500words

Sounds simple, a hole that is black. But what does that mean? It means a region of spacetime where gravity is so strong that nothing can escape from it. This meaning has come about from the theory of general relativity, predicting that a sufficiently compact mass can deform space time to form the black hole. There are so many things not to understand in these sentences, so where to actually start to describe black holes in normal people terms? NASA explains it as a ‘space where gravity pulls so much that even light cannot get out’.  However, black holes aren’t even necessarily black. Quasars, which are the objects at the centre of distant galaxies, are likely to outshine the rest of their host galaxy combined - through radiation generated when the black hole is feasting on new material – meaning there is light in the black hole. The term feasting sounds quite active and scary.  Although the description exists, implying that black holes exist, they cannot be seen by...

As with any blog entry, when I sat down to write about black holes, I had a think about what I already knew about them, and how I could use this to inform what I wrote. But this time all I could come up with was the 2006 song ‘Supermassive Black Hole’ by Muse. It’s an absolute tune and, not going to lie, I listened to it for inspiration, but actually it tells us nothing about black holes. So instead, I have tried to answer my own set of FAQs that should give us all a bit of a better understanding of what a black hole is and does. What is a black hole? NASA defines black holes as regions in space where a great amount of matter is packed into a very small area. The result is a gravitational force so strong that nothing can escape. Most black holes form from the remnants of a large star that dies in a supernova explosion. Bigger black holes can result from stellar collisions. Are black holes really black? Yes, black holes are really black as no light can escape from them. They are...

  On Earth it is not possible to see beyond the horizon, a theoretical line.   In Space the event horizon is an imaginary spherical boundary marking the limit of a black hole, or the boundary between a black hole and rest of the universe, beyond which nothing can be seen and from which nothing, not even light, can escape.   At the event horizon the gravitational force is massive and is equal to the speed of light.   Once anything reaches the event horizon it has reached the point of no return and will inevitably be pulled in (because nothing has sufficient escape velocity to resist).   I imagine it to be something like water going down a plug hole, but much more dramatic and on a massive scale.   There is also backwash from my plug hole because a black hole converts the matter that it consumes into intense radiation that is violently expelled. The Event Horizon Telescope is an international collaboration, launched in 2009.   It is a virtual, planet-E...

                                The Black Hole of Calcutta By the end of the seventeenth century power in the Mogul Empire had fallen into the hands of Nawabs, or provincial governors, whilst the British and the French were building their competing commercial empires in India. The British developed a trading post in Calcutta (now Kolkata) in the 1690s and built Fort William to defend it,  By the middle of the eighteenth century the fort was falling into disrepair and with the imminence of the seven years war bringing tension between the British and the French repairs were started. The Nawab of Bengal, Siraj ud-Daulah, sent orders to the British and the French to stop work on their fortifications.  When the British took no notice he marched on Calcutta with an army said to number 50,000 men, 500 war elephants and 50 cannon.    The governor, his staff ran for the safety of t...

  Sustainable Farming – Cannabis Farming of hemp within the UK is not a modern-day endeavour, with it being widely cultivated throughout Britain between 800-1800 AD. In 1533, King Henry VIII made hemp farming compulsory by law, insisting that for every 60 acres, farmers must grow around ¼ acre of flax or hemp or face being fined. It was even possible to pay your taxes with hemp. It has a variety of uses, with each individual component of the plant having individual benefits and applications. For example, the seeds may make fuel or food, the stalks make fibre, the leaves (which contain CBD) make medicine and the roots cure the soil. ‘Industrial hemp,’ has a very low THC content, meaning, unlike its cousin marijuana, if you set a field of it on fire and inhaled all of the smoke you would still not get high. However, it is categorised as ‘Cannabis’, which is a controlled substance under the 1971 Misuse of Drugs Act. Currently, it is legal to grow hemp in the UK, which is great...

Cannabis sativa is an annual herbaceous flowering plant indigenous to eastern Asia. The flower of the cannabis sativa can be turned into the drug cannabis, or marijuana, which contains the psychoactive ingredient tetrahydrocannabinol (THC). Cannabis is considered an illegal drug in large parts of the world and using it, growing it, or selling it can result in time spent in prison. Some countries have taken steps to legalise marijuana in order to reduce criminal activity connected with the drug and to better be able to control who it is made available to. Uruguay was the first country in the world to legalise recreational cannabis use across the whole nation. In 2013 the government passed a bill establishing a legally regulated market for both medical and non-medical use. Sales in pharmacies began in 2017, and are tightly controlled because customers have to register with the regulator and then are limited to buying 10 grams a week. The price is also set by the regulator, and customer...

    Our dog has arthritis in her legs which causes pain, stiffness and impaired mobility, becoming worse over time.   Because she is elderly, and has underlying gastric conditions, treatment with some painkillers is contraindicated.   What to do? Perhaps other pet owners want to learn more about cannabidiol (CBD) treatment but feel reluctant to discuss it with their vet for fear of being criticised, and I can relate to that, but   I took a deep breath and rang our vet for advice.   While vets are not legally permitted to prescribe CBD, they confirmed there are no know contraindications in relation to her medications.  Basically, go for it. THC is one of 100+ cannabinoids found in the cannabis plant and is the chemical that is responsible for marijuana’s notorious psychoactive properties. CBD is also a cannabinoid, extracted from hemp, but it does not have any intoxicating properties.   Anecdotal reports of cannabis’s ability to ease ch...

Marijuana is a lower classification of the hemp genus. The number of species in the genus is disputed – I imagine because a lot of it is grown and consumed secretly. If no one can actually say how much and where it is growing, it isn’t unreasonable to say that we don’t know how many different varieties there are. In principle it is agreed that there are three types – Sativa, Indica and Ruderalis, all of which come in male and female varieties, which colonise, and may also form hermaphroditic and androgenous plants. There are no scientific differences between these three types, but a general acceptance that these exist. Of the three types, Sativa and Indica are those grown and consumed to provide some sort of sense of escape –for recreational, medicinal or religious purpose – all have mind altering effects and can arguably alleviate pain. Although marijuana has more recently been used as a ‘recreational’ drug, leading to feelings of relaxation and considered to reduce stress b...

  BELFAST ROPEWORKS   Cannabis sativa, also known as Hemp, has long been used for fibre, seeds and their oils,   leaves for use as a vegetable or juice,   medicinal purposes and for recreational uses.   The hemp plant originated in Central Asia and has been recorded as being   grown in China in about 2800B.     Its cultivation spread to the Mediterranean countries in the early Christian era and throughout Europe during the Middle Ages.   It was planted in Chile in 1500AD and a century later in North America. Hemp fibre is long and straight and is manufactured much the same way as linen.   The fibre is longer but less flexible than flax but its strength and durability make it the ideal material for cordage, sacking and canvas.   Not only does it have superior strength but it is   less susceptible to rot when immersed in salt water than other fibres     Because of its durability hemp became a crucial commodity i...