Do Polar Bears Get Lonely?: And Answers to 100 Other Weird and Wacky Questions About How the World Works - Softcover

Do Polar Bears Get Lonely?
1FOOD AND DRINK TWIN CHICKSUpon cracking open my breakfast boiled egg, I found a whole new egg inside. It was not a double-yolked egg, it was a double-egged egg--a completely new egg with a shell and yolk inside another. Can anybody explain it?Liam Spencer 
An egg within an egg is a very unusual occurrence. Normally, the production of a bird's egg starts with the release of the ovum from the ovary. It then travels down the oviduct, being wrapped in yolk, then albumen, then membranes, before it is finally encased in the shell and laid.Occasionally an egg travels back up the oviduct, meets another egg traveling down it, and then becomes encased inside the second egg during the shell-adding process, thus creating an egg within an egg. Nobody knows for sure what causes the first egg to turn back, although one theory is that a sudden shock could be responsible. Eggs within eggs have been reported in hens, guinea fowl, ducks, and even Coturnix quail.Incidentally, it is especially unusual to encounter thisphenomenon in a shop-bought egg, because these are routinely candled (a bright light is held up to them to examine the contents), and any irregularities are normally rejected.Alex Williams 
As the curator of the British Natural History Museum egg collection, I've come across quite a few examples of egg oddities. Double eggs (as opposed to multiple-yolked eggs) are less common than some other oological anomalies and consequently the "ovum in ovo," as the phenomenon described here is known, has attracted specific scholarly attention for hundreds of years.The Dominican friar and polymath Albertus Magnus mentioned an "egg with two shells" as far back as 1250 in his book De animalibus, and by the late seventeenth century pioneering anatomists like William Harvey, Claude Perrault, and Johann Sigismund Elsholtz had also given the phenomenon their attention.Four general types occur--variations of yolkless and complete eggs--but this form in which a complete egg is found within a complete egg is relatively rare. Several theories have been proposed for the origin of these double eggs, but the most likely suggests that the normal rhythmic muscular action, or peristalsis, that moves a developing egg down the oviduct malfunctions in some way.A series of abnormal contractions could force a complete or semi-complete egg back up the oviduct, and should this egg meet another developing egg traveling normally down the oviduct, the latter can engulf the former; more simply, another layer of albumen and shell can form around the original egg.Often when no yolk is found within the "dwarf" or interioregg, a foreign object is found in its center. This object has served as a nucleus around which the albumen and shell were laid down, in a process not dissimilar to the creation of a pearl.Anybody interested in learning more about this subject should try to find a copy of The Avian Egg by Alexis Romanoff and Anastasia Romanoff (New York: John Wiley & Sons, 1949) and read pages 286-95. 
Douglas RussellCurator, Bird Group, Department of Zoology The Natural History Museum, Hertfordshire, United Kingdom A ROUND FIGUREWhy do bottle caps on beer bottles--at least the few hundred thousand that I have drunk from--always have twenty-one sharp bits?Volker Sommer 
We have three explanations for this one. We're still waiting for a bottle-top aficionado (of which there seem to be many) to rule between them.--Ed. 
