Read the extracts below then answer the questions
Extract A: Natural or Artificial Light
The advent of artificial lighting freed us from our dependence on daylight to do most activities, and in doing so fundamentally changed human life. Since the 1820s, technology has enabled us to prevent darkness in ever more efficient ways. This article will investigate how both natural and artificial light can affect human cells and thus health in a positive and, unfortunately, negative way. In recent decades, much research has been done on the effects of both types of light on health and the human body.
While the importance of natural light has been a common knowledge for many centuries, modern science has revealed some significant findings on how natural light can be connected to our health, mood and habits. Rooms with natural daylight have been shown to increase productivity and boost mood and motivation. When exposed to sunlight, the skin absorbs vitamin D, a critical nutrient that prevents bone loss and reduces the risk of heart disease, weight gain, and various cancers.
However, natural light also has dangers associated with it. Long-term exposure to UV from sunlight may damage the cornea and cause cataracts but using artificial light normally is very unlikely to have any similar effects. Over exposure to UV also causes burns in the short term and, over long periods of time, contributes to the risk of developing skin cancer.
The main benefit to artificial lighting is that it allows people to stay awake longer to do more productive work, leading to innovation and invention.Light bulbs were invented for a reason and, like it or not, most of us will spend a lot of time in their glow. It drastically lengthens the number of active hours for humans and gives us extra time for work, schoolwork, and relaxation. Certain artificial lights can even mimic some of the features of natural light.
Artificial light has his disadvantages as well. Melatonin is the neurotransmitter that regulates our day-night sleep cycle. Multiple studies have shown that overexposure to high-blue spectrum light like the light of your mobile phone or television screen can disturb the production of melatonin in our body and thus disrupt natural circadian sleep rhythms. Disturbed sleep patterns can have negative effects on your overall health and wellbeing such as decreased energy levels and increased stress.
Ultimately, finding a balance between the two types of light can bring the benefits of both. Unless you live underground or have sworn off electricity altogether, you will often be exposed to both artificial and natural light
Extract B: Growing houseplants in artificial light
If you’re trying to grow houseplants indoors, you’ll find that some rooms of your house are low in natural light. Sunlight is the perfect balance of wavelengths necessary for plant growth and blooming, but you can also use artificial light to help your plants along. In fact, some plants can grow quite nicely in windowless offices with enough artificial light.
If you grow plants in artificial light, you can provide them with enough ambient light to flower, but here too, the type of light comes into the picture.Plants leaves are the colour they are because they reflect green wavelengths of light into our eyes, therefore appearing green. This means they absorb the other wavelengths of light: red and blue. Blue light is useful for foliage growth and red light is for flowering and fruiting. Plants need a light source with a good mix of both for the best results.
There are many options you can choose from when deciding on what type of light to get. The most common options are fluorescent lights or LED lights. Fluorescent lights come in bulbs or tubes that can screw into regular lamp sockets, and they don’t give off a lot of heat so they can be placed close to plant foliage. Generic fluorescent lights are higher in blue wavelengths, so look for “full-spectrum” or include a mix of “cool” and “warm” bulbs.
LEDs are another low heat option that is much more energy efficient and are generally cheaper too. LEDs use half the electricity and last 5 times longer than fluorescent bulbs. They also deliver a large range of wavelengths and the wavelengths produced are easily customisable.
The other things to look out for once you have found the right type of light to use is the light intensity and duration. The intensity of light that a plant receives is determined by the brightness of the bulb and by how close the plant is to the light source. Plants differ in their need for light intensity. Some plants require a lot more light than others and therefore the lights used must be much stronger or placed closer for them to be effective. Duration is equally important because like us humans, plants also need to rest when it gets dark, so 24/7 light is not good for them. Plants have their own preferred day length ranging from 8 hours to up to 18 hours of light a day depending on the type of plant, so a little research into your plant’s light preferences can go a long way.
While artificial light is no replacement for natural sunlight, using them in conjunction is a great way to help your plants grow. In the right conditions, artificial light can provide the boost needed for your houseplant to thrive
