iron ore and our economy

Well firstly I'm no economist, but that may go for or against me depending on who you ask.

This morning I was reading the Australian and noticed in a discussion on the down turn of fortunes of BlueScope Steel I find this comment:

Since 2003, iron ore export prices have jumped from $US10 a tonne to $US140 a tonne and coking coal from $US50 to more than $US230.

Which would seem like a "wow" sort of figure, that seems like enormous growth in the value of iron ore and coal.

But is there more to it than that? Well I think there is.

the comparison is in US Dollars, which have been taking quite a hammering in value over that period. There have been numerous articles in proper literature (not newspapers) complaining that the US Federal Reserve has been printing too much money and causing inflation. This leads to situations where the dollar becomes worth less. Even if you play monopoly and have an extra stash of money under the table the other players will get angry with you won't they?

So what else can we compare it with? Well I say that money is a formalized exchange media, and that its "floating" is an experiment which history has indicated to be a little unreliable. Other commodities can be a source of exchange. Normally we pick something which is:

1. rare
2. impossible to counterfeit
   
3. desirable (my used tissues are rare and impossible to counterfeit but noone wants them)
   

For some greater part of human history Gold has been exactly this commodity (and also used to underpin currencies until governments over spend and have to un-pin)


Looking at Iron Ore prices in the context of another commodity (Gold) we see a different story.

Both have undergone quite large changes in their "worth" when measured in US Dollars.

So has their "worth" gone up, or has the value of the purchasing unit (the US Dollar) gone down?

Personally I would argue that it is in fact the fiat currency which has undergone deflation in value and that the commodities are undergoing far more normal sorts of supply and demand "valuation" changes.

The Australian starts their article with this quite interesting graph of the data of world Steel Production. It shows some interesting comparisons on the factors such as the Japanese Industrialisation and then the Chinese Industrialisation (which is not yet as matured as that of Japan).

its interesting to note how world steel production remained quite flat between 1971 and around 2000 (the point at which China started to increase its production). This becomes quite clear in the relationships presented in that graph.

This would make it seem reasonably clear that it is actually China driving much of the new demand and is perhaps also inserting itself in the market place and displacing other makers. Either way China has a lot of industrial growth to catch up on if you compare the state of China in the mid 1980's to what other industrialised nations were at that time to that same comparison now.

Eventually China will have to plateau out as did the previous historical demands, perhaps that may be in 5 years, perhaps that may be in 20 years. However "when" is not the question in my mind my question is "what happens then".

Economic theorists would suggest that we arrange our economies such that the author of that article has suggested: "that nations prosper from trading with each other after specialising in what they do best"

This is an ideal world in which many factors (often called externalities) are ignored in the analysis. I would doubt that anyone would suggest that we (for instance) give up on having an armed forces and allowing the nation who does that best to specialise in our national defense?

The natural systems which we observe fail to provide any real examples of this sort of concept, except perhaps the insect world. If things are made in the one place that 'specialises' in it, then diversity will vanish and we will suffer as a result.

Now people may claim we would get diversity because "the market place would demand it", well over the last 40 years of my lifetime equally as many good ideas have vanished from the market in the homologation of product lines as have entirely new products emerged. Just because I can get an iPad now and couldn't then doesn't mean that other tools and products which I valued and were very useful then are all still available now.

• I can buy a whole new hand saw for $12 at Bunnings but try to find a tool for sharpening and putting set back on the teeth?
• Increasingly people know less about stuff and how to fix it, just dump it and buy another.
• Stuff is increasingly less repairable.

My family and I benefit from my simple solar floor heating, which will also lend itself to an interior gas powered floor heating system at night. I was able to design and install that for next to no money. If I had to pay some one to install that it would have had a much longer (perhaps infinite) payback period

None of this matters however if you just stay living in the hive.

Let me adapt a quote from Robert Heinlein to take it outside the context of his novel "Time Enough for Love"

A human being should be able to change a diaper, plan an invasion, butcher an animal hog, design a building, write a poetry, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.

Maybe they would wish us to evolve as a society into something like insects, but I think there is a flaw in that theory. While White Ant hives operate in the manner these economists would direct us, the reality is that we do not yet have a global hive with a single purpose and single ethic. That stuff is the realm of Aldus Huxley and I for one will not be assimilated.

