The Dreamcast Legacy

December 22, 2021 by Matthew Carlson 48 Comments

The Dreamcast is a bit of an odd beast. Coming on the heels of the unpopular Sega Saturn, the Dreamcast was meant to be a simple console built with off-the-shelf parts and released in late 1998. The Nintendo 64 was already tough competition (1996). Ultimately, the Dreamcast fell out of the public eye in the early 2000s as the Playstation 2, Xbox, and Gamecube were all released with incredible fanfare just a few years later. In some sense, Sega’s last console is a footnote in gaming history.

But despite not achieving the success that Sega hoped for, the Dreamcast has formed a small cult following, because as we know, nothing builds a cult-like following like an untimely demise. Since its release, it has gained a reputation for being ahead of its time. It was the first console to include a modem for network play and an easy storage solution for transferring game data between consoles via the VMUs that docked in the controllers. It had innovative and classic games such as Crazy Taxi, Jet Set Radio, Phantasy Star Online, and Shenmue. Microsoft even released a version of Windows CE with DirectX allowing developers to port PC games to the console quickly.

We see our fair share of console hacks here on Hackaday, but what is the ultimate legacy of the Dreamcast? How did it come to be? What happened to it, and why did so much of Sega’s hopes ride on it? Continue reading “The Dreamcast Legacy” →

Plastics: Photopolymers For 3D Printing And Beyond

December 21, 2021 by Dan Maloney 9 Comments

Chances are good that if you’ve done any 3D printing, it was of the standard fused deposition modeling variety. FDM is pretty simple stuff — get a bit of plastic filament hot enough, squeeze the molten goo out of a fine nozzle, control the position of the nozzle more or less precisely in three dimensions, and repeat for hours on end until your print is done. To the outsider it looks like magic, but to us it’s just another Saturday afternoon.

Resin printing is another thing altogether, and a lot closer to magic for most of us. The current crop of stereolithography printers just have a high-resolution LCD display between a UV light source and a build tank with a transparent bottom. Prints are built up layer by layer by flashing UV light patterns into the tank as a build plate slowly lifts it up from the resin, like some creature emerging from the primordial goo.

Of course it’s all just science, but if there is any magic in SLA printing, surely it’s in the resins used for it. Their nondescript brown plastic bottles and information-poor labels give little clue as to their ingredients, although their hydrocarbon reek and viscous, sticky texture are pretty good clues. Let’s take a look inside the resin bottle and find out what it is that makes the magic of SLA happen.

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Is Cloud Seeding Good, Bad, Or Ugly?

December 20, 2021 by Lewin Day 34 Comments

The Chinese Communist Party celebrated its centenary on the 1st of July, 2021. For such a celebration, clear skies and clean air would be ideal. For the capable nation-state, however, one needn’t hope against the whims of the weather. One can simply control it instead!

A recent paper released by Tsinghua University indicated that China had used cloud seeding in order to help create nicer conditions for its 100-year celebration. Weather modification techniques have been the source of some controversy, so let’s explore how they work and precisely what it was that China pulled off.

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The Real Science (Not Armchair Science) Of Consciousness

December 15, 2021 by Steven Dufresne 43 Comments

Among brain researchers there’s a truism that says the reason people underestimate how much unconscious processing goes on in your brain is because you’re not conscious of it. And while there is a lot of unconscious processing, the truism also points out a duality: your brain does both processing that leads to consciousness and processing that does not. As you’ll see below, this duality has opened up a scientific approach to studying consciousness.

Are Subjective Results Scientific?

Researcher checking fMRI images. — Checking fMRI images.

In science we’re used to empirical test results, measurements made in a way that are verifiable, a reading from a calibrated meter where that reading can be made again and again by different people. But what if all you have to go on is what a person says they are experiencing, a subjective observation? That doesn’t sound very scientific.

That lack of non-subjective evidence is a big part of what stalled scientific research into consciousness for many years. But consciousness is unique. While we have measuring tools for observing brain activity, how do you know whether that activity is contributing to a conscious experience or is unconscious? The only way is to ask the person whose brain you’re measuring. Are they conscious of an image being presented to them? If not, then it’s being processed unconsciously. You have to ask them, and their response is, naturally, subjective.

