Solar Impulse, Continuing World-Spanning Trip, Attempts To Cross The Pacific 40
The BBC reports that Solar Impulse has resumed its 'round-the-world attempt, having taken off today from Nagoya, Japan for what is intended to be a 120-hour voyage to Hawaii. [If pilot Andre Borschberg] succeeds, it will be the longest-duration solo flight in aviation history, as well as the furthest distance flown by a craft that is powered only by the Sun. The Pacific crossing is the eighth leg of Solar Impulse's journey around the world.
But this stage has proven to be the most difficult, and has been hit by weeks of delays." The circumnavigation attempt began earlier this year.
It also is the most widely promoted flight... (Score:1)
a bright future (Score:1, Funny)
this is great because it makes it very clear that it's entirely possible to replace our environmentally destructive planes with solar planes. it wont be a simple fix and but it's possible. though naturally it wont happen until it's either mandated by law or becomes more economical.
Re:a bright future (Score:4, Informative)
There's a pretty big difference between a solo flight in an ulta-lightweight solar-powered plane. Note that they've had to wait for months for a clear weather window, and you're claiming that it's now possible to use commercial solar-powered planes? It's sort of like claiming that because we put a man on the moon, we're now ready to build a tourist resort there.
though naturally it wont happen until it's either mandated by law
You can't pass a law of physics through legislation. This is cool and all, but don't mistake a this for any sort of substitution for current aviation tech. It's not, and won't be anytime in the near future. We need to focus our efforts on places where it IS feasible to reduce or replace our use of fossil fuels in the relatively near term. Power plants. Cars. Stuff like that. There are many people who are investigating more sustainable aviation fuels, but for the foreseeable future, these are still going to be carbon-based.
I hate sounding like a naysayer, but you need to be a bit realistic about these sorts of things.
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Oops... first sentence is supposed to end with "and a commercial flight filled with cargo and hundreds of passengers."
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There's a pretty big difference between a solo flight in an ulta-lightweight solar-powered plane and a commercial flight filled with cargo and hundreds of passengers. Note that they've had to wait for months for a clear weather window, and you're claiming that it's now possible to use commercial solar-powered planes?
by changing my claim, you have used the strawman fallacy [youtube.com]. i made no claim that this ultra-lightweight solar-powered plane could be used for a commercial flight filled with cargo and hundreds of passengers, only that the underlying technology made it possible.
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i made no claim that this ultra-lightweight solar-powered plane could be used for a commercial flight filled with cargo and hundreds of passengers,
You did indeed make that claim:
it's entirely possible to replace our environmentally destructive planes with solar planes
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i made no claim that this ultra-lightweight solar-powered plane could be used for a commercial flight filled with cargo and hundreds of passengers,
You did indeed make that claim:
it's entirely possible to replace our environmentally destructive planes with solar planes
you have inappropriately conflated the idea of a solar plane with that particular solar plane's design.
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Re:a bright future (Score:4, Interesting)
As a manned aircraft it's a pure novelty; but its performance is increasingly close to 'like a small satellite; but closer to the ground and requires only a large strip of pavement for launch and recovery', which could definitely find some takers.
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It's pretty profoundly useless as a replacement for a commercial airliner or cargo plane(basically the wingspan of a 747; but transports a single pilot at a painfully tedious 50-100km/h);
you have inappropriately conflated the idea of a solar plane with that particular solar plane's design.
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That particular plane is designed the way it is not because they thought it looked cool, but because the realities of solar power require it. All the methods of harvesting solar power are heavy and bulky per kilowatt compared to something like aviation fuel. That means you need to have a plane that is slow (for energy efficient flight), very large (lots of area for solar panels and big wings for slow flight), and has a small cargo capacity for its size.
Even with improvements in solar panel design, the amo
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The best design for a solar plane with the capabilities of current planes might well be a regular solar farm powering a conventional fuel synthesis plant.
This. As one example, researchers are investigating ways to use sunlight, water, and carbon dioxide in the air itself to synthesize kerosene [sciencedaily.com]. If we can manage to do that on an economically viable scale (which would mean building these plants on a massive scale), it would make a serious dent in curbing our fossil fuel appetite.
