Sorry, the EmDrive doesn’t work
The EmDrive turns out to be the "um..." drive after all, as a new study dubs any previous encouraging EmDrive results "false positives."
06 April, 2021
- The proposed EmDrive captured the public's imagination with the promise of super-fast space travel that broke the laws of physics.
- Some researchers have detected thrusts from the EmDrive that seemed to prove its validity as a technology.
- A new, authoritative study says, no, those results were just "false positives."
<div>When Roger Shawyer's
<a href="https://www.youtube.com/watch?v=wBtk6xWDrwY" target="_blank"> EmDrive</a> was first proposed in 2001, it seemed too good to be true. The proposed electromagnetic drive ("Em" for short) needed no fuel, and therefore was so lightweight that it<a href="https://bigthink.com/paul-ratner/em-drive-the-impossible-rocket-engine-may-be-closer-to-reality" target="_self"> promised</a> to let travelers zip across the cosmos at unprecedented speeds. Never mind that the EmDrive's workings seemed to violate Newton's Third Law of Motion, the one about every action producing an equal and opposite reaction.<br></div><p>
Now it seems that, yep, it
<em>was</em> too good to be true. Scientists at Dresden University of Technology (TU Dresden) appear to have conclusively proven that the EmDrive does not, in fact, produce any thrust. They provide some compelling evidence that small indications of thrust in previous research were simply false positives produced by outside forces.
</p><h2>How the EmDrive is supposed to work</h2><p>
<br>
</p><p class="shortcode-media shortcode-media-rebelmouse-image">
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTk5MjUwMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMTcyNTI0N30.SRlL6DFzkWLW349G50LzbWg8enlBBjZlHH5z-ig4nXo/img.jpg?width=980" id="a8dbd" width="1440" height="1073" data-rm-shortcode-id="392fa218cbb1e5c56322632115f660bf" data-rm-shortcode-name="rebelmouse-image">
<small class="image-media media-photo-credit" placeholder="Add Photo Credit...">Credit: <a href="https://stock.adobe.com/contributor/200768506/andsus?load_type=author&prev_url=detail" rel="noopener noreferrer" target="_blank">AndSus</a>/Adobe Stock</small>
</p><p>
In the EmDrive, says
<a href="http://emdrive.com/" target="_blank"> the company</a> that owns rights to the invention, "Thrust is produced by the amplification of the radiation pressure of an electromagnetic wave propagated through a resonant waveguide assembly." In simpler words, trapped microwaves bounce around a specially shaped enclosed container, producing thrust that pushes the whole thing forward.<br>
</p><p>
They also assert that while the EmDrive is not exactly on speaking terms with Newton's Third Law, the company says it's perfectly in line with the
<a href="http://emdrive.com/principle.html" rel="noopener noreferrer" target="_blank"> second one</a>:
</p><p style="margin-left: 20px;">
"This relies on Newton's Second Law where force is defined as the rate of change of momentum. Thus, an electromagnetic (EM) wave, traveling at the speed of light has a certain momentum which it will transfer to a reflector, resulting in a tiny force."
</p><p>
Interest in the EmDrive has been understandable considering what it was supposed to do. Speaking to
<a href="https://www.popularmechanics.com/space/rockets/a33917439/emdrive-wont-die/" target="_blank"> <em>Popular Mechanics</em></a> last year, Mike McCulloch, the leader of DARPA's EmDrive investigation, describes how the engine could "transform space travel and see craft lifting silently off from launchpads and reaching beyond the solar system." He mentioned his excitement at being able to get from here to<a href="https://en.wikipedia.org/wiki/Proxima_Centauri" rel="noopener noreferrer" target="_blank"> Proxima Centauri</a> — 4.2465 light years away — in just 90 human years.
</p><h2>It doesn't work. Yes it does. No, it doesn't.</h2><p><br></p><p class="shortcode-media shortcode-media-rebelmouse-image">
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTk5MjU3MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTIzNTY4N30.KIcB0qUeygY1_clj-2TqGHfMCfcdMEiQF8hZf6NYYR0/img.jpg?width=980" id="e307c" width="656" height="612" data-rm-shortcode-id="5b1a63983fab1f253ad3c6498ab4bda9" data-rm-shortcode-name="rebelmouse-image">
<small class="image-media media-caption" placeholder="Add Photo Caption...">NASA Eagleworks' EmDrive</small><small class="image-media media-photo-credit" placeholder="Add Photo Credit...">Credit: NASA/<a href="https://commons.wikimedia.org/wiki/File:EmDrive_built_by_Eagleworks_inside_the_test_chamber.jpg" rel="noopener noreferrer" target="_blank">Wikimedia Commons</a></small></p><p><br></p><p>
DARPA, part of the U.S. Department of Defense, is only one of the organizations investigating the claims made for the EmDrive. In 2018 the<a href="https://www.popularmechanics.com/space/rockets/a24219132/darpa-emdrive/" rel="noopener noreferrer" target="_blank"> agency invested</a> $1.3 million to study the device in research that will be wrapping up this May barring any significant last-minute breakthroughs.
