a little bit of science

An American geneticist born in 1902, Barbara McClintock is one of the scientists we have to thank for leading the way in the study of genetics. She spent her whole career studying corn (or maize). She invented a technique that allowed her to see chromosomes, which she described and analysed. This technique allowed her to discover jumping genes. Jumping genes are sequences of DNA that move between DNA. Many consider these jumping genes ‘junk DNA’, but McClintock was convinced that they were to do with the switching off and on of genes. It was not till 1983 when she was awarded a Nobel prize in the physiology of medicine, and science realised how significant jumping genes where.  

Octopuses can change the colour and structure of their skin in a blink of an eye. These two abilities allow octopuses to hide in plain sight, either to jump out and catch prey or to avoid being eaten. This complete control over their skin is due to a number of specialised cells in their skin. Two different types of cells control their colour and one control the texture of their skin. The two types of cells each control different colour waves. Chromatophores control the orange and brown colours. Within these cells, there are many sacs of colour pigments. When the octopus wants to be brown, the brown sac us stretched out to the surface, making that colour visible.  Iridophores work differently. They have the ability to reflect back different waves of light. The colour that is reflected back depends on the angle of which the cells are observed.    

The texture of the skin is controlled by papillae, which are protrusions all over their skin. These protrusions can change size, how they do this is unknown! But it is thought to do with a hydrostatic system, this is basically changing in water pressure within the cell.  Evolution has truly allowed octopuses to a master of disguise! 

No one knows how many stars there are in the Milky Way! Estimates range from 100 billion to 400 billion. That is a big difference. This is because it is impossible to count each star individually (try if you want). So scientists come up with ways to guess the number of stars. For example, one estimate claims that the milky way has a mass 100 billion time the mass of our Sun, and therefore there must approximately be 100 billion stars! But how do we measure the mass of the galaxy? An estimate of the mass of a galaxy can be calculated by the rotation of the galaxy. Using the phenomenon known as redshift. Redshift happens to objects moving away from Earth have there light stretched, shifting the wavelength towards the red side of the visible light spectrum. The opposite happens when an object is moving towards Earth, light gets shifted to the blue side of visible light - known as blueshift. By measuring these changes in the light from different parts of the galaxy, we can work out the rotational speeds of the galaxy, and from this the mass!

Source:  Anup Deodhar / Royal Photography Society International Images for Science / Via rps-science.org

Scientists are working on creating green energy from a technique used by the Sun, fusion. Fusion is the opposite of nuclear fission which is what happens within nuclear power stations. Fusion is the combination of two hydrogen atoms to form an unstable form of helium that decays releasing energy. This is how the Sun makes its energy. 

There are many different approaches to creating reactors for nuclear fusion, but they all need incredibly high temperatures and pressures. Temperatures need to be at least 100 million kelvin, this is achieved using microwaves and lasers. The pressure is achieved using intense magnetic fields to squeeze atoms really close together.  One method of achieving fusion is to place a pellet of hydrogen within a highly pressurised container. Lasers are fired at the pellet converting it into a highly energetic state of matter known as plasma where the hydrogen combines to form helium and releases energy. This method is short lived but theoretically realises 50 to 100 times as much energy need to start the reaction., though this is yet to be accomplished.

Nuclear fusion is being experimentally studied all over the world due to its potential as a clean energy source. It realises no pollution or harmful by-product, just helium. The type of hydrogen need can be extracted from seawater and is incredibly common. It also has promise as use as rockets for deep space missions. 

With many different countries trying to create a power station that is able to produce power from this method, it is only a matter of time before it is a reality. 

You can inherit “experiences” from your parents, within the way your DNA is stored. DNA is the blueprint of you and is present in almost every single cell in your body (there a few exceptions, such as red blood cells). DNA tells your cells what to do and how to do it. It is a long chain of code, made up of four chemical bases and the order of these bases determines everything. 

In each cell, you have so much DNA that if stretched up it would be 2 meters long. That would not fit inside a cell, but it does because of how DNA is so tightly wound. This does, however, present a problem, it is hard to reach certain parts of the DNA. The body has used this to its advantage, it can turn off specific genes or traits by wrapping them up tightly, so the cell never uses them. This is known as epigenetics (above genetics) and is a newly emerging area of genetics. 

Epigenetics is affected by the choices and events that occur in your life. If you smoke or take other drugs, it changes your epigenetics and makes you more susceptible to become addicted. It has been suggested by studies that your epigenetics can be inherited from your parents.  An interesting case study is that traumatic events survivers, such as the Holocaust survivors, have caused mental health issues such as PTSD within their children and grandchildren.  

Source: Wiki Commons