Category: Environment

Podcast: How to Planet! – Episode 5

Welcome! Sadly we still don’t have Daniel with us this week, but Nathan is here to bring you some content!

This week we look at how current CO2 emissions compare to those of past warming events, how that could affect marine life, and how a new species of coral could help us out.

We also look at a synthetic cell and why moths are so obsessed with light. Enjoy!

Sources can be found in the video’s description.

Climate Change and Extreme Weather: The Science of Event Attribution

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Image Source: http://www.canadianunderwriter.ca/insurance/extreme-weather-events-can-quickly-change-a-good-year-to-a-bad-one-1003549353/

With extreme weather becoming increasingly frequent, there is one particular question that logically follows – Did climate change cause these events? As recent as a decade ago scientists would have confidently argued that this question cannot be answered, but thanks to rapid improvements in both the understanding of weather systems and the analytical methods used to study them, they are now able to provide some more meaningful responses.

But even with this new knowledge it’s still not possible to answer the exact question above, as the the question itself is flawed. No weather event ever has a single cause, in fact there are multiple, independent factors, most of which are natural. Climate change is but one variable in many, and it’s influence can be quite subtle.

So what can the scientists tell us? Well, according to a report from the National Academies of Science, Engineering, and Medicine (NASEM) released on March 11th, they can now examine how the likelihood and intensity of an event have been altered. And thus, the science of “event attribution” is born!

However, even when scientists are armed with their new understanding and analytical methods, statements and predictions can’t be made without a HUGE amount of data to back it up. This can be obtained in many ways, with some studies using observational data obtained from similar events in the past, and others using climate and weather models to compare conditions in worlds with and without human-caused climate changes. But no one data set is perfect, and the NASEM report states that results are often most reliable when multiple methods are used.

SO! We now have a rough idea of what event attribution is and how this new area of science works. Let’s start looking at what it can do! So far, the most reliable attribution findings that scientists can give us are for those related to temperature. There is little doubt in the scientific community that human activities have had a noticeable impact on this aspect of the climate, and it’s effect on various weather events are already known.

Apart from increasing the likelihood of extremely hot days and doing the opposite for cold days, a warmer climate can have some rather unexpected effects. Such warming can cause greater evaporation of water from the Earth’s surface, which not only increases the intensity of droughts, but also the amount of atmospheric moisture available to storms. This could lead to more severe heavy rainfall and snowfall events, and you can find an explanation of how that would work in another post I’ve written on the formation of snow.

But the implications of event attribution go beyond simply determining the influence of human-caused climate change. By gaining a deeper understanding of what causes extreme weather events, scientists can improve their ability to accurately predict and project future weather and climate states. If they’re able to predict both the frequency and intensity of extreme events, it could help lessen their impact by avoiding the destruction they could cause. For example, an accurate prediction may allow a community to evacuate long before the event even arrives, and knowledge regarding it’s frequency can help them decide between rebuilding or relocating.

It should now be quite clear what the science of event attribution can offer us, but we should also be aware of the challenges that this relatively new science faces. According to the NASEM report statements about event attribution are quite sensitive to the way the questions are framed, as well as their context. Given this sensitivity, many choices need to be made about defining the duration of the event, the geographical area impacted by it, what variables to study and many more. These decisions will likely drastically improve reliability, as they can all influence how results are interpreted.

But despite it’s problems, the science of event attribution has a lot it can offer to society in terms of limiting the impact of extreme weather, as well as drawing people’s attention to the reality of climate change. Real extreme weather events get people’s attention, and attribution studies could bring an end to the notion of climate change as a distant threat, and help people realise that there is a very real need for us to act on it now. Let’s just hope it can do it fast enough.

Sources not mentioned in text:

Podcast: How to Planet! – Episode 4

Welcome! Unfortunately we suffered multiple technical problems this week, so we weren’t able to record the podcast as usual.

But! We still wanted to give you some kind of content, so we give a brief overview of the articles we planned on discussing, and will provide all sources in the description.

This week we look at how the global economy appears to be decoupling from CO2 emissions, and how various countries and regions have reacted to the COP21 Paris agreement.

We also look at an interesting trial proposed in Florida involving genetically modified mosquitoes, and some seemingly simple questions that science is yet to answer. Enjoy!

