<story><title>Scientists begin building highly accurate digital twin of our planet</title><url>https://ethz.ch/en/news-and-events/eth-news/news/2021/02/a-highly-accurate-digital-twin-of-our-planet.html</url></story><parent_chain></parent_chain><comment><author>jandrewrogers</author><text>I am highly skeptical of this approach. Not only has this been attempted before, it appears to be on course to repeat the same technical design mistakes that caused prior attempts to fail. You can&amp;#x27;t decompose weather&amp;#x2F;climate style supercomputing models below a certain resolution because the fundamental characteristics of the computation are not meaningfully representable that way. Scalable models that correctly and efficiently capture the macro effects of many types of sparse, high-resolution dynamics require much more sophisticated computer science, systems engineering, and ways of representing data. You can&amp;#x27;t brute force it.&lt;p&gt;In particular, this is a notoriously poor approach to modeling complex large-scale interactions between humans and their environments. There was a study I was involved in last year to determine why one of the epidemiological models for COVID was so badly off target. The root cause was modeling human behavior in the same way you would model weather, which is quite inappropriate but the implementors of the epidemiological model did not have the expertise to know better.&lt;p&gt;The selection of GPUs is also not appropriate for the nominal objectives of the program. When modeled correctly, i.e. not as weather, these kinds of things aren&amp;#x27;t the kind of workload GPUs are good at. They tend to look more like very high dimensionality sparse graphs -- latency-hiding is more important than computational throughput. CPUs are actually quite good at this.&lt;p&gt;This looks more like a program more designed to produce press releases than useful results.</text></comment>
<story><title>Scientists begin building highly accurate digital twin of our planet</title><url>https://ethz.ch/en/news-and-events/eth-news/news/2021/02/a-highly-accurate-digital-twin-of-our-planet.html</url></story><parent_chain></parent_chain><comment><author>thisisbrians</author><text>This is an extremely ambitious project, and hopefully turns out to be worthwhile. For complex&amp;#x2F;interconnected systems, building ~accurate simulations can vastly decrease the cost of decision-making, and I&amp;#x27;m very bullish on digital twin technology, generally. Trying things out in a simulation can be a cheap way to guide more detailed engineering analysis and &amp;#x27;rough in&amp;#x27; an approach.&lt;p&gt;As an example, my startup, Bractlet (bractlet.com), uses detailed, physics-based energy simulation (aka &amp;quot;digital energy twin&amp;quot;) technology as a tool to optimize HVAC design and controls in large commercial buildings. I&amp;#x27;m sure efficacy varies widely by domain, but it&amp;#x27;s worked extremely well for us so far; we typically help our customers save about 20-30% on their energy expenditures annually, and the digital twin is the bedrock of our approach.</text></comment>