| Name |
Views and Comments | Date |
| ananymous |
Yankees are the best team ever |
2/9/2009 |
| Nicholas Wonq |
O: i dont get any of this & im trying to figure out why ice is slippery for my exit science project |
12/28/2008 |
| ashley |
So ice is only slippery if you wear skates? So I should be able to walk on ice in flat shoes and not slip...
Also, using the logic in this article, in very cold conditions, ice should not be slippery. |
11/16/2008 |
| Khodabaks |
Maybe the references should include the Martin Chaplins Webbook
"Water Structure and Science"
Dr. Elias Khodabaks |
7/21/2008 |
| Jermaine |
Seems interesting :) |
4/13/2008 |
| Christian Annal |
Doesn't seem very plausible. Even a 2 gram object will slide on ice, because ice is always melting. Unless you freeze it to 0 degrees Kelvin which is impossible. The molecules on the surface of ice therefore are in a state of ice and water (plasma). Evaporation is the cause of slippyness. |
3/30/2008 |
| Alex Krause |
This article needs to be updated to reflect modern experiments and understanding. Please see the New York Times article "Explaining Ice: The Answers Are Slippery" |
12/4/2007 |
| Your Mother |
Those references and this article are incorrect. |
11/8/2007 |
| musa yaro |
what is happening to manchester united football team |
8/22/2007 |
| MUSA YARO |
WHAT IS HAPPENIG TO MANCHESTER UNITED |
8/22/2007 |
| ISMAILA LAWAL |
I WANT TO GET A MATERIAL THAT TALK MAINLY ON WHY IS SLIPPERY |
8/22/2007 |
| Derek Leslie |
That's very interesting, I alwyas assumed that smooth ice is more slippery. I was shocked and amazed. Now that you menton it though, it makes a lot mmore sense this way. |
6/13/2007 |
| becky |
what properties does an ice-skate contain? |
2/27/2007 |
| larissa |
i think a smooth surface of ice is more slippery than a bumpy surface of ice because you wont be able to go that fast on skates because ice is hittingthe side of the skates which causes friction which the slows the skater down please write back |
2/7/2007 |
| D.J., Ph.D. |
So, let's say I've got one skate on a wooden plank, and the other on the ice. If I place all my weight on my skate on the ice, and then slowly shift my weight to my other foot on the plank, why is my skate not now glued to the ice? Ice adheres very well to steel.
Also, if you calculate the pressure required to depress the melting point of ice say 3°C, it is much higher than the strength of the ice. Unless you apply the pressure hydrostatically, which an ice skate cannot, the ice will acutally deform plasticly way before it melts, with some brittle spalling out the side of the skate blade. |
11/16/2006 |
| James Day |
The phase diagram of water shows that a pressure of about 130kg/cm^2 will change the melting temperature by a only a few hundredths of a degree, not by a whole degree (as you state). This is not enough to cause melting. This incorrect explanation is commonly cited (even in textbooks) as why ice is slippery. But, for example, the pressure-melting explanation fails to explain why someone wearing flat-bottom shoes, with a much greater surface area that exerts even less pressure on the ice, can also slip on ice. Physicists still haven't reached a perfect agreement, but likely the surface of ice is always "liquid-like" (as the molecules there aren't as strongly bound as the molecules deep within the solid, resulting in a disordered, watery-ish surface layer). |
11/2/2006 |
| imran |
slippery |
9/19/2006 |
| henning |
This is completely wrong--the pressure could never be big enough. Check the web for more--it's all about pretty complex surface science... |
9/13/2006 |
| Elean |
I just read in Ripley's box that "scientists to this day are not quite sure why ice is slippery" |
5/2/2006 |
| none of your bu |
i think that this is very interesting but not what i am looking for and i think thati already have a science project. |
4/23/2006 |
| alnisa |
The reason why i think that ice is slippery is because if friction. |
4/4/2006 |
| alnisa |
i think that ther eason why ice is slippery because of friction. |
4/4/2006 |
| meerwind |
Ice surfaces have contradicting properties. Obviously the top layer of ice is attached less firmly to the remaining ice than are surfaces of other solids.
The reason why ice is slippery, could be that small parts of the ice are broken off the surface to form a microscopic powder - just as you may slip when small pebbles cover a plan surface.
Possibly this ice powder is not made up of circular units but linear objects or strings that stretch in one direction. These can align perpendicular to the movement when an object moves over the ice. In colder ice these strings would move less, which could be the reason for even less fricition.
