Talk:Black ice

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Contents 1 Terminology 2 Ships 3 Black Ice Versus Clear Ice 4 Black ice Overdrive 5 Comment on NTP for freezing point 6 Interleaved? 7 authoritative? 8 Reinstated edits

[edit] Terminology

In northern New England "black ice" has traditionally referred to a clear form of pond ice that formed in very cold weather. Black ice has the appearance of thick, slightly cracked glass laid on the water, and its transparency reveals the darkness of the pond beneath; hence the name. Black ice is very hard and smooth, and provides conditions that make ice-skaters ecstatic: effortless gliding and extremely smooth, if slow, stopping. (One can skate sideways on black ice, using the right blade angle.)

Black Ice is also the title of a critically-acclaimed memoir by Lorene Cary of her experiences as a young black student at the elite St. Paul's School in the 1970's. It contains the following description: "...a clear, glittering ice that forms when it gets cold enough before the first snow to freeze the dark waters of the lakes. The surface acts like a prism to break winter sun into a brilliant spectrum of browns. Below, in the depths, frozen flora pose. Black ice is the smoothest naturally occurring ice there is, as if nature were condescending to art."

The use of the same term by television weather reporters to describe ice-glazed black pavement is a more recent occurrence of the past few decades.

Time for a disambiguation page? There's also Black Ice (poet), and "black ICE" as a term in Neuromancer for lethal Intrusion Countermeasures Electronics. 86.141.84.1 03:36, 9 January 2006 (UTC)

Black Ice is also a very effective energizer and dietary supplement based on the ECA Stack (Ephedrine, Caffeine and Aspirin). It is available at http://www.thatswholesale.com

[edit] Ships

The section on iceing on ships is very confusing. I requested cleanup fo it --ZPS102 02:48, 9 January 2006 (UTC)

They capsize because in freezing conditions an ice crust forms on the part of the ship above water, making it top-heavy. 86.141.84.1 03:36, 9 January 2006 (UTC)

Ships are normally stable while at rest or slow speed bcz their centers of gravity are below the water line, a condition that is ensured, if necessary, by carrying ballast such as the stone that ships coming empty to New York harbor for cargos brought with them. (Big sections of Manhattan & probably other boroughs are built on top of the ballast that was discarded by ships sailing away with sufficiently dense cargo that the ballast was no longer needed.) When the ship is tipped by wind or wave, it rotates around a fore-to-aft axis parallel to the surface, while keeping the same volume below the surface. It is designed to ensure that this raises the center of gravity, and thus that the net forces on it oppose further tipping and correct most of it quickly. Ice forming above the CoG raises the CoG and can in theory raise it above the water line, in which case the net forces favor tipping further. Probably that is never reached in practice, bcz ice forming high above the CoG, i.e. in the spars and rigging, is especially far from the CoG, and exerts disproportionately strong forces compared to weight close to the CoG, e.g. the ballast. I assume that the resulting increase in angular moment becomes a serious hazard before the CoG rises above the surface: at the same time the CoG is rising and thus being raised less by a tip of a given angle and exerting a smaller restoring torque, the motion of the ice in the high rigging when the ship rolls is also harder to slow down let alone force back up. I expect the ship to first start shipping water from continuing to tip further and further in response to a gust or wave that has already stopped pushing it to that side, but left with motion that the ballast's corrective force hasn't yet overcome even tho the net forces are already slowing the roll.
--Jerzy•t 09:08, 9 January 2006 (UTC)

[edit] Black Ice Versus Clear Ice

In very cold climates the term "black ice" has yet another meaning. It is actually a form of frost that forms on paved roads after a prolonged period of very cold weather (typcially -30 C or colder) followed by warmer, more humid weather. Unlike clear ice, this form of ice is visually indistinguishable from dry pavement, even in broad daylight. But it is nearly as slippery as clear ice.

With experience, a driver can feel the reduced coefficient of friction. But most drivers will not notice it until they have actually begun to skid, at which point it may be too late.

--Tedd 17:50, 20 January 2007 (UTC)

[edit] Black ice Overdrive

There is also an overdrive circuit that can be installed on guitars called the Black Ice Overdrive, that is distributed by Stewart-MacDonald, I think it should get its own article but anyways...

Avyfain 04:40, 27 February 2007 (UTC)

[edit] Comment on NTP for freezing point

Don't you think that specifying NTP for the freezing point of ice is a bit too much? The freezing point's dependence on pressure is slight, so it just adds confusion. It isn't like the boiling point. Why not just say the freezing point (0 C)?

Rerooks 16:17, 23 March 2007 (UTC) Raymond

[edit] Interleaved?

>> In addition, it often has a matte appearance rather than the expected gloss; and often is interleaved with wet pavement, which is identical in appearance. >>

I can figure out what it means in context but "interleaved" is kind of a weird word, does anyone have a better term to use? —The preceding unsigned comment was added by 24.124.29.130 (talk) 04:58, 6 May 2007 (UTC).

Maybe "interspersed"?

Atlant 14:13, 7 May 2007 (UTC)

What on earth has the link to African-Canadians playing ice-hockey got to do with black ice? I came here looking to be a better driver here in our Australian winter, and found no advice, but there is, of course, as is Wikipedia's want... a link to entertainment in the form of ice hockey! Grr...

[edit] authoritative?

"The term black ice is sometimes used to to describe any type of ice that forms on roadways, even when standing water on roads turns to ice as the temperature falls below freezing. However, this use of the term black ice is not included in the American Meteorological Society Glossary of Meteorology." - is the american meteorological society an authority on the name of what is really a road safety condition rather than a form of weather? —Preceding unsigned comment added by Random832 (talk • contribs) 17:36, 14 December 2007 (UTC)

[edit] Reinstated edits

This statement from the Black Ice article was the one that triggered me ito action. "The process of freezing is slowed down due to latent heat given off in sublimation,". Sublimation is the evaporation of a solid not the freezing of a liquid as is stated in the article. Also, sublimation would adsorb heat not liberate it. Another of my edits was to remove the mention of Rime Ice as a type of ice that is a hazard on a road surface. Another of my edits was to remove the mention of a steep atmospheric pressure gradient from the sentence that describes why rain freezes on very cold pavement. Electricmic (talk) 05:00, 9 February 2008 (UTC)