Science – Journeys of Heart and Mind

Autumn colours

Autumn colours at Westonbirt

Image of the day – 205

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image whenever I can.

One of our favourite places to visit, at any season of the year, is Westonbirt Arboretum. My Dad used to call it ‘the tree zoo’. It’s only a 30 minute drive along the route of the old Roman road from Cirencester towards Bath. This time of year the autumn colours are fabulous. The photo focuses on some Japanese maples, Acer palmatum. Acer palmatum is one one of the finest species with cultivars in a rich variety of reds, oranges and yellows. Westonbirt has glades of mature specimens and an area of newer planting. Both were looking glorious when we visited.

Why do the leaves become so brightly coloured?

I was hoping you would ask. During the long months of summer the mature leaves on trees produce the green pigment, chlorophyll, that reflects green light and absorbs the rest. That absorbed light contains energy that the leaves use to break apart carbon dioxide from the air, attaching the carbon atoms to hydrogen from water and expelling the oxygen. In a set of chemical steps, the carbon and hydrogen are converted to sugars used as building blocks to build starch as a storage product, and cellulose as a structural material to make wood. That’s a grossly simplified version of the story, but fundamentally it is correct. In biochemistry and in botany the process is called photosynthsis.

The starch in wheat, potatoes, rice and other plants can be used by herbivores and omnivores (for example humans) as food. We combine the starch with oxygen to recreate water and carbon dioxide, releasing the energy we need to walk, breath, pump blood, and think. Human brains consume a lot of energy. This process, the reverse of photosynthesis is call respiration.

So taking plants and animals together there’s a closed loop involving water, carbon dioxide and energy. In addition to the starch we use for energy, the cellulose in wood can also be combined with oxygen to provide energy. That is called ‘fire’, it also releases water and carbon dioxide. So when you relax in January in front of a wood burning stove you’re using the sun’s heat and light trapped by trees perhaps a hundred years earlier! If you burn coal it was trapped millions of years earlier.

So that’s why plants have green leaves.

Autumn

As the days grow shorter and the weather grows colder, trapping energy by means of chlorophyll becomes less and less efficient. The leaves on trees become a liability, being battered by the wind and worth little to a tree until the weather warms again in the spring. But the leaves contain useful materials that can be recovered before the leaves are discarded. There are other coloured substances in leaves, mostly coloured yellow, and as the leaves stop producing green chlorophyll, these are unmasked and the leaves change appearance from greens to yellows.

Nutrients in the leaves are recovered and stored in the main bulk of the tree so that, when the leaves fall, these nutrients can be called upon in the spring when new leaves need to be made. Some of the bright reds and purples in autumn leaves are synthesised as the weeks go by, and they play a protective role enabling the tree to recover greater amounts of the nutrients. (Waste not, want not for trees!) Not all species of tree have this refinement, and in those that don’t the leaves remain yellow. Once the nutrients have been recovered a weak layer develops near the base of each leaf stalk, a point where wind action will cause the leaf to break away cleanly and fall to the ground. You can watch this happen on any windy autumn day, leaves fluttering down with every gust. In natural woodland the fallen leaves decay, acting as a rich mulch and forming compost where seeds can germinate and grow. In parks and gardens they are swept up for tidiness and composted in bins or heaps.

Our eyes can distinguish the changes in leaf colour and we enjoy the spectacle and joy of glorious autumn colour, then we endure winter but look forward to the lovely, fresh greens of spring.

Exceptions

There are exceptions to every rule, and sometimes exceptions to the exceptions. Conifers are an exception here, they stay green all year round. The exceptions to the exceptions include larch (Larix decidua) which shows autumn colour and loses its needles, swamp cypress (Taxodium distichum), and the dawn redwood from China (Metasequoia glyptostroboides), three conifers with autumn colour. Life is indeed a many-varied thing! The image shows a mature dawn redwood in autumn colour.

Closing thoughts

This website covers a range of topics, one of which is faith. I do my best to follow Jesus, not just in his teaching, but in how he lives and thinks and touches people’s hearts and minds. Sometimes people take faith and science as self excluding opposites; you can choose one or the other but you cannot have both.