</p><p>
Teams from all over the world have been testing Shawyer's idea since it was introduced and releasing often contradictory test results. This may have to do with the fact that teams detecting any EmDrive thrust at all have reported vanishingly small amounts of it, measured in milliNewtons (mN). A mN equals about 0.00022 pounds of force.
</p><p>
As<a href="https://www.space.com/author/paul-sutter" rel="noopener noreferrer" target="_blank"> Paul Sutter</a> wrote in an op-ed for<a href="https://www.space.com/can-emdrive-space-propulsion-concept-work" rel="noopener noreferrer" target="_blank"> Space.com</a>:
</p><p style="margin-left: 20px;">
"Ever since the introduction of the EmDrive concept in 2001, every few years a group claims to have measured a net force coming from its device. But these researchers are measuring an incredibly tiny effect: a force so small it couldn't even budge a piece of paper. This leads to significant statistical uncertainty and measurement error."
</p><p>
For a sense of how minuscule these results are, consider that the possible thrust force<a href="https://ntrs.nasa.gov/citations/20140006052" rel="noopener noreferrer" target="_blank"> reported by NASA</a> in 2014 of 30-50 micro-Newtons is roughly equivalent to the weight of a big ant. Chinese researchers<a href="http://www.emdrive.com/yang-juan-paper-2012.pdf" rel="noopener noreferrer" target="_blank"> have claimed</a> detection of 720 mN in their tests. That would be 72 grams of thrust. An iPhone 11 with a case weights 219 grams.</p><h2>Too small to stand out against background noise</h2><p>
These tiny amounts of EmDrive thrust lie at the heart of what the TU Dresden researchers are saying: The effects are simply too small to rule out effects that don't really come from the EmDrives at all. The researchers have just published three papers. The title of one "<a href="https://www.researchgate.net/publication/350108418_High-Accuracy_Thrust_Measurements_of_the_EMDrive_and_Elimination_of_False-Positive_Effects" rel="noopener noreferrer" target="_blank">High-Accuracy Thrust Measurements of the EmDrive and Elimination of False-Positive Effects</a>" tells the story. The other two studies are<a href="https://www.researchgate.net/publication/350108417_Thrust_Measurements_and_Evaluation_of_Asymmetric_Infrared_Laser_Resonators_for_Space_Propulsion" rel="noopener noreferrer" target="_blank"> here</a> and<a href="https://www.researchgate.net/publication/350108329_The_SpaceDrive_Project_-_Mach-Effect_Thruster_Experiments_on_High-Precision_Balances_in_Vacuum" rel="noopener noreferrer" target="_blank"> here</a>.
</p><p>
When the UT Dresden team turned on their EmDrive based on NASA's EmDrive, they, too witnessed tiny amounts of apparent thrust.
</p><p>
However, says<a href="https://tu-dresden.de/ing/maschinenwesen/ilr/rfs/die-professur/beschaeftigte/portrait_englisch" rel="noopener noreferrer" target="_blank"> Martin Tajmar</a> of UT Dresden to German media outlet<a href="https://www.grenzwissenschaft-aktuell.de/latest-emdrive-tests-at-dresden-university-shows-impossible-engine-does-not-develop-any-thrust20210321/" rel="noopener noreferrer" target="_blank"> GreWi</a>, they soon realized what was going on: "When power flows into the EmDrive, the engine warms up. This also causes the fastening elements on the scale to warp, causing the scale to move to a new zero point. We were able to prevent that in an improved structure."
</p><p>
Putting the kibosh on other researchers' results, the authors of the studies write:</p><p style="margin-left: 20px;">"Using a geometry and operating conditions close to the model by<a href="https://ntrs.nasa.gov/citations/20140006052" rel="noopener noreferrer" target="_blank"> White et al.</a> that reported positive results published in the peer-reviewed literature, we found no thrust values within a wide frequency band including several resonance frequencies. Our data limits any anomalous thrust to below the force equivalent from classical radiation for a given amount of power. This provides strong limits to all proposed theories and rules out previous test results by more than three orders of magnitude."
</p><p>
This would seem to be the definitive end of the EmDrive story.
</p>
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Have scientists at CERN found evidence of brand new physics?
We're cautiously optimistic about our new findings.
05 April, 2021
VALENTIN FLAURAUD/AFP via Getty Images
When Cern's gargantuan accelerator, the Large Hadron Collider (LHC), fired up ten years ago, hopes abounded that new particles would soon be discovered that could help us unravel physics' deepest mysteries.