---

PS: a good question by Joshie Boy ... this is that growth in price for Iron and Ore normalised on the value of Gold

new micro43 stuff

Regular readers of my blog may know of my interest in the micro 4/3 camera system; a system which promises smaller lighter cameras with big sensors as in most DSLR cameras.

Today I read that Panasonic have now released a new lens in the micro4/3 system range which at last brings compact zoom to interchangeable lens cameras.

I found this comparison image as part of an image on the dpreview site (here) and I think it shows just how compact they have managed this new lens is.

The new lens seems to draw upon the sort of motorised lens extension that all digicams have had since about the year 2000. So you get a compact lens for travel that opens out a little for use.

It would seem that the new lens is nearly as compact as the 14mm pancake or 20mm. But importantly it gets OIS while the others don't.

This is actually really significant when doing video. Even though fans of the 20mm will tout how much better it is to have the extra stops of light that only counts for something in stills. In video having OIS means with a reasonably steady hand you've got vid as smooth as if it was on a tripod.

FANTASTIC

As I have mentioned before we just don't see many (until now) compact lenses in the micro4/3 lens range and why can't we have digital cameras with interchangeable lenses which are compact.

Below is my Panasonic G1 with Pentax 110 lenses; a camera from the late 70's which used film of almost exactly the size of the sensor in the 4/3 cameras.



You can see that these lenses are quite compact and light. The one on the left is a 50mm which equates to an effective focal length of 100mm ... that's right a portrait telephoto.

Well it seems that since 2009 we are now starting to see movement at the station.

Fantastic

solar floor heating - rainy windy and overcast results

The last week has been windy, rainy and overcast, so I didn't expect that the solar system would be making any significant impacts.
But a quick trip outside in the day reveals the quiet bzzt bzzt bzzt of the motor pulsing a tiny circulation of water through the floor pipes. More so when there is a break in the clouds and it springs into action immediately.

This is a good sign as this means that at least some thermal mass (of water) is being circulated and doing something to make the floor warmer.

My temperature readings over the last 24 hours (in the blue) indicate that we've kept our inside max temp at the same level of the outside max temp which is great IMHO. Previously if we had a max daytime temp of (say) 20°C during the day the house would never get warmed up that much and would be at more like 16 or 17°C peak and with the inside often being just a few degrees (like 2 or 3) warmer than the minimum (see the magenta line).

I'm quite pleased with these results in the light of the energy input requirements (like freely environmental available) and the floor insulation not only helps bring this into the house but also keep it there.

I'll be very interested to see how this goes when I add in the component of gas heating in the night. I'm guessing that it will bring up my bottom and keep it from falling so low. Mmmmm nice even temps.

NOTE: as I write this at 7pm local time the outside temp has dipped to 16.4°C and the inside is remaining steady at the 20.0°C down from the 20.8°C its was at lunch time.

Keep Australia Beautiful

I heard this morning that litter is getting worse in Queensland compared to each of the mainland states (does this mean that Tassy is the worst?) and that Keep Australia Beautiful have released figures suggesting that:

"The biggest increases in Queensland litter, were recorded at shopping centres and carparks (both up in volume and number), highways (up in number, down in volume) and recreation parks (down in number up in volume)."

See the report here

As one who has been associated with environmental education folks for some time I find this trend to be exactly what I predicted over ten years ago.

I recall a conversation with 2 educators on Fraser Island (while we were collecting shit off the beaches there left by wankers who call themselves fishermen) that the last thing you want to do is encourage more people to come to national parks, even if it does somehow liberate more funding from the government it won't pay for the extra damage caused by the extra bogans.

solar floor heating - why solar will only be part of it

I've been quite happy with my solar floor heating home improvement project, but I am under no illusions that it is a complete solution in itself (see all related posts for the complete project rundown).

Why not?

Firstly it doesn't work well at night ;-)

Secondly on days like today for instance, it started out raining, with the rain moving in late in the evening. This allowed the temperature to drop (no cloud cover keeping the place warm over night) and then little or no effective solar energy to heat the water or drive the pump. The graph below was obtained from the BOM site just this morning and sums up nicely why an auxiliary power supply is needed on some days.