The bottle cap on any bottle is regulated by the internationally accepted German standard DIN 6099, ensuring all bottle caps are the same. Along with specifying the diameter of the bottle neck, the form of the rim around which the cap is crimped, and the materials the cap may be constructed from, this document specifies the form of the crimp. One requirement is that the closure be sufficiently circular to maintain a tight seal all around the circumference, which implies a highnumber of crimps (and thus points). It must also be robust, however, which implies reducing the number of crimps to give each crimp a larger bearing surface. Using twenty-one crimps is a good compromise between these requirements and is mandated in the standard. As to why it is twenty-one crimps rather than twenty or twenty-two, the best answer is simply "because it is."S. Humphreys 
Through trial and error, William Painter, the inventor of the crown cork, or bottle cap, discovered that the optimum number of teeth on a mold made of steel for securing carbonated drinks was twenty-four. He registered a patent for his design and for many years the twenty-four-tooth capping mold was standard. However, around 1930 the steel mold came under threat from a cheaper version made of tinplate. This newer mold could not win a patent if it also had twenty-four teeth, so it was changed to twenty-one to avoid infringing the original design. The new figure is the smallest number of teeth needed to prevent leaks and is now used across the world.Chitran Duraisamy 
The crown cap was patented by Painter on February 2, 1892 (U.S. patent 468,258). It originally had twenty-four teeth and a cork seal with a paper backing to stop drink and metal touching. The current version has twenty-one teeth.The twenty-four-tooth caps were originally fitted to bottles one by one using a foot-operated press. When automatic machines were adopted, the crown caps were loaded into circular feed tubes and the twenty-four-tooth caps frequently jammed. With an uneven number of teeth this doesn't happen, and because the sealing quality of twenty-three teethwas no better than twenty-one, the smaller number was adopted.The height of the crown cap was also reduced and specified in the German standard DIN 6099 in the 1960s. This also defined the "twist-off" bottle cap that is widely used in the United States.Barry Painter CEREAL KILLERMost healthy people I know eat cereal or fruit for breakfast. This gives complex carbohydrates for long-term energy. But I have a physical job as a gardener and I know if I rely on this intake I'll be ravenous by 10 A.M. On the other hand, if I have eggs, I'll be fine until midday. Clearly I need protein, but that shouldn't give me energy. What is going on, and is this common?Steve Law 
It may be that your hunter-gatherer ancestry is responsible for the favorable response to your morning serving of eggs. In the course of human evolution we have become physiologically adapted to the diet that prevailed for most of that time: that of a hunter-gatherer. This diet is assumed to have been dominated by lean meats, fruits, and vegetables. Cereal grains, on the other hand, are a relatively new addition to our diet, having found their place on the dinner table with the onset of the agricultural revolution only ten thousand years ago.It has been suggested that our pre-agricultural diet is the best way to support healthy physiological function, including improved energy production and appetite control. One of the characteristics of this diet is a low "glycemic load,"which means glucose is released slowly into the blood as food is digested. Another is a higher level of lean protein than that eaten by modern humans. These characteristics are found in your eggs, whereas most breakfast cereals and fruit have higher glycemic loads and lower protein content.The low glycemic load of your meal may help to stabilize your blood sugar level, sharp drops of which precede an increase in appetite. The protein in eggs is also a strong inducer of cholecystokinin, a gut-derived satiating hormone. And carbohydrate is not the only source of energy in our diets. The fat in your breakfast eggs provides approximately double the energy of carbohydrate, albeit in a slow-release form.Benjamin BrownTechnical Research Officer Health World, Queensland, Australia SACRED DNAAnimals and plants share a common genetic ancestry, so perhaps vegetarians who refuse to eat meat on ethical grounds should avoid anything that has DNA at all. Is this feasible? Could anybody suggest a menu?Richard Ward 
I'm not aware of any living organisms that don't have DNA, so you'd have a hard time eating any tissues or cell cultures. You could try eating RNA viruses, but you'd need to produce them in a cell culture, which generally requires animal serum to keep the cells alive. Your food wouldn't contain DNA, but you would have used dead animals to produce it.One cheat that springs to mind is red blood cells. In many species, including humans, the nucleus and mitochondria are removed from these cells during the maturation process. This is to make room for more hemoglobin, the iron-bound protein that carries oxygen. Because the nucleus and mitochondria contain all the cell's DNA, you could argue that provided you don't kill the animals, drinking their blood is the ultimate vegetarian diet. You'd need to filter out the white blood cells, which still have plenty of DNA, but the rest of the blood components would be fine. They'd provide you with protein, some sugars, and vitamins, but probably more iron than is healthy.If that doesn't sound appealing, consider totally (bio) synthetic foods. Biologists routinely construct yeast and bacterial lines designed to churn out large quantities of a specific protein or other biological molecule. I assume it would be possible to scale this production up ...