<p> Dark matter, microscopic black holes and hidden dimensions <a href="https://theconversation.com/from-black-holes-to-dark-matter-an-astrophysicist-explains-26019" target="_blank">were just some</a> of the possibilities. But aside from the <a href="https://theconversation.com/explainer-the-higgs-boson-particle-280" target="_blank">spectacular discovery</a> of the Higgs boson, the project has <a href="https://theconversation.com/could-the-higgs-nobel-be-the-end-of-particle-physics-18978" target="_blank">failed to</a> yield any clues as to what might lie beyond the <a href="https://theconversation.com/explainer-standard-model-of-particle-physics-2539" target="_blank">standard model of particle physics</a>, our current best theory of the micro-cosmos.</p><p>So our <a href="http://arxiv.org/abs/2103.11769" target="_blank">new paper</a> from LHCb, <a href="https://theconversation.com/explainer-how-does-an-experiment-at-the-large-hadron-collider-work-42846" target="_blank">one of the four giant LHC experiments</a>, is likely to set physicists' hearts beating just a little faster. After analysing trillions of collisions produced over the last decade, we may be seeing evidence of something altogether new – potentially the carrier of a brand new force of nature.</p><p>But the excitement is tempered by extreme caution. The standard model has withstood every experimental test thrown at it since it was assembled in the 1970s, so to claim that we're finally seeing something it can't explain requires extraordinary evidence. </p>
<h2>Strange anomaly</h2><p>The standard model describes nature on the smallest of scales, comprising <a href="https://theconversation.com/explainer-what-are-fundamental-particles-38339" target="_blank" rel="noopener noreferrer">fundamental particles</a> known as leptons (such as electrons) and quarks (which can come together to form heavier particles such as protons and neutrons) and the forces they interact with.</p><p>There are many different kinds of quarks, some of which are unstable and can decay into other particles. The new result relates to an experimental anomaly that was <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.151601" target="_blank" rel="noopener noreferrer">first hinted at in 2014</a>, when LHCb physicists spotted "beauty" quarks decaying in unexpected ways.</p><p>Specifically, beauty quarks appeared to be decaying into leptons called "muons" less often than they decayed into electrons. This is strange because the muon is in essence a carbon-copy of the electron, identical in every way except that it's around 200 times heavier.</p><p>You would expect beauty quarks to decay into muons just as often as they do to electrons. The only way these decays could happen at different rates is if some never-before-seen particles were getting involved in the decay and tipping the scales against muons.</p><p>While the 2014 result was intriguing, it wasn't precise enough to draw a firm conclusion. Since then, a number of other anomalies have appeared in related processes. They have all individually been too subtle for researchers to be confident that they were genuine signs of new physics, but tantalisingly, they all seemed to be pointing in a similar direction.</p><p>The big question was whether these anomalies would get stronger as more data was analysed or melt away into nothing. In 2019, LHCb performed the <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.191801" target="_blank" rel="noopener noreferrer">same measurement</a> of beauty quark decay again but with extra data taken in 2015 and 2016. But things weren't much clearer than they'd been five years earlier.</p>
<h2>New results</h2><p>Today's result doubles the existing dataset by adding the sample recorded in 2017 and 2018. To avoid accidentally introducing biases, the data was analysed "blind" – the scientists couldn't see the result until all the procedures used in the measurement had been tested and reviewed.</p><p><a href="https://www.imperial.ac.uk/people/mitesh.patel" target="_blank" rel="noopener noreferrer">Mitesh Patel</a>, a particle physicist at Imperial College London and one of the leaders of the experiment, described the excitement he felt when the moment came to look at the result. "I was actually shaking", he said, "I realised this was probably the most exciting thing I've done in my 20 years in particle physics."</p><p>When the result came up on the screen, the anomaly was still there – around 85 muon decays for every 100 electron decays, but with a smaller uncertainty than before.</p><p>What will excite many physicists is that the uncertainty of the result is now over "three sigma" – scientists' way of saying that there is only around a one in a thousand chance that the result is a random fluke of the data. Conventionally, particle physicists call anything over three sigma "evidence". However, we are still a long way from a confirmed "discovery" or "observation" – that would require five sigma.</p><p>Theorists have shown it is possible to explain this anomaly (and others) by recognising the existence of brand new particles that are influencing the ways in which the quarks decays. One possibility is a fundamental particle called a "Z prime" – in essence a carrier of a brand new force of nature. This force would be extremely weak, which is why we haven't seen any signs of it until now, and would interact with electrons and muons differently.</p><p>Another option is the hypothetical "<a href="https://home.cern/news/news/physics/hunt-leptoquarks" target="_blank" rel="noopener noreferrer">leptoquark</a>" – a particle that has the unique ability to decay to quarks and leptons simultaneously and could be part of a larger puzzle that explains why we see the particles that we do in nature.</p>