 

Podcast: How to Planet! – Episode 3

Welcome! In this episode we discuss the concept of a biobased economy, how it could be achieved, and look at some of the industries that would be affected by it.

We also talk about some new gene sequencing technology, potentially the largest solar power plant in North America, and how AlphaGo is defeating humanity. Our funny story is about someone called Brian.

Enjoy!

Podcast: How to Planet! – Episode 1

So I recently got started on a podcast project with a friend of mine focussing on climate change, green energy, sustainability and science of that nature. If all goes to plan this will be a weekly series so keep an eye out for the posts here or subscribe on YouTube if you’re interested.

Episode 1 just went live yesterday, and if you could check it out and leave any feedback it would be greatly appreciated! You can find the link below!

In this episode we discuss climate change, the rising sea levels, and what you can do about it. We also mention an exciting new medical trial going on and look at some more amusing science stories. Hope you enjoy!

Apologies for the unbalanced audio! Lessons were learned and it will be fixed on the next episode 🙂

New Fuel Cell Technology keeps the Environment in mind!

I imagine you’re all pretty familiar with fuel cell technology at this point. It’s been around for quite some time and is often heralded as the answer to green, renewable energy. For the most part that is quite true, as there are a number of advantages that this technology has over current combustion-based options. It not only produces smaller amounts of greenhouse gases, but none of the air pollutants associated with health problems.

That being said, the technology isn’t perfect, with many improvements still to be made. One problem is that a fuel cell’s environmental impact depends greatly on how the fuel is acquired. For example, the by-products of a Hydrogen (H2) fuel cell may only be heat and water, but if electricity from the power grid is used to produced the H2 fuel then CO2 emissions are still too high.

The technology also requires the use of expensive or rare materials. Platinum (Pt) is easily the most commonly used catalyst in current fuel cell technology, and this is a rare metal often costing around 1000 US dollars per ounce. This really hurts the commercial viability of the fuel cell, but research regarding alternative materials is progressing.

While I’m certain these kinks will be worked out eventually, it is still worth considering other options. One such option is the Microbial Fuel Cell (MFC), a bio-electrochemical device that uses respiring microbes to convert an organic fuel into electrical energy. These already have several advantages over conventional fuel cell technology, primarily due to the fact that bacteria are used as the catalyst.

The basic structure of an MFC is shown in Figure 1, and you can see that it closely resembles that of a conventional fuel cell. In fact the method by which it produces electricity is exactly the same, the only differences are the fuel and the catalyst.

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Figure 1: The basic structure of an MFC. Source: http://www.sciencedirect.com/science/article/pii/S1110016815000484

The fuel for an MFC is often an organic molecule that can be used in respiration. In the figure it is shown to be glucose, and you can see that its oxidation yields both electrons and protons. It is worth noting that the species shown as “MED” is a mediator molecule used to transfer the electrons from the bacteria to the anode. Such molecules are no longer necessary, as most MFCs now use electrochemically active bacteria known as “Exoelectrogens”. These bacteria can directly transfer electrons to the anode surface via a specialised protein.

As I mentioned before, this technology has several advantages over conventional fuel cell technology in terms of cost and environmental impact. Not only are bacteria both common and inexpensive when compared to Pt, but some can respire waste molecules from other processes. This not only means that less waste would be sent to a landfill, but would actually be a source of energy. This has already be applied in some waste-water treatment plants, with the MFCs producing a great deal of energy while also removing waste molecules.

Now you’re probably thinking, “Nathan, this is all well and good, but it’s not exactly new technology”. You’d be right there, but some scientists from the Universities of Bristol and West England have made a big improvement. They have designed an MFC that is entirely biodegradable! The research was published in the journal ChemSusChem in July of 2015, and it represents a great improvement in further reducing the environmental impact of these fuel cells.

Many materials were tried and tested during the construction process. Natural rubber was used as the membrane (see Figure 1), the frame of the cell was produced from polylactic acid (PLA) using 3D printing techniques, and the anode was made from Carbon veil with a polyvinyl alcohol (PVA) binder. All of these materials are readily biodegradable with the exception of the Carbon veil, but this is known to be benign to the environment.

