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Fuel Free Spacecrafts Using Graphene
William Robinson writes: While using a laser to cut a sponge made of crumpled sheets of Graphene oxide, researchers accidentally discovered that it can turn light into motion. As the laser cut into the material, it mysteriously propelled forward. Baffled, researchers investigated further. The Graphene material was put in a vacuum and again shot with a laser. Incredibly, the laser still pushed the sponge forward, and by as much as 40 centimeters. Researchers even got the Graphene to move by focusing ordinary sunlight on it with a lens. Though scientists are not sure why this happens, they are excited with new possibilities such as light propelled spacecraft that does not need fuel.
So they'd need to carry hydrogen and split off its electrons or something to neutralize the charge.
(T>t && O(n)--) == sqrt(666)
Where the heck those extra electrons came from? Absorbing photon momentum (more efficient solar sail) sounds feasible, but "accumulating electrons" from nowhere and then emitting them in one direction (where light came from) ... less so.
Paul B.
All great discoveries can be summed up with three simple letters... WTF
Lets test your hypothesis by creating a slashdot poll.
Mod me down, my New Earth Global Warmingist friends!
If only there was a giant source of light in the galaxy constantly releasing more energy then we ever could hope to use that we could harness...
Look, if I can't be pedantic on /., where am I supposed to go?
Having read the article, they've already ruled material vaporization out.
Clearly it collects the electrons from the hydrogen particles in the interstellar gas. Of course, the now-charged hydrogen gas follows it around until it gains critical mass and... FOOM! New sun!
"The most exciting phrase to hear in science, the one that heralds new discoveries, is not Eureka! (I found it!) but rather, 'hmm... that's funny...'" - Isaac Asimov
Usually followed shortly thereafter by "I wonder: was that just a random event or will it do that a second time...."
..."
Sometimes followed by: "... Dialing 911
Visit CryptoGnome in his home.
Well, CRT face is (weakly) grounded, so e- kinetic energy can excite atom for subsequent photon emission, but its charge will happily leak into the ground.
There is no "ground" anywhere next to flying spacecraft!
Actually, on reading the preprint, yes, electrons come from under the Fermi level, get lost in the process and graphene foam (or, spacecraft carrying it) *will* become charged -- it was pointed out in the article as well, but I did miss it on quick read.
AC below actually paints a rather dramatic picture of what can happen next! :)
Paul B.
A quick search on converting photons to electrons turned this up:
http://cleantechnica.com/2013/...
A new discovery by researchers at the ICFO has revealed that graphene is even more efficient at converting light into electricity than previously known. Graphene is capable of converting a single photon of light into multiple electrons able to drive electric current.
So that could be where the extra electrons are coming from.
Better known as 318230.
Existing ion thrusters already use ionized Xenon for propulsion, so it's definitely a possibility (charge the graphene using this technique, ionize the Xenon and use that to neutralize the graphene, use the Xenon as ion thruster fuel). However, electrons are very nearly massless, so unless they're somehow exciting them with massive amounts of energy, the propulsion from the electrons is unlikely to be significant.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
Actually, just what I was thinking (today nobody remembers Crookes (I named a cat after him)). Key bit of missing information in the article - how good a vacuum? Really matters. And just measuring a hard vacuum as made fools out of a lot of people.
There are other possibilities - our country paid people to publish false and misleading papers (no - they have not been retracted) . This doesn't even become news IMO until it is published and replicated.
The amount of technology that has been 'borrowed' by the Chinese is mind boggling - unprecedented. Yet it takes a particular kind of culture to understand the technology in a way that lets them synthesize further progress. A lot of the papers I see coming out of China are just 'cargo cult science' - looks like science - but it isn't. It takes a particular set of values - held dear and close to the heart - to do real science.
The grant proposal industry has diluted the quality of papers so that a very small minority represent real science. I would think of this as likely just bad science once again.
Not any ordinary Xenon, but 136Xe.
In the various Ion Engines designed, built, and occasionally functioning, 136 Xe is the propulsive gas of choice, and pretty much all of the (Unclassified) Literature on the Subject refer only to it.
Under Plasma conditions, Xenon is anything but inert, and there is at least one (Relatively) stable 136xe-3He compound that is only chemically stable when Ionized.
This is also true with certain Helium Hydrides, but for Propulsion purposes, one needs as much Nuclear Mass that is easily Ionized to High Charge States as possible.
They wouldn't let us play with Radon.
Furthermore, their ability to second-guess the credentialed experts is improved exponentially by posting AC.
