Solar

Joan Feynman Found Her Place in the Sun

Hackaday Solar Hacks -

Google ‘Joan Feynman’ and you can feel the search behemoth consider asking for clarification. Did you mean: Richard Feynman? Image search is even more biased toward Richard. After maybe seven pictures of Joan, there’s an endless scroll of Richard alone, Richard playing the bongos, Richard with Arline, the love of his life.

Yes, Joan was overshadowed by her older brother, but what physicist of the era wasn’t? Richard didn’t do it on purpose. In fact, no one supported Joan’s scientific dreams more than he did, not even their mother. Before Richard ever illuminated the world with his brilliance, he shined a light on his little sister, Joan.

Baby Joan works on the Feynman smirk. Image via r/physics A Sign From Above

Joan Feynman was born in Queens, New York City in 1927 to Lucille and Melville Feynman, nine years after Richard came along. Both children were raised to be insatiably curious. Their parents encouraged them to always ask why, and to take notice of the world around them.

Joan deeply admired her brother and was always interested in whatever he was doing. Richard capitalized on this right away, making Joan his first student. He taught her how to add simple numbers together when she was three. Whenever Joan got one right, Richard let her pull his hair and would make funny faces. Anything Richard learned about math or science, he would repeat all over the house, which had the dual effect of reinforcing his understanding and piquing Joan’s interest.

Their working relationship continued, too. When Joan was five, Richard hired her assist him in his bedroom electronics lab. For a few cents a week she would flip switches at the appropriate time. Sometimes she had to put her finger in a spark gap to amuse his friends.

One night when Joan was quite young, Richard pulled her out of bed and led her down the street to a nearby golf course. He told her to look up into the sky, which was ablaze in the brilliant colors of aurora borealis. Joan was mesmerized. In that moment, her destiny became clear to her.

No one could foil Joan’s plans. Image via Popular Science A Woman’s Place is in a College-Level Astronomy Textbook

At the time, no one knew what caused auroras. Joan became determined to unlock their mysteries. Her mother had other ideas, though. When Joan proclaimed to her at age eight that she wanted to be a scientist, her mother told her that “women can’t do science because their brains aren’t able to understand enough of it.” Joan was crushed. From that day on, she doubted her abilities.

Lucille Feynman wasn’t trying to be cold-hearted or unprogressive. She had marched for women’s suffrage in her teens. Still, she believed that women weren’t as intellectually capable as men. This was then.

For a while, Joan’s aspirations were put on hold. There weren’t many women scientists to look up to in the 1930s, anyway, except for Marie Curie. She was iconic, perhaps too much so. Joan saw her as mythological, a majestic unicorn of scientific greatness, not a human woman she could try to emulate.

Even so, Joan wasn’t discouraged enough to lose interest in science. For one thing, Richard had never stopped rooting for her. When she turned fourteen, he gave her a college-level astronomy textbook. She found the material difficult but took his advice to start over from the beginning when she got stuck.

On page 407, Joan found something that would give her the one thing she needed the most to seal her future—validation. On the page was a graph of spectral absorption lines credited to one Cecilia Payne. Joan was ecstatic. A woman scientist! Finally, concrete proof that her mother was wrong. Not only can women understand science, they can have their work referenced in a textbook. Joan’s confidence was renewed.

The science of homemaking. Image via NPR The Science of Homemaking

Of course, becoming a scientist wasn’t that simple. Joan faced adversity everywhere. During her undergraduate studies at Oberlin, she did all the lab experiments while her ill-prepared lab partner got all the credit. A professor at Syracuse University told Joan she should write her dissertation on cobwebs, because she would encounter them regularly as a housewife.

After finishing her PhD in 1958, Joan tried to find a research scientist position by posting in New York Times classifieds. The listings were split by gender, and they told her she wasn’t allowed to post among the men. But who would look for an astrophysicist in the women’s section?

By the early 1960s, Joan was working for a small company that made solid-state devices. She was also raising two young sons with her husband Rich Hirshberg, a fellow scientist she met at Oberlin. When the commute became too much, she quit to try full-time domesticity. For three years, Joan did nothing but cook, care for the boys, and clean the family’s five-bedroom house. The only semblance of science in her life involved baked goods. Joan was miserable. On the advice of a psychiatrist, she went to Lamont Observatory at Columbia University to look for a job, but worried that she’d been away too long. Immediately, she had three offers.

Solar Interference

At Lamont, Joan studied interactions between the magnetosphere and the solar wind. In those days, astrophysicists believed the magnetosphere was closed and tapered like a teardrop. Joan discovered that it’s actually open-ended, and has a long tail on the side opposite the Sun where the solar wind don’t blow. In an open model, the Sun’s magnetic field more directly influences the magnetosphere.