The cathode proved to be more difficult, with many materials being tested for conductivity and biodegradability. The authors noted that conductive synthetic latex (CSL) can be an effective cathode material, but lacks the essential biodegradability. While this meant it couldn’t be used in the fuel cell, it was used as a comparison when measuring the conductivity of other materials.

Testing then continued with egg-based and a gelatin-based mixtures being the next candidates. While both of these were conductive, they weren’t nearly good enough to be used. CSL actually performed 5 times better than either of them. But science can not be beaten so easily! Both mixtures were improved by modification with lanolin, a fatty substance found in Sheep wool, which is known to be biodegradable. This caused a drastic increase in performance for both mixtures, with the egg-based one outperforming CSL! This increase easily made it the best choice for the cathode.

With all the materials now decided, it was time to begin construction on the fuel cell. A total of 40 cells were made and arranged in various configurations. These are shown in Figure 2, and each configuration was tested to determine its performance. Of these three, the stack shown in Figure 2C was found to be able to continuously power an LED that was directly connected. It was also connected to some circuitry that harvested and stored the energy produced, and the authors report that the electricity produced by this method could power a range of applications.

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Figure 2: a) A set of 5 fuel cells connected in parallel. Known as a “parallel set”. b) A stack of 4 parallel sets. c) A stack of 8 parallel sets. Source: http://onlinelibrary.wiley.com/wol1/doi/10.1002/cssc.201500431/full

While there is much to celebrate here, the authors also address some of the concerns associated with this technology. The most notable concern is how long the fuel cells can operate, and the authors report that after 5 months of operation the stacks were still producing power. This could potentially be longer in an application, as the operational environment of a fuel cell rarely mimics natural conditions.

They also discuss how these MFCs didn’t perform as well as some produced in other studies, but these were the first to be made from cheap, environmentally friendly materials. If anything, this research shows that such fuel cells can at least be functional, and are an excellent target for further research.

So we’ll have to wait for more research to see if this technology will actually take off, and given the timescale of this study it’s likely that we’ll be waiting quite some time. Even so, this is an important step on the road to completely sustainable living, as it shows that even our power sources could be made from completely environmentally friendly materials. Now we just have to hope people take notice. Let’s make sure they do!

Sources not mentioned in text:

Snowflake Science!

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Example of a possible snowflake shape. Source: http://feelgrafix.com/group/snowflake.html

It honestly feels like Winter never really happened this year. I remember hearing rumours of snow on Christmas day sometime in November, and I must confess I got excited. Even though weather predictions are known to be near impossible if they’re after more than a few days.

But sadly that snow never happened, and in England at least we’ve had to settle with a near constant Autumn. Its true that we still have all of January and February for Winter to actually happen, but I think its unlikely that we’ll see any snow this year.

So since I still needed my snowy fix I decided to learn a bit about the formation of snow and how that knowledge can be of use to us. It may not be actual snow, but it might make your imaginary snow a bit more realistic.

Let’s start with what a snowflake actually is! Its a pretty broad term, with a huge variety of structures qualifying as a snowflake. The only concrete part of the definition is that the structure consist of more than one snow crystal, which is a single crystal of ice. These form in clouds when water vapour condenses into ice, a process which as two specific conditions for occurring.

The first is known as “Supersaturation”, which occurs when the amount of water vapour in the air exceeds the ordinary humidity limit. What does this mean? Well at every available temperature there is a maximum amount of water vapour that can be supported, with a higher temperature allowing for more water vapour.

If we cool a volume of air that’s already at 100% humidity then it now contains more water than is stable, and has become supersaturated. The excess water will then condense out, either into water droplets or directly into ice.

The second condition is “Supercooling”, or rather the lack there of. This is when a substance remains in a liquid state below its freezing point. It is possible for pure water to remain in a liquid state below 0oC, as the thermal motion of the molecules prevents crystallisation. In fact, the temperature has to drop to -42oC before freezing will occur!

On the other hand, tap water will readily freeze at 0oC due to the impurities it contains. These provide a surface for the molecules to cling to, reducing the effects of thermal motion. The scientific term for what these impurities provide is a “nucleation point”, a starting point for crystal growth. This also occurs in clouds when snow crystals form, as the many impurities such as dust and pollen particles provide nucleation points.