You simply can't beat the efficiency of hydrocarbon fuels in terms of released energy for a given weight and volume (as fuzzy gives us some hard numbers below), and that's crucially
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The exciting thing about solar aircraft(aside from it being cool that they are possible) is that, if you can get efficiency high enough, they are basically your only option for long-to-indefinite loiter. In-air refuelling cos
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I knew a guy in grad school who was working on synthesizing oil and hydrocarbon fuels by microwaving manure. You didn't want to warm up your lunch in his lab.
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Improvements are likely, with better solar panels, better batteries, or both; but you don't beat the fact that optimal insolation is 1366w/m^2; and real world values typically lower, at least on average. A liter of Jet A is 35.3 MJ, so ~9880watt/h. Even at peak insolation, a square meter of solar collection takes a little
Re:a bright future (Score:5, Informative)
Once again : Not, it's not possible.
Here's a comment I posted 5 years ago : http://science.slashdot.org/co... [slashdot.org]
The laws of thermodynamics haven't changed much since.
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Once again : Not, it's not possible.
Here's a comment I posted 5 years ago : http://science.slashdot.org/co... [slashdot.org]
...
Conclusion : The orders of magnitude just don't match, even with 100% efficiency => Commercial flights as we know them & photovoltaics are incompatible.
by adding "[c]ommercial flights as we know them" you have used the black and white fallacy [youtube.com]. solar airplanes could be different in many ways but that doesn't mean they suddenly aren't functional airplanes.
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Let's say that a solar plane is white, and a commercial airplane is black.
I bet that your "functional airplane" is still very much dark gray : you still need a pilot, copilot, food, toilets, a few luggage and minimum space for feet and belly.
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Let's say that a solar plane is white, and a commercial airplane is black.
I bet that your "functional airplane" is still very much dark gray : you still need a pilot, copilot, food, toilets, a few luggage and minimum space for feet and belly.
perhaps you should watch the video i linked because it doesn't seem you understand what i have written. in any case, a solar plane only needs to be solar powered. there is nothing specifying its shape, size, battery capacity or even propulsion system.
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Except laws of thermodynamics, that is.
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Except laws of thermodynamics, that is.
my point does not conflict with the law of thermodynamics. either cite a conflict or concede.
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The burden of proof is on you.
I showed that typical airplanes would need 500m2 of pv panels per passenger in order to fly, even with a perfect propulsion system and maximum solar irradiance.
You need to describe a functional airplane that somehow needs about 10 or 100 times less pv panels to fly.
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The burden of proof is on you.
Don't argue with people who can't do math or know basic science at a secondary level and they eventually go away
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I tend to agree. But it took me a long time to realize just how much energy is contained in one litre of oil. Before that, I also thought that everything was possible for transport.
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You don't seem to understand what you have written.
You claimed that this prototype aircraft "makes it very clear that it's entirely possible" to replace fossil fueled aircraft with solar powered aircraft. The only thing that Solar Impulse has made clear is that a solar powered aircraft can be flown; there is nothing to indicate that a solar powered aircraft of any design or any efficiency can possibly replace fossil fueled aircraft as you claimed.
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Not "commercial flights as we know them", just "commercial flights, period". Commercial aviation only exists because it exists as it does. You mandate solar power, and now you've mandated aircraft that are no faster than wheeled vehicles. Transportation would shift back to those vastly cheaper wheeled vehicles, and commercial aviation would all but go away.
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The laws of thermodynamics haven't changed much since.
Stupid do nothing congress.
Dear Slashdot Management (Score:5, Insightful)
Please return the user interface to how it was. You are just pissing the long term userbase off.
Pulling out the read more link is like pulling the start button / menu from windows 8. It is a user interface disaster because it's not obvious w\
here you should click for the comments.
Slashdot has always been about the comments, if you minimise them by obfuscating the link to them you are left with the news stories from reddit \
a couple of days late and some obvious paid advertising plants.
Implementing aspects of the failed beta interface piecemeal with no discussion seems a bit underhanded.
If you aren't lucky you might succeed at killing slashdot which would be a shame.
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I'm loving the irony of you letting people know where the link is to the comments inside the comments section.
The AC braintrust has done well.
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It's the lack of communication that really upsets people. At least discuss your plans for the site, and explain your decisions.
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True, except for some of the Apollo guys.
Moon Toilet [theatlantic.com]