Tree Cutting Assessment

If you see trees getting close to lines, you can report them to ESB Networks so that they can be cut before lots of customers may be affected by a limb strike and loss of power. This page gives information about cutting trees and trimming hedges on your property, applying for a free tree cutting assessment, safety guidelines for cutting trees, who's responsible, is there a charge? etc.

More information on the ESB Networks website here.

Fungi Using Gamma Radiation in Chernobyl

Image generated by Bing Image Creator.

Plants perform photosynthesis, using their leaves to convert light energy from the Sun, water and CO2 into stored chemical energy in the form of starch and sugars (which we can eat, e.g. potatoes, corn etc). O2 is produced as a waste product. The captured carbon is also used for growth and all the structure of a tree comes from CO2 in the air, not from the ground. This article from the Royal Society of Biology explores the radiotrophic fungi from Chernobyl, discovered in the late 1980s, that appeared to have been using gamma radiation for growth. Gamma radiation is a type of electromagnetic radiation, produced during atomic decay. It's on the same EM spectrum as light, UV, infrared, radio waves and X-rays, but has a much higher frequency and shorter wavelength.
This article in The Biologist, the  journal of the Royal Society of Biology has more information.

Water Works

Inside a pumped shower casing. © Eugene Brennan

More home maintenance, it never stops. This time cleaning the screen filter in the shower because pressure had dropped. I wrote a comprehensive article about this a few years ago, but withdrew it because of liability worries. It's not the sort of thing that should be done unless you are experienced and know the potential hazards and understand the safety precautions which must be taken. This filter could easily be broken too I guess if it's pulled out unevenly or with excess force. And it needs to be seated properly too when it goes back in so that the O-rings fit tightly, so observing such details and how things were before they were disassembled is important. Water spraying inside a compartment onto live parts wouldn't exactly be safe, especially if an RCD isn't fitted at the consumer panel to shut off power in this scenario. Not sure why they put the filter inside. Some manufacturers have made them accessible from outside the enclosure.

Filter housing. © Eugene Brennan

Shower unit filter. © Eugene Brennan

Keyhole Plumbing

© Eugene Brennan

The amount of tools required to try and work a miracle and do keyhole plumbing to get the top off a leaking stopcock underground. The alternative is to dig up the concrete. It's just for the workshop luckily.

Edit. Managed to get the rusted red handwheel off the valve, wringing the retaining nut, just as expected (WD40 sprayed on the night before didn't work). I used scrap valves when doing the original plumbing, rather than a proper stopcock that takes a key. I couldn't get the whole spindle out of the valve, I think these are bonded, but got the packing nut off and packed around the stem with PTFE tape, which took forever because the tape had to be rolled on with one hand. (It was a foot down under the ground below one of those horseshoe-shaped covers, so could only get one hand into the chamber). Seems to be no leaks now. I'll keep the new handwheel indoors and just put it on if the water needs to be turned off. The second photo is what the inside of a gate valve looks like (the ones with red handles that you might have in your hot press). The gate is the cylindrical brass disc.

 

Dismantled gate valve for water. © Eugene Brennan

Trivia Alert! — "AAAA" Size Battery

AA batteries. © Eugene Brennan

Ray Darcy was going on about random stuff as usual today and we heard some trivia about quadruple-A or "AAAA" batteries. These are a bit shorter and narrower than an "AAA" cell, and used for slim devices like styluses, laser pointers, penlights and glucose meters. There was also a single-A cell that is now obsolete and also a newer "A" cell and fractional "AA" cells.

This comprehensive Wikipedia article lists all the various battery sizes, both still used and obsolete.

Good News for Fundamental Research

Editorial image courtesy and by permission of Timothy Hughes Rare & Early Newspapers

L'Organisation Européenne Pour la Recherche Nucléaire (The European Organisation for Nuclear Research) or CERN is an intergovernmental research organisation that operates a particle accelerator in Geneva. This is the Large Hadron Collider or LHC, an underground, 27km diameter, circular ring in which protons are accelerated and collided into one another at almost the speed of light. This initial step of Ireland being accepted to become an associate member of CERN will give Irish scientists the opportunity to become eligible for staff positions at the organisation.

What's a Particle Accelerator? 

