Subject: We-ell...
Author:
Posted on: 2016-11-23 09:36:00 UTC
... at 100W (low-end for an RTG), it looks like an EM drive could push a six-tonne Apollo command module at, uh... 15 nanometers per second squared. That works out to just about 0.5 meters per year squared. We, um, might need a few of them. ^_^
hS
Paper: here
Layman's terms article: here (among others)
So: this is the EM drive. It's basically a copper cone you fire microwaves into, and it generates thrust, around ten times what you can get from a solar sail. In order to do that, it has to break a couple of laws of physics - like Newton's third law.
When first announced, it was widely assumed to be a hoax, but now a NASA team operating out of Houston say they've replicated the result, and that the thrust produced doesn't seem to come from any of the usual sources.
Their hypothesis for how it works involves overturning the Copenhagen Interpretation of quantum mechanics - in other words, goodbye Schrodinger's Cat. The alternative is Pilot Wave Theory, which (very simply) says that particles have actual locations, but are carried along by undetectable waves. It's quite an appealing theory - it perfectly replicates the standard experiments, like the double slit experiment - but hasn't really been taken up before.
I'm having difficulty understanding how pilot waves lead to EM drive; it looks like NASA are suggesting the 'waves' act on the quantum vacuum - meaning that 'vacuum' has an energy all of its own, and isn't properly 'empty' - meaning the drive moves one way, the waves propagate the other, and momentum is preserved. Not really sure, like I said, but they insist it works, and works exactly the same in vacuum and atmosphere, to boot.
Let me be clear: if the EM drive does work, it's simultaneously a reactionless drive (no exhaust), a torch-drive (can be run continuously, making it perfect for least-time courses across space), and a stardrive (it can take you up to appreciable fractions of lightspeed with no input other than electricity). It would fundamentally alter our relationship with space, and (not incidentally) render about half of science fiction as laughably obsolete as Asimov's slide-rules.
I don't think it's real. I know, it's NASA, but this would overturn too much too quickly and too simply. I think they'll find some obvious explanation, just like the superluminal neutrinos a few years back. It will suck, but I expect it.
But I'm not going to make Randall's Wager. I'm going to be an optimist; I'm going to bet you guys the opposite. Here we go:
At some point in the near future, someone (NASA? China? The inventor?) will put an EM drive in space. I bet anyone who chooses to take me up on it that the drive will generate thrust in orbit, and that it will not be shown to do so in a manner we already knew about. If I'm wrong (ie, if the EM drive doesn't work in space), I will give anyone who takes the bet either a short (less than 500 word) story or a picture of their choice. If you take the bet, then you need to say what you're wagering if you're wrong and it does work.
Any takers?
hS
(You can also jump in on my side of the bet. I think that means that everyone on the losing side has to give their wager to everyone on the winning side.)
Lessee... if you're right, and the EM drive works, I'll post a recording of me singing/reading a Tolkien song/poem of your choice--even the Lay of Leithian!--and if I'm right (I hope I'm not, honestly), and the drive doesn't work, I'd like you to draw me a picture of that OC I never stop talking about, Amy. Deal? ^_^
-Alleb
Hilarious as it would be to have you read the entire Lay, I'll think of something slightly shorter. ;)
hS
Specifically, this version by the Tolkien Ensemble (have you heard of them? They are awesome).
Actually, now that I think about it, it's probably in your best interests for me not to sing the Lay. The highest notes are juuuust out of my range, so it results in a lot of screeching. I said I'd sing, I didn't say I'd be good at it.
Speaking of the Tolkien Ensemble, though, they've set practically--in fact, possibly all--of the poems in LotR to very nice music, so whatever you pick, you've got a singing option too. Your preference!
-Alleb
Did you know the artwork was done by the Queen of Denmark? And that they have Christopher Lee singing as Treebeard? They're pretty awesome, is what I'm saying.
hS
I think I'd heard that once, but I definitely didn't internalize it. Awesome! I like this lady. She's a good 'un.
I think he also does one of their versions of the Ring Verse--my favorite version, obviously. That man was awesome. Wait, and doesn't he also do one of Treebeard's songs? I think he does.
...I really need to convert some of their songs to ocarina tabs. I already did part of their version of the Lay, and it wasn't half bad.
