Kilcullen Science and Engineering

Tuesday, October 27, 2026

10 Fun Facts About Carbon and the Greenhouse Effect

Grey cracked limestone pavement stretching to a dry-stone wall under a cloudy sky with sparse grass in the crevices
Karst limestone landscape in the Burren, Co. Clare, Ireland. Limestone is a sedimentary rock composed of carbon amongst other elements.
© Eugene Brennan

1. Carbon is an Element

Unlike water which is a compound and can be broken down into hydrogen and oxygen, Carbon is an element which means it can’t be broken down into simpler substances. It has an atomic number of six which means it has six protons in its nucleus. Carbon also has an atomic mass of 12 which means it has 12 particles in its nucleus. Since a nucleus is composed of protons and neutrons, this means that there are six protons and six neutrons in the carbon nucleus. Also since the number of protons equals the number of electrons in an uncharged atom, there are six electrons in the orbitals of a carbon atom.

Color-coded periodic table of the elements showing all known elements arranged by atomic number with a legend of element groups
The periodic table of the elements. Carbon has an atomic number of six and is represented by the symbol “C”.
AI image generated by Claude
Diagram of a carbon atom with a nucleus of six protons and six neutrons surrounded by six electrons in two shells, and the C-12 symbol
A carbon atom. It has six positively charged protons and six neutrons in its central nucleus and six electrons in its outer shells.
© Eugene Brennan

2. It’s an Abundant Element in the Universe

Carbon is the 4th most comment element in space after hydrogen, helium and oxygen. On Earth it’s not so common and only the 15th most common element in the Earth’s crust.

3. Carbon Has Several Allotropes

The element doesn’t just exist in one form. It can take several forms, with radically different appearances and different mechanical properties. These different forms are called allotropes. Allotropes have different uses and we’ll find out about those later.

4. It Reacts With Other Elements and Compounds to Form Familiar Substances

Carbon reacts with other elements and compounds to form new compounds. A compound is a substance made from two or more different elements. A lot of these compounds are familiar to us. They include:

  • Carbon dioxide. This has the formula CO2. A carbon dioxide molecule is made from one carbon atom and two oxygen atoms.
  • Methane. Natural gas is primarily composed of methane. Its formula is CH4 so its molecule consists of one carbon atom and four hydrogen atoms.
3D ball-and-stick model of a carbon dioxide molecule with a central black carbon atom bonded to two red oxygen atoms on a black background
Carbon dioxide (CO2) molecule
Jynto (talk), Creative Commons CC0 1.0 Universal Public Domain Dedication via Wikimedia Commons
3D ball-and-stick model of a methane molecule with a central black carbon atom bonded to four white hydrogen atoms
Methane (CH4) molecule.
Benjah-bmm27, Public domain, via Wikimedia Commons

5. It Can be Used as a Heating Fuel

Charcoal and anthracite are two fossil fuels that have a high percentage of carbon. Charcoal is effectively boiled and charred organic material such as wood. The process to make it drives off water and volatile organic compounds to leave behind a high carbon mass. Anthracite is a type of coal low in tars. Both burn relatively cleanly and generate a lot of energy for heating homes and cooking.

Close-up of glowing charcoal pieces with bright orange and yellow flames rising from the blackened wood
Charcoal on a barbecue.
Public domain image by llhan llhan via Pexels.

6. Allotropes of Carbon Have Lots of Uses

Carbon has several allotropes:

