Wait, this water bottle wasn't frozen a second ago!

Recently, I was taking a walk with a friend. She grabbed two water bottles from her garage refrigerator and handed me one. It was perfectly pliable and the water a liquid. As soon as I opened the cap it instantly froze. I watched the crystals form and pointed it out to my friend. Even though we just witnessed this phenomenon, she couldn't believe it was possible. Since I had previously looked at information regarding freezing points and pressure, I thought that the change in pressure upon opening the bottle caused it to immediately freeze. Well, I was wrong. After some additional research I figured out that what is happening to the water is that it is being “supercooled”, yet lacks any impurities to actually get the crystallization process started. So as soon as the water bottle is opened, either a speck of dust, an air bubble moving throughout the bottle, or another impurity cause this nucleation process to start. So for detailed explanation, I am including a post from the physics department at The University of Illinois at Urbana Champaign. “[We suspect that what's happening here is that the water in the bottles which did not freeze overnight was "supercooled." Water normally freezes when it is cooled below 0 degrees Celsius, forming ice crystals. Ice crystals form more easily when they grow on existing ice crystals -- the water molecules like to pack themselves in place on a crystal that's already gotten started. It doesn't take much to start the crystallization process going -- a little piece of dust or other impurity in the water, or even a scratch on the bottle are sometimes all it takes to get ice crystals growing. The process of starting off a crystal is called "nucleation." In the absence of impurities in the water and imperfections in the bottle, the water can get "stuck" in its liquid state as it cools off, even below its freezing point. We say this supercooled state is "metastable." The water will stay liquid until something comes along to nucleate crystal growth. A speck of dust, or a flake of frost from the screw-cap falling into the bottle are enough to get the freezing going, and the crystals will build on each other and spread through the water in the bottle. Water releases 80 calories per gram when turning from a liquid to a solid. We suspect your freezer is only a few degrees Celsius below zero (perhaps ten or fifteen?), and the specific heat of water is one calorie per degree per gram. This means that your water, as it freezes, warms up the rest of the water until the process stops at 0 degrees Celsius, freezing perhaps ten or twenty percent of the water. This ice may be distributed throughout the bottle, though, as the crystallization process happens very quickly and heat flows slowly. We suspect you have slush in your bottle rather than hard ice when this is done. You can compare with another bottle which froze hard in your freezer overnight how hard it is to squeeze the bottle and how long it takes to melt. The ice will also take up more room than the water it used to be, and some water may spill out the top. There can also be some small effects of pressure and of dissolved gases on the freezing temperature.]” ment of Physics University of Illinois at Urbana-Champaign

A sun lover's guide to safety.

Being a teenager in the 1980's, laying out in the sun was almost a sport. I can remember trying to get a suntan on 50°F days in my parent's backyard. I still love a suntan and think they look great, but don't really want to risk burning anymore.

As a Mom, I slather my children in a SPF 30 or higher whenever they are in the sun. Have you ever wondered what does that SPF really mean? It tells you how long it will keep you protected. "For example: it is in how many minutes you burn x the number that tells you how long it should last (even though you should reapply often, say every few hours, or more often if you burn easily). So if you burn in 10 minutes of sun exposure without any protection, SPF 30 will keep you protected for 300 minutes (in theory!). If you're using a cream, the amount of sunscreen you should use is about the size of a regular golf-ball, or 1 oz."

I really love the UPF (Ultraviolet Protection Factor)swim shirts. "A fabric with a rating of 50 will allow only 1/50th of the sun's UV rays to pass through. However, a plain white t-shirt only has a UPF rating of 7. A long-sleeved dark denim shirt offers an estimated UPF of 1,700 – which amounts to a complete sun block. In general, clothing made of tightly-woven fabric best protects skin from the sun." But who is swimming in that??? I say stick with the sunshirts.

"To receive The Skin Cancer Foundation's Seal of Recommendation, sun-protective fabrics must have a minimum UPF of 30. We consider a UPF rating of 30-49 to offer very good protection, and 50+ excellent protection."

Sources:

http://www.skincancer.org/sun-protective-clothing.html, http://www.wikihow.com/Stay-Safe-in-the-Sun

You have blues eyes, so that must mean you can't see squat!