<h2>Interpreting the findings</h2><p>So have we finally seen evidence of new physics? Well, maybe, maybe not. We do a lot of measurements at the LHC, so you might expect at least some of them to fall this far from the standard model. And we can never totally discount the possibility that there's some bias in our experiment that we haven't properly accounted for, even though this result has been checked extraordinarily thoroughly. Ultimately, the picture will only become clearer with more data. LHCb is currently undergoing a major upgrade to dramatically increase the rate it can record collisions.</p><p>Even if the anomaly persists, it will probably only be fully accepted once an independent experiment confirms the results. One exciting possibility is that we might be able to detect the new particles responsible for the effect being created directly in the collisions at the LHC. Meanwhile, the <a href="https://www.belle2.org/" target="_blank" rel="noopener noreferrer">Belle II experiment</a> in Japan should be able to make similar measurements.</p><p>What then, could this mean for the future of fundamental physics? If what we are seeing is really the harbinger of some new fundamental particles then it will finally be the breakthrough that physicists have been yearning for for decades.</p><p>We will have finally seen a part of the larger picture that lies beyond the standard model, which ultimately could allow us to unravel any number of established mysteries. These include the nature of the invisible dark matter that fills the universe, or the nature of the Higgs boson. It could even help theorists unify the fundamental particles and forces. Or, perhaps best of all, it could be pointing at something we have never even considered.</p><p>So, should we be excited? Yes, results like this don't come around very often, the hunt is definitely on. But we should be cautious and humble too; extraordinary claims require extraordinary evidence. Only time and hard work will tell if we have finally seen the first glimmer of what lies beyond our current understanding of particle physics.<img src="https://counter.theconversation.com/content/157464/count.gif?distributor=republish-lightbox-basic" alt="The Conversation"></p><p><a href="https://theconversation.com/profiles/harry-cliff-103546" target="_blank">Harry Cliff</a>, Particle physicist, <em><a href="https://theconversation.com/institutions/university-of-cambridge-1283" target="_blank" rel="noopener noreferrer">University of Cambridge</a></em>; <a href="https://theconversation.com/profiles/konstantinos-alexandros-petridis-1219851" target="_blank" rel="noopener noreferrer">Konstantinos Alexandros Petridis</a>, Senior lecturer in Particle Physics, <em><a href="https://theconversation.com/institutions/university-of-bristol-1211" target="_blank" rel="noopener noreferrer">University of Bristol</a></em>, and <a href="https://theconversation.com/profiles/paula-alvarez-cartelle-1219212" target="_blank" rel="noopener noreferrer">Paula Alvarez Cartelle</a>, Lecturer of Particle Physics, <em><a href="https://theconversation.com/institutions/university-of-cambridge-1283" target="_blank" rel="noopener noreferrer">University of Cambridge</a></em></p><p>This article is republished from <a href="https://theconversation.com/" target="_blank" rel="noopener noreferrer">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/evidence-of-brand-new-physics-at-cern-why-were-cautiously-optimistic-about-our-new-findings-157464" target="_blank" rel="noopener noreferrer">original article</a>.</p>
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Why the simulation hypothesis is pseudoscience
The simulation hypothesis is fun to talk about, but believing it requires an act of faith.
02 April, 2021
- The simulation hypothesis posits that everything we experience was coded by an intelligent being, and we are part of that computer code.
- But we cannot accurately reproduce natural laws with computer simulations.
- Faith is fine, but science requires evidence and logic.
<p><em>[Note: The following is a transcript of the video embedded at the bottom of this article.]</em></p><p>I quite like the idea that we live in a computer simulation. It gives me hope that things will be better on the next level. Unfortunately, the idea is unscientific. But why do some people believe in the simulation hypothesis? And just exactly what's the problem with it? That's what we'll talk about today.<br><br>According to the simulation hypothesis, everything we experience was coded by an intelligent being, and we are part of that computer code. That we live in some kind of computation in and by itself is not unscientific. For all we currently know, the laws of nature are mathematical, so you could say the universe is really just computing those laws. You may find this terminology a little weird, and I would agree, but it's not controversial. The controversial bit about the simulation hypothesis is that it assumes there is another level of reality where someone or some thing controls what we believe are the laws of nature, or even interferes with those laws.<br><br>The belief in an omniscient being that can interfere with the laws of nature, but for some reason remains hidden from us, is a common element of monotheistic religions. But those who believe in the simulation hypothesis argue they arrived at their belief by reason. The philosopher Nick Boström, for example, claims it's likely that we live in a computer simulation based on an argument that, in a nutshell, goes like this. If there are a) many civilizations, and these civilizations b) build computers that run simulations of conscious beings, then c) there are many more simulated conscious beings than real ones, so you are likely to live in a simulation.<br><br>Elon Musk is among those who have bought into it. He too has said "it's most likely we're in a simulation." And even Neil DeGrasse Tyson gave the simulation hypothesis "better than 50-50 odds" of being correct.</p><p><br></p><p class="shortcode-media shortcode-media-youtube">
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="b593a3858896012a05180b80b4d24bcd"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/KDcNVZjaNSU?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
<small class="image-media media-caption" placeholder="Add Photo Caption...">Are we living in a simulation? | Bill Nye, Joscha Bach, Donald Hoffman | Big Think</small>
<small class="image-media media-photo-credit" placeholder="Add Photo Credit...">
<a href="https://www.youtube.com/watch?v=KDcNVZjaNSU" target="_blank">www.youtube.com</a>
</small>