In fact there are many, many scientists who also have a faith and many followers of Jesus or other teachers of faith (Mohammed, Buddha and more) who accept the process and findings of science. And we all use technology every day, all of it based on scientific foundations and principles. It makes no sense to accept the successful results while rejecting the reasoning behind them. I will throw away neither science nor faith. I need both, and I am far from alone in that. I recommend you explore both. Make a start on my Welcome page, nobody is excluded; all are welcome, all are invited.

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Cotinus in autumn

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If you enjoyed this or found it useful, please like, comment, and share below. (If you don’t see those links, click the article’s title above the main photo and they will appear.) Send a link to friends who might enjoy the article or benefit from it – Thanks! My material is free to reuse (see conditions), but a coffee is always welcome and encourages me to write more often!

Rainbow over the town

Sunlight makes two internal reflections in a raindrop in mid air and these reflections send the light back at a fixed angle from the sun, but as a ray of sunlight enters a raindrop it is not only bent at an angle, each wavelength (or colour) is bent by a slightly different amount.

Double rainbow over Cirencester Market Place

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Image of the day – 204

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image whenever I can.

On 27th October I walked to town for some shopping, coming out of Boots in Cricklade Street I found it had started raining, so went into Bishop’s Walk to find shelter. As the rain eased I moved toward the entrance and looking out saw a bright rainbow so made my way to the Market Place for a better look.

Rainbows are interesting apparitions. Sunlight makes two internal reflections in a raindrop in mid air and these reflections send the light back at a fixed angle from the sun, but as a ray of sunlight enters a raindrop it is not only bent at an angle, each wavelength (or colour) is bent by a slightly different amount. The same happens again as the light leaves the raindrop. So these rays of separated, coloured light now come back at similar but not identical angles from the sun so raindrops in exactly the right place send back a single colour to the viewer eyes. The rainbow is part of a circle, cut off where it meets the ground as there are no raindrops below that point.

Furthermore, a small amount of the light is reflected three times internally in each raindrop and comes out at a wider angle. If there are enough raindrops in the air, you can then see another rainbow outside the circle of the main bow. This outer rainbow is faint and not always visible though you can just make it out in the photo. The colours in the outer rainbow are reversed because of the additional reflection inside the raindrops. In the second photo (click it to enlarge it), I’ve increased the intensity of the colours for you. You can just see the outer rainbow in both images (look above the chimneys over the yellow shop on the right (Joules). You may notice the colours are reversed in the outer bow, red on the inside and blue outside.

Finally, took a look at the final photo where I’ve pushed things to the limit. I’ve enlarged a small part of the photo and enhanced the colours even more. Again, click the image for a closer look. Traditionally a rainbow was said to have seven colours – red, orange, yellow, green, blue (a pale blue), indigo (a deeper blue) and violet. In actual fact it’s a steady slide through the range of colours.

Do you notice anything else about this rainbow? If so, leave a comment below.

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A glorious colour contrast

Dark sky, bright light

Wall art in a cafe garden

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Butterfly dead or alive?

Like all living things, butterflies have a metabolism in which interlinked biochemical processes are always active. On death these processes cease and the remains are consumed as food by other organisms or colonised by fungi and bacteria which digest and reprocess the remains.

Painted lady

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Image of the day – 200

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image whenever I can.

This painted lady butterfly was feeding on nectar from flowers of Verbena Bonariensis at Sizergh Castle in the southern Lake District. There were bees working these flowers as well, mostly bumble bees but also honey bees. The entire garden was buzzing with activity.

Why dead or alive?

This is not as random a question as it might sound. I’m part of a group of around ten people who meet weekly to think together about following Jesus in meaningful ways. We’d been considering Ephesians 2:1-10 where Paul writes that we were dead but have been given new life. I chose a random animal, a simple butterfly and asked the question – ‘What is the difference between a dead butterfly and a living one? We didn’t go into the answer in any depth, so I thought I might consider the differences here instead. Let’s make a list and work our way down.

