Category: Nature

What Is Dark Energy and How Does It Work?


What Is Dark Energy and How Does It WorkWhen you do post a ball into the air, it slows down gradually, stops somewhere in mid air, and then starts falling and eventually to the ground. Suppose you throw the same ball to the air, and instead of it falling to the ground, it accelerates to the sky. This is what scientists are investigating with vigor; a phenomena that happens to the entire universe. It is believed that dark energy can accelerate the expanding rate of the universe.

What Is Dark Energy?

The term dark energy refers to an entity (a strange entity), that makes up the majority of the mass-energy density of the universe. Dark energy is studied under astronomy and physical cosmology. However, one should note that dark energy is still a mysterious concept and it is still under investigation. In fact, the main reason why it is known as dark energy is because there is little information and consensus about its nature and functionality.

Evidence for Dark Energy

The following shows the evidence for dark energy:

– Measuring the shape of the universe through the radiation of the cosmic microwave background (the density of the mass energy is 27 per cent. So what is the missing 73 per cent? It could be dark energy).

– Supernovae observation (a strong explosion that takes place when a massive star gets to the end of its life).

– The cosmological constant, otherwise known as the vacuum energy, has explained observations through the vacuum energy density.

How Does It Work?

What Is Dark Energy and How Does It WorkWhereas “normal” matter slows down the rate of acceleration, dark energy does the direct opposite of that; acceleration. This is attributed to its negative pressure. One of the day to day examples of negative pressure is an inflated tire or even a balloon that pushes out to the membrane that encloses it.

Einstein relativity states that both energy and pressure have a significant contribution to gravity. Dark energy possesses a strong negative pressure that the ultimate effect is not a push but a pull.

The universe’s rate of expansion is a timescale, and not speed. Similarly, velocity of galaxies is proportional to its distance, and therefore its not a constant figure.

In 1998, scientists realized that stars were actually dimmer than typical and previous results. The only explanation to this theory is that the stars were at a further distance than previously thought. Another deduction states that in normal gravity applies in small scale, but in large-scale, the repulsive force of gravity applies, in other words, dark energy.

Another thing to note about dark energy is that it was small in size 13.7 billion years ago. However, today, the dark energy takes a significant portion in the universe. It will be interesting to see what cosmology will come up with regarding the future of dark energy.


Albert Einstein observed that the concept of an empty space is not nothing after all. In addition to that, astronomers believe that the empty space has the ability to possess energy of its own. However, scientists are facing a number of challenges in the study of dark energy. For example, it is very difficult to carry out lab tests on the same due to the problem of isolating it. Despite that, scientists are hopeful that they are going to have more comprehensive findings on dark energy.

How Does a Wind Turbine Work?


How Does a Wind Turbine WorkIn the search for minimizing the use of fossil fuels, households as well as commercial enterprises are appreciating the use of renewable energy for sustainable energy use. Wind energy is one of the best options in renewable energy. When harnessing wind energy, there is a need of conversion of kinetic energy to electrical power, and this is done using a device known as a wind turbine. Wind power is one of the simplest forms of harnessing electricity- all you need is a windy area and plugging the turbine into electric power.

It is not overly difficult to understand how a wind turbine works. In this regard, it is recommended that you gain some knowledge about how a wind turbine works.

The Basics

How Does a Wind Turbine WorkA turbine is a machine, which through spinning traps the energy that is passing by and transforms it into a more useful form of energy- electricity. In general, it is the grind which later turns to electricity.

There are two main designs of wind turbines: the horizontal-axis and the vertical-axis. On one hand, the vertical axis turbine produces less noise and is placed lower on the ground.

It is most suitable for residential places. Another great advantage with this option is that they are versatile and can be used in cases of unstable winds. On the other hand, the horizontal axis wind turbines is most suitable in a large wind project. However, it is heavy and does not produce optimal energy in case the wind is unstable.

There are three main parts of a wind turbine: the tower that is used in connecting and anchoring it on the ground, the blades, and the nacelle. The nacelle is used to accommodate the generator. In quite a number of cases, a utility company places wind turbines in a row or groups in order to exploit as much energy as possible from the wind, such rows or groups are known in other words as wind farms.

In order to understand how a wind turbine works, note that it is the direct opposite of how a fan works: a fan uses electricity in order to make fresh wind, whereas a wind turbine uses wind in order to produce electricity.

The wind energy turns the propeller-like blades (two or three) around its rotor. The rotor is then connected to the shaft. The shaft then spins the generator and produces electricity.

The Blades

How Does a Wind Turbine WorkThe blades have a curved shape, just like an airfoil wing of an aeroplane. When wind passes through them, the blades rapidly spin. Consequently, energy is transferred from the wind to the turbine.

However, one should note that wind undergoes a great variation. These largely depend on vegetation, water bodies, as well as terrain. Similarly, the output of the blades and the turbine vary a great deal.

In case there is an emergency, or there is need to prevent wear and tear, there is an automatic breaking system.


With more innovation, the energy industry will witness more wind power opportunities and equipment. For example, there will be offshore wind turbines in the lakes as well as the oceans. There will also be more efficient wind turbines that are going to offer an even better service.