One way to invest in yourself for our planet is by exploring the story of the living Earth.
This "Deep Time Walk", along this beautiful section of the North Cornwall coast, is ideal for those wanting to further understand our planet from its very beginnings to today.
The 4.6 km walk is based on the free app, book and page at www.deeptimewalk.org which you can use independently if you want to walk it on your own.
The walk starts and ends at the Pentire National Trust car park and centre where there are toilets, food and drink. It can also be started from Polzeath itself and also ended at the NT carpark at Pentire.
I've mapped and marked the whole route at https://explore.osmaps.com/en/route/11309788/Deep-Time-Walk and placed waymarks along the route to help you. You just have to locate them hidden in the walls and along the path. Sometimes tricky as some people pick them up and take them home or hand them in at the NT office!
If you come with me as your guide you don't need to worry about finding the stones and I'll let you know where you are in time and space! Plus I'll gift you a "to scale" card of the last 100,000 years of Earth's History. It'll help you better understand our place in Earth's 4,600 million year history.
The actual walk only takes about an hour and a half but you'll need extra time for stopping and finding out where you are along the way. Also it's a good idea to have time together at the end of the walk, in the orchard or inside having a coffee at the NT centre, to talk about your new perspective on life, the universe and your place in it all!
The moon's already broken away but now, 4100 million years ago, there’s just ocean. You’ve walked a long way already (well half a km) but Baby Bay's not far.
If you are walking in winter then you may have just walked a rather muddy path down from the orchard and NT carpark so I am hoping that you have worn appropriate footwear!
BBC's "Richard Hammond's Journey To the centre of the Planet" is a useful TV documentary that explains graphically the importance of the early formation of the earth.
Watch out for all the stone waymarks on your walk. MYA stands for Millions of Years Ago. There have been 4,600 million years since the earth started to form and "we" have been around for just 2 of them. At least it was 2 million years ago that Lucy was found by scientists in Ethiopia while they were listening to a song by the same name by the Beatles. "Picture yourself on a boat on a river"...you probably can sing the rest. Now you can think of "Lucy in the sky with diamonds" slightly differently.
Earth's magnetic field is powered by the solidification of the planet's liquid iron core. The cooling and crystallization of the core stirs up the surrounding liquid iron, creating powerful electric currents that generate a magnetic field stretching far out into space. If it wasn't there, neither would we! You get to see these magnetic fields in the Northern lights which are very occasionally visible from Cornwall
Some locals call Pentire Haven, Stinky Bay, so perhaps it's easy to remember that Bacteria come in around here 3400 MYA (million years ago) and we have an awful lot to be grateful for that they did. Afterall you are more bacteria than you are you! Easy to forget this and other amazing things about bacteria.
1) Older Than Dirt (Really!)
Bacteria has been on the planet for more than 3.5 billion years old, making them the oldest known life-form on earth.
2) They’re Fast
A bacterium can typically move about 100 times its body length in a second. To put that into perspective, a large fish can move only about 10 times its body length in the same time.
3) You Eat It
That yogurt you ate this morning? That’s made with bacteria. Many snacks like yogurt, cheese, Kimchi, and miso are all made with bacteria.
4) Most Are Good
Your body has far more bacterial cells than human cells. They help with processes such as digestion and they defend your body from bad bacteria. Of all the bacteria in the world, less than 1 percent will make you sick.
5) They Go For Light Years
Lined up from end to end, bacteria would stretch out around 10 billion light years. That’s the distance from here to the edge of the universe.
6) Discovered in 1674
They weren’t discovered until 1674, when Dutch scientist Antonie van Leeuwenhoek spotted them as he was looking at scrapings from the human mouth under a newly invented microscope.
7) They Adapt Fast
Bacteria adapts quickly, making it hard to find an antibiotic that will work consistently. If you take antibiotics too often, bacteria can become resistant. This is why people with a long history of antibiotic use should undergo household testing to ensure there are no harmful bacteria present.
They’re Single-Celled
Bacterium (single bacteria) are made up of only one simple cell.
9) Unique Shape
Bacteria is most frequently shaped like a sphere, rod, or spiral. Some bacteria varies, and can be shaped like a comma or corkscrew.
10) They’re Tough
Different bacteria can survive in a variety of extreme conditions. From ice to hot springs, and even radioactive waste.
Ref https://www.novatx.com/household.../10-fast-facts-bacteria/
Coming up the slightly tricky bit of path out of Stinky Bay (Pentire Haven), you’ll see that this old wall boundary is where our testament (fossil record) starts... 3200 MYA
First Continents 3100 MYA. Stone on the post by the re- fenced-off collapsed cavern at Gravel Caverns. I remember when the cave below fell in some 8 years ago and how fast the sea was at taking away the entire contents of the roof from a huge pile on the gravel beach. Cornwall, you might be surprised to know was up on the equator at the time of the first continents!
Between one billion and 620 million years ago, the continental crust that would one day be known as Britain formed tiny parts of a giant supercontinent called Rodinia (approximately 500 million years before the formation of Pangaea, a later supercontinent). All of Britain was south of the equator, with some parts as far as 60 degrees, further than Australia and the southernmost tip of South America today. The rifting or splitting apart of this supercontinent began around 760 million years ago to form a second supercontinent continent known as the ‘Vendian’ supercontinent.
What a truly amazing thing this was!
The process of photosynthesis is commonly written as: 6CO2 + 6H2O → C6H12O6 + 6O2.
This means that the reactants, six carbon dioxide molecules and six water molecules, are converted by light energy captured by the chlorophyll in green leaves into a sugar molecule and six oxygen molecules.
Those products of photosynthesis changed meant the world to us and the world as we know it. A little further along the path we get to a point where it says Gaia and we had a living earth that was self regulating!