So you can see from the graph that not only is it cooler its also more humid and (dangerously from the perspective of mold and fungus as I have already blogged about) the dew point is VERY close to the ambient temperature. This is reflected in the relative humidity (which is sitting at about 87% outside as I write this).

By heating the interior of the house at this time we get some significant benefits (apart from being warm) by effectively lowering the relative humidity inside the house and thus preventing everything becoming sticky and damp. Also as the sun comes out now and then and starts to heat up the air outside we don't have the problem of the interior of the house being cooler than air outside and thus causing some condensation of moisture happening as the warmer moist are comes inside the house and touches cooler things.

That green line of dew point means that water will start to condense out of the air when things are at (in the case above) 13 or so degrees C. That's why glasses with cold water in them start to look frosty and why polished wood starts to feel tacky.

Insulation also works best when its got some thermal mass to insulate. An empty thermos bottle won't stay warm long with no water in it (try heating the interior with a hair dryer and see for your self). Since our house has no thermal mass heated up to a higher temperature for the walls, floor and ceiling to insulate it will loose heat quickly at night and over time the next day without the addition of heat.

So by modifying my design to have the common pool:



I can now incorporate something like a gas heating system to heat the water and a small auxiliary power supply for the solar pump (on the floor circuit) to heat the water in the common pool, and then move that warm water around the floor pipes; without wasting that heat in the solar heat collector section.

In my view gas provides the most effective way to store and purchase energy for heating. It gives excellent efficiency and burns very cleanly (no nasty toxins such as sulphur). However I don't want to burn gas inside my house, as it will produce micro-soot; CO₂ as well as potentially leak gas in the house.

This is of course not news to Canadians who have been burning their furnaces in a way that keeps house air separated from combustion and puts combustion gasses back outside where they belong. Even open fire places have a chimney right?


My solution to this is to get a small low flow gas hot water systems such as this one. These are designed for caravans and other low flow outdoor situations. They are rated at about 6Liters per minute which is a bit more than I'll need. I can turn the water temperature (meaning gas consumption rate) down as I need only have the water at about 35°C

By using a water heater like this I then get to keep my combustion outside and not mix it with my internal house air.

I can run it of a 9Kg cylinder and pump the water through it to the common water bus with a low power 12v pump.

My intention is to set this up on a timer which will turn it on at about 6pm, run it for busts (say 20min on 20min off) till about 10pm then turn it on again at about 5am to start heating the floor.

This in turn will make my solar system more effective as the water will already be warm in the morning when it starts up giving it a head start on warming it up.

Of course this adds to the complexity and cost of the system, these systems sell for about AU$200 and I'll probably need another $100 for the pump, timer and circuitry.

I'm estimating that the gas use will be something like 18Kg of gas for the winter months (or about $50 today).

We get to have polished wooden floors that are slightly warm underfoot and that heat the house. Just like the large surface area radiators are not too hot to burn you (unlike smaller bar radiators) the floor heating has an even larger surface area and so keeps the house warm too.

Polished floors are cleaner than carpet (got any pets? Cat hair and carpet ... mmmm my favorite for allergy, oh and do you see carpet in many hospital rooms?) and feel lovely under foot when not cold. So now that we're heating them there is even less reason to cover them up with festy filthy carpet.

Low cost, low energy and effective ... not bad I'd say

why discussion gets nowhere

I often hear in the news and among some segments of the community that we need to have a debate in the community about this or that topic. This seldom happens and when it does all too often becomes nothing more than a yelling match, especially when one or the other side is not "winning" the arguments.

I see that there are some fundamental flaws in the way we go about this and the preparedness of the vast majority of community to actually engage in such a conversation.

I was impressed when I lived in Japan when discussing things with "ordinary workers" that people in that society had an assumption that "I'm an ordinary worker, so I don't know much about that", which was in total contrast to Australia where people are more willing to step up to the plate and say "I think that's wrong" soon to be followed by resistance and defensiveness when you start establishing they are wrong. Yet they often (the Aussies) started out not knowing a bloody thing about the topic.

So if we begin with a debate (rather than asking questions) people take sides and then defend their choice. This is perhaps because debate is a formalized argument which is intended to produce a winner - not explore an issue.

I don't think its helpful for the community to be taking sides and attempting to win the argument, this is simply a form of conflict, and I think we already have enough of that now.

