Wing's wonderland: Things that you are wondering too but too lazy to search

My boyfriend and I went to a printing shop last month and saw a poster with different paper sizes, from A0 to A8. What do these numbers mean and how are they defined? Definition of A-series paper sizes The A-series paper follows the ISO 216 standard of writing paper and certain classes of printed matter. There are three main requirements: The length divided by the width (aspect ratio) is 1.4142 (√2). The A0 size has an area of 1 square meter. Each subsequent size is defined as the previous size cuts in half parallel to its shorter side. For instance, A1 has half of the area of A0 and it can be created by folding an A0 paper parallel to its shorter side. The dimension of an A0 paper is 841 mm x 1,189 mm to the nearest millimetre. An A1 paper has a  dimension of 594 mm x 841 mm. The image below compares different paper sizes in the A series. Image from Wikipedia The magic root 2 An advantage of the A-series paper is that it can be up/down scaled to other A-series sizes without any di...

  Living things are magical when it comes to the ability to repair and regrow. We need this ability to maintain the healthy functioning of our bodies so as to increase the chance of survival. Some animals have better regeneration ability than human, here is a video to show how salamander regenerates its limb: The salamander is known for its regeneration capacity. They can regrow the limb, heart, tail, brain, eye tissues, kidney and spinal cord. To understand how they do it, let's look at what stem cells are. Stem cells Our body is made up of different types of cell. Most cells have a specific function, such as red blood cells, nerve cells, and heart cells. Stem cells provide new cells for the body and replace lost or damaged cells. They can divide into new stem cells or specialised cells that made up other body parts. Image credit: Genome Research Limited There are 3 types of stem cell:  embryonic ,  adult , and  induced pluripotent  stem cells.  Embryonic ...

  8% of our body weight is made of blood. It carries oxygen, nutrients, hormones and other substances around our body to keep us alive. We learnt from school that there are four blood type categories: A, B, AB and O. But what are the differences between these blood types and why can't we just donate blood to another person with a different blood type? Antigens and antibodies Blood type is identified by different antigens and antibodies contained in the blood. Antigens are protein molecules on the surface of red blood cells (RBC). Antibodies are proteins in plasma. They form a defence system in our body, which detect foreign substances like germs and alert the immune system to destroy them. The ABO blood types Type A : Contains type A antigen on RBC and anti-B antibody in plasma. Type B : Contains type B antigen on RBC and anti-A antibody in plasma. Type AB : Contains both type A & B antigens on RBC but no antibodies in plasma. Type O : Has no type A nor B antigen on RBC but bot...

 This question came into a discussion with my colleagues tonight when talked about having a vegan diet. Being a vegan can be something to do with religion, concern with animal welfare, health, and for the sake of the environment. To answer the question, let's look at how do chickens lay eggs.  Illustration: The Spruce / Ashley Nicole Deleon The lifespan of a chicken is 5-10 years, and hens start laying eggs around six months old. Eggs are formed from the inside to the outside. Each hen has a thousand yolks (ova) at birth. When a yolk is mature, it will be released from the ovary to the oviduct. This takes 15 minutes to half an hour, and fertilization happens here if the hen mates with a rooster. Next, the yolk travels down to the magnum and the isthmus sections of the oviduct. The inner and outer shell membranes are formed to hold the egg content together loosely. It takes about 2-4 hours. After that is the most time-consuming part: forming the eggshell. The shell gland in the...

  Have you ever wonder why bird poop is white? Actually, the white part is not poop but pee. Unlike human, birds do not have separate exits for solid and liquid waste. Both urine and feces are eliminated through an organ called cloaca. Our body excretes urea in the form of urine, while birds convert nitrogenous waste into uric acid. The benefit of peeing uric acid instead of urine is that it minimizes water loss. However, that is also why bird droppings are white and sticky! Have you been the unlucky one who got bird droppings on the windshield of your car? A study in England found that red cars are more likely to be the targets of bird poop and green cars are less favourable. Maybe the easiest way to avoid it is not to park under a big tree!

  According to the Cambridge Dictionary, "come out of the closet" is a phrase used to tell people that you are gay after previously keeping this secret. But where does this phrase actually come from?  Some said it is related to the idiom "skeleton in the closet", which means someone hidding a human body (a secret) in the closet so long that the it had decomposed to the bone. Thus, skeleton out of the closet means revealing the secret that you hid for a long time and it slowly evolved into the term "come out of the closet". It carriers a negative narrative that a homosexual/bisexual person is not accepted by the mainstream value and he/she has to hide the sexual orientation from the outside world. Surprisingly, according to wikipedia, the expression "coming out" is way more positive with empowering. Instead of saying "coming out of the closet", it was rather "coming into" a homosexual society that is not so small, isolated, nor...