It is often thought that people perceive the passage of time in steady increments. This is known as the theory of the universal internal clock. A new study suggests that this theory is incorrect. The study, conducted by three psychologists at George Mason University in the United States, involved 170 volunteers. The volunteers were asked to look at images. These images varied in size and content. Some were full of objects, while others seemed almost empty. The volunteers were then asked to estimate how long they had been looking at each image. In some cases, they were asked to rate how memorable they found each image. The volunteers often overestimated how long they had been looking at the messy images. Alternatively, they underestimated how long they had been looking at the emptier images. In many cases, their estimates were more accurate with the images they felt were memorable. These results suggest that there is no universal internal clock. Rather, people may perceive time based on their environment.

When you think of a smile, the first emotion that comes to mind is probably happiness. However, not all smiles mean the same thing. Researchers have discovered 19 different types of smiles. Of them, only six smiles are related to feelings of joy. Below are three types of smiles that might have surprising meanings↵
Qualifier smile↵
Qualifier smiles are used to make bad news sound better. This smile is sometimes followed by a slightly downward tilt of the head. Usually, people have no choice but to smile back, even if they do not like the news that they are hearing.↵
Contempt Smile↵
Contempt smiles occur when people try to hide feelings of resentment. It might not be appropriate to show anger, so people try to cover up their anger with a smile. Contempt smiles may look happy, but the corners of the mouth are usually tight.↵
Fake Smile↵
Fake smiles are very common because smiles are usually used. as greetings. It is normal for people not to show their true feelings when saying hello. People also use fake smiles to make people like them more.

In the United States, people all across the country celebrate Independence Day on July, 4th. It is also called the Fourth of July. This holiday commemorate the signing of the Declaration of Independence in 1776. The historic document officially declared 13 American colonies to be independent from Great Britain.↵
History of Independence Day↵
The Declaration of Independence was drafted by Thomas Jefferson and signed by many of America's founding fathers. Congress vote in favor of independence from Great Britain during the Revolutionary War fought between 1775 and 1783. The document explained why the colonies wanted freedom. It started that all people had the right to life, liberty and the pursuit of happiness.↵
How People Celebrate↵
People celebrate the Fourth of July with various festivities. Almost all events involve spending time outside and socializing with friends and family. Most commonly, people attend picnics, barbeques, and parades. It is also a tradition for people to show their patriotic spirit by wearing the colors of their nation's flag: red, white, and blue. Fireworks shows are also incredibly popular on Independence Day. This tradition began in Philadelphia in 1777, when a ship's cannon fired a 13-gun salute to honor the 13 colonies. Nowadays, beautiful fireworks light up the sky every year on July 4th.

In late March, last year, 2016, I became a parent for the first time. Like so many parents, I wondered how I was going to balance my work with my new role as a parent, and in that moment, I remember that the statistic for the US's policy on maternity leave flashed through my mind. American women are currently entitled to 12 weeks' unpaid leave. American men are entitled to nothing. I remember thinking to myself, "If the practical reality of pregnancy is another mouth to feed in your home and America is a country where most people are living paycheck to paycheck, how does 12 weeks unpaid leave economically work?" The assumption and common practice that women and girls look after the home and the family is a, stubborn and very real stereotype that not only discriminates against women, but limits men's participation and connection within the family and society. These limitations have broad-ranging and significant effects, for them and for children. We know this. So why do we continue to undervalue fathers and overburden mothers? Let us lead by example in creating a world in which women and men are not economically punished for wanting to be parents. Along with UN Women, I am issuing a call to action for countries, companies and institutions globally to step-up and become champions for paid parental leave. The whole world grows when people like you and me take a stand because we know that beyond the idea of how women and men are different. Thank you.