A dead butterfly cannot move, it just lies on the ground motionless unless someone picks it up, the ants carry it away as food, or the wind blows and sweeps it along the ground. A living butterfly generates usable energy by feeding on the sugars in nectar from a flower and uses that energy to flap its wings for flight. And a simple brain controls the direction of the flight while the butterfly uses sight and smell to home in on useful flowers to collect more sugars. Being capable of directed movement is a key difference between death and life.
Appearance is another difference; a living butterfly has beautifully coloured wings. A recently deceased butterfly might look just the same for a short time, but those lovely wings will lose their lustre as the butterfly dries out. The colourful patterns will fade, dust and cobwebs will contaminate the surfaces. This is typical for all creatures, while they live they maintain and clean themselves, but after death these processes stop.
Ability to sense danger. When a butterfly is alive, if it’s resting in the sushine on a leaf or a flower and your shadow passes over it, it will launch itself into the air and fly away. The butterfly can’t distinguish between you and a predator (like a bird or a dragonfly) so it gets out of the way just in case.
Butterflies, like all lifeforms, are capable of reproduction. Adult butterflies mate, the males fertilise the female’s eggs, the eggs are laid on the plant that this particular butterfly needs for the growth of its caterpillars, the eggs hatch as baby caterpillars and these voraciously eat the leaves of the foodplant and grow and grow, then pupate on a stem, in a crevice, or underground to emerge as butterflies in the following spring or summer. It’s a complex life cycle, far more complex than that of a mammal, but it works well for butterflies. If a butterfly dies before it is able to mate, it will not contribute to the ongoing future of the species. If it dies after mating it will make a contribution to the next generation. Timing is everything!
Like all living things, butterflies have a metabolism in which interlinked biochemical processes are always active. On death these processes cease and the remains are consumed as food by other organisms or colonised by fungi and bacteria which digest and reprocess the remains through their own, different metabolic processes.

So it appears there are quite a few distinctions that can be made between something that is dead and the same thing when it’s alive. So, leaving biology aside for a moment, if we are aiming to follow Jesus, what might the difference between dead and alive look like? Can we gather some clues from the butterfly?

I’ve written another short article about that question.

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The Lake District

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An old castle made new

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Climate emergency!

If you’ve made it to this point, then ‘Thank you for watching and thinking it over’, and thank you also for anything you can do, however small, to reduce your impact on our climate in the days and years ahead. Many small impacts can add up to something really significant.

Climate emergency!

ad hoc post – 7

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The UK Government commissioned a video nine months ago to launch their response to what is now seen as a full blown climate emergency. It’s a good video; it includes presentations by people who are experts in their fields; it’s informative; and it’s very hard-hitting. It’s not widely available except through a series of local meetings throughout the UK where it’s being used very effectively to get people thinking and responding in useful ways at the local community level.

Click the video below to watch the Earth turn on its axis. Your home is here, can you spot it as it rolls by? This planet is home to every single one of us.

The UK Government video is available, however, on YouTube, published there by GB News.

Whether you live in the UK or not, I suggest you watch this video in full. (Note that the useful content ends at 2 hrs 41 mins into the video. There are plenty of natural breaks between speakers so you can watch it in sections if you find that more convenient.)

If you live in the UK, I also suggest you attend one of the many local meetings currently available, discuss what you have seen with others at the meeting, and try to get other local friends and family to join you. If you can’t find a meeting, you can always organise one yourself. as you watch, jot down anything that strikes you as particularly important or significant.

Finally, go through anything you wrote down and consider how it will affect you, your friends, your family, and your community. Is there anyone else you should share this with? Could you watch the video again with friends, family or neighbours and talk it over together? Also (and just as importantly) think about ways of reducing your individual impact on the climate.

If you’ve made it to this point, then ‘Thank you for watching and thinking it over’, and thank you also for anything you may do, however small, to reduce your impact on our climate in the days and years ahead. Many small impacts can add up to something really significant. That, after all, is how we got into this mess in the first place. It may also play a significant part in getting us out of the dangers we now face.

I have one last thing to say, and this is primarily for anyone involved in church in any shape or form; but please don’t let that stop you reading it. Jesus was prophetic and that’s a gift with two characteristics. On the one hand it forges links between people here on the planet we call Earth and the Father we think of as living in heaven. But also the prophetic gift involves bringing people together here on Earth, forging links between opposing sides, rebuilding trust and a willingness to work together, mending broken fences. Prophetic people are always demanding justice and aiming to reforge broken links. A sort of conciliation service. If we ever needed a conciliation service we need one now.