Well, in my case, that happens to be true. However, the truth is that it is merely coincidence. Over dinner the other night somebody was telling me that people with light color eyes have poorer vision than people with brown eyes. Right away my little mental alarm went off. By the end of the discussion, I was being teased about how I would look it up. I wonder if my friends could just be setting me up. Regardless, I was compelled to find out for myself.

Since the color pigmentation lies in the iris and vision depends upon many things like the lens, retina, and the shape of the eye (astigmatism), it seems that color would have no affect on vision. However, eye color may affect vision in high glare situations, but doesn't actually mean your eye sight is worse. It seems as if my friend only got part of the story. Read the following from

http://eccentricscientist.wordpress.com/2007/03/02/do-brown-eyes-see-better-than-blue/


"But does your eye color influence how you see?

It turns out that it does. The darker the eyes, the more light is absorbed as light waves pass through the eye, and the less light is available to reflect within the eye. Light reflection (scatter) within the eye can cause susceptibility to glare (e.g. sun or headlights) and to poor contrast discernment. Thus it seems that people with darker eyes may have better vision in high-glare situations – perhaps this makes them better night drivers, for example.

Eye color may also affect your color vision. Here it seems that lighter eyes may provide some advantages.

So, if hind sight is 20-20 (no pun intended :)), then the moral of the story is to gather all of the information.

References
Coppens JE, Franssen L, van den Berg TJ (2006) Wavelength dependence of intraocular straylight Exp. Eye Res. 82(4):688-92

Coren S, Porac C (1978) Iris pigmentation and visual-geometric illusions Perception 7(4):473-7.

Dain SJ, Cassimaty VT, Psarakis DT (2004) Differences in FM100-Hue test performance related to iris colour may be due to pupil size as well as presumed amounts of macular pigmentation Clin. Exp. Optom. 87(4-5):322-5.

IJspeert JK, de Waard PW, van den Berg TJ, de Jong PT (1990) The intraocular straylight function in 129 healthy volunteers; dependence on angle, age and pigmentation Vision Res. 30(5):699-707."

Do cell phones really cause brain tumors?

Unless we have conclusive evidence, are we all going to give up or limit our cell phone usage? I doubt it! I did some research on the subject of cell phones and increased tumors. The most trusted information that I came across was from the National Cancer Institute.

The issue in question is really radio frequencies (RF). These are a form of electromagnetic radiation, but are a low frequency, non-ionizing form, unlike the ones emitted from x-ray machines. These low frequency RF waves are emitted by the cell phone antennae. One way to reduce the amount of RF without giving up or limiting cell phone usage is to increase the distance between the cell phone and the user, by going hands free.

So far the results from several major studies about the following types of tumors (cancerous and non-cancerous), gliomas, meningiomas, and neuromas, have all showed NO link. However, "further evaluation of long term exposure (more than 10 years) is needed to be conclusive."

According to the NCI website the following study is being performed, but it gave no date when it would be concluded.

“A series of multinational case-control studies (comparing individuals who have a disease or condition [case subjects] with a similar group of people who do not have the disease or condition [control subjects]), collectively known as the INTERPHONE study, are being coordinated by the International Agency for Research on Cancer (11). The primary objective of these studies is to assess whether RF energy exposure from cellular telephones is associated with an increased risk of malignant or benign brain tumors and other head and neck tumors. Participating countries include Australia, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, New Zealand, Norway, Sweden, and the United Kingdom (12).”

Since these are long-term, case controlled studies, their findings will carry a lot of weight and credibility.

My information came from the following source: http://www.cancer.gov/cancertopics/factsheet/Risk/cellphones

Additionally the NCI quoted the following site for further information:

“The Federal Communications Commission (FCC), which regulates interstate and international communications, provides consumers with information about human exposure to RF energy from cellular telephones and other devices at http://www.fcc.gov/oet/rfsafety on the Internet. This Web page includes links to information about the specific absorption rate (SAR) of cellular telephones produced and marketed within the last 1 to 2 years. The SAR corresponds to the relative amount of RF energy absorbed into the head of a cellular telephone user. Consumers can access this information using the phone's FCC ID number, which is usually located on the case of the phone."

Lastly, we can’t go through life worrying about things that may be discovered 10 to 20 years from now. Technology is the road to our future. We cannot stop it and someday we might need it to save human kind.

What do I do with these expired vitamins?

