring that is when you would call the violation?

[bob jenkins]

Originally Posted by BillyMac

from Wikepedia.

There's your mistake.

[bob jenkins]

Originally Posted by Johnny Ringo

Would you say that the ball, if going upward from underneath the basket, clears the ring that is when you would call the violation?

Yes -- and, for me, personally, I wouldn't split hairs here. I'd give the benefit of the doubt to "it went through the basket."

[mbyron]

Originally Posted by bob jenkins

There's your mistake.

Right -- it's 'Wikipedia'.

[mbyron]

Originally Posted by BillyMac

How can one look at a finite section of something that is already finite?

Every section of a finite figure or solid is itself finite, including the section that constitutes the figure. Infinite figures are more difficult to define and depend on the kind of space (Euclidean, Reimannian, etc.).

Originally Posted by BillyMac

Our basketball cylinder, as described in basketball interference, has a bottom, the ring, but has no top, theoretically, the center being a ray, so it's not a true cylinder. Is it a right cylinder, with only a "bottom", and no "top"?

Technically not a right circular cylinder unless both ends are closed.

[riverfalls57]

What signal do you use for this violation? How about for a fist violation?

[Adam]

Same signal you use for a throwin violation.

[M&M Guy]

Originally Posted by riverfalls57

What signal do you use for this violation? How about for a fist violation?

Since there is no specific signal for either violation, the normal accepted method is to simply blow the whistle and use the open palm for a violation, then verbalize the specifics. "Ball came up through the basket from below." "Used the fist." Since signals are simply a method of communication, some officials might use some sort of hand signal (maybe a fist into a palm for the fist violation, but be careful about trying to come up with a signal for ball up through the basket...). But it's usually better to stick with the approved signals, and simply use your voice to communicate the violations that do not have a signal associated with it.

The FT not contacting the rim is another example of a violation that doesn't have a signal. I've seen many officials use the "swirly"/reset the shot clock signal, but it is not an approved signal.

[BillyMac]

Originally Posted by M&M Guy

I've seen many officials use the "swirly" signal, but it is not an approved signal.

I would love to see the NFHS make the "Swirly" an approved signal. Let's start a petition.

[Adam]

Originally Posted by M&M Guy

Since there is no specific signal for either violation, the normal accepted method is to simply blow the whistle and use the open palm for a violation, then verbalize the specifics. "Ball came up through the basket from below." "Used the fist." Since signals are simply a method of communication, some officials might use some sort of hand signal (maybe a fist into a palm for the fist violation, but be careful about trying to come up with a signal for ball up through the basket...). But it's usually better to stick with the approved signals, and simply use your voice to communicate the violations that do not have a signal associated with it.

The FT not contacting the rim is another example of a violation that doesn't have a signal. I've seen many officials use the "swirly"/reset the shot clock signal, but it is not an approved signal.

Kinda like the traveling signal on a throwin violation. It signifies a different violation.

[Nevadaref]

Originally Posted by BillyMac

I would love to see the NFHS make the "Swirly" an approved signal. Let's start a petition.

I'll give you a swirly...