  • Amporphous carbon is a soft, black material. Soot is primarily composed of amorphous carbon. Its uses include toner for printers, as a pigment in inks and paints, and in the form of carbon black, added to tyres to improve wear resistance.
  • Graphite is familiar to us all as the material used to make pencil lead. Graphite is a slippery material, so it’s also a useful lubricant. Another use is in nuclear reactors because of its ability to withstand high temperatures and being able to moderate (control) the flow of neutrons. Brushes in electric motors are made of graphite.
  • Diamond is a white or pale yellow material. It’s the hardest known substance with several uses. Diamonds are used in jewellery making, but the hardness of diamond is what makes it really useful. A diamond tool can be used for scratching glass, enabling it to be snapped and cut. Diamond powder is used to coat cutting wheels, helping them to abrade and cut through steel and concrete more easily. Diamond bearings are used in critical machine applications because of their low friction and resistance to wear.
Collage showing a clear faceted diamond, a green pencil with eraser, and a pair of hands covered in black soot held over green grass
Allotropes of carbon: Diamond, graphite pencil lead and soot on hands which is essentially amorphous carbon.
Top two images public domain via Pixabay, bottom image © Eugene Brennan

7. Carbon is an Electrical Conductor

Copper and aluminium are two metals widely used in the form of cables for conducting electricity, but carbon is also a conductor. However its conductivity or ability to conduct electricity is several hundreds times less. Carbon rod electrodes are used in arc lights, and graphite brushes conduct electricity to the armature (the rotating part) inside electric motors. Again, graphite’s property of being slippy and having low friction makes it suitable for this application. Volume controls on audio and video appliances are connected internally to electronic components called potentiometers. The potentiometers use tracks made of carbon. Nowadays, tungsten filaments are used in incandescent lightbulbs — originally, carbon filaments were used.

Black-and-white photograph of two uniformed people operating a large cylindrical searchlight that projects a bright beam into the night sky
Arc light search lights from WW2. Arc lights were also used for film projection in cinemas.
Imperiial War Museum London. Public domain image via Wikimedia Commons

8. Carbon is Essential for Life

Along with hydrogen, oxygen, nitrogen and sulphur, carbon is one of the essential elements for life. All life on planet earth, both animal and plant is carbon based. Silicon is in the same column in the periodic table of the elements and a topic of discussion is whether life on other planets could be carbon based. Plants also use carbon in the form of carbon dioxide. They absorb it and using a biological process called photosynthesis, turn it into oxygen, structural materials to build the plant and stored food resources. All the wood in a large tree comes from carbon dioxide extracted from the air, as does the starch and sugars stored for future use (e.g. potatoes and sugar in cane sugar).

9. Burning it Creates Greenhouse Gasses

We mentioned previously that carbon combines with oxygen to form CO2. All materials that contain carbon in their molecular makeup create CO2 when burned, not just pure carbon. These include hydrocarbon fossil fuels such as oil and gas but also non-fossil, carbon-neutral fuels like wood. Plastics and sugars produced by plants are also combustible and generate carbon dioxide when burned. CO2 is actually necessary and without it, the temperature of the surface of the Earth would be too low for plants and animals to survive. However, since it absorbs radiation coming from the Sun and also radiation reflected back from Earth towards space, too much of it isn’t good. This is known as a greenhouse effect and causes the air and sea temperatures to rise. The greenhouse effect results in faster rate of melting of polar ice caps, rises in sea levels, more intense storms, higher rainfall and migration of species northwards to avoid the heat or take advantage of the warmer environmental conditions.

Illustrated diagram of the greenhouse effect showing the sun, Earth, yellow sunlight arrows, and red arrows of heat trapped by greenhouse gases
The greenhouse effect.
Efbrazil, CC BY SA 4.0 international via Wikimedia Commons
Graph of the solar radiation spectrum with yellow area for sunlight without atmosphere, red area for sea-level radiation, and labeled absorption bands
Absorption of solar radiation by the Earth’s atmosphere. The black curve represents ideal black body radiation. The yellow area is solar radiation at the top of the atmosphere and red is that at sea level.
Robert A. Rohde, CC SA 3.0 Unported via Wikimedia Commoms. this is a screenshot of the original SVG

10. Carbon Based Charcoal is Used in Water Filters and Gas Masks

Charcoal is an effective filter. Its sponge-like structure is such that it acts as a material with a huge internal surface area. Imagine a sponge with lots of tiny holes. The sponge has an external surface area, but the area of the internal walls of all the tiny holes put together far surmounts this. Poisonous gases passing through a gas mask or chlorine in water can be absorbed by the solid mass of the charcoal, but they can also be adsorbed and stick to these internal surfaces, removing the contaminants.

