Why do hot baked products 'fall' if not given a resting period?

Most baked products have an infrastructure of starch (from flour) reinforced with egg proteins, and filled with fats and sugars and the most important - air. The starch portion of the flour gels and creates a web-like protein-gluten mesh. The carbon dioxide from the baking powder or baking soda will expand the cake. The protein-gluten mesh holds those bubbles in place.
These air bubbles need to set. If given proper resting time the whole protein network hardens and holds the bubbles in cakes. But when the gluten is hot, it's still very soft and can easily collapse is exposed to cold air. When you expose it to a sudden cold air, the bubbles contract, with the protein mesh not firm enough to hold. That’s why when you take a cake out early from an over, the cake can collapse because a structure hasn’t set yet. The simple answer as to why cakes collapse is the network of proteins and starches are not strong enough to hold the expansion of air.

What is difference between values, morals and ethics?

Life is a universal, objective value. We might take this point for granted, but we all have the life value, or we would not be alive. Life is also a dual value – we value our own life and the lives of others.

Values have an intrinsic worth in usefulness or importance to the possessor. Values are the things people determine to be the most important in their lives. 

Morals are relative values that protect life and are respectful of the dual life value of self and others. Morals have a greater social element to values and tend to have a very broad acceptance. They are far more about good and bad than other values.

Ethics are moral values in action. Ethics tend to be codified into a formal system or set of rules which are explicitly adopted by a group of people. Ethics are thus internally defined and adopted, whilst morals tend to be externally imposed on other people.

To summarize, 'Values motivate, morals and ethics constrain'. In other words:

•  Values are our fundamental beliefs, describes individual or personal standards of what is valuable or important 
•  Morals are values which we attribute to a system of beliefs
•  Ethics is about our actions and decisions

Why do we dream?

A dream can include any of the images, thoughts and emotions that are experienced during sleep. It is an involuntary activity. 

Despite improvements in medical technology and sleep research, experts today still have not reached a conclusion about why people dream. They have, however, developed some interesting theories.

Some experts believe dreams are a way to process all the events and emotions we experience throughout the day. They believe dreams play an important role in our physical, mental and emotional health. Similarly, other experts claim dreams are a form of problem-solving. They believe our dreams provide us with a safe place to work through problems, questions and dilemmas in our lives. Some researchers suggest that dreams serve no real purpose is a mere bodily function. On one side of the debate are those who think dreams are random images, and on the other are those who think there is deeper significance to what we see in our mind's eye. Some scientists believe dreams are the cortex's attempt to find meaning in the random signals that it receives during REM (Rapid Eye Movement) sleep.

Ranging from spiritual associations to a means of relieving stress, little conclusive research has been accomplished.

How does a sponge suck up water against gravity?

When a sponge is placed in a container full of water, it tends to suck up water, and get wet, even above the remaining water level. How does this water get sucked up against gravity?

This happens due to effect called capillarity, that causes water to move up narrow cylindrical channels. Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity. 

The pores of sponge are sufficiently narrow that the cohesion between water molecules and adhesion between the water and the surfaces of the pores combine to lift the water into the pores.Specifically the adhesion between the sponge fibers and the water molecules is high enough that water prefers to be touching the sponge more than other water molecules and so there is a tendency for it to "creep" up the sponge. In short, the capillary action, due to the pressure of cohesion and adhesion  causes the liquid to work against gravity.

Why do we see dust particles in bright narrow beam of light?

The particles are always present in air. Normally, they reflect less light, because the particles are very small. They can only be seen when a strong beam of light passes through the air. This is called Tyndall Effect. A very strong concentrated light beam reflects off of the dust in the air which can be seen in a darkened room, which is normally not seen.
Our eyes become more sensitive to light in dark rooms, especially if we give them a few minutes to adjust. Also the illuminated dust in a beam of light shows up because of the contrast between it and the dark background when the room is dark.

Why do dead bodies of animals/humans smell bad, while dead plants do not?