So! Now that we know what a snowflake is and the conditions for their formation, we can look at the process of crystal growth. It begins when the water molecules arrange themselves around the nucleation point. There are actually 14 possible lattice structures for ice, but ice 1h (short for “Form 1 Hexagonal”) is the most stable between 0 and 100oC, so its the most common form found in nature. In this arrangement the water molecules bond in a hexagonal lattice structure shown in Figure 1.

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Figure 1: The hexagonal lattice structure of an ice crystal. Red spheres represent Oxygen atoms, and white spheres represent Hydrogen. Source: http://www.thenakedscientists.com/HTML/articles/article/science-of-snowflakes/

The growth then continues as shown in Figure 2, with “rough” areas filling in faster than “smooth” ones. Why do they do this? Well a rough surface is one with multiple binding sites available, as more surface molecules are exposed. This makes it easier for incoming molecules to bind in these locations, and this growth pattern defines the hexagonal shape of the initial crystal.

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Figure 2: Diagram showing how additional water molecules bind as the ice crystal grows. Source: http://www.thenakedscientists.com/HTML/articles/article/science-of-snowflakes/

This crystal continues to grow as atmospheric water binds and becomes incorporated into the structure. However, from here on the growth is not uniform, with the corners growing fastest since they now offer the most exposed surface molecules. This is what causes the six “arms” that extend out from the corners of the central hexagon, and their size and shape will be determined by the ever changing conditions as the snowflake moves through the air.

The final shape of the snowflake will be determined by many factors including temperature, humidity, and how those conditions varied during it’s formation. This makes it extremely unlikely that you’ll ever find two identical snowflakes, as the number of possible combinations and variations is truly staggering.  Its actually made even less likely when you consider that the majority of snowflakes will not be perfectly symmetrical, as different parts of the snowflake can experience different conditions as well.

Now, while this is all very interesting, what is the actual point of studying the complex formation of snowflakes? Given that snowflake formation was successfully simulated by a research team from both Germany and London, it would be nice to know its not all for nothing! Well it turns out that this knowledge, while not having many immediate applications, could be very useful in the future.

Crystals are applied and used in many areas these days. These include semiconductor crystals for electronics, optical crystals for telecommunications, artificial diamonds for machining and grinding, the list goes on. So by studying snowflakes we gain a deeper understanding how crystals form and grow. Knowledge that may help us form new and better types of crystals in the future.

Some more interesting, and perhaps more important, things we can learn are the principles behind self-assembling structures. While us humans usually make things by carving structures out from a block of material, nature often has structures assembling themselves from smaller components. This production method will likely become HUGELY important as the electronics industry constantly moves towards smaller devices.

So now you can see that snowflakes are not only both beautiful and amazingly scientific, but also potential useful to us. Something I must confess I was unaware of before writing this post. Now while all this doesn’t change the fact that IT HASN’T SNOWED YET (this makes me very sad), at least you can madly rant about the science when it does.

Sources not mentioned in text:

An Ocean of Problems

You can be sure, or at least hope, that the many effects of climate change will be addressed this week in Paris, and I’ve got my fingers crossed for some truly meaningful progress to be made. But there is one problem that many people remain startlingly unaware of; the effect that climate change is having on the world’s oceans.

At first glance that might not seem like much of a problem. I mean, what does the ocean do for us? Right? Well it turns out it actually does an awful lot for us humans, and all these services are at risk as the effects of rising temperatures mount up.

The ocean is actually an integral part of the climate system, taking up around 90% of excess energy in the form of heat. It still continues to take up heat to this day, and is an important factor in slowing the atmospheric warming we are so much more concerned about. This heat uptake causes the ocean water column to warm as well, and it is now detectable around the globe to depths greater than 2000m. This not only has a negative effect on ocean ecosystems, but weakens it’s ability to absorb heat in the future.

This is due to the phenomenon known as “Thermohaline Circulation”, meaning the circulation of both heat (thermo) and salt (haline) within the ocean. The mixing occurs due to differences in density, which is determined by both the temperature and salinity of the sea water. The colder and more saline the water, the greater the density. This means that colder water will sink, and will rise again as it travels the worlds ocean currents and warms.