Assortment of military-style gas masks in black, brown and green hanging from a wooden rack outdoors
Gas masks.
SweetMellowChill, public domain image via Pixabay

References

Electrical conductivity – elements and other materials. Engineering ToolBox. (n.d.).

Basics of climate change. US EPA – U.S. Environmental Protection Agency. (n.d.).

Disclaimer

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualised advice from a qualified professional.

© 2023 Eugene Brennan

Saturday, October 24, 2026

Psyche Probe on Its Way to Asteroid Belt

Artists's illustration of space probe with solar panels against a background of dark space
Image credit: NASA/JPL-Caltech/ASU/Peter Rubin

Powered by a Hall thruster producing "250 millinewtons of force — about the amount of force that you would feel from the weight of holding one AA battery." 

Newton's first law of motion states that an object continues in its state of rest or uniform motion in a straight line, unless acted on by an external force. So once you give something a push in space, it keeps going. That doesn't happen on Earth because the external force in this case is drag, due to friction from the air. That slows an object down. Newton's second law of motion basically says that acceleration is proportional to force, so while the quarter-newton propulsion force is small and provides little acceleration, velocity increases over time. So unlike conventional rocket propulsion which generates high acceleration for a short period of time, Hall thrusters gently accelerate spacecraft for periods of months or years, to slowly build up velocity.

You can read more about the Psyche mission in this article on the NASA website. 

Sunday, October 18, 2026

New Home and Garden Website

Website screenshot with a post showing a cordless drill
© Eugene Brennan
You might like my new website, Home and Garden Guidebook. It features comprehensive and practical guides, with tips and advice for home improvement, gardening, DIY and everyday projects.

Friday, October 16, 2026

The Abolition of the Leap Second

Abstract image with clocks and the globe
AI image created using Bing Image Creator

You may have heard Dr Shane Bergin speaking about this on Today with David McCullagh this morning. Leap seconds are being abolished and replaced by a system that will eventually allow a leap hour to be added, although that is unlikely to happen for thousands of years.

Leap seconds were introduced because a day isn't exactly 86,400 seconds long. Billions of years ago, a day was only about five hours long. According to a research article published in the academic journal Paleoceanography and Paleoclimatology, a day lasted approximately 23.5 hours during the Cretaceous Period, around 70 million years ago.

The gravitational interaction between the Earth and the Moon produces tidal effects that gradually slow the Earth's rotation. Leap seconds were added at irregular intervals to keep the time shown on our clocks closely aligned with the Earth's rotation and, consequently, the apparent motion of the Sun across the sky.

The last leap second was added on 31 December 2016, at 23:59:60 UTC. It was the 27th leap second added since 1972. The adjustments can cause problems for computer systems and other digital infrastructure, so international timekeepers have now agreed to phase them out in favour of a system that allows a much larger difference between atomic time and time based on the Earth's rotation.

In contrast, we will still need leap years because the Earth takes approximately 365.25 days to orbit the Sun, rather than exactly 365 days. Adding an extra day to February in leap years keeps our calendar aligned with the seasons. Without this adjustment, the dates of the seasons would gradually drift through the calendar, and Christmas would eventually fall in summer.

 

You can read more about the changes here on Scientific American. 

