How is a rainbow formed ? | Natural Hub

  The Sun and a wet weather are the main components of the Rainbow. When the sunlight with its white light rays cross the water drops, the different colours that constitute the white light split up, to be scientifically accurate, the colours are refracted, thus forming a rainbow. White light is refracted through the drops of water which displays all the colours, but the human eye can only see one colour per drop, and that is why the height of the drops is a crucial determinant in the order of the colours which is always respected. The highest drops to the outside allow us to see red, while the lowest drops inward allow us to see purple. Between red and purple, we see the orange, yellow, green, blue and indigo colours in that order which makes the seven colours of the rainbow. The more the drops of water are big, the more the rainbow is colorful. Nature never ceases to amaze us, we need to uncover its mysteries that surround us...

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How much does a cloud weigh ? | Natural Hub

 Clouds come in many forms and weights.

A weight that depends on three essential factors : size, temperature and the water content called density.

Scientists estimate that a small cloud can weigh more than 500 tons of water.

But what’s frightening is the clouds that cause thunder, they can reach a weight of 500,000 tons and even more in regions where rainfall is intense, such as tropical areas.

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How is rain formed ? | Natural Hub

 The liquid precipitation from the sky, called rain, is the result of the evaporation of moisture that exists in nature and specifically in different sources of liquid such as seas, lakes, rivers, oceans...

Clouds form when evaporated water is condensed into liquid water. The presence of small particles in the air facilitates and helps the formation of droplets and that’s how a cloud is formed.

The inside of a cloud composed of a mixture of moist air and water droplets is the scene of several formations, droplets move at different speeds and multiple directions, sometimes colliding with each other, and that is how the droplet increase in size and bigger drops are formed.

Once, the drops are large enough, Earth's gravity takes over and the drops fall on the surface of the Earth as precipitation, namely rain.

The rain is a blessing from heaven, and especially after a dry season.

Our water supplies depend on precipitation and especially our crops.

Water is a source of life, we must take good care of it.

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Where does the colours of the sky come from at sunset ? | Natural Hub

 Sunset is a magical moment that reveals one of nature's wonders.

Why does the sky lose its blue colour and give way to this red-orange one that we are so fascinated about?

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Views of psychoanalyst on Racism

Awareness of racism increased as Black Lives Matter protests spread across the country last summer. In response, psychoanalysts suggest three ways to change attitudes about race — curiosity, courage, and building intimate relationships with others.Curiosity starts with self-education and self- reflection to better understand our beliefs as well as talking to others about ethnicity and racism.Courage is necessary to confront our own unacknowledged biases and recognize where some of them come from, including our upbringing or involvement in various groups, or from society at large.Finally, one of the most profound ways of changing attitudes about others is engaging in close relationships with people from other ethnicities. Building and maintaining relationships with individuals of differing backgrounds allows recognition of our common humanity and shared struggles.However, experts point out that being aware of, acknowledging, and changing deeply-ingrained racist ways of thinking is difficult and takes time and effort.The human mind resists change to protect our self-esteem from uncomfortable truths, and our minds unconsciously work diligently to avoid uncovering painful and distressing knowledge about ourselves. Even making change we know will make us feel better, such as exercising more, can be hard to initiate and sustain."Often, changes to how we think or do things require a shift in how we view ourselves, our needs, and our relationships," says Deeba Ashraf, MD, member of the American Psychoanalytic Association (APsaA). 

"And changing attitudes about race can be especially hard because these attitudes are usually learned when we are very young."Beverly J. Stoute, a child and adolescent psychoanalyst and psychiatrist, says children develop awareness of and curiosity about racial differences early. 

"As children grow, parents, teachers, media representations, and interactions with different groups can either powerfully facilitate or thwart children’s openness to racial and ethnic differences," said Dr. Stoute, also a member of APsaA.There are many ways we try to protect ourselves from painful feelings or unwanted truths about our own beliefs. One way is by asserting that unpleasant truths are not real, otherwise known as denial. Another way is to imagine these "horrible truths" only exist in others and not in ourselves. 

This is called projection and it involves attributing qualities like laziness or criminality to a particular group; while overlooking how these traits might apply to ourselves, or those in our own group.Hence, "group identity," also presents a challenge to changing attitudes about racism. Being part of a group can offer a sense of connection and protection, and in some cases, prestige. Many group identity attitudes are passed on from generation to generation, but also part of ongoing relationships with others who share the same ideas. Trying to change an entrenched attitude can result in group members feeling threatened or fearing a loss of group membership, according to APsaA experts.

Yet, when people can break through these unconscious ways of protecting their self-image, they may recognize the costs of racism and look at the loss and pain it inflicts on oneself and others. It may be possible to reevaluate one’s own ideas of what is healthy and growth-oriented.

 This process can be difficult, but managing the discomfort these efforts provoke can motivate a desire to change, psychoanalysts say."I am reminded of a quote from James Baldwin, ‘People can cry much easier than they can change’," says Ebony Dennis, PsyD, clinical psychologist and psychoanalyst who is also an APsaA member. "Changing attitudes about racism will take time and effort, and occasionally some hurt feelings. But it is through these growing pains that real, lasting change happens."

At what temperature wood burns ? | Natural Hub

 Self-ignition of materials without external ignition source differs from one material to another.

For wood, its self-ignition point is 300° C.

Heated to this temperature, wood releases hydrocarbons which when mixed with atmospheric oxygen causes a reaction that ignites wood.

To cite just one example, cotton has a higher resistance which is located around 407° C.

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What’s a lightning bolt ? | Natural Hub

 During bad weather, children and adults alike dread the deafening sound of thunder when they see lightning in the sky.

This climatic phenomenon happens during storms.

Huge masses of air move and gain electricity charge by friction resulting in the accumulation of several charges in the huge black clouds.

The water molecules go up and get positive charges while the heavy water molecules remain at the base and get negative charges.

When the electrical load is too large, a discharge of lightning occurs between the areas of opposite charges, causing a huge spark and thus lightning in all its beauty is formed.

Lightning can occur between clouds and the ground or inside the cloud in several forms, it can be branched, fulminated or sinuous...

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