Science

1283 Articles

Sharkskin Coating Reduces Airliner Fuel Use, Emissions

August 23, 2023 by 66 Comments

The aviation industry is always seeking advancements to improve efficiency and reduce carbon emissions. The former is due to the never-ending quest for profit, while the latter helps airlines maintain their social license to operate. Less cynically, more efficient technologies are better for the environment, too.

One of the latest innovations in this space is a new sharkskin-like film applied to airliners to help cut drag. Inspired by nature itself, it’s a surface treatment technology that mimics the unique characteristics of sharkskin to enhance aircraft efficiency. Even better, it’s already in commercial service! Continue reading “Sharkskin Coating Reduces Airliner Fuel Use, Emissions” →

The Clathrate Gun Hypothesis: Unearthing Puzzles Of Warming Events Past

August 21, 2023 by 36 Comments

As the Earth continues to warm at a worrying rate, scientists continue to work to understand the processes and mechanisms at play. Amidst the myriad of climate-related theories and discussions, the clathrate gun hypothesis stands out not only for its intriguing name but for the profound implications it might have on our understanding of global warming events.

Delving into this hypothesis is akin to reading a detective novel written by Mother Earth, with clues hidden deep beneath the ocean and Arctic ice. It’s a great example of how scientists attempt to predict the future by unpicking the mysteries of the past.

Continue reading “The Clathrate Gun Hypothesis: Unearthing Puzzles Of Warming Events Past” →

Several video clips of a robot arm manipulating objects in a kitchen environment, demonstrating some of the 12 generalized skills

RoboAgent Gets Its MT-ACT Together

August 20, 2023 by 7 Comments

Researchers at Carnegie Mellon University have shared a pre-print paper on generalized robot training within a small “practical data budget.” The team developed a system that breaks movement tasks into 12 “skills” (e.g., pick, place, slide, wipe) that can be combined to create new and complex trajectories within at least somewhat novel scenarios, called MT-ACT: Multi-Task Action Chunking Transformer. The authors write:

Trained merely on 7500 trajectories, we are demonstrating a universal RoboAgent that can exhibit a diverse set of 12 non-trivial manipulation skills (beyond picking/pushing, including articulated object manipulation and object re-orientation) across 38 tasks and can generalize them to 100s of diverse unseen scenarios (involving unseen objects, unseen tasks, and to completely unseen kitchens). RoboAgent can also evolve its capabilities with new experiences.

Continue reading “RoboAgent Gets Its MT-ACT Together” →

Measuring Planck’s Constant (Again)

August 18, 2023 by 8 Comments

There are many well-known physical constants, but it always interests us when someone can approximately measure them using equipment you probably have. We could pretend it is because we want to help kids do science projects, but who are we really kidding? It is just the cool factor. [Stoppi] shows us several neat ways to measure Planck’s constant (German language, Google Translate link) using things like LEDs, solar cells, and common test equipment. If you don’t want to translate the web page, you can also see the setup and the math behind it in the video below.

If complex math triggers you, this might not be the video for you. The particular test in the video does require a very low current measurement, but that’s not very hard to arrange these days. There are actually several methods covered in the post, and one of them uses one of those familiar “component testers” that has an Atmel CPU, a socket, and an LCD. These can measure the forward current of LEDs, and if you know the wavelength of the LED, you can determine the constant. There’s even a custom device that integrates several LEDs to do the job.

Continue reading “Measuring Planck’s Constant (Again)” →

Why Nuclear Bombs Can’t Set The World On Fire

August 17, 2023 by 64 Comments

Before the first atomic bomb was detonated, there were some fears that a fission bomb could “ignite the atmosphere.” Yes, if you’ve just watched Oppenheimer, read about the Manhattan Project, or looked into atomic weapons at all, you’ll be familiar with the concept. Physicists determined the risk was “near zero,” proceeded ahead with the Trinity test, and the world lived to see another day.

You might be wondering what this all means. How could the very air around us be set aflame, and how did physicists figure out it wasn’t a problem? Let’s explore the common misunderstandings around this concept, and the physical reactions at play.

Continue reading “Why Nuclear Bombs Can’t Set The World On Fire” →

Building A DIY Cloud Chamber

August 16, 2023 by 7 Comments

[RCLifeOn] happened to come into possession of some radioactive uranium ore. He thus decided to build a cloud chamber to visualize the products of radioactive decay in a pleasing visual manner.

The construction is fairly straightforward stuff. A 3D-printer build plate was used to heat isopropyl alcohol to a vapor, while a bank of thermoelectric coolers then cool the alcohol down to -30 C to create a dense fog. The build uses a glass chamber with a bank of powerful LEDs to illuminate the fog, making it easier to see the trails from radioactive particles passing through. [RCLifeOn] later used a variety of radioactive sources to deliver a bunch of particles into the chamber for more action, too. He also experimented with blocking particles with a variety of materials.

It’s one of the bigger cloud chambers we’ve seen, and seems to work great. You can build a simple version pretty easily, or you could travel to a local museum or science center if you’re too busy to tackle it at home. Video after the break.

Continue reading “Building A DIY Cloud Chamber” →

Giving Solar Power’s Mortal Enemies A Dusting Without Wasting Water

August 16, 2023 by 28 Comments

A prerequisite for photovoltaic (PV) and concentrated solar power (CSP) technologies to work efficiently is as direct an exposure to the electromagnetic radiation from the sun as possible. Since dust and similar particulates are excellent at blocking the parts of the EM spectrum that determine their efficiency, keeping the panels and mirrors free from the build-up of dust, lichen, bird droppings and other perks of planetary life is a daily task for solar farm operators. Generally cleaning the panels and mirrors involves having trucks drive around with a large water tank to pressure wash the dirt off, but the use of so much water is problematic in many regions.

Keeping PV panels clean is also a consideration on other planets than Earth. So far multiple Mars rovers and landers have found their demise at the hands of Martian dust after a layer covered their PV panels, and Moon dust (lunar regolith) is little better. Despite repeated suggestions by the peanut gallery to install wipers, blowers or similar dust removal techniques, keeping particulates from sticking to a surface is not as easy an engineering challenge as it may seem, even before considering details such as the scaling issues between a singular robot on Mars versus millions of panels and mirrors on Earth.

There has been research into the use of the electrostatic effect to repel dust, but is there a method that can keep both solar-powered robots on Mars and solar farms on Earth clean and sparkling, rather than soiled and dark?

Continue reading “Giving Solar Power’s Mortal Enemies A Dusting Without Wasting Water” →