So if you are involved in any form of church, now is the time to recognise your prophetic gift (whether strong or weak) and use it to call as loudly as possible for everyone to work together to save this planet at last from the danger we have put it in. There is no time to lose. We need to bridge the gulf between those who would profit in the short term with no concern about next year or the decades and centuries ahead, and those who would do without in the here and now to secure a long term future for children, grandchildren and great-great- grandchildren.

Prophetic voices would give vision to the former, and hope to the latter. Indeed, there are many prophetic voices in the government film you just watched. It would be a serious mistake to think that church has a monopoly on gifts like this.

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Stars dancing in the sky

There is beauty in so many natural things – a waterfall, a flower opening from a bud, the swirling patterns in a shoal of fish or a murmuration of starlings at dusk.

Cirencester’s church tower

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Image of the day – 195

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image whenever I can.

On a clear evening during late May or early June, take a look at the western sky after sunset and you’ll see two very bright stars quite close together. They’re not stars at all, in fact. They are the planets Venus and Jupiter. The brightest of the two is Venus, setting slightly earlier than Jupiter until the beginning of June. The photo was taken on 25th May while the two planets were still far apart in the sky. Venus is brighter, the same side of the sun as Earth is. It’s just to the left of Cirencester’s Church tower in the photo. Jupiter is a little fainter, up in the top-left corner. Jupiter is a larger planet than Venus (about ten times the diameter, but it’s also much further away; far, far beyond the sun from our point of view. If you’re struggling to find the planets click the thumbnail image to expand it and you’ll see them both quite easily.

Passing close

The two planets will pass very close indeed in the first week of June. As I mentioned above, it’s merely a line of sight closeness, there’s no chance of a collision. Astronomers call a coming-together in the sky a planetary conjunction. At one time people thought the star of Bethlehem might have been a close conjunction like this, but these events can be predicted accurately far into the future and we now know there are no events from 2000 years ago that would fit the idea.

Nonetheless it’s a beautiful thing to see and you don’t even need a telescope. It’s something you can watch evening by evening with the naked eye or a pair of binoculars (providing the weather cooperates). Serious warning, don’t look until the sun has set. You can damage your eyes by looking at the sun, and seeing it in binoculars is particularly dangerous. Hint: go on watching after the planets move further apart, you’ll get a continuing sense of how active our Solar System can be.

What makes something beautiful?

It’s hard to pin down, isn’t it? There is beauty in so many natural things – a waterfall, a flower opening from a bud, the swirling patterns in a shoal of fish or a murmuration of starlings at dusk. There is beauty in athletics, the perfect pole vault, a new world record, a plunging, almost splashless entry into the water from a high board after a long series of breathtaking manoeuvres on the way down. A special sunset or sunrise. A list of beautiful things could go on for ever!

There’s also beauty in human relationships, children playing together, smiling and laughing; the elderly chatting together about times past. There’s beauty in the flavours of food and drink as well, some combinations are just so special, cheese and fruit, even really simple things like a ripe apple and a chunk of mature Cheddar, or some Brie with ripe grapes and crispy crackers.

Beauty seems, at its heart, to depend on everything good and right. Kindness and gentleness are beautiful things, anger and violence are ugly.

What about me? How can I become more beautiful? Think about it from your own point of view if you are reading this; what can you do or say or think or display that will make other people catch their breath and think, ‘Ah, there’s something beautiful here, something commendable, something I can appreciate and value.

Living and behaving in beautiful ways costs nothing, and greatly benefits those around us. So what is not to like? If everyone on the planet was determined to live better and more kindly today than they did yesterday, what a wonderful world this would become!

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Life together

The Lake District

Category: Science

Autumn colours

Image of the day – 205

Why do the leaves become so brightly coloured?

Autumn

Exceptions

Closing thoughts

See also:

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Useful? Interesting?

Rainbow over the town

Image of the day – 204

See also:

You might also like:

Useful? Interesting?

Butterfly dead or alive?

Image of the day – 200

Why dead or alive?

See also:

You might also like:

Useful? Interesting?

Stars dancing in the sky

Image of the day – 195

Passing close

What makes something beautiful?

See also:

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Useful? Interesting?