</p><p><br></p><p>Maybe you're now rolling your eyes because, come on, let the nerds have some fun, right? And, sure, some part of this conversation is just intellectual entertainment. But I don't think popularizing the simulation hypothesis is entirely innocent fun. It's mixing science with religion, which is generally a bad idea, and, really, I think we have better things to worry about than that someone might pull the plug on us. I dare you!</p><p>But before I explain why the simulation hypothesis is not a scientific argument, I have a general comment about the difference between religion and science. Take an example from Christian faith, like Jesus healing the blind and lame. It's a religious story, but not because it's impossible to heal blind and lame people. One day we might well be able to do that. It's a religious story because it doesn't explain how the healing supposedly happens. The whole point is that the believers take it on faith. In science, in contrast, we require explanations for how something works.<br><br>Let us then have a look at Boström's argument. Here it is again. If there are many civilizations that run many simulations of conscious beings, then you are likely to be simulated.<br><br>First of all, it could be that one or both of the premises is wrong. Maybe there aren't any other civilizations, or they aren't interested in simulations. That wouldn't make the argument wrong of course; it would just mean that the conclusion can't be drawn. But I will leave aside the possibility that one of the premises is wrong because really I don't think we have good evidence for one side or the other.<br><br>The point I have seen people criticize most frequently about Boström's argument is that he just assumes it is possible to simulate human-like consciousness. We don't actually know that this is possible. However, in this case it would require explanation to assume that it is not possible. That's because, for all we currently know, consciousness is simply a property of certain systems that process large amounts of information. It doesn't really matter exactly what physical basis this information processing is based on. Could be neurons or could be transistors, or it could be transistors believing they are neurons. So, I don't think simulating consciousness is the problematic part.<br><br>The problematic part of Boström's argument is that he assumes it is possible to reproduce all our observations using not the natural laws that physicists have confirmed to extremely high precision, but using a different, underlying algorithm, which the programmer is running. I don't think that's what Boström meant to do, but it's what he did. He implicitly claimed that it's easy to reproduce the foundations of physics with something else.<br><br>But nobody presently knows how to reproduce General Relativity and the Standard Model of particle physics from a computer algorithm running on some sort of machine. You can approximate the laws that we know with a computer simulation – we do this all the time – but if that was how nature actually worked, we could see the difference. Indeed, physicists have looked for signs that natural laws really proceed step by step, like in a computer code, but their search has come up empty handed. It's possible to tell the difference because attempts to algorithmically reproduce natural laws are usually incompatible with the symmetries of Einstein's theories of Special and General Relativity. I'll leave you a reference in the info below the video. The bottom line is it's not easy to outdo Einstein.<br><br>It also doesn't help, by the way, if you assume that the simulation would run on a quantum computer. Quantum computers, as I have explained earlier, are special purpose machines. Nobody currently knows how to put General Relativity on a quantum computer.</p><p><br></p><p class="shortcode-media shortcode-media-rebelmouse-image">
<a href="https://www.flickr.com/photos/ibm_research_zurich/50252942522" target="_blank"><img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTk1ODk0OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1ODU5OTcxNn0.U3xbR0iTv-cCJcI07qiVMnUhN1dajCkL41NkVCkbP90/img.jpg?width=980" id="2f1d5" width="1599" height="1066" data-rm-shortcode-id="94501595521be74eb05fe1869786b762" data-rm-shortcode-name="rebelmouse-image" alt="IBM quantum computer "></a>
<small class="image-media media-caption" placeholder="Add Photo Caption...">IBM's quantum computer</small><small class="image-media media-photo-credit" placeholder="Add Photo Credit...">Credit: <a href="https://www.flickr.com/photos/ibm_research_zurich/" rel="noopener noreferrer" target="_blank" title="Go to IBM Research's photostream">IBM Research</a> via Flickr and licensed under <a href="https://creativecommons.org/licenses/by-nd/2.0/" target="_blank">CC BY-ND 2.0</a></small></p><div style="display: none;"><a href="https://www.flickr.com/photos/ibm_research_zurich/50252942522" target="_blank"><img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTk1ODk0OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1ODU5OTcxNn0.U3xbR0iTv-cCJcI07qiVMnUhN1dajCkL41NkVCkbP90/img.jpg?width=980" id="2f1d5" width="1599" height="1066" data-rm-shortcode-id="ef6726f4f3bf15978acd1f9cdbc32f09" data-rm-shortcode-name="rebelmouse-image" alt="IBM quantum computer "></a></div><p><br></p><p>A second issue with Boström's argument is that, for it to work, a civilization needs to be able to simulate a lot of conscious beings, and these conscious beings will themselves try to simulate conscious beings, and so on. This means you have to compress the information that we think the universe contains. Boström therefore has to assume that it's somehow possible to not care much about the details in some parts of the world where no one is currently looking, and just fill them in case someone looks.<br><br>Again though, he doesn't explain how this is supposed to work. What kind of computer code can actually do that? What algorithm can identify conscious subsystems and their intention and then quickly fill in the required information without ever producing an observable inconsistency? That's a much more difficult issue than Boström seems to appreciate. You cannot in general just throw away physical processes on short distances and still get the long distances right.