Metaculus Help: Spread the word
If you like Metaculus, tell your friends! Share this question via Facebook, Twitter, or Reddit.
An attempt to prove reaction-less EM drive technology in space?
Like low-energy nuclear energy generation, the "reactionless EM drive" (aka the "Cannae Drive") involves tantalizing experiments, a dedicated and very hopeful fan base, a mixed record of publications, and an incredibly skeptical community of scientists.
As summarized in this recent story, the tantalizing experiments involve putting radiation in a cavity and finding that – somehow – this creates a net force on the cavity.
There is no extant credible theory for how this can be possible given that quantum field theory conserves momentum, and should be perfectly adequate to describe this system. (And the two papers listed in the story do not appear to this author to violate this statement.)
Nonetheless, there are a number of independent experiments claiming to see this effect, and it is not obvious what accounts for the results.
It is difficult to get a clean resolution criterion on this type of matter, but the new story, suggesting that a Cannae drive might be put into orbit, makes it possible! We ask:
By start of 2019, will a "reactionless EM drive" (broadly construed) be launched on a rocket?
To resolve as positive, the drive need not make it to orbit, deploy, work, etc. The question only concerns whether the financing and "will" shall be assembled to put one on a launch pad and fire it up.
Metaculus help: Predicting
Predictions are the heart of Metaculus. Predicting is how you contribute to the wisdom of the crowd, and how you earn points and build up your personal Metaculus track record.
The basics of predicting are very simple: move the slider to best match the likelihood of the outcome, and click predict. You can predict as often as you want, and you're encouraged to change your mind when new information becomes available. With tachyons you'll even be able to go back in time and backdate your prediction to maximize your points.
The displayed score is split into current points and total points. Current points show how much your prediction is worth now, whereas total points show the combined worth of all of your predictions over the lifetime of the question. The scoring details are available on the FAQ.
Note: this question resolved before its original close time. All of your predictions came after the resolution, so you did not gain (or lose) any points for it.
Note: this question resolved before its original close time. You earned points up until the question resolution, but not afterwards.
This question is not yet open for predictions.
Metaculus help: Community Stats
Use the community stats to get a better sense of the community consensus (or lack thereof) for this question. Sometimes people have wildly different ideas about the likely outcomes, and sometimes people are in close agreement. There are even times when the community seems very certain of uncertainty, like when everyone agrees that event is only 50% likely to happen.
When you make a prediction, check the community stats to see where you land. If your prediction is an outlier, might there be something you're overlooking that others have seen? Or do you have special insight that others are lacking? Either way, it might be a good idea to join the discussion in the comments.