Trip the light fantastic during International Year of Light

It’s the International Year of Light. That’s not some airy-fairy notion about positivity; it’s a chance to focus on the science of light.

In 2013, the UN gave the designation to the year, stating that light technologies (photonics) could promote sustainable development and provide solutions to global challenges in agriculture, education, energy and health.

And throughout 2015, there have been a number of events around the world promoting awareness of photonics, while also reflecting back on the history of optics – not to mention the discoveries that led to the current technologies now powering the internet.

Karen McCarthy is the public engagement and outreach officer at the Irish Photonics Integration Centre (IPIC), a Science Foundation Ireland research centre led by the Tyndall Institute at University College Cork.

“Photonics and light-based technology is present throughout the world, particularly within our own homes,” she says. “Photonics provides the backbone of technologies such as smartphones and laptops, as well as driving our high-speed internet. Away from the home, it is hugely important in modernising healthcare.

“Biophotonics is the use of light-based technologies in medical sciences, and can be used for detecting diseases through non-invasive imaging techniques. We also frequently rely on modern photonics in endoscopes and micro-cameras that are the diameter of a single hair.”

One of the most energy-efficient technologies in the world, the light-emitting diode (LED), was developed from photonics research and is now being used more and more in our daily lives, including for torches, direct lighting and, most of all, fibre-optic communication.

Upgrading

Over time, optical fibres have evolved to use thin strands of glass through which a laser or LED optical device sends a signal that can be changed into an electronic one and transmitted at rapid speeds across large distances; this is usually the digital information created by computers and telephones. It’s the basis of the internet.

The organisers of Light2015 say that the 21st century will depend as much on photonics as the 20th century depended on electronics. New technologies are constantly being developed.

“The next big push for fibre-optic communications is upgrading all current systems to fibre, and delivering fibre-to-the-home services, allowing all of us to have access to superfast internet,” says McCarthy.

“Photonics can have many applications across our lives and help tackle global problems such as energy and health.”

Events

The International Year of Light has already seen a number of events in Ireland, including the lighting of the Spire in Dublin which was timed to coincide with the St Patrick's Day festival. A special event at Newgrange celebrated the light of the winter solstice with tours, dinner and talks on October 21st.

The celebrations will continue until the end of the year. In Cork, Beyond the Bulb is an ongoing exhibition of unique prints from an open-source photographic collection, curated by Harvard University, which is allowing different audiences to learn about photonics through art.

During Science Week, the IPIC will lead a series of DIY workshops that will allow students to make their own spectroscope and see the secret spectrum.

For more details, see science.ie/events

Try this at home

Light experiment An Irish physicist, John Tyndall, showed how light can travel in a curved stream of water.

This DIY experiment is based upon his original “light pipe” experiment: it’s easy to do and allows you to see it for yourself, but it also highlights the fundamentals of optical fibre.

Materials

Plastic bottle (2-litre capacity)
Tape
Water
Small bright torch
Paper towels
Large shallow tray or dish
Corkscrew
Large books

Method

Set up your work area: place the plastic bottle in the shallow tray, and cover the surrounding area with paper towels.

Place some dark tape around the midsection of the bottle.

Punch a a hole in your plastic bottle using the corkscrew – ideally the hole should be midway along the bottle, on the taped area.

Fill your plastic bottle with water. You should notice that the water will start to flow from the puncture into your tray.

Line up your torch on some books to achieve the right height: you want the flashlight to be at the same level as the hole in the plastic bottle, but facing the other side of the bottle.

As the water is flowing out of your bottle, turn on the light beam and watch how the beam follows the flow of the water stream into the dish, almost as if the beam is bending.