The 'impossible' EmDrive could reach Pluto in 18 months? • Hacker News Board

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#71

Post by dogma1138 » Mon, Jul 27, 2015, 9:10 AM UTC

api wrote: post #26

saalweachter wrote: post #11

Earlier quoted context omitted.

Smaller effect size as studies improve is the classic sign of a non-event. ESP and the like went through similar cycles - impressive early studies followed by a series of more rigorous studies with diminishing effects until people got bored and moved on to the next big thing.

In this case different tests have occurred at different power levels. Has anyone normalized the results? Of course with only a couple replications its early for a meta study.

In this case the tests weren't even normalized, this is one of the 1st tests that was conducted in vacuum under shielding, many of the earlier tests were not even thermally or electromagnetically shielded, considering the tiny amounts of thrust generated by both the "predictions" and the tests pressure difference due to thermal variance as well as magnetic forces could explain it just as well.

I also have a strong gut feeling that this some none issue but it never hurts to test it the US, Russia, China and to lesser Extent the UK, France and other European powers have all conducted studies into ESP, the cost of such testing is ridiculously low compared to the potential discovery.

When it costs near to nothing to explore a phenomenon that can change how we understand physics it's worth exploring no matter how ridiculous it is.

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#72

Post by adrianN » Mon, Jul 27, 2015, 9:12 AM UTC

thaumaturgy wrote: post #56

nickff wrote: post #51

Earlier quoted context omitted.

Photoelectric cells were invented before we understood the photoelectric effect, alcohol and preserves were used to store drinks and foodstuffs before we understood microbes, forging and annealing used before anyone had a theory on metallic crystal formation, and incandescence was used before anyone understood electromagnetic radiation; to name but a few examples. Why would it be surprising that someone invented a de…

Oh! This is one of my favorite questions about scientific progress. People seem to regard scientific progress as this kind of wave function, where some theory comes along and then some other theory or discovery disproves the previous one and so on and so forth. But if you want to think of scientific progress that way, then you have to think of it as a dampened sine wave ( https://en.wikipedia.org/wiki/Damped_sine_wav…

Relevant essay by Asimov: The Relativity of Wrong

http://chem.tufts.edu/answersinscience/relativityofwrong.htm

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#73

Post by javert » Mon, Jul 27, 2015, 9:12 AM UTC

cabinpark wrote: post #58

javert wrote: post #39

Earlier quoted context omitted.

Thanks, nice summary. > I think the last thing anyone wants to see here is "new physics". I really want to see new physics, because I want to see us get off this rock and far away. I think most people want to see new physics. I think that's why this topic is so popular. That said, I can understand physicists not wanting to see new physics. Wait. In a way, that sentence is crazy . In a way, physicists should want to s…

I'd love to see new physics! Every physicist I know loves new physics. But if you claim to violate the conversation of momentum, everyone is going to be skeptical and not believe it. We have hundreds of years of experiments and observations that support the law and have looked in many places from small to large and not seen violations. This is what makes people not believe it and thus physicists are going to assume y…

That makes sense, but that's not how I interpret "nobody wants to see new physics" in the ancestor comment. (But who knows.)

I mean, wouldn't it be really frustrating to find out the law of conservation of momentum is not universal? Exciting, but also frustrating? Maybe even embarassing for physics? It would be like someone proving P=NP.

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#74

Post by javert » Mon, Jul 27, 2015, 9:14 AM UTC

ttctciyf wrote: post #61

cabinpark wrote: post #58

Earlier quoted context omitted.

I'd love to see new physics! Every physicist I know loves new physics. But if you claim to violate the conversation of momentum, everyone is going to be skeptical and not believe it. We have hundreds of years of experiments and observations that support the law and have looked in many places from small to large and not seen violations. This is what makes people not believe it and thus physicists are going to assume y…

> Every physicist I know loves new physics. If physicists don't want new physics, they should stop doing research!

Only as long as the new physics is in your little sphere of influence so you can keep the grant money gravy train flowing. Presumably.

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#75

Post by thaumaturgy » Mon, Jul 27, 2015, 9:15 AM UTC

eevilspock wrote: post #64

nickff wrote: post #59

Earlier quoted context omitted.

