Sea Level: How Do We Measure Global Ocean Levels And Do Rising Oceans Change That Benchmark?

March 8, 2021 by Adam Zeloof 34 Comments

Every summer you go down the shore, but lately you’ve begun to notice that the beach seems narrower each time you visit. Is that the sea level rising, or is the sand just being swept away? Speaking of sea levels, you keep hearing that they rise higher every year — but how exactly is that measured? After all, you can’t exactly use a ruler. As it turns out, there are a number of clever systems in place that can accurately measure the global sea level down to less than an inch and a half.

Not only are waves always rippling across the ocean’s surface, but tides periodically roll in and out, making any single instantaneous measurement of sea level hopelessly inaccurate. Even if you plan to take hundreds or thousands of measurements over the course of weeks or months, taking the individual measurements is still difficult. Pick a nice, stable rock in the surf, mark a line on it, and return every hour for two weeks to hold a tape measure up to it. At best you’ll get within six inches on each reading, no matter what you’ll get wet, and at worst the rock will move and you’ll get a damp notebook full of useless numbers. So let’s take a look at how the pros do it.

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We’re Cloning Animals From The “Frozen Zoo”; Like A Seed Bank But For Animals

March 4, 2021 by Zoe Skyforest 30 Comments

Seed banks are facilities of great value to biodiversity and agriculture around the world. These facilities are used to house stocks of seeds of a wide variety, helping to maintain genetic diversity and avoid the permanent loss of various plant species. While there are some challenges, the basic requirements to run a simple seed bank are to keep a selection of seeds at low temperature and humidity to maximise their viable lifespan.

When it comes to animals, things become more difficult — one can’t simply plant an old seed in the ground and grow a fresh new meerkat, for example. Preservation of animal genetic material poses its own unique set of challenges — ones that the San Diego “Frozen Zoo” don’t shy away from. They’ve recently shown the viability of the program with the healthy birth of a ferret cloned from an animal that died in 1988.

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What Uses More Power Than Argentina But Doesn’t Dance The Tango?

March 3, 2021 by Jenny List 180 Comments

There’s been a constant over the last few weeks’ news, thanks to Elon Musk we’re in another Bitcoin hype cycle. The cryptocurrency soared after the billionaire endorsed it, at one point coming close to $60k, before falling back to its current position at time of writing of around $47k. The usual tide of cryptocurrency enthusiasts high on their Kool-Aid hailed the dawn of their new tomorrow, while a fresh cesspool of cryptocurrency scam emails and social media posts lapped around the recesses of the Internet.

This Time It’s Different!

The worst phrase that anyone can normally say about a financial bubble is the dreaded phrase “This time it’s different“, but there is something different about this Bitcoin hype cycle. It’s usual to hear criticism of Bitcoin for its volatility or its sometime association with shady deals, but what’s different this time is that the primary criticism is of its environmental credentials. The Bitcoin network, we are told, uses more electricity than the Netherlands, more than Argentina, and in an age where global warming has started to exert an uncomfortable influence over our lives, we can’t afford such extravagance and the emissions associated with them.

Here at Hackaday we are more concerned with figures than arguments over the future of currency, so the angle we take away from it all lies with those power stats. How much energy does Argentina use, and is the claim about Bitcoin credible?

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Using Phase Change Materials For Energy Storage

March 3, 2021 by Zoe Skyforest 35 Comments

Renewable energy sources are becoming increasingly popular. However, such energy can be wasted if an excess is available when it’s not yet needed. A particularly relevant example is solar power; solar panels provide most of their output during the day, while often a household’s greatest energy use is at night.

One way to get around this problem is by storing excess energy so that it can be used later. The most common way this is done is with large batteries, however, it’s not the only game in town. Phase change materials are proving to be a useful tool to store excess energy and recover it later – storing energy not as electricity, but as heat. Let’s take a look at how the technology works, and some of its most useful applications. Continue reading “Using Phase Change Materials For Energy Storage” →

An Homage To Daft Punk In Fan-Made Helmets Through The Years.