If the community has polarized views on topics then arguing will just lead to entrenching that division. Further there is a growing body of evidence to suggest that "no matter what", people just are unwilling to accept any new facts if it conflicts with their existing viewpoint.

A Professor from Georgia State University, Jason Reifler conducted a series of experiments that looked at whether people changed their views when they were presented with the correct facts. He found that not only did they not, but it reinforced their will to keep a grip on their existing views.

Clearly this has a significant effect on the politics around any public dialog; a quote from an (ABC interview) with him:

JASON REIFLER: When we told people that the United States had not found weapons of mass destruction, conservatives, compared to conservatives that we didn't correct actually believed more strongly that the US had found weapons of mass destruction.

So that by telling them that in fact the US didn't and pointing to a CIA report known as the Duelfer report citizens actually, their response was, well actually now I believe it more strongly.

ELEANOR HALL: So not only did they not believe the facts that you were putting before them; they actually reinforced the incorrect views they originally had.

JASON REIFLER: Exactly.

ELEANOR HALL: What hope is there then for truth in politics?

JASON REIFLER: The downside of the research that my co-author and I have done to date is that it's very depressing. We don't have a terribly good understanding yet of ways to try and improve public debate, to try and improve political dialogue.

So people seem to treat discussion like a footy match; with a winner and a looser at the end of the match and go home still rooting for their team.

as just mentioned people are unwilling to accept that discussion may lead to them being wrong or that they may learn something they didn't know before (which should lead to them changing their point of view).

One of my favorite cartoons recently was a graph, it tries to sum up the ideas above in a nutshell.

Essentially when you have zero knowledge you still have some confidence in your viewpoint being right, the more you begin to learn the more you gain confidence in your views.

Its only after you learn enough that you start to question your views and wonder if they are right. At this point we see the graph starting to fall. Eventually when you know quite a lot you actually have very little confidence that your views are correct.

This is what we commonly call wisdom. The vast majority of the community do not have much wisdom. In fact if asked don't usually value it or do anything to obtain it. They'd rather have a beer and watch the footy.

Recently I was watching the program Catalyst and was left simply stunned at the incredible ignorance people have of the most basic physical facts. I was totally gobsmacked to see that people just didn't grasp that something feels cold because its a good conductor and feels warm because its a good insulator. If we were talking to the most primitive uneducated tribal native they would be no less unaware of these basic facts and perhaps even more aware of them.

I was particularly stunned by the guy in the green jacket, its hard to imagine someone making more wrong conclusions and yet he probably reaches conclusions on issues like global warming. My favorite comment from him was

"Alluminium would be bad for the environment because it was thawing out the ice a lot quicker"

So kiss bye bye to any meaningful climate change community debate when people can't even grasp these dead simple issues.

This ABC video explains a lot

Sadly this video does not embed properly now, so I'll have to direct you to the ABC web page here.

The comment "we're creatives not intellectuals" sums it up to me. Yet the blond girl was the only one who seemed to have have learned from the book and the hard drive that her assumptions may have been wrong. But she was in the minority there...

I was very encouraged how each of these people accepted the outcomes as described by the presenter. All of these people (despite thinking he was lying) eventually seemed to accept he was right. The guy in the green jacket also accepted that he "wasn't a scientist" and also seemed to accept the logic of the demonstration.

All these people would (if asked separately) quite likely identify themselves as being smart, as having meaningful input into discussions on (say) climate change, and quite likely all have gone to high school and maybe some of them on to University. That they don't know much about the ultra basics of the modern world speaks reams about the total failure of our educational system to actually bring people up to speed with the complexity of the modern world.

Yet all these people vote, and its likely all these people will go into a debate feeling their opinion is right and in the context of a debate, most likely be unwilling to listen to the other side.

It will be a win or lose event.

If enough of these people then behave as Jason Reifler observed in his research then I'd say we're fucked. But the above video also seems to show that if the arguments are presented appropriately that people do accept them.

The problem remains however how to deal with people using tools like straw man arguments, syllogism and many other logical tricks to prove their points and convince the less rigorous listener.

