Cecilia Payne-Gaposchkin Saw Through The Stars

We as humans are limited in the ways we can look at things ourselves, and rely on on the different perspectives and insights of others to help make sense of things. All it takes is one person to look at a data set and find something completely different that changes our fundamental perception of the universe.

Cecilia Payne-Gaposchkin discovered that stars are primarily made of hydrogen and helium, at a time when astronomers thought that the Sun and the Earth had no significant elemental differences. She proposed that hydrogen wasn’t only more common, but that it was a million times more common.

This outlandish conclusion was roundly dismissed at the time, and she aquiesced to tone down some of the conclusions in her thesis, until her findings were widely confirmed a few years later. Truly groundbreaking, the discovery of the prevalence of hydrogen in stars paved the way for our current understanding of their role as the furnaces for the heavier elements that we know and love, and indeed are composed of.

Meteorites, Comets, and Bee Orchids

Cecilia Helena Payne was born May 10th, 1900 in Wendover, Buckinghamshire, England. She was one of three children born to Emma and Edward, a lawyer, historian, and musician. Her father died with she was four years old, leaving her mother to raise the family alone. Continue reading “Cecilia Payne-Gaposchkin Saw Through The Stars”

Fuel Cell Drone Aims For Extended Flight Times

The RC world was changed forever by the development of the lithium-polymer battery. No longer did models have to rely on expensive, complicated combustion engines for good performance. However, batteries still lack the energy density of other fuels, and so flying times can be limited. Aiming to build a drone with impressively long endurance, [Игорь Негода] instead turned to hydrogen power.

The team fitted a power meter to the plane, aiming a camera at it to measure power draw during flight.

With a wingspan of five meters, and similar length, the build is necessarily large in order to carry the hydrogen tank and fuel cell that will eventually propel the plane, which uses a conventional brushless motor for propulsion. Weighing in at 6 kilograms, plenty of wing is needed to carry the heavy components aloft. Capable of putting out a maximum of 200W for many hours at a time, the team plans to use a booster battery to supply extra power for short bursts, such as during takeoff. Thus far, the plane has flown successfully on battery power, with work ongoing to solve handling issues and determine whether the platform can successfully fly on such low power.

We’re eager to see how the project develops, particularly in regards to loiter time. We can imagine having a few pilots on hand may be necessary with such a long flight time planned — other drones of similar design have already surpassed the 60-minute mark. Video after the break.

Continue reading “Fuel Cell Drone Aims For Extended Flight Times”

Fuel From Water Using Only An Arc Welder

Water, high currents, blinding balls of plasma, and a highly flammable gas that’s toxic enough to kill you in three minutes if you breathe enough of it. What’s not to love about this plasma-powered water gas generator?

In all seriousness, [NightHawkInLight] is playing with some dangerous stuff here, and he’s quite adamant about this one being firmly in the “Don’t try this at home” category. But it’s also fascinating stuff, since it uses nothing but a tank of water and an electric arc to produce useful amounts of fuel very quickly. It’s easy to jump to the conclusion that he’s talking about the electrolytic splitting of water into the hydrogen-oxygen mix HHO, but this is something else entirely.

Using a carbon electrode torch connected to his arc welder, a setup that’s similar to the one he used to make synthetic rubies, [NightHawkInLight] is able to strike an underwater arc inside a vessel that looks for all the world like a double-barreled bong. The plasma creates a mixture of carbon monoxide and hydrogen which accumulates very rapidly in the gasometer he built to collect the flammable products produced by a wood gasifier.

The water gas burns remarkably cleanly, but probably has limited practical uses. Unless you live somewhere where electricity costs practically nothing, it’ll be hard to break even on this. Still, it’s an interesting look at what’s possible when plasma and water mix.

Continue reading “Fuel From Water Using Only An Arc Welder”

Are Hydrogen Cars Still Happening?

Potentially coming to a service station near you.

In every comment section, there’s always one. No matter the electric vehicle, no matter how far the technology has come, there’s always one.

“Only 500 miles of range? Electric cars are useless! Me, and everyone I know, drives 502 miles every day at a minimum! Having to spend more than 3 minutes to recharge is completely offensive to my entire way of life. Simply not practical, and never will be.”

Yes, it’s true, electric cars do have limited range and can take a little longer to recharge than a petrol or diesel powered vehicle. Improvements continue at a rapid pace, but it’s not enough for some.