<br><br>Climate models are an excellent example. We don't currently have the computational capacity to resolve distances below something like 10 kilometers or so. But you can't just throw away all the physics below this scale. This is a non-linear system, so the information from the short scales propagates up into large scales. If you can't compute the short-distance physics, you have to suitably replace it with something. Getting this right even approximately is a big headache. And the only reason climate scientists do get it approximately right is that they have observations which they can use to check whether their approximations work. If you only have a simulation, like the programmer in the simulation hypothesis, you can't do that.<br><br>And that's my issue with the simulation hypothesis. Those who believe it make, maybe unknowingly, really big assumptions about what natural laws can be reproduced with computer simulations, and they don't explain how this is supposed to work. But finding alternative explanations that match all our observations to high precision is really difficult. The simulation hypothesis, therefore, just isn't a serious scientific argument. This doesn't mean it's wrong, but it means you'd have to believe it because you have faith, not because you have logic on your side.</p><p><br></p><p class="shortcode-media shortcode-media-youtube">
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="1aa95dd66711446e578ef5c36cf593c8"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/HCSqogSPU_Q?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
<small class="image-media media-caption" placeholder="Add Photo Caption...">The Simulation Hypothesis is Pseudoscience</small>
</p><p><br></p><ul class="ee-ul"></ul><p><em>Republished with permission of Dr. Sabine Hossenfelder. The original article is <a href="https://backreaction.blogspot.com/2021/02/the-simulation-hypothesis-is.html" target="_blank">here</a>.</em></p>
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‘Smoking gun’ dark matter signature possibly identified
Researchers propose a new method that could definitively prove the existence of dark matter.
31 March, 2021
Credit: NASA, JPL-Caltech, Susan Stolovy (SSC/Caltech) et al.
- Scientists identified a data signature for dark matter that can potentially be detected by experiments.
- The effect they found is a daily "diurnal modulation" in the scattering of particles.
- Dark matter has not yet been detected experimentally.
<p>Dark matter, a type of matter that is predicted to make up around 27 percent of the known universe, has never been detected experimentally. Now a team of astrophysicists and cosmologists think they found a clue that may lead them to finally detect the elusive material, so hard to find because it does not absorb, reflect, or emit light.</p><p>The existence of dark matter has so far been predicted by inference from its gravitational effects on the motion of the stars and galaxies rather than direct observation. No existing technologies can pick it out. This has led researchers at the Shanghai Jiao Tong University and the Purple Mountain Observatory of the Chinese Academy of Sciences to identify characteristic dark matter signatures that would be easier to detect.</p><p>Their new paper proposes a new type of effect that relates to the so-called "sub-GeV dark matter" which is boosted by cosmic rays. Looking for this effect can potentially allow direct detection of dark matter using nuclear recoil techniques.</p><p><br></p><p class="shortcode-media shortcode-media-rebelmouse-image">
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTkyNzg3NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzIwMzU3M30.ydjA30MZQJENzi_2BLJz2Kgyd3whtPT9o1OWcG6_WOE/img.jpg?width=980" id="32cc2" width="1202" height="598" data-rm-shortcode-id="e3d3488fe6631f8c81dc2eed1046d191" data-rm-shortcode-name="rebelmouse-image">
<small class="image-media media-caption" placeholder="Add Photo Caption...">The diurnal effect of accelerated dark matter rays. </small><small class="image-media media-photo-credit" placeholder="Add Photo Credit...">Credit: Ge et al.</small></p><p><br></p><p>The research team included Shao-Feng Ge and Qiang Yuan, who explained that their approach is to look for a prominent signature of accelerated dark matter particles that come from the galaxy's center, where dark matter and cosmic rays are at high density. They found that these particles have a "diurnal modulation" – a scattering pattern that is linked to the time of day. At periods when the Galaxy Center faces the side of the planet that's opposite the location of the detector, the Earth shadows a large amount of these particles. At other times, they come in as a signal with "higher recoil energy."</p><p>"The conventional diurnal effect is only for slow moving (nonrelativistic) DM particles in our galaxy (so-called standard DM halo)," Ge and Yuan said to <a href="https://phys.org/news/2021-03-diurnal-effect-cosmic-ray-boosted-dark.html" rel="noopener noreferrer" target="_blank">Phys.org.</a> "The effect is negligibly small either from direct experimental constraints, or due to the detection threshold. For light DM particles, on the other hand, the DM-nucleus interaction is much less constrained, which leaves room for strong diurnal modulation."</p><p>Researchers Ning Zhou and Jianglai Liu, who were also involved in the study, said in an <a href="https://phys.org/news/2021-03-diurnal-effect-cosmic-ray-boosted-dark.html" rel="noopener noreferrer" target="_blank">interview</a> that the signature they are proposing could be "a smoking gun of cosmic ray boosted dark matter detection".</p><p>The researchers plan next to look for the signature in previously gathered data, as well as in underground dark matter experiments.</p><p>They are also encouraging scientists around the world to look for this signature in their data.</p><ul class="ee-ul"></ul><p>Check out the new paper "Diurnal Effect of Sub-GeV Dark Matter Boosted by Cosmic Rays" published in <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.126.091804" rel="noopener noreferrer" target="_blank">Physical Review Letters</a>.</p>
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'Spacekime theory' could speed up research and heal the rift in physics
Can spacekime help us make headway on some of the most pernicious inconsistencies in physics?