Decomposition of body begins at the moment of death, caused by two factors: autolysis, the breaking down of tissues by the body's own internal chemicals and enzymes, and putrefaction, the breakdown of tissues by bacteria. These processes release gases that are the chief source of the unmistakably putrid odor of decaying animal tissue.Decomposition of plant matter occurs in many stages. It begins with leaching by water; the most easily lost and soluble carbon compounds are liberated in this process. Another early process is physical breakup or fragmentation of the plant material into smaller bits which have greater surface area for microbial colonization and attack. 

During decomposition of animal carcass various chemicals such as ammonia, cadaverine, hydrogen sulfide, and putrescine are produced by the consumption of proteins by anerobic organisms which are characterized by their foul smell. However in the case of plants, due to a low protein content the extent of production of these foul smelling gases are very small. Therefore decomposition of plants are usually oudourless. Moreover the plants are primarily composed of cellulose and lignin, which are acted upon by very few microorganisms, which ultimately results in much delay in decomposition of the plant.

Why is it easier to tear paper along a crease?

Paper is made from wood, and wood is made from long fibers. Paper is made out of cellulose fiber material, and these fibers line up in a particular direction, during the manufacturing process.  There is a distribution of the fibre sizes,  the finer ones penetrate into the web of larger ones holding them together. Typically the manufacturing process leaves the fibers are more or less parallel. So it is easier to tear in the direction that separates fibers from neighboring fibers than in the direction that breaks fibers. Creasing paper breaks and/or separates some of the fibers, making it easier to break/separate the rest. Excessive weakening of the paper happens along the fold line because the fiber-to-fiber bonding along the fold gets loosened. Hence, once the tear is started, pulling the paper apart a little propagates the tip of the tear a little farther. Because of the loosened bonds, the pressure of tearing acts more effectively along this direction rather than getting diverted by the larger and stronger bonded fibres. So the tear follows the crease.

Why does burning stuff give out smoke?

During a fire, the air around it becomes heated. The heated air sweeps up water vapor (molecules of water that float in the air) and tiny specks of the fuel (the material being burned) into a dark cloud of smoke. If the temperature gets high enough, these compounds burst into flame. Once they start burning, there is no smoke because the hydrocarbons are turned into carbon dioxide and water (both invisible) when they burn.
 The more incompletely something burns, the more smoke it produces, because more particles are left to be swept up into the air. Smoke gradually spreads out and drifts away.

Why is honey the only food that does not go bad?

Pure honey does not go bad. Most honey is a supersaturated with sugar. Sugar being hygroscopic, its attractiveness to moisture makes honey a dehydrating agent. Most microorganisms do not grow in honey because of its low water activity. Molds and bacteria that land on the honey lose their own moisture(desiccate) to the honey, Thus their growth cycle is compromised and spoilage is reduced.
Over the time, honey may get crystallized. Crystallized honey can be re-liquefied by heating. You should never leave a jar of honey standing open. The supersaturated sugar solution will absorb moisture from the air and gradually become weaker, losing its anti-bacterial properties.

Why does mouth water when we see or smell delicious food?

When we see or smell good food, the brain registers that food is coming, and it instructs the salivary gland underneath our tongue to produce saliva in anticipation. Saliva helps break down the food as we chew it and makes it softer as it enters the gullet. As this is a subconscious reaction, it will occur even if we just see or smell the food.

Why do we get lumps in our throats when we hold back tears or are about to cry?

The ‘lump’ is actually not a lump at all but a counter-reaction to the body’s automatic nervous system. When humans are exposed to stressful situations,  the body automatically increases blood flow to vital organs and muscles. This is our typical ‘fight or flight’ biological reaction to things. Consequently, in order to get more oxygen to the body, one biological response is to expand the glottis in your throat.
But, being the social creatures we are, there are times when we try to suppress the urge to cry and often constrict or stop breathing altogether. Hence we have a battle between the body’s natural response to stress by widening the muscle in the throat to get more oxygen, and one’s wish to avoid shedding tears where we often stop breathing and thus constrict the muscle in our throat.  Hence, the vocal chords are fighting themselves to both compress and expand at the same time - and that's when we experience the tension as a lump. 

What does 20/20 vision mean?

