TE
科技回声
首页24小时热榜最新最佳问答展示工作
GitHubTwitter
首页

科技回声

基于 Next.js 构建的科技新闻平台,提供全球科技新闻和讨论内容。

GitHubTwitter

首页

首页最新最佳问答展示工作

资源链接

HackerNews API原版 HackerNewsNext.js

© 2025 科技回声. 版权所有。

Gravity Modification Experiment Works – APEC Propulsion Conference 8/31/24

2 点作者 stuckinhell8 个月前

1 comment

jepler8 个月前
Fringe science here. APEC is &quot;Alternative Propulsion Engineering Conference&quot; so these are the EM drive people, etc. The probability that &quot;this is anything&quot; is low.<p>Now, I have no idea what the explanation is for the observation in this presentation &amp; the videos. But, it would be important to exclude <i>known</i> effects, and I see no effort to do that.<p>There are at least two obvious &quot;not new physics&quot; things that could be changing the measured weight in the load cell experiment: interaction with Earth&#x27;s magnetic field causing a net force on the coils, and thermal expansion having an unanticipated effect.<p>For instance, current through a conductor creates a field; per <a href="https:&#x2F;&#x2F;physics.stackexchange.com&#x2F;questions&#x2F;338069&#x2F;why-doesnt-the-earths-magnetic-field-affect-electronics" rel="nofollow">https:&#x2F;&#x2F;physics.stackexchange.com&#x2F;questions&#x2F;338069&#x2F;why-doesn...</a> &quot;if you have a meter of wire carrying one ampere of current from east to west, it&#x27;ll feel a magnetic force of 0.5×10−4N [...] That force corresponds to the weight mg of an object with mass m=5mg&quot;<p>6A in 5m of wire would approximate the 0.15g figure shown in &quot;GEM effect data&quot; on slide 34, and neither 6A nor 5m seem improbable values for a commercial 3 phase motor. Did you take care to control for the expected force imparted in this way? no.<p>What about heat production? The way the 3-phase experiment is mounted is, charitably, hard to make out from the photos. Suppose any wire undergoes thermal expansion; this could take up some of the weight that is otherwise on the load cell. Some kind of temperature expansion effect would also explain the asymmetry of the weight vs time graph: Heating would occur quickly (several amps through a wire) and cooling would occur slowly (heat removal only via convection). Any analysis of thermal effects? no.<p>Coincidentally (along with measurement error), thermal effects &amp; electromagnetic interactions are two of the sources of erroneous thrust measurements in the &quot;EM drive&quot; acknowledged in Yang&#x27;s work at NWPU. So, like, this isn&#x27;t something people aren&#x27;t aware of.