What the increasing temperature of the oceans means is that, due to the fact that a certain volume of water can only absorb so much heat, any excess heat will be taken up by the less dense water being mixed downwards, causing the lower, colder areas of the ocean to warm. This will cause warming throughout the entire water column and the Thermohaline Circulation will become stabilised, as the increasing temperatures mean that density differences will be reduced.

This means that the mixing process will be slowed, maybe even stopped altogether if the warming continues, and the transportation of heat energy around the ocean will become much less efficient. This would make the ocean much less capable of absorbing heat from the atmosphere, as there would be fewer areas of water that are cold enough to absorb a meaningful amount. So where would that heat go now? Well… nowhere. It would remain the atmosphere above the ocean, and its warming would proceed at a much faster rate due to the loss of this regulatory system.

But ocean circulation would not be the only thing affected by the ocean warming. The intensity and frequency of extreme weather would also change, as well as the extent of the areas affected by them. Cyclones and extreme weather events pick up a lot of energy from the ocean in the form of heat. The air above the ocean’s surface contains a great deal of water vapour, and as this air rises and the vapour condenses, the heat absorbed during evaporation is released into the surrounding air. This causes an expansion of the air and a decrease in pressure, which then facilitates the rising of more air from the ocean’s surface. This process feeds more energy into the cyclone or weather system, increasing it’s intensity.

A warming ocean not only increases the amount of heat energy available to these weather events, but since the warming is occurring across the globe the energy exchange can occur over a much larger area. This means that previously unaffected areas of the world may have to rapidly adapted to dealing with these storms, and a poleward shift in the zones of maximum intensity has already been observed.

I hope you’re now thinking “Wow, this could actually really fuck things up”. Well there is more bad news to come my friends, as the ocean is not only getting warmer, it also is getting more acidic. The oceans also does us the service of removing some of our CO2 emissions from the atmosphere, and has absorbed around 28% of human-produced CO2 since the start of the industrial revolution. Doesn’t sound like much? Well it’s equal to approximately 150 billion tons of the stuff.

The trend in ocean acidification is now 30 times greater then the natural variation thanks to us, and the average surface ocean pH has dropped by 0.1 unit, which is a significant increase in acidity. While the large scale effects of acidification remain unknown, it is already clear that it is affecting marine wildlife.

Certain organisms rely on Calcium Carbonate (CaCO3) to form their skeletons or shells, and it is known that CaCO3 formation is disrupted if the environment is too acidic. This can also have indirect effects on other organisms, as some CaCO3 reliant structures, such as coral reefs, provide homes for many other forms of marine life.

It is also known to be slowing the release of sulphur from the ocean and into the atmosphere. This will directly increase the amount of atmospheric warming, as gaseous sulphur contributes to the reflection of solar radiation back into space.

But it has to end there, right?! There can’t possibly be more problems. Did you even read the title? There are many more. The last issue we’ll be discussing affects us more directly, as it has to do with our food supply. Fisheries currently generate $195 billion for the US every year, and fish is a key food source for many people worldwide. Fishing stocks have usually been quite predictable and reliable, as certain populations tend to stay in certain areas. But fish populations are beginning to move, flourish, or whither, depending on the species, due to the many effects we have already discussed.

It is estimated that around 70% of fish species are shifting their ranges, according to a major survey lead by ecologist Malin Pinsky of Rutgers University. This makes fish stocks much less predictable, and it can have surprising economic and political implications.

Over the past decade, huge amounts of Mackerel began appearing of the coast of Iceland, indicating that the populations were moving further north. Iceland took advantage of this during a financial crisis in 2009, and increased the amount of Mackerel they were catching. This was not taken well by competing fleets in the EU and Norway, who had rights to the majority of the catch, claiming that Iceland’s increased Mackerel haul was affecting their own stocks.

This prompted quite a fierce debate on the science of monitoring fish populations. Parties disagreed on the size of the whole population, whether competing fleets were even catching from the same population, and even what waters should be included in the Mackerel’s range.

Luckily, it would appear that this “Mackerel War” has come to a close, with new fishing quotas being agreed on by all parties involved. But it remains a very real example of how the changing environment of the ocean can affect the world of us landlubbers.