If you've ever seen the inside of an old CRT TV or computer monitor, you would have noticed the long glass tube attached to the back of the screen. That was the electron gun that shot beams of electrons, known as cathode rays, at the back of the phosphor coated screen. The collision of the cathode rays caused the phosphor coating to emit light and by scanning the beam, a composite image could be formed. (Although only a single dot was visible at any one time, persistence of vision making it seem like the full screen was illuminated). An X-Ray tube operates on a similar principle, except the beam of electrons strikes a metal target, causing the emission of X-rays. A particle accelerator is a device, just like an X-ray tube or CRT, that uses electromagnetic fields to accelerate electrons and protons so they collide with each other or a target, and this liberates other particles which can then be detected. By observing and analysing the behaviour of the emitted particles, fundamental knowledge can be gained about the nature of matter. Our only Nobel laureate for physics, Ernest Walton and his colleague John Cockcroft were involved in this type of research in the 1930s, described at the time by the media as "splitting the atom". A synchrotron like the LHC is a type of particle accelerator that uses massive electromagnets to accelerate protons to close to the speed of light. The advantage of the accelerator being circular, unlike linear accelerators, is that particles can be given a boost in speed as they repeatedly circulate in the tube. Eventually when a certain velocity is reached, two beams travelling in opposite directions are collided and the dynamics of the "fragments" of the collision are studied.

More information in this RTÉ news report:

 

Also this, "Remembering Ernest Walton: Splitting the Atom".

Energy Saving Tip

Image public domain via Wikimedia Commons

If you had clothes on the line yesterday or over the last week or so, you'll have noticed there was "great drying". That's because winds were coming from a generally eastern direction and east winds are usually dry with low humidity. Unlike the prevailing winds that come from a SW direction, carrying moisture from the Atlantic, easterlies come overland from continental Europe and moisture content isn't as high. So clothes dry faster and you'll have noticed the ground and fallen leaves dried up too.
I bought a dehumidifier recently, mostly to deal with condensation problems in a utility room that isn't heated. Ideally insulating walls would help solve the problem, but this is a stopgap solution. The dehumidifier also comes in handy for drying clothes, but first some science. Skip it if you just want to know about clothes drying.

 

Relative humidity 

 

Relative humidity (RH) is defined as the ratio of moisture in air to the maximum amount of water that air can contain, expressed as a percentage. So 100% is saturated and 0% is completely dry air. In the winter in Ireland, humidity is typically over 80% and often near 99% on warm, damp days. Air can only hold a certain amount of moisture per unit volume. Once it becomes saturated, i.e a relative humidity of 100%, water starts to condense out. Now the amount of water air can hold depends on temperature. As temperature drops, it can hold less. That's what causes fog after a sunny day in autumn when temperature plummets and also why water condenses on window panes and cold walls because they're cooler than the ambient temperature in a room. So the RH of the air increases as it hits such surfaces and possibly reaches the dew point. (Not always though, because the RH may have been low to start with) The dew point temperature is the temperature that air with a certain RH and a certain temperature must be cooled to for it to reach an RH of 100% and condensation to occur.

 

How does a dehumidifier work?

 

A dehumidifier works more or less the same as a fridge. Coils in the appliance containing a refrigerant are cooled and a fan circulates air from a room over them. Air is cooled to below the dew point and water condenses out to be collected in a container. Usually a desired RH can be set on the appliance and it will cut in and out to maintain that set point. 

 

Drying clothes with a dehumidifier

 

If you can't dry clothes outside, you can put them in a tumble drier. That typically uses two units per hour. The alternative is to put them on a clothes horse or radiators, but that can cause condensation problems because the water has to go somewhere. Ventilation might be an issue if you're limited to where you can dry your clothes and opening windows isn't an option. An alternative is to use a dehumidifier to regulate RH so that clothes hung indoors dry faster. It isn't as quick as using a drier, but if you have a day to spare, it speeds things up by reducing the humidity, allowing water to evaporate faster. Dehumidifiers are cheaper to run than a drier, typically the power use is about 150 W, compared to the 2000 W or so of a tumble drier.

Asbestos, the Wonder Material

From the Ladybird Book, Rocks and Minerals

From one of my Ladybird books (Rocks and Minerals). I have a slab of this that my father brought me home from the Curragh, used probably for boiler lining. I think I used to use it on a portable gas stove when heating stuff. There was also a layer of asbestos on the gauze mats we placed on tripods in chemistry class in school. That was to prevent the direct flame of a Bunsen burner cracking glass beakers and flasks.