Also, I'm expanding my end of the bargain a bit. Provided I've learned enough Quenya by the time the outcome of the bet is revealed (which I almost certainly will have), I will translate any Tolkien poem/song into Quenya, and then sing/read it, your preference. Linguistics, ftw!
-Alleb
If it works, I'd like you to draw me a picture of Agent Miguel Correa. If it doesn't, I'll...let's see...I'll record myself reading one of your missions (you tell me what agent team you want) and post it to the Board. (Probably as an embedded Tumblr vid or something.) Sound good?
Suppose human extinction takes a small step backwards, oy?
But, so, assuming the whole thing actually does work well, and we can pop up into space and knock about with the grey aliens and the mi-go and all the elastic bands that people have flicked slightly upwards, missed their targets, and are now orbiting the planet, what would we all actually do with it? I mean, for our first steps?
I mean, there's a whole lot of stuff about faffing with Mars, so I'd imagine we might do something there, and there's all that mining and probing and whatnot, but, y'know. Anything else, you reckon?
*squees for hours on end*
Humanity could be just about to get off this mudball for realsies!!! Of course, getting into the shallow end's easy- there are already private space flights. We just need a shuttle going to some kind of space dock for this glorious little microwave to sail out into the vacuum. If this works, that is FANTASTIC NEWS, and I will live my life in squalor saving up to go, if it means I get to see that vast empty (suck it up, Casimir) sea filled with shining stars, barren planets, and cottony nebulae!!!
And, fanboying aside, is no one gonna mention the theory all of this is based on? This fundamentally changes the way I understand physics! Particles could all be sailing on some ethereal sea, caught adrift in an invisible wind, and I hadn't the slightest clue!!! This is beautiful.
I truly hope this works as well as we think it does. At the moment, I'm far too happy people are willing to practically consider such a ridiculous idea (space wind!:D)as the means of propelling mankind across the solar system, to make that bet.
~~Aegis, who is geeking out over the fact that his laptop is running off the same stuff that could be powering a star drive if this ends up proven 100%
...and the general No-Fun-Allowed guy, but everyone in this thread seems to be missing the point that:
a) The Emdrive is nowhere powerful enough to carry a manned mission outside Earth orbit
b) It's not been reproduced yet
c) We're not even sure if it works in the field
d) It's not FTL, calm down
e) It relies on an obscure model of physics that, while not invalid, is not favoured by the cutting edge research institutes
f) Multiple sources of error still exist in this experiment and the validation of even one of them torpedoes the entire study
g) The logistics of a manned mission far surpass anything that one government can possibly organise
So... yeah. Do not get carried away. I want to be proven wrong-- it's the only way science moves forward after all-- but you're hopping on the hype train a little too early here. Save the champagne when we've actually made it work up there!
Going over your points in order:
a) Yes it is. Even low thrust, if run constantly, adds up to massive velocity. It just means you start gradually.
b) The Eagleworks test /is/ a reproduction. It hasn't been done a third time, no.
c) It works in 10-6 torr vacuum, which is a good start. Orbit is the next big step.
d) Never said it was. But it can hit arbitrarily large speeds, which means it can go relativistic. That means that by its internal clocks, every star is essentially the same distance away.
e) No, it relies on the fact that it (seems to) work. The precise physics behind it may be wildly wrong, but if it works, then /some/ model will be found to explain it. Demonstrable effect trumps unlikely cause.
f) Yep. Which is why I said from the start that it probably won't work. But NASA think it's promising enough to push out a peer-reviewed paper...
g) Well, America managed the moon. And the biggest issue with long trips is the need to boost all that fuel into orbit, which this does away with. Yes, there's more to it - there always is - but it's certainly feasible.
h) Take the bet. Make Randall's Wager. If you're right, you get a thing. If you're wrong, you get a torchdrive. Either way, you win.
hS
Most of my points was in response to people going "the stars are near!" Well, no. The solar system beckons, yes, but not the stars. We're so not there yet.
And I will take up that offer. If it turns out that the Emdrive works once in orbit, I'll double my annual donation to Doctors Without Borders. Might as well keep on doing good while we're at it, eh?
I'm in on the bet- but I'm going to take the Munroe side. I hereby bet a thousand words of short story (characters and prompt of the winner's choice) that when an em drive test device is launched, it will prove useless for space travel. (So, even if it only works inside the earth's magnetic field, I still lose. Low earth orbit reactions thrust is still huge.)