During an eye test, eye doctors use eye charts to measure how well you see in the distance, compared with other human beings. The eye chart displays letters of progressively smaller size and it compares a person's vision to the that of the average for the population. "Normal" vision is 20/20. This means that the test subject sees the same line of letters at 20 feet that a normal person sees at 20 feet. 20/40 vision means that the test subject see as 20 feet what a normal person sees at 40 feet.
20/20 means that the person whose vision is being tested is normal.

What is blue moon?

A Blue Moon is commonly the name given to the second full moon in a calendar month. Since a full moon occurs every 29 1/2 days, if there is a full moon on the 1st or 2nd day of a month, there is a good chance there will be a second full or blue moon that month. Blue moons happen every two to three years. The moon looks like a regular full moon and not blue in color.
'Once is a blue moon' is frequently used expression which means ‘not very often,’ or ‘very rarely'.

Why do rain clouds float inspite of carrying water?

Rain clouds have bigger volume but very small mass,hence very low density (lower than that of air) because of which they float. Clouds generally form, survive and grow in air that is moving upward. Rising air expands as the pressure on it decreases, and that expansion into thinner, high-altitude air causes cooling. Enough cooling eventually makes water vapor condense, which under gravity falls as rain. So, even though typical clouds do contain a lot of water, this water is spread out for miles in the form of tiny water droplets or crystals, which are so small that the effect of gravity on them is negligible. 

Does a blood transfusion change our DNA?

Red blood cells, the primary component in transfusions, have no nucleus and no DNA. When blood is donated, it is processed in a number of ways but one important way is 'leukodepletion' - which is the removal of the white blood cells. If this wasn't done, the donated white blood cells would attack your body's tissues and cause inflammation.
A transfusion is supposed to give someone enough blood to last until they can make their own. So while it is theoretically possible to have other's  white blood cells DNA in a sample, those cells will eventually be eliminated from the body. 

What is the dot over letters 'i' and 'j' called?

Usually in many languages, specific characters are added to an alphabet to denote a particular accent.  This a mark added to a letter that is meant to signal a change in either the sound or meaning of a character.
The small distinguishing mark you see over a lowercase 'i' and a lowercase 'j' is called a tittle- which seems like a combination of tiny and little.  It was added to the letter i in the Middle Ages to distinguish the letter from adjacent vertical strokes. Tittle is also referred as a superscript dot or a jot.  

Why are umbrellas mostly black in color?

Basically, the umbrella was initially meant for rainy seasons. In the olden days umbrellas were made of thick cotton cloth. When they got wet in the rains, they would take a long time to dry up. It was found that umbrellas made of black cloth dried faster than those made of cloth of other colors. So it became a standard practice to use black cloth in the making of umbrellas. Black cloth dries faster because black or dark surfaces absorb more heat from the surroundings than lighter surfaces and as a result the evaporation process is faster.
Today, umbrellas are made of fabrics that do not soak water, and so, as drying is no longer a problem, umbrellas come in all shades and colors.

Why does blowing on a candle extinguish it?

To put out a fire you either need to remove the fuel, oxygen or heat. When you blow on a candle the movement of the air across the wick removes the heat from the flame. Cooler air takes its place. This lowers the temperature of the burning wax to below its ignition point. The wax stops burning and the candle goes out.

Why are there no B batteries, while A, C and D exist?

In 1924,the ANSI - American National Standards Institute, USA, proposed a simple system to designate cell sizes, based on the letters of the alphabet, starting with the smallest cell in volume and going in ascending order, A, B, C, etc.
B batteries never really caught on commercially, at least on the consumer end of things.  B batteries were primarily used in devices that used vacuum tubes which is outdated technology. A size batteries are hard to find as well, because they were primarily used in really old laptop batteries.
The ones that were most popular just ended up being the AA, AAA, C, and D. Most batteries (AA, AAA, C, D) all carry the same voltage, 1.5 volts, but they differ in their capacities, their physical size.

Are zebras white with black stripes or black with white stripes?

Zebras are native to central and southern Africa. They are black with white vertical stripes on the head, neck, forequarters, and main body, usually with horizontal stripes at the rear and on the legs of the animal.
Zebras are dark animals with white stripes where the pigmentation is inhibited. The pigment of the hair is found solely in the hair and not in the skin.