Robin Perception

© Eugene Brennan

This isn't really a very scientific experiment, well it wasn't really an experiment, but after hand feeding and taming robins every year during the winter, over the last 15 years or so, I've discovered they don't differentiate between people. So once tamed, I've found they'll accept handouts from anyone (well two "participants" in my experiment, so as I say, not scientific) Not sure whether this is because they can't distinguish faces (cats and dogs can), or they just don't care or don't have the mental capacity to do so. Perhaps they just perceive the overall shape of a human? Would someone dressed up in a stick-man costume work?

How do animals differentiate between trees with limbs swaying in the wind or leaves blowing on the ground and genuine threats?
I guess this is why it's safe to handle spiders and other creatures with lesser intelligence if no sudden movements are made. They just identify our hands as surfaces to walk on and don't perceive them as part of a larger organism.

Visibility Improvement on Junctions

© Eugene Brennan

Lots of places I can think of around the town that would benefit from hedge removal on junctions to improve visibility. I presume it costs the council tens of thousands of euros to do this sort of thing per improvement, if the cost of any recent improvements are anything to go by. Maybe farmers or other landowners could remove hedges themselves, or at least cut them really low and save KCC money. They have to plant twice the amount of hedge they remove according to this Irish Farmers Journal article. Is there lots of red tape involved I wonder?

It's All Greek!

The letters of the Greek alphabet are pronounced somewhat different to what you learned in maths.

Alpha, beta, gamma, delta, epsilon, theta, iota, lambda, mu, pi, rho, sigma, phi, psi and omega are the most commonly used Greek letters used in maths, physics and engineering.

Pi (π) is probably the most well known Greek letter, used in maths to represent the ratio of the circumference to the diameter of a circle. However it's pronounced "pee" in modern Greek, not "pie"

Switching Your Electricity Provider

© Eugene Brennan

In case you're considering switching your supplier, I've made up an Excel spreadsheet of costs for the main suppliers. Prices are discounted values including VAT for a 24 hour tariff on a standard or smart meter, for new customers signing up for a 12 month contract and online paperless billing, paid by direct debit. Which supplier works out cheapest depends on unit usage and the bonus might make your bill cheaper if you have low usage. The rightmost column is with the new customer bonus subtracted from the bill. I've double checked the numbers, but don't blame me if they're wrong. Please let me know if there are errors. Other T&C apply. Check the small print.

Santorini Tremors

Scenes from Santorini © Eugene Brennan

A beautiful island with its scenic cliff-top walk from the town of Fira to Oia (pronounced E-ah) in the north. And the 600 or so steps from the old port to the top of the cliffs are good leg exercise! The Minoan eruption, one of the largest eruptions in recorded history, occurred 3600 years ago, leaving a collapsed caldera surrounded by water at the centre of the island. In 1956, an earthquake with a magnitude of at least 7.4 caused huge damage on the island, killing 53 people. Santorini is one of the islands of the Cyclades group, on the boundary of the African and Aegean tectonic plates, where tremors are common. Santorini and neighbouring Milos both have dormant volcanoes.

More information in this BBC News report:

 

"Santorini rocked by more earthquakes as uncertainty grows"

13 A Fuses Don't Blow Instantly When Current is > 13 Amp

© Eugene Brennan

Did you know that the rating of fuses and MCBs is the current they can carry indefinitely without overheating, not the current they blow at? For instance Type B MCBs, used in domestic installations will trip at a current of 3 to 5 times their rating. A BS1362 13 A fuse, used in 3-pin plugs must allow a non-fusing current of 1.6 times 13 A or approximately 20 A to pass for at least 30 minutes. BS1362 also specifies the fusing current as 1.9 times the rating or 24.7 A for a 13 A fuse. The fuse must blow in less than 30 min when current exceeds this value. The function of fuses in plugs is to protect the power cord, not necessarily the appliance. Lower rating fuses are often incorporated into appliances such as TVs that use smaller gauge wiring internally, to prevent against fire.

 

More info here:

 

BS 1362 Fuse Operation Characteristics

Check your plugs regularly to make sure they're not getting hot, especially when powering high wattage items like electric heaters (warm is normal for such appliances). Hot plugs are a symptom of a loose connection such as screws not tightened down fully in terminals or worn spring contacts in sockets (requiring a socket replacement). Any of these scenarios can potentially cause a fire.

UN Planetary Defence Slightly Worried

Generated using Bing Image Creator.

