Category Archives: small budget

Why LED lamps are best

There’s a lighting revolution underway. You can no longer buy the old incandescent lamps that are still the symbol of a good idea . Instead there’s a bewildering array of alternatives. So which ones should you buy?

Here are the lamps I saw for sale recently at the supermarket. So many options, each with most of the fittings you could want – including the standard screw and bayonet fittings that are still standard in most older houses like mine.

LEDs and other lamps for sale - whole rack

They have a wide range of wattages, lumens, hours and price tags. What does is all mean?

close up of lamps for sale

  • Watts are the amount of power used. The higher the watts, the great the energy being used.
  • Lumens are the amount of light emitted. The higher the lumens, the brighter the lamp. In some places, like kitchens, we want lots of light. We may want less from our bedside lamp.
  • Hours of operation differ between lamps. If a lamp lasts for many thousands of hours, you may not have to change it for a decade.
  • To really understand the price tag, you need to put all of this together. A lamp that uses minimal energy, emits lots of light, and lasts for a decade is cheaper in the long run than one that uses more energy and blows quickly.

LEDs, or light emitting diodes reportedly have the lowest watts per lumen for any lights available in Australia (see the light globe conversion table at the end of this link). A key reason is that they convert electricity into light, and not heat.

I tested this using a thermal imaging camera to compare an old incandescent with a compact fluorescent and LED lamp. Each had been on for half an hour before I tested their temperature.

The hottest point on the incandescent lamp was 161 degrees Celsius. That’s a lot of electricity being converted into heat, instead of light.

The hottest point on the compact fluorescent lamp (CFL) was 134 degrees Celsius. Still pretty hot.

The hottest point on the LED lamp was 65 degrees. Most of the power is going into light, not heat.

LEDs contain less toxins than other lamps, being free of mercury, lead and phosphorous and are also fully recyclable. So there are fewer waste problems with LEDs than with other lamps. CFLs in contrast, contain mercury so it is important to recycle those.

I’m convinced. I had already swapped all of my incandescents for CFLs. Now its time to change over to LEDs. And if the quoted hours are right on these new lamps they might outlive the house.

Science and the MOOC

By Su Wild-River

This post was first published at

Have you heard of the new Massive On-line Open Courses that are both exciting and terrifying universities around the world? Heralded as a fundamental challenge to the university education system, these courses are being offered free by some of the world’s best teachers from leading universities.

Yes that’s right – you can get a certificate from Harvard, Yale, MIT, Stanford and hundreds of other universities without paying a cent or leaving your desk.

MOOCs are available to anyone with an email address and password. Some courses offer a verification option with a small fee and an identity check each time you submit work. I took a verified ‘Signature Track’ course with Coursera, registering by using my computer’s camera to photograph my driver’s licence, my face, and by typing a short phrase. Then each time I submitted work, I again photographed my face and typed the same phrase to verify it was still me. The programming was excellent, so this was all very simple and quick.

Coursera is the world’s biggest MOOC provider. EdX is another big, high-profile MOOC with many prestigious partner universities. Udacity is also noteworthy, since it first popularised MOOCs. The graphs here show the recent growth for these three. Other MOOC providers are also on the rise, including CourseSites, Open2Study, Stanford Online, and Allversity.

I’m interested in this pedagogical revolution, and so I completed four MOOCs from four universities and three providers during the last three months. These included:

  • Networked Life, University of Pennsylvania, Coursera.
  • What a Plant Knows, Tel Aviv University, Signature Track, Coursera.
  • Our Energetic Earth, University of Toronto, EdEx.
  • Charles Darwin, Evolution and Tropical Australia, Charles Darwin University, CourseSites.

Overall I learned that studying MOOCs is fun. They are berries of education. Exciting, enticing and moreish with quick rewards and no calories.

Most course structures are simple, and forums suggest we like it that way. A generic pattern is three 10-minute lectures, 10-question tests, and readings, each week over the 4-12 week life of the course. Sometimes there are ‘peer reviewed’ assignments, where you mark others’ work and they mark yours. Sometimes there are final exams, and some MOOCs have webinars.

Classes are obviously much bigger, but drop-outs also proportionally higher than in traditional courses. About 10% of the 32,000 enrolled in one I took received a final certificate, and 2% met the 95% distinction level.

Can you learn science this way? The big MOOC providers quote research showing that on-line learning methods are about as good as face-to-face. I’ve been impressed with the quality of science teaching which has covered research methods, failed and successful experiments, flawed and quality hypotheses, and truly significant discoveries. We were asked to do simple, safe experiments and students discussed their results in the forums. I’d say yes – science can be learned through MOOCs.