So as I say often, with the rights in society come obligations. If you want to be part of the political process then you have an obligation to participate to in that and not just get fooled by the shells game played by many politicians.

buying Australian made in Australia

In the past I was never one to buy Australian made unless it also happened to be what I wanted. Years of living in Finland with my family who are stout "buy local" products combined with my personal views on environment and sustainablity (that would be the three pillars of sustainable development as outlined in the Johannesburg convention of 2002) have led me to feel that I should (unless there is an overwhelming case against it) prefer to purchase as much Australian product as I can, especially food items.

So since returning to Australia I have been trying to do just that (just as we bought Finnish food in Finland).

The problem is that its increasingly difficult to do.

Today while shopping I noticed that my normal brand of Orange Juice has changed from being 100% Australian oranges to
- not mentioning it (and having in the fine print "made from local and imported ingredients") to
- now having an attempted apology printed on the label. The text reads "Due to an orange shortage in Australia ... bla bla"

Well that's strange isn't it, as just a few days ago on the ABC Radio I heard representatives from the Orange growers saying that due to the dollar being so high now it was almost impossible for them to shift their product.

So it seems that there is actually a glut of Orange product on the market in Australia; but these guys are saying there is an orange shortage in Australia?

They can't both be right ... Hmmm ...

I thought I'd link to that particular program here which has a mp3 podcast associated with it for you to download and listen.

So if you would prefer to buy your OJ from our free trade partner across the pacific (who isn't buying ours I bet) then go for it, but mean time I'm really pissed off with Nudie for trying to pull this stunt off. Clearly its aimed at increasing their profit.

Sorry guys but if I wanted to buy cheap OJ I'd buy one of the cheap brands, not pay premium prices for a product which pretends to support our farmers and our economy and gives jobs to Australians.

So the bottom line is : read the labels carefully as there are assholes out there trying to trick you into buying their product.

---

United Nations. (2002). Report of the World Summit on Sustainable Development. New York: United Nations.

solar floor heating - part 3

developments

I've had a time to complete a bit more of my ideas and have a few findings in my Solar Floor heating project which I thought I'd take the time to document and pass on (to anyone who finds this and attempts to replicate my work for their own benefits).

I've completed my next phase of prototype for heat collector. Essentially this is a length of poly pipe wound around onto a wire mesh backing with a sheet of PET plastic to cover it. The first one was just one length of poly pipe (Bunnings sells them in 20 meter lengths) wound around a wire mesh to hold it in a coil and face the sun ...


The version I wanted to complete next takes this concept further by putting more pipe per square meter and adding a covering of clear wind proof insulation material to act as a "glass house" to reduce (eliminate?) losses of gathered heat due to wind convection cooling the pipes (while the sun is heating them).


The collector is about 1 meter by 1 meter and the pipe is wound tightly around with care taken to not kink or fold the pipe which would restrict the water flow.


This collector now contains 60 meters (or $12 worth) of poly pipe and with the PET sheet ($15) is now far more effective at gathering water than my older one (which only had 40 meters of pipe too).

problems (and solutions?)

It seems that this experiment is not without problems which need consideration to find solutions. The first is:
Bubbles
The system works on the principle of least energy required, so moving the water around the system requires that the principles of a siphon are used.

But as my inlet bucket and outlet bucket are the same point (as you can see in the above video) the water will simply remain in the pipe.

That would seem pointless if it wasn't for the fact that 1) my pipe is what is gathering the heat and 2) I have the pump to move it around.

I was finding however that after a week or so the flow would be markedly reduced. Flushing the system (with a more powerful pump called the garden hose) revealed that bubbles were coming out and it was this air in the system which was causing my system to fail.

I am still not entirely certain what the problem is, but I suspect that it is gasses such as chlorine (used in the reticulated water system) coming out of solution in water (as say the temperature changes) and then gathering in a location ...

I am not sure where the bubbles are forming, in my floor circuit or in my heating circuit. As I have also been wondering how to provide alternative heating systems to this (like to heat it at night too) I thought that an elegant solution was to employ a "bus" solution or "common pool" which would mean that:
1) heating siphon was separate from floor
2) heat could be added by a third (separate) circuit which simply heated the water in the common pool.

Just roughly this looks like the figure below where I have my old single circuit on the left and my new multiple circuit system on the right.



This allows me to

1. work out if bubbles are in one side or the other
2. add a night time heating of the water (say by gas or off peak electricity)
3. not waste my heated water by putting it through the solar heating panel (which would just act as heat loss out into the night air and give me no return)

I'll keep you posted on this as I only completed this section yesterday.