30 March, 2021
Credit: marcoemilio via Adobe Stock
- Our linear model of time may be holding back scientific progress.
- Spacekime theory can help us better understand the development of diseases, financial and environmental events, and even the human brain.
- This theory helps us better utilize big data, develop AI, and can even solve inconsistencies in physics.
<p>We take for granted the western concept of linear time. In ancient Greece, time was cyclical and if the <a href="https://www.quantamagazine.org/big-bounce-models-reignite-big-bang-debate-20180131/" rel="noopener noreferrer" target="_blank">Big Bounce theory</a> is true, they were right. In Buddhism, there is only the eternal now. Both the past and the future are illusions. Meanwhile, the <a href="https://www.bbc.com/news/science-environment-13452711" rel="noopener noreferrer" target="_blank">Amondawa</a> people of the Amazon, a group that first made contact with the outside world in 1986, have no abstract concept of time. While we think we know time pretty well, some scientists believe our linear model hobbles scientific progress. We're missing whole dimensions of time, in this view, and our limited perception could be the last obstacle to a sweeping <a href="https://www.space.com/theory-of-everything-definition.html" rel="noopener noreferrer" target="_blank">theory of everything.</a> </p><p>Theoretical physicist Itzhak Bars of the University of Southern California, Los Angeles, is the most famous scientist with such a hypothesis, known as <a href="https://bigthink.com/philip-perry/there-are-in-fact-2-dimensions-of-time-one-theoretical-physicist-states" target="_self">two-time physics</a>. Here, time is 2D, visualized as a curved plane interwoven into the fabric of the "normal" dimensions—up-down, left-right, and backward-forward. While the hypothesis is over a decade old, Bars isn't the only scientist with such an idea. But what's different with <a href="https://www.socr.umich.edu/spacekime/" rel="noopener noreferrer" target="_blank">spacekime theory</a> is that it uses a data analytics approach, rather than a physics one. And while it posits that there are at least two dimensions of time, it allows for up to five. </p><p>In the spacekime model, space is 5D. Besides the ones we normally encounter, the extra dimensions are so infinitesimally small, we never notice them. This relates to the <a href="https://plus.maths.org/content/kaluza-klein-and-their-story-fifth-dimension" rel="noopener noreferrer" target="_blank">Kaluza–Klein theory</a> developed in the early 20th century, which stated that there might be an extra, microscopic dimension of space. In this view, space would be curved like the surface of Earth. And like Earth, those who travel the entire distance would, eventually, loop back to their place of origin. </p><p>Kaluza-Klein theory unified electromagnetism and gravity, but wasn't accepted at the time, although it did help in the search for quantum gravity. The concept of additional dimensions was revived in the 1990s with <a href="https://physicstoday.scitation.org/do/10.1063/PT.5.6195/full/" rel="noopener noreferrer" target="_blank">Paul Wesson's</a> <a href="https://wp.towson.edu/5dstm/introduction/" rel="noopener noreferrer" target="_blank">Space-Time-Matter Consortium</a>. Today, proponents of superstring theory say there may be as many as <a href="https://bigthink.com/philip-perry/physicists-outline-10-different-dimensions-and-how-youd-experience-them" target="_self">10 different dimensions</a>, including nine of space and one of time. </p><h2>The Spacekime model</h2><p>Spacekime theory was developed by two data scientists. <a href="http://www.socr.umich.edu/people/dinov/" rel="noopener noreferrer" target="_blank">Dr. Ivo Dinov</a> is the University of Michigan's <a href="http://www.socr.umich.edu/html/SOCR_Support.html#:~:text=SOCR%20is%20a%20not%2Dfor,based%20instruction%20and%20scientific%20computing." rel="noopener noreferrer" target="_blank">SOCR</a> Director, as well as a professor of Health Behavior and Biological Sciences, and Computational Medicine and Bioinformatics. SOCR stands for: Statistics Online Computational Resource designs. Dr. Dinov is an expert in "mathematical modeling, statistical analysis, computational processing, scientific visualization of large datasets (Big Data) and predictive health analytics." His research has focused on mathematical modeling, statistical inference, and biomedical computing.</p><p>His colleague, <a href="https://socr.umich.edu/people/Milen_Velev.html" rel="noopener noreferrer" target="_blank">Dr. Milen Velchev Velev</a>, is an associate professor at the Prof. Dr. A. Zlatarov University in Bulgaria. He studies relativistic mechanics in multiple time dimensions, and his interests include "applied mathematics, special and general relativity, quantum mechanics, cosmology, philosophy of science, the nature of space and time, chaos theory, mathematical economics, and micro-and-macroeconomics."