Many students take MOOCs for the lifelong learning. I also like the certificate even though on the non-verified option the disclaimer is longer than the acknowledgement. They don’t affirm that I was enrolled, confer a grade, credit or degree, and don’t claim to know who I am. The verified version is far more confident that I am who I claim to be.

And finally, what do MOOCs mean for traditional university education? I think MOOCs can be powerful advertisements for universities, showcasing great teachers and courses. I think they can have a role in filtering students into the degrees that best match their interests. And MOOCs simply don’t offer small-class interactions that for many alumni seem to lead to life-long friendships and close professional networks. But MOOCs do seem like a threat to boring lectures and restrictive pedagogical options. And as MOOC providers continue expanding, and begin offering degrees, universities will need to move quickly and creatively or they may well lose their dominance in higher education.

Curious? Check out the offerings and have a go. It turns out I love MOOCs and I continue to enrol. Tell me what you are taking and I’ll look for you in the forums.

Comparing Providers

10 beginners tips for practical food preserving

By Su Wild-River

Have you ever wished you were ‘one of those people’ with colourful cupboards full of bottled tomatoes, jams, pickles and fruits? Are you scared off by advice on the hazards of preserving? Here are some tips to make the transition so that you can make all the preserves you desire without fuss or stress.

But first, let us consider the costs and benefits of preserving food.

1) The only equipment you need is a saucepan and some metal-lidded jars

The professionals use custom-made products like Vacola and Kilna and perhaps one day you will too. But to make a start, all you need is some metal-lidded jars. So the next time you are in the supermarket, choose products in metal lidded jars. When you have used the product, clean the jar carefully and store it for your preserves. Build up your collection more quickly by asking friends to do it too.

Preserving food in Autumn for Winter and Spring.

Preserving food in Autumn for Winter and Spring.

2) You don’t have to grow it to bottle it

My entire fruit crop was taken out last year by a severe, late frost, but that didn’t stop me from making preserves. Buy bulk, in season, direct from farmers if you are lucky enough to have a farmers’ market or street stall in your area. Although it doesn’t have the same inner glow as food you grew yourself, it’s still fresh, probably cheap, and certainly has low food miles compared with supermarket fruit and vegetables.

3) Learn the basics

There are many wonderful recipes on the web and in books, and I won’t repeat them here. But its helpful to know the basic options available to you. The essence of preserving is to slow the decay of real food so that you can eat it long after it was fresh. This is achieved by removing the elements that make it decay and also by adding other ingredients that help keep it edible longer. The main elements that cause food to decay are moisture, air, bacteria, light and heat. Some common ingredients that help keep food longer are salt, sugar, acid (vinegar).

Here are some of the main options:

  • Simple bottling: Just as the name suggests, this is the easiest option and a good way to start. It generally involves just one type of fruit or vegetable (eg peaches, plums, apricots, tomatoes), optionally with a preserving additive. This method works by removing bacteria and air and is achieved by boiling the produce until it is well cooked, and bottling it while it is very hot. Avoid bacteria by using clean, sterilised jars. Avoid air by filling them to the top and banging or pushing out as many bubbles as possible. Because the jar and produce are hot when the lid is sealed, the small remaining air pocket forms a vacuum, and this essentially removes the air. You can easily check that there is a vacuum, because the lid will ‘suck in’ when the jar is cool. Some of the professional bottles allow you to cook food in the jars, and seal the lids when you are done. The big advantages is that the cooking process kills all bacteria in the jar, ensuring that the bottle is sterilised. I choose not to do this with my gathered metal-lidded-jars, because I’m not sure that the sealant will cope.
  • Bottle mixtures: Bottled mixtures include jams, pickles and sauces. All of the same principles apply as with simple bottling, so jars need to be clean, sterilised and full. Recipes for bottled mixtures include preserving ingredients like sugar (for sweet things), salt, vinegar, mustard seeds etc for savoury, along with a range of flavours.
  • Smoking and drying: These methods work by removing the water from within the cells of food. The food will last longer if it is kept dry, cool and dark and the more you achieve all three of these, the longer it lasts. So a smoked trout will last a very long time (years?), while one in the cupboard may last several days.
  • Freezing: This method works by cooling food down to avoid decay. Its very common for vegetables like peas, beans and corn. Its often good to boil before freezing, partly to kill any bacteria, partly because it makes the colour brighter, and also because they retain their fresh flavours and shape better that way.