Scientists just voted to redefine how the world keeps time 

Wednesday, October 14, 2026

Solar Lighting for Dark Spots in the Town

Streetlight on dark laneway
Solar powered lighting
 Image created by Grok

I'm looking at the datasheets for these Philips SunStay streetlamps, which could be an option for lighting up dark areas in the town. One advantage is that an ESB Networks connection wouldn't be necessary, reducing installation costs. However, the luminaires can also be powered by mains electricity if desired. I haven't looked at the price, though. The entry-level model has the following specs:

  •     2000 lumen output, 28/35 W solar panel

  •     11 W LED output (with an efficiency of 175 lm/W)

  •     PIR sensor with a 5 metre range

  •     The streetlamps operate at 30% output throughout the night, ramping up to 100% when a pedestrian is detected

  •     A "ClearField" amber-red light recipe can be factory-configured for the LED module, producing a shorter-wavelength, lower colour temperature, amber-red output, making lights less disruptive to bats (see link below). However, efficiency is lower and typically 70 lm/W. I.e, lights appear dimmer


Solar irradiance is worst in December, with a worst-case scenario of 1 peak sun hour (PSH) per day in the north of the country to 2 PSH in the south, according to Met Éireann. For a 35 W panel, that's a potential storage of 35 watt-hours (Wh) of energy. When the 2000 lumen model is operating at 30% output, consumption is 30% x 11W = 3.3 Wh per hour. So a lamp wouldn't quite last a full night on a solar charge, but probably up to 10.5 hours.
Might be useful for the Valley park, the walkway between the AFC and GAA pitches, the Sunny Hill road from Cnoc na Gréine to the Newbridge Road etc.
Maybe worth trialling one?

Signify was formerly Philips Lighting, but became a spinoff and independent company in 2016.

This is the 2000 lumen model:

SunStay — All in one solar street light

 
Bat-friendly options:

A lighting solution — minimizing the night-time disturbance of bats

Met Éireann sunshine information:


Sunshine and Solar Radiation

Friday, October 09, 2026

ESB Report on Rainfall Management

Graph of water level
Water level in the Poulaphouca Reservoir. Graph courtesy ESB.

Water level in the Poulaphouca Reservoir is now at 183.68 mOD, roughly midway between the upper and lower operating levels of 186.30 mOD and 179.90 mOD respectively. According to the Wicklow County Council-commissioned Blessington eGreenway Flood Risk Assessment document, 

"The flood period operation begins when the conditions require spilling of excessive flood waters until normal operating conditions are re-established. This flood period operation occurs when the Poulaphouca Reservoir level is greater than 186.30mOD Poolbeg (183.6mOD Malin)"

Water level is well below this and has plateaued over the last 6 days, with water inflow equal to water outflow. This July report from the ESB details how the lake acted as a buffer and managed heavy rain during the early part of 2026. Without the lake to moderate flow, huge amounts of flooding in towns downstream would be possible. 

Graph courtesy ESB website. 

Monday, September 28, 2026

Beam Steering in the LHC: New Magnets Reach Full Power

View of the LHC tunnel sector 3-4
View of the LHC tunnel sector 3-4
Maximilien Brice (CERN), CERN Document Server, Attribution-Share Alike 3.0 Unported

Within the 8.5 km-diameter Large Hadron Collider (LHC), sub-atomic particles are accelerated to close to the speed of light by electric fields in radiofrequency (RF) cavities.

Friday, September 11, 2026

Teeth Are Harder Than Steel

Infographic showing a list of items with varying degrees of hardness
Hardness of various materials
Infographic created by Grok

Did you know that on a modified Mohs hardness scale that runs from 1 to 10, tooth enamel would rank at 5? That's harder than mild steel at 4.0 to 4.5 and softer than glass at 5.5.

Thursday, September 03, 2026

Reduction in Rate of Water Level Decrease in Poulaphouca

Graph of water levels
Water level in the Poulaphouca Reservoir
Image courtesy ESB

The water level in the Poulaphouca Reservoir is still dropping, albeit at a slower weekly average than a month ago, when it was falling by about 2 cm to 2.5 cm per day.

Saturday, August 29, 2026

Printer Frustration and Vodafone Broadband Goes Down

Frustrated man fixing a computer printer

I resorted to dismantling my printer during the outage. Didn't have any success with that. Three blank cartridges — one filled with Quink ink (which worked successfully for over a year) and a brand new one wouldn't work.

