The Anonymous Widower

Using The Strange Property Of Water To Advantage

Most people, except perhaps those, who live in hot climates, know from their personal experience that ice floats on water. But most people don’t know that water is at its densest at 4°C. So water at this temperature sinks, but it rises at all others.

I once heard somebody use the existence of this property as a reason why God exists. He argued that if it didn’t, then life would have been impossible in water. It was all a bit contrived, but it is still as a strange property.

This morning, I was listening to Wake Up To Money, when a company called SureChill was mentioned. So I looked them up and found that they are using this property to create a new type of refrigerator. This page explains it all. This section describes the solution.

Sure Chill is a brand new kind of cooling system. It doesn’t need a constant power source. In an on-grid situation with intermittent power, it works perfectly well. In an off-grid situation, where a solar panel may be used, a Sure Chill powered refrigerator doesn’t even need a rechargeable battery. It shouldn’t work but it does. And it works beautifully.

Water surrounds a Sure Chill refrigeration compartment. When it has power, the water cools and forms ice above the compartment leaving only water at four degrees cooling the contents. When the power is switched off, the water warms and rises while the ice begins to melt, keeping only four-degree water cooling the contents of the compartment. So it has its own internal and entirely natural energy store that maintains a completely steady temperature. The system can operate like this, without power, for days and weeks.

People think physics is boring. Outside of Metier, I’ve done well in my career and made quite a bit of money by understanding the laws of physics that govern our lives.

My surprise at this idea, is that the technique could have been implemented in a refrigeration system decades ago. Artificial refrigeration was first performed by William Cullen in 1755. My bible; Nelkon amd Parker says that the maximum density of water was first measured by Thomas Charles Hope in 1804.

That is a long time from experimental proof to reality!

November 21, 2014 Posted by | Design, World | , , , | 2 Comments

How Much Water Vapour Is In A Cubic Metre Of Air at A Given Temperature And Relative Humidity?

I needed to know this as if I knew the temperature and relative humidity in my bedroom, when I went to bed and got up, I could work out how much water vapour had transferred to or from the air during my sleep.

One of my friends at school is an expert on these sort of calculations for industrial clients.

He came round on Friday night and we discussed it through, but I don’t think I got more than a basic grasp.

The reason is that he works from charts, whereas all my working life, I’ve started with proven formulae and worked everything out from first principles. But then I trained as a Control Engineer.

A problem I had with the psychometric charts he uses, is that they are all in a measurement system, that is totally foreign to me – Imperial. This is because most of the publishers are across the pond and they still use units, I last used in my early teens. When I went to work at ICI in the late sixties, the company had metricated in 1955 or so.

At least after our meeting and discussion, I now know what I’m searching for.

I finally found this web page, which gives a table of saturated vapour density for water in air. Although, it’s an American web site, at least it gives this in gm/cu. m.

The web page gives the SVP in gm/cu. m. at various temperatures

  • 0°C – 4.85
  • 10°C – 9.4
  • 15°C – 12.83
  • 20°C – 17.3
  • 25°C – 23
  • 30°C – 30.4
  • 37°C – 44
  • 40°C – 51.1

As an illustration, suppose you have a temperature of 25°C and a relative humidity of 50%. I measure it on my Maplin meter.

Maplin Hygro-Thermometer

Maplin Hygro-Thermometer

At that temperature a cubic metre of water can hold 23 grams of water. But as the relative humidity is 50%, it is actually only holding 11.5 grams of water. As my bedroom is about five metres square and two and a half metres high, that means the room contains over 719 grams of water.

Now look at 30°C and the same relative humidity of 50%.

The same calculation gives 950 grams of water in the room.

So if with the central heating, the electric blanket and the fact that each person probably is equivalent to a one bar electric fire, your bedroom, about the same size as mine, goes from say 25°C to 30°C, the air will need another 230 grams of water to be in equilibrium, or in layman’s terms, happy with how it relates to everything.

So from where does the air get this water it needs?

You!

No wonder a lot of people go to bed with a night bucket, so they can replenish the fluid they’ve lost to the air.

