# Hey babe, want to get horizontal..slap!!..is that a no? **URL:** \ **Category:** Factual Questions\ **Created:** [October 8, 1999, 4:59pm UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792 "1999-10-08T16:59:00Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Buck\_Naked](https://avatars.discourse-cdn.com/v4/letter/b/c6cbf5/32.png) [@Buck\_Naked](https://boards.straightdope.com/u/Buck_Naked)\ **Post date:** [October 8, 1999, 4:59pm UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/1 "1999-10-08T16:59:00Z")
What is the vertical equivalent of horizon? * * * I feel more like I do now than I did when I got here. ---
**Author:** ![tanstaafl](https://avatars.discourse-cdn.com/v4/letter/t/ba8739/32.png) [@tanstaafl](https://boards.straightdope.com/u/tanstaafl)\ **Post date:** [October 9, 1999, 5:04am UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/2 "1999-10-09T05:04:00Z")
A vertical. ---
**Author:** ![aseymayo](https://avatars.discourse-cdn.com/v4/letter/a/a88e57/32.png) [@aseymayo](https://boards.straightdope.com/u/aseymayo)\ **Post date:** [October 9, 1999, 5:12am UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/3 "1999-10-09T05:12:00Z")
A plumb line. ---
**Author:** ![AuraSeer](https://avatars.discourse-cdn.com/v4/letter/a/c2a13f/32.png) [@AuraSeer](https://boards.straightdope.com/u/AuraSeer)\ **Post date:** [October 9, 1999, 5:16am UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/4 "1999-10-09T05:16:00Z")
Vertex. _Vertices_ is the plural. The adjective form is _vertical_. ---
**Author:** ![Keeves](https://avatars.discourse-cdn.com/v4/letter/k/f05b48/32.png) [@Keeves](https://boards.straightdope.com/u/Keeves)\ **Post date:** [October 9, 1999, 5:18am UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/5 "1999-10-09T05:18:00Z")
“zenith” is when the sun is directly overhead. That’s not a line like the horizon is, but still, that’s my suggestion. ---
**Author:** ![tanstaafl](https://avatars.discourse-cdn.com/v4/letter/t/ba8739/32.png) [@tanstaafl](https://boards.straightdope.com/u/tanstaafl)\ **Post date:** [October 9, 1999, 5:18am UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/6 "1999-10-09T05:18:00Z")
Under some circumstances. Here is the definition: > [@](#): > > Main Entry: ver·ti·cal > Pronunciation: 'v&r-ti-k&l > Function: adjective > Etymology: Middle French or Late Latin; Middle French, from Late Latin verticalis, from Latin vertic-, vertex > Date: 1559 > 1 a : situated at the highest point : directly overhead or in the zenith b of an aerial photograph : taken with the camera pointing straight down or nearly so > 2 a : perpendicular to the plane of the horizon or to a primary axis : UPRIGHT b (1) : located at right angles to the plane of a supporting surface (2) : lying in the direction of an axis : LENGTHWISE > 3 a : relating to, involving, or integrating economic activity from basic production to point of sale \ b : of, relating to, or comprising persons of different status \ > > - vertical noun > - ver·ti·cal·i·ty /"v&r-t&-'ka-l&-tE/ noun > - ver·ti·cal·ly /'v&r-ti-k(&-)lE/ adverb > - ver·ti·cal·ness /-k&l-n&s/ noun > synonyms VERTICAL, PERPENDICULAR, PLUMB mean being at right angles to a base line. VERTICAL suggests a line or direction rising straight upward toward a zenith \. PERPENDICULAR may stress the straightness of a line making a right angle with any other line, not necessarily a horizontal one \. PLUMB stresses an exact verticality determined (as with a plumb line) by earth’s gravity \. Definition 2 is the one I was using. (Note that vertical can also be a noun.) Plumb is also mentioned. ---
**Author:** ![AuraSeer](https://avatars.discourse-cdn.com/v4/letter/a/c2a13f/32.png) [@AuraSeer](https://boards.straightdope.com/u/AuraSeer)\ **Post date:** [October 9, 1999, 5:21am UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/7 "1999-10-09T05:21:00Z")
Whoops, I answered the wrong question. The “vertical equivalent of the horizon” is a line perpendicular to the plane of the horizon. Mathematically, this is called the _normal_. In construction, as aseymayo said, it’s a plumb line. * * * Laugh hard; it’s a long way to the bank. ---
**Author:** ![pluto](https://avatars.discourse-cdn.com/v4/letter/p/f08c70/32.png) [@pluto](https://boards.straightdope.com/u/pluto)\ **Post date:** [October 9, 1999, 5:32am UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/8 "1999-10-09T05:32:00Z")
Just a quibble, Aura, but _normal_ can refer to any line at right angles to another line or plane. It’s just as correct to refer to the horizon as the normal of the vertical. You are guilty of gravity chauvinism, which we free-floating thinkers abandoned long ago, on our way to the fourth dimension. ## Speaking of dimensions, I suppose the third member of our triad of lines (side to side, up and down, front to back) would be the _heading_ or _bearing_, that is, the line straight ahead of us. Any other thoughts on this? “If you had manifested _fatigue_ upon noticing that you had been an ass, that would have been logical, that would have been rational; whereas it seems to me that to manifest _surprise_ was to be again an ass.” Mark Twain _Personal Recollections of Joan of Arc_ ---
**Author:** ![Cap\_n\_Crude](https://avatars.discourse-cdn.com/v4/letter/c/b9e5f3/32.png) [@Cap\_n\_Crude](https://boards.straightdope.com/u/Cap_n_Crude)\ **Post date:** [October 8, 1999, 8:36pm UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/9 "1999-10-08T20:36:00Z")
Throwing out a couple of ideas to asnwer the “vertical equivalent of horizon.” Normally I’d just put down the right answer (either from knowledge or research) but I’m weary and very sick today. Azimuth Right Ascension Do either of these work? * * * –Da Cap’n ---
**Author:** ![pluto](https://avatars.discourse-cdn.com/v4/letter/p/f08c70/32.png) [@pluto](https://boards.straightdope.com/u/pluto)\ **Post date:** [October 8, 1999, 9:10pm UTC](https://boards.straightdope.com/t/hey-babe-want-to-get-horizontal-slap-is-that-a-no/3792/10 "1999-10-08T21:10:00Z")
(BTW, I spend a lot of time each day writing navigation software.) Azimuth and right ascension are measures of distance (angular distance) along the horizon. As such I don’t think they meet the criteria of the OP. Corresponding measures along the vertical (didn’t we decide that was the right word?) are altitude and declination. To be precise (and what are we if not precise?) right ascension and declination are equatorial coordinates rather than horizon coordinates, i.e., they refer to angles along and above the celestial equator, rather than the horizon.