A 1.3% chance of hitting Earth according to this BBC article. But Earth should really be called "Water", because when viewed from the Pacific side, there's little land to be seen other than New Zealand and Australia. So even if it hits Earth, there's a high probability of it ending up in the ocean, just like spacecraft that are decommissioned and re-enter Earth's atmosphere. Even if the odds of it hitting our planet increase, and something has to be done about it, deflection technology has been proven to work. In 2022, the Double Asteroid Redirection Test or DART spacecraft, launched in 2021, collided with the asteroid Dimorphos, nudging it and adjusting its orbit.

Some Aircraft Have Rats

Ram air turbine on Airbus A320. Image courtesy Curimedia, CC BY 2.0, via Wikimedia Commons.

Ram air turbines that is, or RATs. If main power is lost, the small windmill-like turbine is lowered from the belly of the fuselage and uses ram pressure or force of the moving air to drive an electrical generator or hydraulic pump. This is a last resort scenario though. Usually an aircraft's engines generate electrical power as well as thrust for propulsion. If they fail, an auxiliary power unit (APU) provides power for electrical systems. This also provides system power before the main engines start up, when an aircraft is on the runway. An APU is a mini jet engine, usually mounted in the tail of the aircraft, independent of the main engines and not involved in propulsion.

References:

Naidu, A. (2024, December 29). Redundancy approaches to flight safety: The curious case of the b737’s absence of a ram air turbine compared to the A320". LinkedIn. https://www.linkedin.com/pulse/redundancy-approaches-flight-safety-curious-case-b737s-andrew-naidu

Lomas, C. (2024, March 11). What is the Auxiliary Power Unit (APU)?. Flightradar24 Blog. https://www.flightradar24.com/blog/auxiliary-power-unit/

NHK World Japan

Japan Broadcasting Corporation or Nippon Hōsō Kyōkai is a Japanese public broadcasting channel. The international version is NHK World Japan and it's an interesting channel with lots of documentaries about Japanese culture, crafts and technology, as well as news. Japan's Top Inventions is a series about the various inventions that originated in Japan. The program broadcast this evening was about how automatic door openers using PIR sensors replaced older types that used foot operated pressure switches. (I remember the novelty of coming across these for the first time in Dublin Airport in 1972. Did Woolworths have them too?)

Eye See: How Our Brains Hide Some of the Things We See.

Artwork by Holly Fischer, CC BY 3.0, via Wikimedia Commons

I was at the opticians on Thursday for my two-yearly check-up. The optician was showing me the image of my retina on the computer and pointing out the salient features: the blind spot, the macula and fuzzy parts of the image due to floaters. The blind spot is the region of the retina where the optic nerve connects all the rods and cones to the brain. Cones are structures in the retina, responsible for sensing colour in the daytime, and rods are more sensitive for night vision, but they can't discern colour.
The macula is the area of the retina that has the highest concentration of rods and cones. It's located towards the centre of our vision and what allows us to see greatest detail. When people develop a disorder called macular degeneration, the function of the macula is degraded, making it more difficult to read and perform other tasks. If you hold your thumb in front of your eye, blocking your central vision and try to focus on text in the distance, but not looking directly at it, you'll find it difficult to make out detail and read the text.
Floaters are pieces of debris, the remains of cells, floating about in the vitreous humour, a gel-like material that fills our eyeballs. If you try to look at them, they flick into the centre of vision, then slowly sink again.
The eye does the mechanics of converting an upside down image focused on the retina into an electrical signal and sending it to the brain, similar in principle to the charge coupled device (CCD) sensor in a digital camera. But that's only part of the story. Perception is something done by the brain, effectively "projecting" what we see onto the equivalent of a cinema screen. But what appears on that screen isn't exactly what's "out there" and not a one-to-one mapping like what would happen on a television or cinema screen. For starters, the image on the retina is upside down, so that has to be turned the right way up. We think we see a high resolution image of what's in front of use, but our eyes are really scanning a scene, building up a collage of images from the macula, so that makes a sort of composite image that our brain remembers. We can't see anything from the region of the retina where the optic nerve joins it, so the brain "fills in" that blank spot in the image we perceive. What's most amazing I think is how we don't see the blood vessels in our eyes. They're visible in the retinal image taken by an optician, but our brain does something like the post processing used in movies to remove wires that support flying actors. If you look at the ceiling just as you wake up and open your eyes, you can sometimes see the blood vessels as black lines, like the roots of a tree, for a split second before your brain kicks in and removes them. The optician hadn't experienced this phenomenon, but said she'd look out for it. Optical illusions are another quirk of perception where what we see isn't necessarily what's out there. Two illusions are worth checking out, including the checker shadow illusion and the simultaneous contrast illusion.