To these diehards, hydrogen fuel cell vehicles may have some attractive benefits. By passing hydrogen gas through a proton-exchange membrane, electricity can be generated cleanly with only water as a byproduct. The technology holds a lot of promise for powering vehicles, but thus far hasn’t quite entered our daily lives yet. So what is the deal with hydrogen as a transport fuel, and when can we expect to see them in numbers on the ground?

Continue reading “Are Hydrogen Cars Still Happening?”

A Hydrogen Fuel Cell Drone

When we think about hydrogen and flying machines, it’s quite common to imagine Zeppelins, weather balloons and similar uses of hydrogen in lighter-than-air craft to lift stuff of the ground. But with smaller and more efficient fuel cells, hydrogen is gaining its place in the drone field. Project RACHEL is a hydrogen powered drone project that involves multiple companies and has now surpassed the 60 minutes of flight milestone.

The initial target of the project was to achieve 60 minutes of continuous flight while carrying a 5 kg payload. The Lithium Polymer battery-powered UAVs flown by BATCAM allow around 12 minutes of useable flight. The recent test of the purpose-built fuel cell powered UAV saw it fly for an uninterrupted 70 minutes carrying a 5 kg payload.  This was achieved on a UAV with below 20 kg maximum take-off mass, using a 6-litre cylinder containing hydrogen gas compressed to 300 bar.

While this is not world record for drones and it’s not exactly clear if there will be a commercial product nor the price tag, it is still an impressive feat for a fuel cell powered flying device. You can watch the footage of one of their tests bellow:

Continue reading “A Hydrogen Fuel Cell Drone”

Fun With A Hydrogen Thyratron

There’s something oddly menacing about some vacuum tubes. The glass, the glowing filaments, the strange metal grids and wires suspended within – all those lead to a mysterious sci-fi look and the feeling that strange things are happening in there.

Add in a little high voltage and a tube that makes its own hydrogen, and you’ve got something extra scary. This hydrogen thyratron ended up being just the thing for [Kerry Wong]’s high-voltage, high-current experiments. One would normally turn to the solid-state version of the thyratron, the silicon controlled rectifier (SCR), to switch such voltages. But the devices needed to handle the 30 amps [Kerry] had in mind were exorbitant, and when the IGBTs he used as a substitute proved a little too fragile he turned to the Russian surplus market for help. There he found a TGI1-50/5 hydrogen thyratron, a tube that has a small hydrogen gas generator inside – thyratrons are actually gas-filled rather than vacuum tubes and switch heavy currents through plasma conduction. [Kerry] set up a demo circuit with a small RC network to provide the fast switching pulse preferred by the thyratron, and proceeded to run 3500 volts through a couple of 1/4-W resistors with predictable results. The video below shows the fireworks.

Can’t get enough of the thyratron’s lovely purple glow? We’ve seen it before on this beautiful old switch-mode power supply. The versatile tubes also helped rebuild the first vocal encryption system.

Continue reading “Fun With A Hydrogen Thyratron”

The Hydrogen Economy May Be Coming Through Your Cooker

About an hour’s drive from where this is being written there is a car plant, and as you drive past its entrance you may notice an unobtrusive sign and an extra lane with the cryptic road marking “H2”. The factory is the Honda plant at Swindon, it produces some of Europe’s supply of Civics, and the lane on the road leads to one of the UK or indeed the world’s very few public hydrogen filling stations. Honda are one of a select group of manufacturers who have placed a bet on a future for environmentally sustainable motoring that lies with hydrogen fuel cell technologies.

The hydrogen-powered Honda Clarity FCV, a car most of us will probably never see. Lcaa9 [CC BY-SA 4.0].
The hydrogen-powered Honda Clarity FCV, a car most of us will probably never see. Lcaa9 [CC BY-SA 4.0].
The trouble for Honda and the others is that if you have seen a Honda Clarity FCV or indeed any hydrogen powered car on the road anywhere in the world then you are among a relatively small group of people. Without a comprehensive network of hydrogen filling stations such as the one in Swindon there is little incentive to buy a hydrogen car, and of course without the cars on the road there is little incentive for the fuel companies to invest in hydrogen generating infrastructure such as the ITM Power electrolysis units that seem to drive so many of the existing installations. By comparison an electric car is a much safer bet; while the charging point network doesn’t rival the gasoline filling station network there are enough to service the electric motorist and a slow charge can be found from most domestic supplies. Continue reading “The Hydrogen Economy May Be Coming Through Your Cooker”