Quite frankly, I haven't ever worried too much about vitamins (or medicines) going bad myself. I know that all manufacturers build in a buffer zone with expiration dates. That means that their vitamins must pass all stability and analytical tests at least to the end of their life cycle, if not well beyond. So if a vitamin passes all of it's efficacy testing on the day it expires, how can it be bad the next day? It takes quite a while for them to degrade. Therefore, I believe that they just lose effectiveness and aren't really dangerous. With that said, I am not telling anyone what to do with their expired vitamins and medicines, I am not a M.D. So if you decide to get rid of them, they should be flushed down a toilet. That is the safest way to dispose of pills, so that an animal or child doesn't find them in the trash. The following information was from: the website:
www.vitamin-insight.com/mailbag/mailbag-question-39.aspx

{Vitamins gradually lose potency as the pills become exposed to sunlight, oxygen and moisture. While they may not become toxic or harmful, expired vitamins may not provide the results you want. Vitamin manufacturers set expiration dates by performing stability tests. These tests show how much the product will degrade over time. Vitamin manufacturers then add enough of the raw nutrient to compensate for any lost potency. Furthermore, certain vitamin formulations contain fillers and stabilizers that have a recommended shelf life.}

Will old meat really kill me?

One of my readers asked a question about the dates printed on meats purchased at the supermarket. I have always been afraid to eat anything after a few days. This neurosis was probably brought on by a Mom who was meticulous about food safety. My Mom had lived with her Aunt for a while during her college years and her Aunt was a Nutritionist. She never let me eat anything that wasn't washed. I mean anything...whole fruits that you cut into like cantaloupe or watermelon, canned food that you cut open with a can opener, soda in a can. After all, the blade cuts through the dirty part and then into the clean. Sounds a little crazy right?? However, Mom is actually right, you can get all sorts of nasty things from the rind of a cantaloupe. Of course in my rebellion, I let my kids eat strawberries right out of the container in the supermarket and I've managed to keep them alive! My Mom also used all meat within 2 days of purchase or she froze it. Again, Mom was right...imagine that! So here is some info on meat expiration..Sell By, Use By, Die By:
From www.Businessweek.com :
{According to Jeanne Goldberg, professor at the Friedman School of Nutrition Science and Policy at Tuffs University, "It's a very inexact science since those dates include a wide margin of safety."
"Date Data: The dates, for one, mean quite different things. The sell by date is more of a guide for the store to know how long it can display a product for sale. The best before or best if used by date refers to a quality or flavor of the food. Use by works more like an expiration date, similar to that on medicines, and taking them after the date is not recommended." (More on that in a later post.)
"Worse, some dates can actually be quite misleading. For instance, when you buy meat, that even if the sell-by date is five days away, the refrigerator at home usually isn't cool enough to keep meat fresh for more than two days."(Go Mom!) "Usually raw meat is kept around 30 degrees F, while the home refrigerator's temperature is set around 40 degrees F to keep other things in the fridge from freezing. So, food safety experts suggest that whether its ground meat, or a pound of steak, or chicken consumers either eat or freeze it within two days of buying.")}

Now as a scientist, I also know that if you handle that spoiled meat correctly and cook it to the recommended temperatures, that you aren't likely to get sick from it. This is because heat actually kills the bacteria, rendering it ineffective in making you sick. However, I don't recommend eating cooked spoiled food, because it wouldn't taste good! Why waste the calories. :)

How clean are dog's mouths?

For years my husband has been saying, "a dog's mouth is cleaner than a human's". Well of course I was sure this was crap and an urban legend. So at game night last night, this was brought up again after we told the story of my 80 pound black lab eating the 2.5 pound homemade meatloaf I had prepared, plus 5 oven roasted potatoes the night before. (And yes, I mean whole potatoes!) My husband admitted to eating what was left, YUCK!
So the question is fact or fiction?: Fiction-DUH? There is the reason I called it Dianaisalwaysright!

From About.com
"{If a dog's mouth is sterile how could it transmit rabies, tetanus, pasteurella or any other types of infections associated with dog bites. As we all know, dogs aren't particularly fussy about where they put their tongues or what goes into their mouth. "A dog's mouth contains a lot of bacteria," confirms Dr. Gary "Ask the Vet" Clemons. "Remember a dog's tongue is not only his wash cloth, but his toilet paper," says Dr. Gary.}"
For the rest of the history from where this urban legend came, go to http://urbanlegends.about.com/od/dogs/a/dog_breath.htm