Lastly

I thought I'd provide a little more details about the pump. As I mentioned I bought if from Jaycar and it cost $49.95 Its the 7v model which moves about 140L / hour of water (in full sunlight).



I thought that this was a 'good number' (upon experimentation) to start with and the more expensive 12V model (twice the price) moved 200L / hour which I thought may be too fast for heat gathering.

As it turns out I think that the 140 would be too fast, but as it also turns out there is enough resistance pumping the water around that it works out to be about half that in practice.

For reference:

•   Part 1 and
•   Part 2 with some extra details at
•   some measurement here and
•   here about the gas heating of the water in the junction tank and
•   here about windy rainy days observations

this is before I decided to move to more high powered pumps (as a solution to the bubbles issue). While these are are not strictly about solar they are about the other components of this project.

lego humor

Matches and petrol sold separately. Facebook and Twitter accounts not included.

ohfukbutdatzfunnyinnit?

sometimes I miss travel

Alberta Canada is a beautiful place

click for larger view

not much else to say really ...

PS: just for balance living in these places brings with it stuff like this when driving your car.

how to meet carbon targets

stop doing anything industrial in the country and move it all to another country. Import everything and transform our economy to a 'service based economy' where we don't make anything but charge for it.

from there we can cast off with all nasty and dirty jobs (like growing food) and we can all live in...


... a housing bubble (BTW I love that poor lip syncing in that clip there. Unlike our leaders who actually say what the mean, not just what someone tells them to say)

Ok, so after that brief examination of policy detail, can someone tell me again how it is that with WA being among the largest Natural Gas producers on the planet, they can't get to keep enough of that gas to meet domestic needs?

Ahh ... must be helping meeting carbon reduction targets.

stranded on a beach

I heard on the news today that a whale calf had beached itself on the beach opposite Surfers Paradise, and that people were trying to get it back into the water.

My wife toddled down and took these pictures



a video of the rescue team leader describing what they were going to do:







so with the tide coming in the plan seemed to be to dig a ditch up the beach to allow the water to float it off











I'm told that the litle fella was very happy to be returned to water and splashed about for a bit before being led out (herded?) to sea by some people on JetSki's.

Hopefully they find the mother and the calf will be ok

:-)

electric or petrol

why not both?

A common axiom in software development is that if your tool is a hammer then everything starts to look like a nail.

There are people who are "pro" Electric Vehicles and people who are anti EV. Personally I'm a pragmatist and a flexible one at that. I take the position that both nail guns and hammers have their best use still, and that one does not cancel out the other.

A favorite among PRO-EV crowd is that the internal combustion engine is at its end, and that Electric is just starting. This ignores the fact that we have had EV's in society functioning in roles for as long as we have had petrol ones. Clearly this argument is a QED only for the ignorant and very young (and if your older live in the west and remain ignorant well ... that's your fault really).

I don’t think that combustion engines are at a dead end any more than burning gas to heat your water or cook your meal is. Petrol may have a number of nasty disadvantages but it is a very compact energy storage method. We have come to make a large number of assumptions about vehicles and one of the nice things about concept cars is they allow us to remove ourselves from the baggage of conventions and imagine how things could be.

When you examine any of the working and effective electric cars you find at the heart a few assumptions which if applied to petrol engined cars would afford similar efficiency gains. Its just that somehow when you tell people that a petrol car will weigh 300Kg have reduced acceleration, reduced interior comfort and reduced collision protection they go “no way” while being willing to accept it with electric ones.

I submit that a vehicle more like a recumbent trike with some aerodynamics and an efficient fuel injected petrol motor driving electricity generation for battery replenishment would be lighter and sufficiently powerful. It seems to be accepted technology in the diesel electric locomotives we have been using for some dozens of years (nay decades). Such a small motor could be tuned to operate at a static RPM and be exceptionally efficient as well as quiet.

I have no doubt I could make the journey on the highway to work at 80Kmh and have efficiency of the order of 1L/100km and minimal exhaust emissions. Heck, I could probably run it on LPG or other biofuel too

The thing is however we would need to remove the freight and other heavy traffic from the roads as they would make impacts fatal.

Of course we could simply just use bicycles?