</p><p>Drs. Dinov and Velev began developing spacekime theory around four or five years ago, while working with big data in the healthcare field. "We started looking at data that intrinsically has a temporal dimension to it," Dr. Dinov told me during a video chat. "It's called longitudinal or time varying data, longitudinal time variance—it has many, many names. This is data that varies with time. In biomedicine, this is the de facto, standard data. All big health data is characterized by space, time, phenotypes, genotypes, clinical assessments, and so forth." </p><h2>A better way to manage big data </h2><p>"We started asking big questions," Dinov said. "Why are our models not really fitting too well? Why do we need so many observations? And then, we started playing around with time. We started digging and experimenting with various things. And then we realized two important facts. </p><p>"Number one, if we use what's called color-coded representations of the complex plane, we can define spacekime, or higher dimensional spacetime, in such a way that it agrees with the common observations that we make in (the longitudinal time series in) ordinary spacetime. That agreement was very important to us, because it basically says, yes, the higher dimensional theory does not contradict our common observations. </p><p>"The second realization was that, since this extra dimension of time is imperceptible, we needed to approximate, model, or estimate, one of the unobservable time characteristics, which we call the kime phase. After about a year, we discovered that there is a mathematically elegant tool called the <a href="https://lpsa.swarthmore.edu/LaplaceXform/FwdLaplace/LaplaceXform.html" rel="noopener noreferrer" target="_blank">Laplace Transform</a> that allows us to analytically represent time series data as kime-surfaces. Turns out, the spacekime mathematical manifold is a natural, higher dimensional extension of classical <a href="https://simple.wikipedia.org/wiki/Minkowski_spacetime" rel="noopener noreferrer" target="_blank">Minkowski</a>, four-dimensional spacetime." </p><p>Our understanding of the world is becoming more complex. As a result, we have big data to contend with. How do we find new ways to analyze, interpret and visual such data? Dinov believes spacekime theory can help in some pretty impressive ways. "The result of this multidimensional manifold generalization is that you can make scientific inferences using smaller data samples. This requires that you have a good model or prior knowledge about the phase distribution," he said. "For instance, we can use spacekime process representation to better understand the development or pathogenesis to model the distributions of certain diseases.</p><p>"Suppose we are evaluating fMRIs of Alzheimer's disease subjects. Assume we know the kime phase distribution for another cohort of patients suffering from amyotrophic lateral sclerosis, Lou Gehrig's disease. The ALS kime-phase distribution could be used for evaluating the Alzheimer's patients," and many other neurodegenerative populations. Dinov also thinks spacekime analytics could help improve political polling, increase our understanding of complex financial and environmental events, and even the innerworkings of the human brain, all without having to take the huge samples required today to make accurate models or predictions. Spacekime theory even offers opportunities to design novel AI analytical techniques. But it goes beyond that.</p><h2>The problem of time </h2><p>Spacekime theory can help us make headway on some of the most pernicious inconsistencies in physics, such as <a href="https://plato.stanford.edu/entries/qt-uncertainty/" rel="noopener noreferrer" target="_blank">Heisenberg's uncertainty principle</a> and the seemingly irreconcilable rift between quantum physics and general relativity, what's known as <a href="https://www.quantamagazine.org/quantum-gravitys-time-problem-20161201/" rel="noopener noreferrer" target="_blank">"the problem of time."</a> </p><p>Dinov wrote that the "approach relies on extending the notions of time, events, particles, and wave functions to complex-time (kime), complex-events (kevents), data, and inference-functions." Basically, working with two points of time allows you to make inferences on a radius of points associated with a certain event. With Heisenberg's uncertainty principle, according to this model, since time is a plane, a certain particle would be in one position or phase, time-wise, in terms of velocity, and another phase, in terms of position. </p><p>This idea of hidden dimensions of time is a little like Plato's allegory of the cave or how an X-ray signifies what's underneath, but doesn't convey a 3D image. From a data science perspective, it all comes down to utility. Dinov believes that if we can calculate the true phase dispersion of complex phenomena, we can better understand and control them. </p><p>Drs. Dinov and Velev's book on spacekime theory comes out this August. It's called "<a href="https://www.amazon.com/Data-Science-Complexity-Inferential-Uncertainty/dp/3110697807" rel="noopener noreferrer" target="_blank">Data Science: Time Complexity, Inferential Uncertainty, and Spacekime Analytics</a>". </p>
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