I hope that by now you have a good idea of the problems the ocean is facing, but I’d like to point out that there is much I didn’t mention to make this post a reasonable length. Given the prominent role of the ocean in the climate system I’m surprised we haven’t heard about this in the past, and I encourage you to go and find out more. Our ignorance of what’s going on in the ocean is what allowed things to get this bad, and once we’ve educated ourselves we need to start setting up efforts to better understand and counteract these problems.

Let’s hope this at least gets mentioned in Paris, and that someone there decides that enough is enough.

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The Flowers of the Future!

What do I mean by flowers of the future? I mean cyberplants! Researchers working at Linköping University in Sweden have found a way to create a rose plant with electronic circuitry running through its tissue, and the effects and implications are very interesting indeed.

Now the idea of cyberplants is not entirely new, as some research by Michael Strano at the Massachusetts Institute of Technology revealed that spinach chloroplasts can incorporate carbon nanotubes (CNTs) into their structure. The report stated that this boosted the rate of photosynthesis, as the CNTs could absorb wavelengths of light that the chloroplasts could not. So if this has been done before, what makes this new discovery special?

Well, this research is the first example of someone incorporating a working electronic circuit into a plant’s anatomy. This was done with a polymer known as PEDOT, or Poly(3,4-ethylenedioxythiophene) if you’re one of our chem nerds, and the structure can be seen below. This material is an excellent conductor when hydrated and is commonly used in printable electronics, making it an excellent contender for the cyberplant project.

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The repeating unit structure of PEDOT. Source: https://en.wikipedia.org/wiki/Poly(3,4-ethylenedioxythiophene)

The researchers tested many materials before they made their choice, but none of them were ideal. Some caused the plant to produce toxic compounds, essentially poisoning it, while others clogged the plant’s water transportation systems. They eventually settled on PEDOT, which didn’t cause any noticeable problems, and found a way to incorporate it into the plant’s stem and leaves. They created the world’s first cyber-rose!

This was done by soaking each component in separate PEDOT solutions, and then manipulating them in some way to cause the polymer to migrate into the plant tissue.

In the case of the stem, natural capillary action pulled the polymer out of solution and into the plant’s vascular tissue. The natural structure of the stem then allowed the polymer to self-assemble into wires up to 10 cm long! The conductivity of these structures was then measured using two gold (Au) probes, and the performance was found to be on par with conventional printed PEDOT circuits according to Magnuo Breggren, one of the team members.

The leaves proved to be more tricky. They were first placed in a mixed solution of PEDOT and cellulose nanofibres, then a vacuum was applied. This caused all the air in the leaf tissue to be expelled, and the PEDOT then moved out of the solution and into the empty space the air left behind. This gave the leaves a very interesting property, causing the colour to shift between blueish and greenish hues when a voltage was applied.

Now, while this all seems very interesting, some scientists have questioned what the practical implications of this research could be. “It seems cool, but I am not exactly sure what the implication is” says Zhenan Bao, who works with organic electronics at Stanford University in California.

But Breggren suggests that these electronics could provide an alternative to genetic engineering for monitoring and regulating plant behaviour. While the genetic modification of plants is safe and extremely easy, certain traits, such as flowering times, might be too disruptive to an ecosystem if there is a permanent change. Especially if those changes get passed on to other plants in the area. But electronic switches would not have this risk, and could be easily reversed when needed.

However, if this research progresses to practical applications, the team would have to show that the polymers they use are not harmful to the environment in any way, and in the case of food crops, that the material doesn’t end up in any edible portions of the plant. But this may not be a problem in the future, as the team hopes to make use of biological chemicals to create the circuitry, bypassing any potential environmental and health hazards.

Given the success of their initial study, the team is now collaborating with biologists to develop their research further, and investigating any new directions it could go in. For example, Breggren is apparently investigating whether these PEDOT devices could be used to develop a system to allow the plant to act as a living fuel cell, a project he has rather amusingly named “flower power”.

Regardless of how well this research pans out in the future, it does have the value of being inherently interesting, a trait that drives a great deal of scientific research. But what really interests me, as is this case with a lot of the stuff I write about, is that this is yet another step close to the world of science fiction. We’re getting closer people! All we have to do is wait.

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