This "ice powder" would never become warm enough to melt into water. The ice powder will recombine to the solid ice immediately after an object, e.g. an ice scater, has passed by. Thus it will be difficult to look at this ice powder in experiments. So we will live with uncertainties when and why we stlip for some more time. |
3/9/2006 |
| Tom |
Bob Larson is absolutlely correct.
Please update this article ASAP and dispel the myth that
slipperiness is caused by pressure-melting |
1/2/2006 |
| tds |
This explanation is not accurate |
1/2/2006 |
| john |
Really interesting article. |
12/8/2005 |
| mk pandit |
yes,you are right. |
11/28/2005 |
| mk pandit |
fine,it is not much important whether ice is slippery or not,but it is rather amazing and wonderfull tehat such kind of questions arising in our mind.it is greate exercise for the development of inteligence and vision to see the world in the differnt angle.more and more such questions should arise in our mind. |
11/28/2005 |
| ruth |
you lied to me? |
10/23/2005 |
| bobbie jo |
why is ice slippery |
8/31/2005 |
| ryan fisher |
what is th point of ice |
12/14/2004 |
| Bob Larson |
Regarding your explanation of "why is ice slippery",
complete bunk.
This is a topic that has come up time and again in discussions of ice skating, skiing, etc. and is
a pet peeve of mine.
The claim is often made that ice is slippery because
of the reduced melting point caused by pressure of,
say, an ice skate blade (or whatever).
Your column is one example,
but a quick search will reveal many such examples.
The truth is that the sorts of pressures we can
apply to ice with a skate blade reduce the melting
point only a tiny bit, not enough to cause
the ice to melt. Nor is slipperiness caused by
friction melting. That is a common fall back, but
makes no sense on its face. It is the
same as saying friction causes a lack of friction.
The truth is that ice is slippery because of
surface properties that are present at
ambient temperatures and pressures whether
added pressure is applied or not. The
molecules of water in the surface layer are not
as tightly bound to the ice crystal lattice
and (unlike many other crystal surfaces)
exhibit fluid-like properties. Don't confuse
"fluid-like" with liquid water: there is still
a transition energy between this ice phase
and liquid water. Ice is ice, and is slippery
all the time. For a description from a more
reputable source, I will
attach an excpert from Science Now, below:
From Science Now, online journal of AAAS/Science Mag
9 December 1996
Getting a Grip on Ice
Ice has always been a slippery subject. As simple as an ice cube may seem, scientists have long been baffled about why its surface is so slick. But an upcoming paper in Surface Science may give researchers a firmer grasp of ice's surface subtleties by hinting that its outermost molecules behave like a liquid.
That would give the surface layer drastically different properties from those of the bulk of the crystal, says Gabor Somorjai, a surface chemist at the Lawrence Berkeley National Laboratory. The liquidlike layer could explain, for instance, why it is more fun to skate on ice than on concrete. According to Somorjai's colleague, Michel van Hove, the popular conception that ice's slipperiness comes from pressure-induced melting is wrong. "It doesn't work out," says van Hove. "You put data into the formula, and there's not enough pressure." The slippery layer, he says, is there to start, even at very low temperatures.
Somorjai and van Hove discovered this layer when they probed the surface of thin layers of ice with low-energy electron diffraction, a technique that uses electrons to determine the surface structure of a crystal in the same way as x-ray diffraction reveals the crystal structure of a solid. The researchers expected to see the scattering signature of the first three layers of ice molecules, but they only saw two. After determining that the invisible top layer did, indeed, exist, the researchers hypothesized that its water molecules were vibrating three or four times faster than those in the lower layers--blurring its diffraction pattern to invisibility. Although the water molecules are bound in the lattice like a solid, says Somorjai, "the vibrational amplitude is like a liquid."
Besides making ice slippery, says Somorjai, the liquidlike layer could help explain how ice crystals in the upper atmosphere help catalyze the chemical reactions that deplete ozone. The finding, says Steve George, a chemist at the University of Colorado, "illustrates how we don't understand the simplest things we know about."
|
11/29/2004 |
| David Vanderham |
This is no longer the accecpted theroy please do more research |
10/4/2004 |
| BigRedBurk |
That means that there would be a tempature low enough to overcome the pressure of an ice skater and the ice wouldn't melt fast enough to skate. It also means that if it got even colder, it wouldn't be slippery at all. It would be like concrete. |
9/11/2004 |