Wednesday, August 26, 2026

Hard-to-Read Maps: Issues With Google Maps and OpenStreetMap

Map screenshot
Tailte Éireann map

Whenever I'm out and about, it's nearly impossible to make out L roads on maps on my phone in bright sunlight because of the low contrast.

Saturday, August 15, 2026

"Flood" on the River?

Grove of flow versus tiem
Flow versus time for Golden Falls dam
Image courtesy ESB hydro
Does anyone know whether the ESB are generating from the Golden Falls power station? Forecasted flow has been 3 m³/s for the last week or two. However actual flow is tabulated at 2 m³/s.

Friday, August 07, 2026

How Fast Is the Level Dropping in the Poulaphouca Reservoir?

A lake shoreline, bordered with trees, viewed from behind a large, silhouetted tree

Poulaphouca lakeside
© Eugene Brennan 

A question was asked on the Blessington Blog today to the effect, “Will the lake get as low as this again over the next weeks?” It showed a photo of the Poulaphouca Reservoir taken during a previous drought, in which neat linear piles of rocks could be seen along the shoreline, clearly marking the locations of the walls of houses that were submerged when the valley was flooded in the 1940s.

Friday, July 24, 2026

What Are Clicks?

Hammar hitting a nail, with a damped oscillation graph, and bats flying around
Image made by Grok.

What's the difference between a click or thump sound (e.g. when you hit something with a stick or hammer a nail) compared to striking a bell or a string in a musical instrument? It's mainly due to the amount of damping involved.

Thursday, July 23, 2026

How To View What's Behind Your Washer Drum

Inside of a washing machine drum
© Eugene Brennan

You can check what's between the inner and outer drums of a washing machine, or check for limescale build-up on the heating element, by spinning the drum and illuminating it with a bright torch.

Sunday, July 12, 2026

Three Reasons the Summer is Warmer Than the Winter

Cartoon of people sweltering on a beach
Created with ChatGPT.

A common misconception is that the Earth is closer to the Sun in summer, but it's actually further away. Diagrams would be better for explaining this. I'll get around to it, but I'll try to do it with words for now. 

Friday, July 03, 2026

What Are Voltage Regulators Used For?

A pile of 3-pin voltage regulator chips

78XX series of voltage regulators. E.g. 7805 and 7812 having regulated outputs of plus 5 volts and plus 12 volts respectively. Silverxxx, CC BY SA 3.0 Unported via Wikimedia Commons.

We're surrounded by electronic gadgets and appliances, and even devices that don't appear to be electronic may use electronic circuitry internally. For electronics to work properly, it's imperative that voltage be stable and constant.

Sunday, June 28, 2026

How to Measure Length, Distance and Area on Google Maps

A Google Map
Public domain image from Canva

The Google Maps measuring tool can be used to measure the distance between two points, and the result is displayed in feet and metres. Alternatively, values are displayed in miles and kilometres if a user zooms out to view a greater-sized region of the map.

Friday, June 26, 2026

Resistors in Series and Parallel: Formula Derivation and Examples

Schematic of two resistors in series
© Eugene Brennan

Formulas for Resistors in Series and Parallel

Resistors are ubiquitous components in electronic circuitry both in industrial and domestic consumer products. Often, in circuit analysis, we need to work out the values when two or more resistors are combined. In this tutorial, we'll work out the formulas for resistors connected in series and parallel.

Friday, June 19, 2026

The Cork-Dublin Transmission Pipeline and Gas Distribution to Kilcullen

Map of gas distribution network in kilcullen
Gas distribution network in central Kilcullen from the interactive Dial Before You Dig website. Image courtesy Gas Networks Ireland.

On 4th March last year, a press release was issued by Uisce Éireann to media and local public representatives to the effect that:

“Civil Engineers are carrying out pre-work activities on the 225mm pipeline, which involves a localised crossing over the High Transmisison (sic) Gas main under the supervision of Gas Networks.”

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