The Physics Behind Pressure Cookers

Pressure cooker. Image courtesy www.yourbestdigs.com/reviews/the-best-pressure-cooker, CC BY 2.0  via Wikimedia Commons.

Water boils at 100 °C. But that's only at atmospheric pressure at sea level. All liquids boil when their vapour pressure exceeds the ambient atmospheric pressure. Vapour pressure varies with temperature (see graph below) and also different liquids have different vapour pressures at the same temperature. The ambient atmospheric pressure effectively "holds" the molecules of a liquid in, preventing them from escaping. Vapour pressure is defined as the pressure exhibited by vapour present above a liquid's surface. When water reaches 100 °C, its vapour pressure is 1 atmosphere. That's equivalent to 1 bar, 15 pounds per square inch (PSI) or 101325 pascals (Pa) in metric. Since that equals the ambient atmospheric pressure (which is 1 atm absolute above vacuum), any increase in temperature will increase the water's vapour pressure, allowing it to boil.

 

Vapour pressure versus temperature for water. No machine-readable author provided. Adam Rędzikowski assumed (based on copyright claims), CC BY-SA 3.0

 

Volatile Liquids 

 

Some liquids have higher vapour pressure for the same temperature. Alcohol for instance which has a value greater than that of water and ethanol, a type of alcohol, boils at 78 °C.

 

Pressure cookers

 

Pressure cookers work by increasing pressure within the cooking vessel as the temperature of the contents increases. Gay-Lussac's law states that at constant volume, pressure of a gas increases proportionately with absolute temperature. If you've ever put an empty juice or milk carton in the fire, with the cap tightly shut, you'll know that it bulges up and eventually bursts. A pressure cooker typically operates at a pressure of 2 atm absolute (or 1 atm gauge above atmospheric pressure). Water temperature has to increase so its vapour pressure equals this before it boils. This occurs at approximately 120 °C and it's this higher temperature that increases the cooking speed of the contents. Also steam at 120 degrees has more energy than water at the same temperature. This is because when water undergoes a phase change to steam, it gains energy, known as latent heat of vaporisation. When steam comes in contact with food, it has to lose that energy first before it turns back into water, transferring that energy to the food.

 

Cups of Tea on Mount Everest 

 

The reverse is true for temperature and pressure. At high altitudes, ambient atmospheric pressure is reduced. So water boils at a lower temperature of 68 °C on Mount Everest, not so good if you like milky tea.

Is Water Actually Wet?

Generated using Bing Image Creator

Scientists aren't sure. In this article on ScienceFocus, we learn how it all boils down to which force is stronger: the cohesive force pulling like molecules of the same substance together or the adhesive force attracting them to the surface they're on. Mercury is a liquid, but it doesn't wet surfaces. Alcohol is better at wetting than water. Adding detergents which act as surfactants reduces cohesion and surface tension, improving wettability. Surfactants are added to paint to make it spread and wet a surface.

Thatched Cottage Inventory for Kildare

Thatched cottage near Aglish, County Kilkenny. Image courtesy David Hawgood, CC BY-SA 2.0 , via Wikimedia Commons

Off topic again, but this inventory on the Kildare County Council website is interesting. I spend a lot of time virtually travelling around the country and down country lanes (also on the bike in real life) and discovered another cottage locally since Google Street View imagery was updated last September and cul-de-sacs not imaged before were included (which some people mightn't be happy about because of security concerns and invasion of privacy). That makes four thatched cottages within a range of about five miles. Any more? Two were lost in the last 30 years or so. Ennis's cottage at Knockbounce when preliminary roadworks were done in advance of the Kilcullen Bypass and another near Yellow Bog on the road by Des O'Briens. Does anyone remember that?

Flight Engineers

Concorde flight deck. Image courtesy James E. Petts, CC BY-SA 2.0, via Wikimedia Commons

Once upon a time, aircraft had flight engineers or "flight mechanics" as well as pilots. Their job was to look after the aircraft's complex flight systems such as engines, electrics and hydraulics, avionics and fuel delivery systems. The function of the flight engineer has mostly been replaced by complex computer automation systems.
Concorde was a supersonic airliner, but its technology dated from the late 60s and was never updated like that in more modern aircraft such as the 737 (flown by Ryanair and many airlines worldwide). There have been four generations and several variants within each generation of the 737 since the original 737-100 made its maiden flight in 1967.
In this article from CNN, Concorde flight engineer Warren Hazelby talks with journalist Francesca Street about his career.