August 31, 2014 Posted by | World | , | 4 Comments

The Robert Hooke Biodiversity Bell

I passed this work by St. Paul’s Cathedral.

It is mentioned on many web sites, but it doesn’t seem to have a serious entry on the web. This blog gives a good explanation.

To me Robert Hooke is best known for Hooke’s Law, one of the basic laws of physics, that anybody who studied that subject will probably know. But Hooke did a lot more than find the law that bears his name.

He is one of those amazing characters thsat populate the history of science.

June 19, 2014 Posted by | World | , , | Leave a comment

Lighting The Way Affordably

I have dabbled in the past with photoluminescence and C and myself were once enchanted by the starry ceilings of the Hotel Windsor in Nice, but up to now most of the applications have been small.

So I commend Hammersmith and Fulham Council’s plans to use the phenomenon to light up the path in William Parnell Park, as is reported here in the Evening Standard.

There are lots of places, where the proiperty of photoluminesence can be successfully used, although safety applications as detailed here predominate.

We may giggle at the idea now, but in a few years time, this type of lighting, will be used all over the place.

If you’d like to put stars on a child’s bedroom or something similar, there is this UK manufacturer in Bury.

February 20, 2014 Posted by | World | , , | 1 Comment

In Search Of Lise Meitner

Lise Meitner is one of my heroes and as she was born in Vienna, I had to see if I could find her birthplace. She was supposedly born at 27, Kaiser Josef Strasse according to a web site I found.

This was the nearest I could find.

In Search Of Lise Meitner

In Search Of Lise Meitner

I would assume that the house has been knocked down.

I’ve just looked from my home computer and I was looking in the wrong place.

I really should have taken it with me or searched for an Internet cafe.

April 14, 2013 Posted by | World | , , , | 1 Comment

The Mpemba Effect

I was alerted to this tale of a scientific curiosity by The Times.

A Tanzanian student; Erasto Mpemba, found that hot water freezes quicker than cold water, contrary to what would be expected. It is now called the Mpemba effect.

I don’t find it surprising that no-one has fully explained the phenomenon, despite it apparently being known to such as Aristotle.

I think it does show though, that sometimes anybody can make a scientific discovery with the most basic of equipment. And in most cases, to be taken seriously by the establishment.

There are some curious phenomena out there in the real world.

One is that when water freezes it expands and thus ice always floats on ponds.  If it didn’t you wouldn’t get any fish in water that could freeze.

And then there is the odd property of the speed of sound in air and water. In the former it is 343.2 metres/second and in water it is 4.3 times as fast at 1484 metres/second. Now I know my physics and when asked what the speed of sound in a bubbly mixture of air and water is, I did what I thought was obvious and said somewhere in between.

I was of course wrong, as surprisingly it is less than 50 metres/second.  There’s an interactive display here.

I have used this phenomenon to mix oil and water.  They do mix, if you get the parameters right.

January 11, 2013 Posted by | News, World | | 2 Comments

Is This The Best Microwaveable Gluten-Free Sunday Lunch?

I wasn’t feeling too well this morning, as I probably got too hot in the sun at the Paralympics yesterday. It seemed to make my hand and arm go rather cold. So I picked up one of Marks & Spencer, roast pork loin with apple & cider sauce dinners from their Fuller Longer range, as I didn’t want the hassle of cooking properly.

Roast Pork Loin With Apple & Cider Sauce

It really is rather a nice meal for something that you just put in a microwave. I wonder whether when John Randall and Harry Boot, invented the cavity magnetron in 1940 at the University of Birmingham, ever visualised, nearly everybody having one in their homes.

September 9, 2012 Posted by | Food, World | , , , , | Leave a comment

The Odd Physical Properties of Mixtures of Air and Water

Richard Hammond today, in his program called Engineering Connections about the Space Shuttle, showed how NASA use a wall of water droplets to protect the shuttle and the launch platform from the immense sound waves created by the rocket engines on lift off. I have seen a shuttle launch and even some miles away the noise was awesome and in some ways the most unexpected part of the event.

