Your questions about energy
Please take a look at my Energy Guide before you ask me a question. You may find I’ve already answered it! If you’re still puzzled by something to do with energy which isn’t answered on this page or in my energy guide send me your question using the form below
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Hi. I have to research up on food additives and e numbers etc. (all bad stuff in food)i typed in some stuff on google search and it came up with your website. i would like to congratulate you for making such an excelent page. it really helped me to understand why my parents keep saying to me ‘dont eat too much of this! its unhealthy!’ but i was wondering if you could give me any info on food additives and e numbers. eg. what they are… why they are so bad… Thank you for your time. Miss Stevenson
Additives are put into food for various reasons. Some are quite innocent (like vitamin C) and others are not. Many are put in to make food look good or taste so good that you want to eat more than you should. E numbers for additives are intended to make it simple to find out what a particular additive is and what it does. Just because a food has E numbered additives in it doesn’t necessarily make it bad… though it could be. On the whole, the more additives there are, the more processed the food is and, in general, processed food is not particularly wholesome; not ‘good for you’. The best food is organic and fresh. [more on food additives]
Dear Tiki, I’m Katie and I’m in third grade. I think it’s a bit silly to ask this question but……….. Is there such thing as eating too much veggies or fruit? From Katie
Dear Katie: It’s a perfectly sensible question! Some types of food you shouldn’t eat too much of but I don’t think you can eat too much veggies and fruit. In fact, most people eat far too few of these healthy foods. The only thing I’d suggest is that you don’t ‘pig out’ on any one veg or fruit (like eating carrots and nothing else!) but eat lots of different types and colours.
How does food get to our plate?
Here’s a very simple example of how food gets to your plate. Imagine you have a garden. You grow some vegetables and keep some chickens (farming). You want to eat a meal so you dig up or cut some of your vegetables and collect some eggs (harvest), you put your harvest in a basket and carry it into your kitchen (transport), you take the stuff out and wash it and cut it up (process it) and then cook it. Then you serve it out and eat it.
These days, most food is harvested by machines and is often processed in factories. It’s transported by road (trucks), sea (ships) and air (aircraft) to shops like supermarkets where most people buy their food. Often, it’s already processed and cooked so all you have to do is put it on a plate and eat it.
Have you looked at my Food Guide, by the way?
Tiki, We just read your website in our 3rd grade Social Studies lesson. We are learning about Pollution. We are wondering what we can do to get public schools like ours to serve only organic food to kids. Mrs. Nestel’s 3rd grade class.
That’s an interesting question and I don’t know the answer. But school food comes from somewhere so what you have to do is find out where that is and who pays for it. If you pay for it yourselves, you should have a right to choose what you want to eat. Does your school have a board of governors? Could you collect a petition in your class asking them to ensure you have an organic option? I’m sure your teacher will be able to help with these and other ideas. I wish you luck!
Could you please tell me… how much sugars an average person should eat a day? and how much sugars an average person should have in their body i have looked on the internet but i cant seem to find the answer anywere. many thanks
This is not easy. Nobody needs to eat sugar at all but most people like to because sugary things taste good. Your body needs sugars for energy and it makes all it needs from foods called carbohydrates (like bread, potatoes and rice). How it does this is quite complicated and involves a special substance called insulin which regulates the amount in your bloodstream all the time. Your needs for blood sugar (= energy supplies to your muscles and brain) depend upon how active you are. If you’re lying in bed watching TV, your needs are low. If you’re climbing a mountain, they are high. So it’s not really possible to answer your second question. .
can u help me find some thing about junk food?
Try this Wikipedia link. Ask the Dietitian is also good
Dear tiki: if landfill sites that have waste food in them – like potato peelings – make methane, don’t compost heaps do the same thing? puzzled, tara
Dear Tara: It’s all to do with the bacteria. Bacteria in compost heaps are aerobic – which means they thrive in airy conditions when there’s plenty of oxygen. The aerobic microbes break down the waste food and make useful compost which gardeners and farmers use to improve their soils. Sometimes very large compost heaps are made by companies who deal with garden ‘waste’ by the truckload. But although these are large, the bacteria still get plenty of air because machines regularly turn them over.
In landfills, organic waste (like food, babies’ diapers, paper and so on) just gets compacted together with everything else, rammed down by big machines. This means that any air left in the stuff quickly gets used up by the aerobic bacteria which then die. The waste then becomes anaerobic, which means there’s no oxygen. Some bacteria – anaerobic bacteria – can live in these conditions because they don’t need oxygen. The decay process is slow and smelly and one of their waste products is methane gas. In well managed landfills, this gas is collected and burned to make heat and electricity (on a small scale). If it isn’t burned, the methane escapes into the atmosphere where it becomes a powerful greenhouse gas.
So all in all, it’s better to make compost out of waste food.
alright tikki: could you please tell us how we get energy from plants and animals thank you tikki
The sun gives energy to the plants which make food which animals eat. That gives the animals energy. Some animals eat other animals rather than plants but the energy they get from doing this still comes from the plants and the sun.