Several years later at NASA’s Jet Propulsion Laboratory (JPL), Joan was able to demonstrate that aurora happen when solar particles penetrate the magnetosphere. As these particles mix with those in the magnetosphere, the collisions manifest as brilliant colors.

Solar Wind vs. Magnetosphere. Image via NASA

She also studied sunspot cycles and coronal mass ejections (CME). These are solar storms that can greatly affect the magnetosphere and are capable of disabling satellites and interrupting terrestrial communications. At the time, CMEs were difficult to pinpoint. Joan’s research showed that wherever there are CMEs, there is also a significant increase of helium in the solar wind.

Joan also proved that CMEs occur in groups. From this research, she devised a statistical calculation to predict the number of high-energy particles that could bounce off the average spaceship during its lifetime. This important development resulted in better designs with greater longevity. In 1999, NASA honored her with an Exceptional Scientific Achievement Award.

Joan retired from JPL in 2002. Since then, she has turned her focus to the effect of solar cycle variations on climate change  and historical climate anomalies. At the age of 90, she’s still fascinated by all the crazy things the Sun does and is still determined to find explanations.

Joan thinks the Sun is excellent. Image via BBC

 


Filed under: Hackaday Columns, History, Original Art, solar hacks

Mendocino Motor Drives Cubicle Conversations

Hackaday Solar Hacks -

Mendocino motors are solar-powered electric motors that rely on pseudo-levitation.  The levitation comes from magnets mounted on either end of the shaft, which repel same-field magnets fixed below them into the base.  When light shines on the solar panels, current flows through connected magnet wire windings, creating an electromagnetic field that interacts with a large stationary magnet mounted underneath. These constantly repelling forces spin the shaft, and the gaps between the solar panels provide the on-off cycle needed to make it spin 360°.

As [Konstantin] discovered, building this simple motor and getting it to spin depends on a lot of factors. The number of windings, the weight of each solar panel, and the magnet sizes all figure in. [Konstantin]’s struggles are your gain, however. His Instructable takes the guesswork out of the tolerances and he designed a nice, open-source 3D-printed structure to boot.

You’re right, these motors can’t do much work. But it would definitely look cool on your desk and might even start a conversation or two. If not, whip up this little electromagnetic train.


Filed under: how-to, solar hacks

Quick and Easy Solar Hot Air Balloon

Hackaday Solar Hacks -

[Becky Stern] likes to harness the power of the Sun. Most of us will immediately think of solar cells and other exotic solar energy techniques. But [Becky] shows how to make a hot air balloon using nothing but tape and garbage bags.

The idea is quite simple. You form a large envelope from black trash bags and fill it with air. Becky does that by just running with it, tying it off, and topping off with a little manual blowing. Once the sun heats the black bag, it floats.

We were hoping she’d show us if there was any margin for payload, but she didn’t. However, electronics are getting smaller and lighter all the time. Sure, batteries weigh a lot, but maybe there would be an opportunity to mount some solar-powered device on the balloon to further harness the sun’s energy.

If you want to have a go at that, [Becky] has a free solar class that covers using the sun to engrave wood and using solar panels to charge a battery or power an Arduino.

We doubt this solar zeppelin will perform like a propane-powered balloon but it is still fun and educational. It doesn’t seem likely that you are going to reach space with it either.


Filed under: solar hacks

A Solar Freakin’ Walkway

Hackaday Solar Hacks -

Looking to add a little pizzazz to your back garden? Are those strings of lights hung in the trees looking a little dated? Why not try lighting your garden path with DIY solar-powered pavers?

If [jfarro]’s project looks like a miniature version of the much-touted solar freakin’ roadways concept, rest assured that there are huge differences. For one, these lighted pavers actually work — trust me on this; I live not far from the demo site for the Solar Roadways and the degree to which it underwhelms cannot be overstated. Granted, a garden path is a lot simpler to engineer than a road, but many of the challenges remain.

Using recycled glass blocks that are usually reserved for walls and windows, [jfarro] figured out how to attach Neopixel rings to the underside and waterproof them with a silicone conformal coating. The 12 lighted pavers he built draw considerable current, so a 45-watt solar array with charge controller and battery were installed to power the pavers. An Arduino and a motion sensor control the light show when someone approaches; more complicated programs are planned.

Hats off the [jfarro] for taking on a project like this. We don’t often see builds where electrical engineering meets civil engineering, and even on a small scale, dealing with dirt, stone, and water presents quite a few challenges. Here’s hoping his project lasts longer than the Solar Roadways project did.


Filed under: home hacks, solar hacks
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