Tag Archives: science

Under Pressure

Under Pressure 1

This is what my water bottle from the plane looked like when I got back to Cape Town, after my month away in the UK.

Generally speaking, a large plane flying at high altitudes, like my Boeing 747-400 cruising at 12,200 m (40,000 ft), has to pressurise the air inside the cabin, because the outside air at that altitude is at a much lower pressure than is good for you!

Even so, they don’t quite match the pressures you might experience down on the ground; cabin pressure is usually set to that which you would experience at 1500 m to 2440 m (5000 ft to 8000 ft).

Under Pressure 2

When I got back to my house and took out my water bottle (that had been opened and resealed while up in the air on the plane) the increase in atmospheric pressure here in Cape Town at sea level was enough to squish the plastic bottle.


In fact, the pressure that day, according to the barometer in my lounge, was a whopping 104 kPa (780 mm Hg).

No wonder I had a headache!


And how could I have a post with this title and not mention  David Bowie and Queen Under Pressure.


post script: It has taken me a while (9 drafts) to put this post together, with all the reference material. And though I know that a post like this will not be generally popular, I find it interesting.

In case you’re also interested, here are a whole lot of links so you can read up on this subject. You’re welcome!

cabin pressure  versus air pressure   and cabin altitude

Physics experiment of a plastic bottle on a plane.

Table of atmospheric pressure at different altitudes.

Diagram of how cold it is at different altitudes.

Health advice before you travel by air.


Is there Life on Mars?

Untouched Sunrise in the Western Cape

Untouched Sunrise in the Western Cape

If you stood on Mars and looked up, the Martian sky might look something like this: without the skyline of course!

Mars has a thin atmosphere, made up mostly of carbon dioxide. There are also lots of iron oxide dust particles, all of which contribute to the sky appearing a bright orange/red during the day.

So, Is there life on Mars?

I’d like to think that, if not now, then once upon a time, long, long ago, maybe something lived there.

After all, we are still finding new life, albeit microbes, surviving as extremophiles, in the most inhospitable places, here on Earth.

These life forms can be found:

– deep under the sea in the Mariana Trench

– in lakes of sulphuric acid

– in lava vents of volcanoes

– in boiling acid springs

– in Antarctica, half a mile under the ice, in the dark and extreme cold

– in radioactive waste disposal sites

Some bacterial spores have been found that are 40 million years old. They are still viable. Let me just repeat that. They are still viable! Basically, they’re immortal!

You can read more about extremophiles here:  one two three four

So yeah, maybe there is life on Mars. But would we recognise it when we saw it?

It’s life, Jim, but not as we know it!


For the definitive answer to the question, “Is there life on Mars?” let us ask David Bowie.


post script: The Mars theme might seem topical, after the movie and the book, ‘The Martian’ by Andrew Weir, (which I read in December, in 2 days; it was that good!) but I started a draft of this post way back in June 2014!

Why has it taken me so long to finish the post? Well, I like to get all my facts straight and it takes time to find appropriate links. Mostly, I keep my posts short, so they don’t take so long.

Why do I bother, you ask, since hardly anyone ever clicks on the links?

I do it for myself. I like my posts to be the best they can be. I want the facts there at a click, for when I read this again sometime. And you never know, someone else might have the interest and time to read them too.


Reverse Engineering

Bloom 1

Bloom 1

I found this gorgeous bulb blooming outside someone’s house on one of my dog walks. There was such a sharp contrast between the petals in full sunlight and those in shade that it added a great deal of colour to the flower.

Bloom 1

Bloom 2

It also reminded me of being taught in art class at school that no colours in nature are ever pure black.

I really like the contrasts between the stamens just catching the sun and their shadows formed on the petals.

Bloom 3

Bloom 3

Nature truly is stunning.


post script: Reverse engineering is taking apart an object to see how it works in order to duplicate or enhance the object. This practice, taken from older industries, is now often used on computer hardware and software, as in the Ben Affleck movie, Paycheck.


Distant Galaxy



The most distant galaxy  discovered so far is 13.1 billion light-years away from Earth. It’s the fuzzy blue one in the photo. Called EGS-zs8-1 (what’s wrong with a real name, like say  Edmund?) it is one of the earliest (oldest) galaxies to form.

Of course it doesn’t look like this now. It looked like this 13.1 billion years ago, when light from the galaxy started travelling our way.

Galaxy 2

Galaxy 2

These galaxies form part of a chain of galaxies, only visible with the aid of high powered instruments, such as the Hubble Space Telescope.

Galaxy 3

Galaxy 3

Or do they?

Actually, they are Solar powered fairy lights, photographed during load shedding in Cape Town the other night.

Did I get ya? Did I? Did I? Or are you far too savvy to fall for my little games by now!

And here’s how to make a Galaxy in the poinsettia in your garden.

Galaxy 4

Galaxy 4

The fairy lights are reflected through the window onto the right hand side of the poinsettia outside. The other lights, resembling fairy lights, are the last rays of a setting sun filtering through the foliage.


I could have called this post “Things to do for fun during a power cut” but that would have given the game away!



Blue Moon

Blue Moon

Blue Moon

I love seeing the Moon during the day; hanging there in the sky.

How did I take such a marvellous photo of it? (Yes, I can hear you laughing!)

I only have a trusty old Canon 10MP point and click. This is the best I’m gonna get! And quite frankly, I am amazed there is any definition at all!

post script: What is a Blue Moon? Normally a season has only 3 full moons. When it has 4, the 3rd moon is then referred to as a Blue Moon. There is a Blue Moon about once every 32 months on average, which may be the reason for the expression Once in a Blue Moon. An ‘actual’ Blue Moon, is when the moon appears blue due to atmospheric conditions eg after  volcanic eruptions.

Now you’ve all got that song stuck in your head have a listen to the 1961 version by the Marcels – Blue Moon


The Double Apple Gene

Double Apple Gene

Double Apple Gene

I suffer from the double apple gene! Never heard of it? Well, you probably know that people with a pear-shaped figure are supposed to be healthier and live longer than those with an apple-shaped figure? Both my parents were apple-shaped – so I must have inherited the Double Apple Gene!

It simply means that while a normal person eats chocolate, and gains a little weight, us poor “doubles” only have to think about chocolate to pile on the kilos.

It’s OK though. As long as I eat more healthy food than I care for, eat less yummy food than I’d like, and exercise way more than I want to – then I can maintain my weight.

As for apples – I don’t really care for them! So, how do I keep the doctor away?

Vodka – of course!




What am I? Bugs on a slide viewed through a microscope? Macrophages? Abstract art? Answer appears upside down at the bottom of this post.

Did you really turn your laptop upside down? hehe

Answer: Photo is the pattern left on the stoep from two dog mats that had been caught out in the rain. I particularly like the fine detail of the fringes. Did you guess?

What is a stoep? Afrikaans for a veranda.