Tiki: apparently there is an energy source available to mankind that is infinite, and this source is Tidal Energy. why doesn’t everybody use this resource if it won’t run out? and why aren’t there more tidal energy plants? Yours Sincerely, Jake
Hello Jake: Yes, you’re right about tidal energy. It won’t run out but there are problems with using it. There’s only one commercial tidal barrage in the world – at La Rance in France. This has been running for many years and has been quite successful. The problems mostly are that there aren’t many suitable places (where there are really big tide ranges and where some kind of barrage – dam – can be built) in the world. The best known candidate is probably the Bay of Fundy (east Canada) where there are huge tides. On the other hand, there are many parts of the world where the tides are very small (like in the Mediterranean Sea) so tidal power’s no use there. There’s another big problem too: electricity made from tidal energy would have to be transmitted very long distances to power big cities far from suitable parts of the sea. Transmission of electricity for such long distances means losing some of the power from the transmission lines and transformers which are needed for this task. This makes it uneconomic.
There’s yet another objection to tidal power from barrages: they would completely change the environment in the estuary (an example would be the Severn estuary in the UK), affecting sea creatures and birds for a start. They’d also stop ships navigating into any port which happened to lie inside the barrage without complex systems of locks, like the Panama canal. And a huge amount of energy (for quarrying and transporting materials) would go into building them. But all is not lost. There are new machines being tested in the Orkney islands (UK) where there are strong tidal currents. These will be attached to the sea floor and will work rather like wind turbines on land. No barrages will be needed and they’ll be completely under the water so there would be no environmental objections. Trouble is that the power humans need is vastly greater than any number of these machines could provide. The best solution seems to be to ‘mix and match’: use wind power where there’s a lot of wind, use wave power where there’s waves and tidal power where there are strong tidal currents and so on. [more on tidal power]
Hello Tiki, I am in grade 7 and Im doing a project on Biomass energy, and I need some help. Could you tell me a bit about Biomass energy or give me some good websites that are on biomass energy? Thanks! Chris
I think the National Renewable Energy Laboratory should be a useful link for you. I don’t have anything much about this topic on my site. Good luck with your project!
hello. I am chris. I cant find how can i make electricicty
How do you make electricity? It’s not easy. You need a generator and a motor of some sort to drive it. This is usually a steam turbine which in the past was always powered by burning fossil fuels, usually coal. Today, much electric power is generated by burning fossil fuels, mostly natural gas — and by nuclear energy. Again, these heat sources are all used to raise high presure steam to drive turbines. But increasingly, much of the world’s electricity is generated by wind turbines and photovoltaics and, of course, by water power. Each of these last three are renewable and will, when fossil fuels are phased out, be people’s only source of electric power, Perhaps you should see if you can have a trip round a power station. Many power stations run guided tours.
My daughter has a question for you, WHAT ENERGY IS STORED IN FUEL, FOOD & PLANTS
Your daughter’s question is easy to ask but difficult to answer in simple terms. Has she looked at my Energy guide? This answers much of the question – which is why it is there.
Hi, at school we learned about solar cars and how they are better for the enviroment. But i would really love to learn more do you know anything else about them? Thanks, Jess
Hello Jess: As I expect you know, solar cars run directly from the sun’s power by converting its radiation into electricity via special solar cells. The energy the cells make gets stored in a battery so that the car can continue to run for a while without the sun. But you do need a lot of expensive solar cells, a very lightweight and streamlined car and a lot of sunshine for this to work. It’s not likely to be a solution to the problems of transport and pollution which we have today.
Fuel cells are much more likely to power future cars. These make their own electricity from hydrogen gas (or methanol) and do not themselves create pollution. But where will the hydrogen come from?
hello, I am doing a topic on energy from fuels in my science lessons but am very confused about what hydrocarbon fuels are and also how lots of energy can be wasted when burning fossil fuels. Please email back and help me to understand this. Thank you very much. Amy
Dear Amy: Hydrocarbon fuels are basically the same as fossil fuels. I describe what those are in my energy guide. The name ‘hydro’ (short for the chemical element hydrogen) and ‘carbon’ (another chemical element) is really short for ‘hydrogen-carbon’. So hydrocarbons are chemical compounds made up of hydrogen and carbon. The simplest of these is methane, natural gas. Oil is a hydrocarbon fuel because it’s made up of various different compounds rather like methane, but it is liquid rather than gas. Coal is different because it’s made up almost entirely of carbon… so it’s not a hydrocarbon. But it, and all the hydrocarbon fuels like natural gas, propane, petrol and so on are all fossil fuels. OK?
When people burn fossil fuels, they do it to make heat. That heat can be used to make steam to drive electricity turbines (see my Guide), to heat houses and offices, and to power machines like cars, trucks, ships and aeroplanes. Generating electricity wastes almost two thirds of the heat (for complicated reasons). Heating houses can waste a lot of heat if the houses aren’t properly insulated – which most are not. And the heat made in transport which is not converted into ‘push’ (making the car or whatever move) is all wasted. That wouldn’t matter so much if there wasn’t pollution from all this fossil fuel burning. I explain a lot more about all this in my pollution and energy guides.
Ask a question
Do you have a question which I haven’t answered in my guides or on my Questions pages? Do you think I could help you understand something you can’t find out for yourself? If you do, just fill in the form below to send me your question. I promise I’ll reply to all serious questions. (That means I won’t reply to silly ones! I haven’t got time.). PLEASE be sure to tell me your first name, your age and the country you live in. And pleeeease do let me know if my answer helped! And sorry, but I can’t do your schoolwork or homework for you! That’s for you clever kids to get sorted. simple penguinRemember, I’m just a simple penguin.
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