Yesterday. in the Northern Hemisphere we celebrated our annual longest day -the Summer Solstice. The Solstice is the moment when the earth's tilt toward the sun reaches its maximum and the sun is directly over the Tropic of Cancer - a line around the Earth at 23.5 deg latitude north of the equator. The solstice is due to the tilt of the Earth's rotational axis. If the planet's rotational axis was straight up and down, we would have no change in the length of daylight or nighttime and therefore no seasons. But, due to the axial tilt, the Northern Hemisphere is tilted toward the sun in June and away from the sun in December. Of course the opposite occurs in the Southern Hemisphere. So yesterday for our friends Down Under - they experienced the shortest day (their winter solstice). Planetary scientists theorize the Earth's axial tilt was created when the protoplanet Theia collided with our early Earth, 4.5 billion years ago. This pushed early Earth over on its side - 23.5 degrees. This impact is also presumed to be the time when our moon was created from the ejecta thrown into space during the collision event.

Yesterday, June 21 was special for another reason: 50 years ago Universal Pictures released the second film directed by Steven Spielberg - Jaws. The film had a great impact on its audience as people were scared out of the ocean, and even some swimming pools. But the fear it created didn't last long and soon the public opinion of sharks changed. The film increased shark awareness and yes, we still hear about the rogue great white attacks along the New England and Australian coasts, but it also increased awareness of just what sharks are. Conservation is on the rise. Sharks have swum in our oceans for more than 400 million years - they existed before there were trees on land or Saturn had its iconic rings. Today, shark populations are in severe decline. Fishing practices, chemical pollution, plastic contamination, food source degradation, climate change and water temperature increases are having deleterious effect on sharks. Yes, even the media is responsible for shark death as their sensationalized reports continue to feed fear. However, consider this: more people are bitten by other people on the NYC subway than are bitten by sharks annually. Whale sharks - the largest of the species (18-20m in length) - are filter feeders and clean the ocean of dead and decaying matter as they scoop up other tiny organisms. We need sharks to maintain healthy oceans be they predators or gentle giants. (Celebrate Jaws)

As most of you know we love sports, especially the statistically-driven game of baseball. Are you asking yourself what has baseball got to do with sharks? Well, in 2019 Gerrado Parra, a member of the Washington National baseball team had a unique and totally addictive walk-up song - Baby Shark. We hear all you parents groaning. This tune was played every time Parra came up to bat and when the Nationals played the Houston Astros in the World Series - the song and the batter had a global audience. Sharks were front and center for the event - from fin-hats to full on shark costumes, fans in the stadium honored sharks at each game. (Listen to the fans here - Baby Shark Song)

Advances in Climate Science: Each year, climate research is recognized at the Frontiers Planet Prizes. This year and for the first time, two of the three awards went to women - Arunima Malik from the University of Sydney for her work on sustainability of supply chains in global trade routes; Zahra Kalantari from the KTH Royal Institute of Technology for work on the carbon-footprints of cities; and, Zia Mehrabi at the University of Colorado, Boulder for work on increasing biodiversity through management of crops and animals on individual farms. No prize in science is truly won by a single individual. It takes a village to do science. As an example, Dr. Mehrabi's paper was co-authored by 60 others and involved hundreds of other researchers, students and lab technicians while they partnered with thousands of farmers.  (Women Scientists for Climate)

Do Bans Work?: From 2016 through 2023 more than 45,000 shoreline clean-ups have been conducted along the coasts of the United States and around the world. Researchers correlated what was picked up to geographic areas with bans or bag-fees on single-use plastic bags. Where policies instituted bans or fees - single-use plastic bag pollution was reduced by up to 45%. Anna Papp, a post-doc at MIT found that plastic bag policy has a direct correlation to the reduction of plastic waste in the environment. The policies are working. An additional finding was areas with bans also had fewer reported wildlife entanglement incidents. Although this finding is observational, as wildlife incidents are not uniformly recorded, it was a significant noted improvement. A negative finding across the 7 year study period is that while plastic bag pollution may be declining with policy changes the overall amount of plastic pollution is increasing. Internationally, findings in Ireland showed a 95% decrease in plastic bag pollution. Bans do work! (No Plastic Bags and They work)

Summer Heat Rises Higher: Rising global temperatures are impacting areas that lack air conditioning or lack access to enough energy to install cooling methods more than elsewhere. Heat related illnesses and deaths are increasing each year - what can be done to cool a home in these areas? Scientists in humid, hot Singapore have invented a paint which 'sweats' and cools the home by reflecting sunlight as it fosters slow evaporation of water from its surface. This slow evaporation creates passive cooling and requires no energy input. Several commercially-available cooling paints have been on the market for some time. Most do not incorporate reflective qualities and are not effective in humid climates. The Singapore researchers created a cement-based paint product which cools three-ways: radiative cooling (returning heat from the surface back into the environment), evaporative cooling (what your skin does as it perspires) and solar reflective cooling (albedo effect). The paint has a porous micro-structure which retains water and slowly releases it through evaporation. It is white and reflects 92% of the sunlight hitting it. And it emits 95% of the heat it absorbs back into the air. Multi-year tests show houses with their product used 30-40% less energy for cooling processes. (The Secret's In The Sauce)