Disconnecting a Power Line

 

Opening a HV power line. Current continues to flow through the arcs on the three-phase line because the air becomes an ionised plasma, providing a conductive path (just like when arc welding). Under normal circumstances, air is an insulator (doesn't conduct electricity). However if voltage is high enough, it does breakdown and become conductive as evidenced by the phenomenon of lightning. Its dielectric strength is 3 kV/mm, meaning that between rounded electrodes, it takes 3000 V for air to breakdown and become conductive when conductors are spaced 1 mm apart. However conduction continues when the conductors are separated to beyond 1 mm, the plasma sustaining conduction. Eventually when the spacing is great enough, an arc between them will extinguish. Circuit breakers in sub-stations are filled with oil with a high dielectric strength so that when contacts open, the oil quickly extinguishes the arc.

Science Friday Podcast — AI Is Coming Up With Brand New Molecules, Fuelling Drug Discovery

Flora Lichtman talks with two biotechnology experts in the latest podcast about how AI is being used for drug discovery such as new antibiotics: Dr. César de la Fuente, bioengineer and presidential associate professor at the University of Pennsylvania in Philadelphia and Nobel laureate Dr. David Baker, director of the Institute for Protein Design and professor at the University of Washington in Seattle.

Big Picture Science Podcast — Sceptic Check: Drone Panic

The bright planet Venus is often misidentified as a UFO. If you look SW, you can see it in the evenings at the moment. In the latest podcast, astronomer Seth Shostak from the SETI Institute (a regular on the epic 80s space documentary Cosmos) and science journalist Molly Bentley talk to various experts about UFOs, or as they're now known, unidentified anomalous phenomena (UAPs).

USB Extender

Before USB, RS232 serial ports on computers had a range of up to 15 m, however USB is limited to a max cable length of 3 to 5 m, depending on data rate. If you can't use wireless and want to extend your USB connection up to 45 m, you can use one of these. The adapters are connected together using Cat 5 network cable. (I've used ordinary alarm cable, but it's supposed to be screened I think). It's only USB 1.1 standard, so not exactly for transferring lots of data fast, but could be useful for connecting to remote measuring instruments.

This product from RS extends USB up to 45 m.

Wind Loads on ESB Poles

Public domain image courtesy Manfredrichter on Pixabay

Back of envelope calculations suggests a 760 N (approximately 76 kg) load on poles for force 10 winds, which doesn't seem like much. But that's for average wind speed. I've asked Kildare Weather have they any recorded gust speeds. Forces increase exponentially with wind velocity. So doubling the wind speed quadruples the load. Presumably poles break when they're rotten at the base and I would think "healthy" poles are unlikely to fail under normal circumstances unless there's a split in the timber.

Edit: Kildare Weather have come back to me with a figure of 85 km/h for Naas and 95 km/h for Maynooth. (Both gust speeds). The latter figure gives a load of 710 N or 72 kg. (For a flat surface. There's probably a factor in the force calculation for round profile objects). Poles are fixed at one end. I.e They're cantilevered. The wind load spread over a pole creates a torque at the base of the pole equal to half the force on the pole multiplied by its length (are poles longer than around 7 m above ground?)

Slingshotting Satellites Into Orbit

Only a third scale prototype at the moment and the company SpinLaunch has raised $150 million in investment. The centrifugal launcher spins the rocket in a vacuum to reduce drag and releases it at the right instant so it leaves the launcher at almost 7500 km/h. Once the rocket reaches a certain altitude, engines ignite to boost the projectile to an orbital velocity of 27,600 km/h. The advantage of the technology is that it dispenses with multistage rockets requiring enormous quantities of fuel, potentially reducing the cost of launching payloads into space.

Wall Damage

© Eugene Brennan

Ivy on the wall at the end of the field adjacent to the car park at New Abbey Cemetery caught the wind and pulled a chunk off the top into the field. The rest of the wall seems to be crumbling and losing stones over the years. Meanwhile there were no trees down in New Abbey woods, although this ash or sycamore was felled by Storm Darragh. There's an increasing amount of tree trunks lying in the river adjacent to the woods. I wonder will a dam eventually form, as the trees catch more debris floating down the river?

(If the colours look weird, it's because it was nearly dark and I had to bring up the brightness and contrast. The auto white balance on my phone seemed to have trouble making up its mind too. Manual white balance set to cloudy didn't improve things)

© Eugene Brennan

 

© Eugene Brennan

 

© Eugene Brennan