Do you ever get the paranoid feeling that someone is occasionally modifying the laws of physics in order to advance the plot?
"Oh look, they're going to be stuck on Earth for an excruciatingly long time due to the exponential-propellent-scaling problem. Let's add a new capability to graphene that will give them a work-around for that."
I claim that two years ago the exact same graphene experiment would have shown no unexpected results; but now in 2015 we see this suspiciously useful behavior appear. I'm not sure how to test my hypothesis though :)
I don't care if it's 90,000 hectares. That lake was not my doing.
I wonder if they've weighed the sponges. One possibility is that the sponges are deteriorating in a particular direction, thus engaging in conventional "stuff out one end makes you go the other way" propulsion. And also becoming traditional "will get used up" style fuel in the process. :)
Though it'd be all kinds of awesome if it was creating coherent motion out of energy delivered by photons without wearing out. Now *that* could be a space drive.
I've fallen off your lawn, and I can't get up.
The key point with ion drives is they don't eject charged particles. They strip the electrons from Xe, accelerate it towards a grid anode (essentially this is a lot like a CRT) and then the electrons hook back up with the Xe ions on the way out, neutralizing them. So you end up with a high speed stream of neutral atoms, not ions. The spacecraft never develops an overall charge.
And lest anyone be fooled, electric charges are VERY powerful, you would generate a negligible amount of delta V before your spacecraft's propulsion system completely stopped working. Nor does any fancy juggling act change that, if you lose negative charges you've got a huge problem.
"Malo periculosam, libertatem quam quietam servitutem." -- Jefferson
> technology should be indistinguishable from magic
That would be Clarke, Arthur C.
You don't really have to have much knowledge about anything to second guess experts in any field. Just hold to the rule that "all amazing results are caused by inaccurate measurement, poor sampling, cognitive leaps or coincidence" and you'll be right 70% of the time.
The actual breakthroughs will be so old hat by the time they have been tested properly that nobody will talk about them and you'll never eat crow.
Remember, cynicism and wisdom lead to the same result most of the time, only wisdom is so much harder to learn.
When Argumentum ad Hominem falls short, try Argumentum ad Matrem
Article says they tested for that, and the tests show that the material is not losing atoms. It seems (according to further tests) that the graphene sponge is absorbing energy from the directed light (they repeated the experiment with sunlight and a traditional lens, with similar results) and finally reaches some sort of critical mass, and sheds electrons in a stream, rather than in random directions, resulting in thrust. If this whole hypothesis pans out, the difficulty in making a space craft that makes use of this phenomenon is that it would eventually build up a large positive charge, which would eventually damage the craft, if it can't be dealt with.
I've decided to Diversify my Holdings. I've divided my cash between my left and right pockets, instead of all in one.
Welp, I've got a laser pointer and a table, you find us some graphene sponge and a vacuum chamber, and we'll test it. Which is the whole point of this. Its literally:
"Hey scientists of the world, we pointed a laser at some graphene, and something weird happened. Here's what we did, will you give it a go and see if we're tripping balls, or have discovered something awesome?"
I've decided to Diversify my Holdings. I've divided my cash between my left and right pockets, instead of all in one.
I'm no physicist, but I'm pretty darn sure a spaceship's gotta move a whole lot further tan 40 cm to get anywhere.
File under 'M' for 'Manic ranting'
Of course this means that you need to have a fuel source but it's likely to be far more efficient than current rocket fuel plus there it no need for it to be something explosive like hydrogen
I'm assuming we're referring to space propulsion not launch since the former requires very high thrustand so the efficient techniques don't generally work. Given that, Hydrogen isn't explosive: it requires oxygen for that and there's none of that in space. A tank full of liquid hydrogen in space is pretty inert as these things go.
SJW n. One who posts facts.
No, it's not pseudoscience.
If a researcher perfoms an experiment and gets a very strange, unexpected result, what should he do? Say "that result is clearly impossible, so I shall just disregard it"?
No, he will try to repeat the experiment, gather data, and try to figure out what's going on. Maybe (most likely) there's a perfectly valid explanation within existing scientific frameworks, maybe it's a setup or measurement error, or maybe, just maybe, this is a new effect that hadn't been discovered yet. So the scientist tries to figure that out, and tells others about the experiments so they can try the same thing and see if they get similar results.
That's how science works.
I'm sure you would have called the theory of relativity "pseudoscience" back in the day of Newtonian physics. New things do get discovered sometimes. As long as it's being researched using scientific methods, that's science and not pseudoscience. Yes, they probably will be wrong. That doesn't mean it's not science.