March 2, 2021 by Jenny List 32 Comments

It’s with sadness that we note the end to an end. The French dance music duo Daft Punk have split up, announced in a video that’s has already clocked 22 million views.The band have inspired hardware geeks across the world not just with their music but the way they present themselves. A perennial project has been to replicate in some way their iconic robot helmets.

Ben Heck's 2009 take on the helmet — Harrison Krix’s 2009 take on Guy-Manuel de Homem-Christo’s helmet.

The artists themselves have been reticent about the exact technology that powers their headgear, but while this is a source of endless mystery and speculation to the music press it’s safe to assume from our perspective that their designers have the same parts at their disposal as we have. Microcontrollers, EL wire, and LEDs are universal, so the challenge lies in artistic expression with the helmet design rather than in making the effects themselves. We’ve reached into the archives for a bit of Daft Punk helmet nostalgia, so stick on Harder Better Faster and lets take a look at them, er, one more time.

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Wind Turbines And Ice: How They’re Tailored For Specific Climates

March 1, 2021 by Bryan Cockfield 75 Comments

Wind turbines are incredible pieces of technology, able to harvest wind energy and deliver it to the power grid without carbon emissions. Their constant development since the first one came online in 1939 mean that the number of megawatts produced per turbine continues to rise as price per megawatt-hour of wind energy continues to fall. Additionally, they can operate in almost any climate to reliably generate energy almost anywhere in the world from Canada to the North Atlantic to parts beyond. While the cold snap that plowed through the American South recently might seem to contradict this fact, in reality the loss of wind power during this weather event is partially a result of tradeoffs made during the design of these specific wind farms (and, of course, the specifics of how Texas operates its power grid, but that’s outside the scope of this article) rather than a failure of the technology itself.

First, building wind turbines on the scale of megawatts isn’t a one-size-fits-all solution. Purchasing a large turbine from a company like GE, Siemens, or Vestas is a lot like buying a car. A make and model are selected first, and then options are selected for these base models. For example, low but consistent wind speeds demand a larger blade that will rotate at a lower speed whereas areas with higher average wind speeds may be able to get by with smaller and less expensive blades for the same amount of energy production. Another common option for turbines is cold weather packages, which include things like heaters for the control systems, hydraulics, and power electronics, additional insulation in certain areas, and de-icing solutions especially for the turbine blades.

In a location like Texas that rarely sees cold temperatures for very long, it’s understandable that the cold weather packages might be omitted to save money during construction (although some smaller heaters are often included in critical areas to reduce condensation or humidity) but also to save on maintenance as well: every part in a wind turbine has to be maintained. Continuing the car analogy, it’s comparable to someone purchasing a vehicle in a cold climate that didn’t come equipped with air conditioning to save money up front, but also to avoid repair costs when the air conditioning eventually breaks. However, there are other side effects beyond cost to be considered when installing equipment that’s designed to improve a turbine’s operation in cold weather.

Let’s dig into the specifics of how wind turbine equipment is selected for a given wind farm.

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Should I Use Wheels Or Tracks?

February 26, 2021 by Zoe Skyforest 32 Comments

When it comes to dominating offroad performance, many people’s first thought is of tracked vehicles. Bulldozers, tanks and excavators all use treads, and manage to get around in difficult terrain without breaking a sweat. Today, we’re exploring just what makes tracked vehicles so capable, as well as their weaknesses.

It’s All About Ground Pressure

The various parts of a tank’s propulsion system.

Let’s first look at how tank tracks work. There are a huge variety of designs, with differences depending on application. Different trends have been followed over time, and designs for military use in combat differ from those used for low-speed construction machines, for example. But by looking at a basic tank track design, we can understand the basic theory. On tanks, the track or tread itself is usually made up of individual steel links that are connected together with hinges, though other machines may use rubber tracks instead. The tracks are wrapped around one or more drive wheels, often cogged, which directly pull on the track. On the bottom of the vehicle are the road wheels, which ride on top of the track where it lies on the ground. The weight of the vehicle is carried through the road wheels and passed on to the tread, spreading out the load across a broader area. Outside of this, the track system may also have one or more idler wheels used to keep the track taught, as well as return rollers to guide the track back around without touching the road wheels.

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