Posts Tagged‘heat’

Goodyear BH03 Thermoelectric Tires are Total Wank.

There’s nothing like a healthy dose of snakeoil to remind you that some ideas, whilst sounding amazing in theory, are just not worth pursuing. In this age of 3D renders and photoshop it doesn’t take long for an idea to make its way into what looks like a plausible reality and the unfortunate truth of the Internet holding novelty above all else means such ideas can permeate quickly before they’re given the initial sanity check. Worst still is when well established companies engage in this behaviour, ostensibly to bolster their market presence in one way or another with an idea that may only have a passing relationship with reality. In that vein I present to you the Goodyear BH03, a concept idea that will simply never work:

Sounds cool right? Your tyres can help charge the battery of your shiny new electric car by using the heat it generates from the road and even from the sun when it’s parked outside! Indeed it sounds like such a great idea it makes you wonder why it’s taken so long for someone to think of it as even regular cars to could do with a little extra juice in the battery, potentially avoiding those embarrassing calls to the NRMA to get a jumpstart.

Of course the real reason as to why it hasn’t been done before is because it simply won’t do what they say it will.

You see translating heat into electricity is a notoriously inefficient exercise. Even RTGs, the things that we use to power our deep space craft like Voyager, can only achieve a conversion rate of some 10% of the total heat emitted. That means that kilowatts of heat generated by a red hot lump of decaying plutonium end up being maybe a hundred or so watts of usable electricity. Compare that to the surface area of a tyre, which is at most a square meter, receiving approximately 1KW worth of sun energy under ideal conditions, and you can maybe get 400W under perfect conditions with ideal conversion rates with all 4 tyres.

If you say the tyres spend about 8 hours a day under those conditions (again incredibly ideal) and you’ll get a grand total of 3.2KW into the batteries which, if we use a Tesla as an example, would give you about 15kms worth of range. If you want a more realistic figure with say only half the tyre exposed and the ideal duration much smaller then you’re looking at cutting that figure to less than half. It’s the same problem with putting solar panels on the roof of electric cars, they’re simply not going to be worth the investment because the power they generate will, unfortunately, be minimal.

Still they look cool, I guess.

Our Moon is a Softy at Heart.

The moon is a barren and desolate place. The face which every human on Earth has stared at for centuries was shaped long ago by the innumerable impacts that peppered its surface. This is in stark contrast to say the surface of planets (or even some other moons) whose surfaces have been shaped through volcanic or tectonic means. This lack of surface activity is what led us to believe that the Moon was dead, a solid ball of rock that solidified many billions of years ago. However recent studies have shown that the Moon might not be as dead as we first thought with its center being not unlike that of our own Earth.

Moon LandscapeData from the Selenological and Engineering Explorer (SELENE or Kaguya as it’s known to JAXA), as well as information gleaned from other missions, was used to model the Moon’s interior at different levels. We’ve known the rough structure of the Moon’s interior for some time now, ever since the astronauts on the Apollo missions deployed seismometers, however we never had much insight into the viscosity of those layers or whether or not the core was molten. This research shows that the mantle actually has 2 sections, the upper layer with a high viscosity and a lower layer that’s low viscosity. This would then suggest that there’s a source of heat in the Moon’s core that’s causing the lower mantle to become more liquid, indicating that the Moon’s core is likely molten.

Since the Moon is much smaller than Earth the processes that keep our core molten aren’t likely to have as much of an effect which is why it was long thought to be dead. However it appears that tidal forces, the same things that responsible for warping and shaping the moons around other planets, is what is responsible for causing the heating in the Moon’s core. In all honesty I didn’t think Earth would have the mass required to exert a strong enough tidal force to do that, we’re not exactly sitting on a gas giant, however it appears that Earth has sufficient mass to accomplish this.

Whilst this won’t be fueling the next revolution in space exploration it does open up some interesting possibilities for future expeditions to our celestial sister. Having some kind of temperature gradient opens up the possibilities of using that heat for useful work on the Moon’s surface from things like power generation to good old fashioned heating. Of course the challenge of drilling a couple kilometers into the lunar surface in order to do this is an exercise I’ll have to leave up to the reader but it’s at least an option instead of a science fiction fantasy now.

 

A Rather Novel Way Of Starting A Fire.

If you trace back along the path of human evolution (the homo genus to be more specific) there’s a period where our species started to undergo rapid changes. The actual time varies wildly depending on the sources you read but the cause isn’t: it was when we learnt to control fire. Fire enabled our ancestors to do many things that simply weren’t possible before like cooking food (which provides easier access to calories and nutrition), doing activities at night as well as during the day and even protecting themselves from animals and insects. Indeed the species were are today, one that is well adapted for cooked food, is because of our beginnings as masters of fire.

I’m also somewhat fascinated with the creation of fire, possibly from a purely primal level, but also because there’s numerous different ways to do it and each of them exploit a physical principle. One of the most interesting ones I saw recently was someone using a hammer to light a cigarette:

At the highest level what is being done here is that kinetic energy, from the hammer falling on the piece of metal, is being translated into heat. This is accomplished by the bending and warping of the metal that occurs when its struck by the hammer which breaks down the bonds between the metal atoms causing them to release heat. The second part of the trick here is that they then utilize a highly flammable tinder, I.E. the cigarette, which has a flash point below that of the temperature of the metal. Drawing air over it provides more oxygen and with that you have all the ingredients you need for fire.

Of course it’s not the most practical way of creating fire given the materials required to do it. You’re much better off with a flint and steel as they produce sparks with temperatures that far exceed that of hammered metal. That is of course if you don’t have any matches, cigarette lighters or any number of modern fire making devices handy but for pure reliability you really can’t go past a good old fashioned piece of flint and steel.