Much, much later on we'll have a world where the O2 levels reach the sort of levels needed for animals, us included. We need the atmosphere to contain about 19 percent O2 to survive.
Every cell in an animal requires oxygen to perform cellular respiration. Cellular respiration is the process by which animals take in O2 and exchange it for CO2.
Even a fish will drown if it can't breathe O2 under water. Dissolved oxygen (DO) refers to the oxygen gas that is dissolved in water. Fish absorb the DO directly from the water into their bloodstream through their gills as anyone with a fishtank will tell you.
O2 burns the food within any animal's body and releases energy for various activities. Half of the world's oxygen is produced via phytoplankton photosynthesis. The other half is produced via photosynthesis on land by trees, shrubs, grasses, and other plants.
It is estimated that 6% of Earth's land surface is covered by lichen and they can survive in the most extreme places...here on Pentire Head it gets quite a hammering in the winter and in the summer very dry at times.
Lichens are a symbiotic collection of fungi and cyanobacteria or algae. The fungi provide a moist, sheltered habitat for the cyanobacteria or algae, and, in turn, they provide food for the fungi. Cyanobacteria, also called blue-green algae, are microscopic organisms found naturally in all types of water. These single-celled organisms live in fresh, brackish and sea water. Because, unlike other bacteria, they contain chlorophyll they can use sunlight to make their own food and share it with fungi if they want to combine to make Lichen!
Algae are defined as a group of predominantly aquatic, photosynthetic, and nucleus-bearing organisms that lack the true roots, stems, leaves, and specialized multicellular reproductive structures of plants.
If you have been on The Deep Time Walk with me you'll know that photosynthesis came in all the way back near Cowrie Bay and that Lichens, amazingly, are on the home straight to Pentire Farm well before the world as we know it that comes in (near the carpark at the Old Lead Mines) with the Cambrian Explosion.
Did you spot in the pictures above:
A sunburst lichen on the hawthorn growing on the coast path
Ramalina siliquosa, also known as sea ivory, is a tufted and branched lichen with a colour that my wife wants to use to paint some walls.
A Cornish hedge is a style of hedge built of stone and earth found in Cornwall, south-west England. Sometimes hedging plants or trees are planted on the hedge to increase its windbreaking height. A rich flora develops over the lifespan of a Cornish hedge. The Cornish hedge contributes to the distinctive field-pattern of the Cornish landscape, and form the county's largest semi-natural wildlife habitat. This one being totally exposed to the wild west winds on the exposed north coast is treeless but contains plants like thrift or sea pink, grasses and of course some wonderful lichen.
Alan Titchmarch came to North Cornwall to study the lichen on St Genny's church at Crackington Haven? IWalk Cornwall probably know but I could find no reference on their walk information except that :"Lichens are a partnership of two different organisms: a fungus providing the "accommodation" and an alga or cyanobacterium providing the "food" through photosynthesis. The fungal partner provides a cosy, sheltered environment for the alga and tends it with mineral nutrients. However, the alga partner is more than simply an imprisoned food-slave: it is such a closely-evolved alliance that the fungus is dependent on the alga for its shape and structure. If the fungal partner is isolated and grown on an agar plate, it forms a shapeless, infertile blob."
Truly Fantistic Fungi. Early mult-cellular fungi 1500 MYA were around so much longer than you can imagine unless you do this walk!
Evidence from DNA analysis suggests that all fungi are descended from a most recent common ancestor that lived at least 1.2 to 1.5 billion years ago. It is probable that these earliest fungi lived in water, and had flagella.
The earliest terrestrial fungus fossils, or at least fungus-like fossils, have been found in South China from around 635 million years ago. The researchers who reported on these fossils suggested that these fungus-like organisms may have played a role in oxygenating Earth's atmosphere in the aftermath of the Cryogenian glaciations.
About 250 million years ago fungi became abundant in many areas, based on the fossil record, and could even have been the dominant form of life on the earth at that time. They possibly still are! According to the first big assessment of the state of the world's fungi, the fungal kingdom is vital to life on Earth. Yet, more than 90% of the estimated 3.8 million fungi in the world are currently unknown to science. Fungi represent about 25% of the biomass on Earth. Most fungi are too small to see. A single fungal filament is 10 times thinner than a human hair. Today our world is visually dominated by animals and plants, but would not have been possible without fungi.
The Cambrian Explosion 542 million years ago, just half a kilometre to go, starts on the tarmac at the top of the road! Everything seems to happen in this last stretch down passed the turning to the Old Lead Mine Carpark and back to our start. But of course if you have walked 4 km already you'll know that so much has led to this point in Earth's history.
We’re just about back but so much of what we think is Earth’s History is packed into the last few steps of your walk! This stone says "First Primates 50 MYA and now you just have to grab a coffee and trace the last steps of the walk back into the orchard. Everything we think we know seems to happen now!
Perhaps this is a good time to reflect on on our rather skewed view of our self-importance! Hopefully your deep time walk will at least have made you think. Maybe we are more important now than we have ever been? Maybe you are and have an role to play in the unfolding story of life on earth. Who knows!
I hope too that you have enjoyed your deep time walk. You have certainly been walking around one of the most beautiful parts of the North Cornwall coast. It's a good place to renew and perhaps also a good place to appreciate something profound about your beautiful planet.
Feel free to call me if you’ve got questions or need help setting-up a Deep Time walk for others.
This is an important walk and one I'm happy to give for free if the private price is the only thing putting you off. Please just ask because the best things in life really aren't things and sharing this walk with those who appreciate it is actually priceless!
I am more than happy to share my ideas so that you can help others engage with this walk at an appropriate level.