I'm sorry, but your reasoning completely escapes me. The only things that are left are very big, and very small? In addition to this being an incredibly vague catchall (which misses all the possible discoveries of 'black swans', that is phenomena and occurrences we have never seen), your statement more importantly misses the fact that humans don't even understand what something as common and important as light (or el…

I agree. I also take issue with > rapidly zeroing in on the truths of our reality The truths? No, humans are as likely to arrive at the truths as ants an understanding of a microwave oven.

A fair reading of that part would assume that I meant truths like, "the cosmos is expanding", not philosophical truths.

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#76

Post by baq » Mon, Jul 27, 2015, 9:15 AM UTC

gilgoomesh wrote: post #12

idlewords wrote: post #4

Has any independent laboratory confirmed this effect and published on it in a peer-reviewed journal?

Not exactly a journal but NASA reproduced the Cannae and EmDrive style devices and documented it: http://ntrs.nasa.gov/search.jsp?R=20140006052 Turning 17 watts of microwave power into 40-91 micronewtons of thrust isn't exactly stunning, though.

from the wikipedia ion thruster article:

> Ion thrusters have an input power spanning 1–7 kilowatts, exhaust velocity 20–50 kilometers per second, thrust 20–250 millinewtons and efficiency 60–80%.[1][2]

3 orders of magnitude less thrust than for not needing to accelerate any fuel all the way into orbit? i'll tell you space companies will send trucks full of money to anyone who can make a reliable one.

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#77

Post by dogma1138 » Mon, Jul 27, 2015, 9:19 AM UTC

Filligree wrote: post #67

dev-da0 wrote: post #63

Earlier quoted context omitted.

Explanations aside, if in the slight chance it's workably better than ion thrusters for certain applications, that's great. If it turns out to be snake oil or a hoax, that would not be a huge surprise either.

An ISP of infinity would be quite a lot better than ion thrusters, yes, and that's what they're suggesting.

Ion thrusters still require expendable fuel as well as an electrical power supply, if you can cut out the need for expendable fuel that would mean allot for space travel especially to the outer solar system and beyond.

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#78

Post by thaumaturgy » Mon, Jul 27, 2015, 9:20 AM UTC

adrianN wrote: post #72

thaumaturgy wrote: post #56

Earlier quoted context omitted.

Oh! This is one of my favorite questions about scientific progress. People seem to regard scientific progress as this kind of wave function, where some theory comes along and then some other theory or discovery disproves the previous one and so on and so forth. But if you want to think of scientific progress that way, then you have to think of it as a dampened sine wave ( https://en.wikipedia.org/wiki/Damped_sine_wav…

Relevant essay by Asimov: The Relativity of Wrong http://chem.tufts.edu/answersinscience/relativityofwrong.htm

Thank you! I had read this in the past, and it was one of two major influences on my thinking about scientific progress, but I couldn't remember exactly what it was I had read.

Asimov naturally describes it much better than I could.

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#79

Post by lawlessone » Mon, Jul 27, 2015, 9:59 AM UTC

Natsu wrote: post #15

Niten wrote: post #7

It's good to see that someone finally got around to testing this in a vacuum. Here's the paper mentioned in this story: http://arc.aiaa.org/doi/abs/10.2514/6.2015-4083 High levels of skepticism are still warranted, as much as I would love for this to pan out. Every time this gets tested—presumably more and more carefully—the measured force gets smaller. The original test at Chinese Northwestern Polytechnical Universi…

What would it take to get one of these into space?

from the looks of how testing is going, a good old fashioned rocket.

Re: The 'impossible' EmDrive could reach Pluto in 18 months?

#80

Post by leni536 » Mon, Jul 27, 2015, 10:03 AM UTC

nickff wrote: post #51

evincarofautumn wrote: post #49

Earlier quoted context omitted.

Well, it’s improbable, not nonsensical. If someone goes and implements a technology that trounces our working theories, we certainly need to update those theories. It’s just that that’s exceedingly unlikely to happen.

Photoelectric cells were invented before we understood the photoelectric effect, alcohol and preserves were used to store drinks and foodstuffs before we understood microbes, forging and annealing used before anyone had a theory on metallic crystal formation, and incandescence was used before anyone understood electromagnetic radiation; to name but a few examples. Why would it be surprising that someone invented a de…

Inventing a device which is not well understood and inventing a device which contradicts things that are thought to be well understood are two different things. The photoelectric effect was pretty big news though and it did break existing laws that time so it doesn't really fit here.