If I ask an averagely serious engineer or physicist to tell me the speed of sound in air and also that in water, they will give answers of 343.2 and  1497 metres per second respectvely with various conditions like dry air and pure water. So sound travels a lot faster in water than air.

So if you have a mixture of bubbles of air in water or vice-versa, a logical person would think it lies somewhere between the two.

But they would be wrong!  According to this paper from 1969, by D. McWilliam and R. K. Duggins, it can be as low as 18.2 metres per second.  This creates all sorts of problems and benefits.  NASA’s engineers used it in one way and I invested in a company that used it to make an aerosol valve.

But it is a property that hasn’t been used to the full.

They say that oil and water do not mix.

But I have seen an experiment where bubbles of air was introduced into a mixture of water and oil and the resulting mixture was passed through a choke or restriction. A creamy liquid emerged, because the air bubbles in the restriction in trying to get into some form of steady state, mixed evetrything up.

I know that explanation isn’t very good, but who cares as the technique works.

In places like Saudi Arabia, there are large lakes of tar, that are just dumped in the desert. Perhaps by using natural gas as the gas, could this pollution be burned, whilst it is still hot?

I don’t know!  But I do know that this abnormal property of mixtures of gases and liquids is not used for all the applications it can be.

June 5, 2011 Posted by | World | , , , | 1 Comment

Building Scientific Models with Computers

This was the title of a lecture at University College London, that I attended yesterday lunchtime.

It was an excellent lecture and in some ways it was like going back forty years to when I worked at ICI Plastics in Welwyn Garden City. In fact two topics, that were discussed by Professor Catlow, were similar to problems I tackled all of those years ago.

The first was the problems of turbulent and other flows.  We had been interested in what happened inside an extruder as you used it to force plastics, such as polyethylene, polypropylene and PVC into moulds to produce the products needed.  It was an intractable problem then and I suspect it might be almost as bad today. Although computers are now bigger and can handle many more nodes than the hundred or so, we could handle on our PACE 231R or with IBM 360/CSMP.

I also found his discussion of the various forms of molecules and how they could be predicted fascinating and if we’d had someone with his knowledge, we’d have got a lot farther with another problem.

When you create polymers, you create long chains of molecules like ethylene and propylene etc. which lock together like a series of odd-shaped Lego bricks. These chains then bind together to form the items we need.

At the time, ICI were trying to create an engineering plastic, which would be stronger and have a greater temperature range. I won’t name it here, as I don’t want to break any confidentiality, but suffice to say that the monomer or polymer building block, needed to be created as a straight molecule for the integrity of the plastic. It was known that several forms of monomer could be created and that there was a rather complicated separation process to extract the straight ones.  Just as in Professor Catlow’s example yesterday, water in the reaction, was one of the factors, that  affected the proportion of desired monomer.

Now I’m not a chemist but I was asked to look at the physics and dynamics of the reaction, with respect to removing the errant water from the reaction vessel as soon as possible after its creation, to reduce the damage it could do.  In the end, I made myself very unpopular, as I often did, by finding a method that removed the water.  I can remember searching Chemical Abstracts and finally found the data I wanted in a paper published by a Chinese researcher working in Canada in 1909. We don’t know how lucky we are with Google and the Internet.

I left ICI soon after I completed this work, so I don’t know the final outcome!

But to me, the exercise proved the value of using dynamic computer models based on differential equations, to understand difficult systems.

In some ways, I was able to do this work, because I was properly taught calculus and how to form differential equations at school.  Would such an important subject now be taught to sixteen-year-olds  as was regularly done in the 1960s at schools similar to the one I attended?

January 21, 2011 Posted by | Computing, World | , , , | 2 Comments

A Christmas Present for the Woman in Your Life!

I had a well-educated lady round for lunch today and she saw the book below on the counter.

Lise Meitner: A Life in Physics (California Studies in the History of Science)

In my view it is one of the best reads, if you are interested in science between the wars and especially in Germany. It also tells the story of one of the greatest women scientists of all time; Lise Meitner.

November 19, 2010 Posted by | World | , | 1 Comment