Skepticism about subjective results along with a lack of tools, held back scientific research into consciousness for many years. It was taboo to even use the C-word until the 1980s when researchers decided that subjective results were okay. Since then, here’s been a great deal of scientific research into consciousness and this then is a sampling of that research. And as you’ll see, it’s even saved a life or two.

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Orbital Safety: The Challenges Of Surviving Space Junk

December 14, 2021 by Maya Posch 22 Comments

Hanging around in earth orbit is like walking into the middle of a Wild West gunfight — bullets are flying around everywhere, and even though none are purposefully aimed at you, one might have your name on it. Many of these bullets are artificial satellites that are actively controlled and monitored, but we also find dead satellites, remnants of satellites, discarded rocket stages, tools lost during spacewalks, and even flecks of paint and rust, much of it zipping around at multiple kilometers per second without any guidance.

While removing this space debris directly would be ideal, the reality is that any spacecraft and any spacesuit that has to spend time in orbit needs to be capable of sustaining at least some hits by space debris impacting it.

Orbital Mechanics

That it’s easy to create new debris should come as no surprise to anyone. What may take a bit more imagination is just how long it can take for this debris to make its way towards earth’s atmosphere, where it will uneventfully burn up. Everything in orbit is falling toward the earth, but its tangential velocity keeps it from hitting — like a marble spinning around the hole in a funnel. Drag from the planet’s atmosphere is the friction that eventually slows the object down, and where it orbits in the planet’s atmosphere determines how long this descent will take. Continue reading “Orbital Safety: The Challenges Of Surviving Space Junk” →

Mining And Refining: From Red Dirt To Aluminum

December 13, 2021 by Dan Maloney 29 Comments

No matter how many syllables you use to say it, aluminum is one of the most useful industrial metals we have. Lightweight, strong, easily alloyed, highly conductive, and easy to machine, cast, and extrude, aluminum has found its way into virtually every industrial process and commercial product imaginable.

Modern life would be impossible without aluminum, and yet the silver metal has been in widespread use only for about the last 100 years. There was a time not all that long ago that aluminum dinnerware was a status symbol, and it was once literally worth more than its weight in gold. The reason behind its one-time rarity lies in the effort needed to extract the abundant element from the rocks that carry it, as well as the energy to do so. The forces that locked aluminum away from human use until recently have been overcome, and the chemistry and engineering needed to do that are worth looking into in our next installment of “Mining and Refining.”

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Keynote Video: Dr. Keith Thorne Explains The Extreme Engineering Of The LIGO Hardware

December 9, 2021 by Mike Szczys 18 Comments

The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a huge installation measured in kilometers that is listening for wrinkles in space-time. Pulling this off is a true story of hardware and software hacking, and we were lucky to have Dr. Keith Thorne dive into those details with his newly published “Extreme Instruments for Extreme Astrophysics” keynote from the 2021 Hackaday Remoticon.

Gravity causes space-time to stretch — think back to the diagrams you’ve seen of a massive orb (a star or planet) sitting on a plane with grid lines drawn on it, the fabric of that plane being stretch downward from the mass of the orb. If you have two massive entities like black holes orbiting each other, they give off gravitational waves. When they collide and merge, they create a brief but very strong train of waves. Evidence of these events are what LIGO is looking for.

Rai Weiss had the idea to look for gravitational waves using laser interferometers in about 1967, but the available laser technology was too new to accomplish the feat. In an interferometer, a laser is shot through a beam splitter and one beam reflects out and back over a distance, and is then recombined with the other half using a photodetector to measure the intensity of light. As the distance in the long leg changes, the relative phase of the lasers shift, and the power detected will vary.

LIGO is not your desktop interferometer. It uses a 5 kW laser input. The 4 km legs of the interferometer bounce the light back and forth 1,000 times for an effective 4,000 km travel distance. These legs are kept under extreme vacuum and the mirrors are held exceptionally still. It’s worth it; the instrument can measure at a precision of 1/10,000 the diameter of a proton!

Continue reading “Keynote Video: Dr. Keith Thorne Explains The Extreme Engineering Of The LIGO Hardware” →