4) Get on a roll

Preserving doesn’t have to be a big event. I have learned to bottle up tomatoes every time I have enough to fill a saucepan. That’s a few times a week in the mid-season. I just cut them up and put them in a pot with a little salt when I’m starting to make dinner, and then leave them cooking until bed-time, because the longer you cook them the better they are. At bed-time, I take them off the boil and ladle them into clean jars (see ‘clean your jars’ below) and presto – preserved tomatoes for winter.

You can get on a roll most easily for simple preserves with one main ingredient, but once you master jams, pickles and other preserves, you’ll find you can do it with them too. A friend of mine regularly cooks up one or two jars of raspberry jam.

5) Treat it as an adventure

Your preserves don’t have to win awards, or be textbook perfect every time. The beauty of practical preserving is that every batch has its own personality. My very best jam was the ‘burnt heatwave apricot jam’ of 2013, which was burnt on the stove, not by the heatwave. I’m down to the last jar now and everyone is mourning it. But my ‘runny apricot jam’ from 2012 was great as a topping for pies, and the chooks eventually enjoyed ‘crystallised apricot jam’ of 2011.

The thing is, we are not preserving food to make products like the mass produced stuff of supermarkets. We do it for the love of good, local food that contains delight as much as nutritional value.

6) Label your preserves

Since each batch will be a bit different, you probably get the message its a good idea to put labels on your preserves stating the date they were made, and naming any special features. I don’t bother with the tomatoes, as I end up with so many jars each season, all pretty much the same. But jams are individuals, and so are pickles. Make your last, half-filled jar the taster, and name the batch a few days after cooking, once you have tasted and evaluated your results.

7) Look after your food needs

Preserving your own is the perfect way to avoid the foods you can’t eat, while favouring those you can. Last year a health practitioner advised me to slow down on the sugar….. just at the start of the stone fruit season. I wondered how I could preserve the abundant local peaches without sugar. I did some research and it turns out that the trick to making preserves without sugar is….. don’t add sugar. The peaches aren’t as sweet as they would have been with sugar, and they are not as brightly coloured. Apparently they won’t last as long either, but luckily I know how to deal with that (see ‘check your preserves before eating them’ below).

8) Clean your jars

If your jars have any bacteria on them, the preserves will go off very quickly. So make sure your preserves go in spotlessly clean jars.

Most importantly, you need to clean them well before putting them away for storage, since that’s the easiest time to clean them. The trick is to check that all of the ‘bits’ are gone. Check the inside of the lid, and all the way to the bottom corners, and be meticulous. If you can see, feel or smell anything that isn’t part of the jar then the jar isn’t clean.

Sterilise the jars again before you put in the food. A simple approach is to collect up the jars you plan to put your food into while your preserves are cooking, then boil the jug and pour boiling water into both jars and lids. Wear some rubber gloves and be careful to avoid burning, swirl the water around and then discard it into the sink. Be careful not to touch the inside of the lids or jars after this sterilisation process, and also to keep the rims up so that they don’t touch the benches. The remaining water will evaporate, and you’ll have a sterilised jar.

9) Keep them in the dark

Yes, they are beautiful. And they are a source of pride. But if you have them on display the light, and variable temperature within a living room will cause the food to decay faster. Better to keep them in a dark cool cupboard.

10) Check your preserves before eating them

OK, so there is a risk that your food may go off before you open the jar to eat it. This happens every so often, for the same reason that shop-bought preserves can go off. Maybe you left them too long and the few bacteria that were alive in the bottle grew babies. Whatever happened, the thing to remember is that it is within your power to make it safe.

When you first remove your preserve from storage, check it thoroughly. Can you see any mould? Has the lid popped out? Is there a discharge from around the seal of the container? When you open it, continue to check for mould, but also assess the smell. In particular, take a good, big sniff of it the moment you open it up. It should smell pretty well the same as when you put it away for storage – that is, delicious and totally edible. If there is a bad smell, or a release of air from a jar (like when you open a carbonated drink like beer or soft-drink), then its probably no good and to be on the safe side, you should throw it away and reach for another jar. I will occasionally still eat produce that had a tiny amount of mould on the top, but only ever after I have scraped off a good inch, and then repeated the sniff test and tasted a bit as well.

The thing is that one of the definitions of REAL food is that it CAN go off. Any food that doesn’t go off needs serious questioning about whether indeed it actually is food. So the mere fact that your preserves can, and sometimes do go off is a source of celebration, not distrust. Use your senses and your smarts to decide whether to eat what you have preserved, and you will be able to keep yourself, your friends and your family safe and healthy.