But seriously, holy carp, etc. Eagleworks is a big-name research group and you know they all walked into this one as skeptically as any physicist would be when given a perpetual motion machine. And this was peer-reviewed, too, which is another layer of skeptical physicists.
(Some restrictions apply on what I am willing to write, etc.)
Hmm... if it did only work in a magnetic field, I can see great things for it out around Jupiter and Saturn. Imagine not having to loop through convoluted orbits, but just torchshipping from moon to moon. Though you might face power issues that far out, if you stuck to solar... even so, though.
I was really, really shocked to see the announcement. I figured this was just another cold fusion-style lie, but... seriously. Seriously. I so hope it's true.
hS
It really doesn't need all that much power. A small power source can sustain it— and a nuclear battery certainly fits the bill.
Also, a conventional nuclear reactor is a massive affair. It generates electricity by heating steam and shoving it through turbines— such a system in space is going to be an unwieldy affair, needing water and air and plumbing and maintenance to work properly. Also, we've never needed to build one in space before, so a design would have to compensate for the lack of gravity. All in all, a rather challenging power solution, yes.
... at 100W (low-end for an RTG), it looks like an EM drive could push a six-tonne Apollo command module at, uh... 15 nanometers per second squared. That works out to just about 0.5 meters per year squared. We, um, might need a few of them. ^_^
hS
https://en.m.wikipedia.org/wiki/TOPAZnuclearreactor
https://en.m.wikipedia.org/wiki/Romashkareactor
<a href="https://en.m.wikipedia.org/wiki/Kosmos954">https://en.m.wikipedia.org/wiki/Kosmos_954
Yes, until something goes wrong at the launch and you scatter all that wonderful power source material across the atmosphere. Granted, as spacecraft don't carry that much radioactive material, it won't necessarily be too bad, provided we don't use it as apower source to actually leave earth's gravity behind (yes, that does sound horribly unphysic-y, but I hope you understand what I mean). Still, the bad publicity would result in cut fundings, which is bad.
...the Voyager probes, Cassini, and New Horizons all carry RTGs? Besides, Pu-238's half-life is a mere 87 years compared to a nuclear weapon's 24000+. By comparison, it's clean as can be. Besides, not much else can generate heat or electricity in deep space.
And, as hS pointed it out, an Emdrive will not replace a chemical rocket to escape Earth's gravitational potential well. The spacecraft hitches a ride on, say, an Arianne or a Soyuz, deploys in space, and uses its RTG to power the Emdrive.
Fingers crossed that the results can be replicated! And fingers crossed that your average Joe will be able to go into space within my lifetime. I've always wanted to see the stars...
The downside of this tech - even if it works precisely as advertised and can be dramatically scaled up - is that it's not a launch engine. Once you're in orbit, you can go anywhere you want with even a weak engine - it's just a matter of acceleration time. But to get to orbit, you need to make at least one gravity of thrust (ie, you need to counter the gravitational pull of the Earth). And right now, that takes a massive engine with an alarmingly high chance of exploding.
It should take a simple trip up the space elevator, but we don't have that tech yet - or the money to build it if we did.
"And I want it so much
Close my eyes, I can taste the Mars dust in the air
In the darkness the space stations shimmer in orbits that I will not share..."
hS
Way too good. Suspiciously so.
I bet my socks that research teams worldwide are scrambling to replicate these results and verify the Eagleworks paper. There are multiple sources or error for this experiment and every single one of them can spell doom for the conclusion of this article-- but I want to be proven wrong.
This is uncharted territory. Should the EM drive be proven to work, the entire solar system is ours for the taking. The stars are still too far away-- a hypothetical trip to Proxima Centauri would take the better part of a decade-- but I'd argue that our solar system is more than enough already.
For now, cautious interest should be the name of the game. We have an anomalous situation on our hands-- we need to investigate it.
Also, inb4 all of the trash science news claims we invented a stardrive. It's not been 100% proven yet, jeez.
Then even if it doesn't work, you still get something out of it.
(I'll even add that if they don't launch one because someone else proves it doesn't work before they get round to it, I lose.)
hS
PS: Oh no, a whole decade? No space mission will ever be able to run that long.
If this is real, and the stars are in our grasp at last... we might actually have a shot at this whole "species" lark. We're not just angry monkeys with delusions of grandeur, we are beings capable of thought and achievement.
We are lightning bolts that learned to dream.
EVERYONE