More than 7000. The number of StarLink satellite in low-Earth orbit. Most have been found leaking radio signals not related to Internet access. Earth-bound astronomy uses more than visible light - it also uses many other portions of the electromagnetic spectrum including x-rays, gamma-rays, ultra-violet, infrared and radio. The radio frequency leakage from StarLink is having a profound impact on radio telescopes which observe distant, very faint radio sources. (We Can't Hear You)

On my birth date - the Hubble Telescope captured this image of the Stars in the Galactic Core. These colorful stars reside at the heart of our Milky Way galaxy, about 26,000 light-years from Earth. Aging red-giant stars coexist with their more plentiful younger blue cousins, and the smaller, white, Sun-like stars, in this crowded region of our galaxy’s central hub. Credit: NASA

To see what Hubble was looking at on your birth date go to: (It's Your Birthday)

It wasn't easy for Cecilia Payne-Gaposchkin to leave England in the early twentieth century and be the first to earn a PhD in astronomy from Radcliffe college. Or the first woman to be promoted to full-professor at Harvard University. The first to be head of department there. Or the one to discover the atomic composition of stars. This easy-to-read biography will take you to the stars as we travel along on her amazing journey -  (The Stars in Heaven)

In this new section, we will explore the impact decision-making has on science and science-related topics. As we said above, if this isn't to your liking skip over this section.

We cannot celebrate the Solstice or sing Baby Shark and not consider another happening on 21 June 2025. The United States Air Force and Navy, at the order of the President, bombed three nuclear research and production facilities (Isfahan, Natanz, and Fordow) in the sovereign nation of Iran. 

We will not offer an opinion on this action, we will however provide some science facts and perhaps allow our readers to be a bit better informed about Iran's nuclear programs, facilities and expertise. Knowledge is power - be wise as you take in all the news about this incident - be curious and do some research on your own.

The History: Iran has had a nuclear program since 1957 when President Eisenhower signed a nuclear cooperation agreement with Shah Pahlavi. The result was the construction of the first light-water nuclear reactor in 1967. This reactor ran on highly-enriched U²³⁵ nuclear fuel supplied by the US. In 1974, the Shah expanded their nuclear programs and formed the Atomic Energy Organization of Iran (AEOI) to build a network of nuclear reactors over 20 years. French and German companies were contracted to begin construction. These included a full-scale fuel cycle: from uranium mining through fuel fabrication in Isfahan. After the Islamic Revolution in 1979, efforts slowed. Then from 1980-1988, most nuclear programs were canceled due to the Iran-Iraq war. Under the Ayatollahs in the late 1990s to 2002, Iran began a new set of parallel projects - an overt civilian energy project and medical isotope effort and a covert weapons program. Reactor operations in Bushehr was accelerated with the input of Russian and Chinese expertise. These countries also provided technical plans, tools and components for the construction of enrichment centrifuges. In 2000, using a Chinese design, Iran expanded operations at Isfahan to produce uranium hexafluoride gas. Concurrently, the Iranian Army launched a missile research program.

What Iran Needs?: It takes four things to produce a viable nuclear weapon - a nuclear warhead (armed with 90% or greater enriched U²³⁵ or plutonium Pu²³⁹), a rocket housing, a navigation/guidance system and fuel to propel the missile/rocket. Iran has all four components at this time.

The process:

1. Raw Ore: Iran is the 18th largest producer of raw uranium ore in the world, capable of excavating 132,000 tons per year. A newly discovered and now the largest deposit has just come into production in  the Yazd region in 2024. Three new discoveries have been made in Khoshoumi region, Charchouleh, and Narigan and exploration is advancing.

2. Processing: raw ore is crushed and then placed in leaching pits where acids remove the uranium from of the ore. Ion-exchange processes concentrate the uranium from solution which is then dried into an uranium concentrate called 'yellowcake'. Yellowcake solid contains about 80% uranium in the form of U₃O₈ (tri-uranium octoxide). The uranium is >99.9% U²³⁸ and less than 0.1% fissionable U²³⁵. Thus, the yellowcake must be processed or enriched to recover the minute amount of U²³⁵ from the solid. This is primary production of yellowcake is done in a facility in Ardakan.

3. Enrichment: Iran has two known fuel enrichment facilities - Fordow and Natanz - as well as, newly stated facilities in unknown locations. At the two enrichment sites, the solid U₃O₈ is combined with fluorine gas to produce uranium hexafluoride gas (UF₆). This gas is transferred to a series of centrifuge cascades (16 cascades at Fordow contained 3000, 6-meter tall, advanced IR-1 gas centrifuges). In the centrifuge, the gas is spun at high speeds to separate the two uranium isotopes by weight using centripetal force - physically separating the light U²³⁵  atoms from heavy U²³⁸ atoms. Because the fissionable U235 is in such tiny quantities, the gas must be spun multiple times - each recovered light-weight alloquot moves from one centrifuge to the next in series or cascade, the product of each advancing amount of gas becoming more concentrated in U²³⁵. Most nuclear reactors use fuels with less than 5% U²³⁵, isotopes needed for medical purposes are produced from 20% enriched U²³⁵. Fission-bomb weapons require material containing 90% or > U²³⁵ known as weapons-grade uranium. The latest estimates by the International Atomic Energy Agency (IAEA) is Iran possesses 400 kilos (9722 pounds) of 60% or greater enriched U²³⁵ - it takes only one additional enrichment step to reach 90% material. The Hiroshima bomb contained a 17.3cm (6.8") sphere of highly-enriched U²³⁵ - the sphere weighed 56kilos. Less enriched material can be used to make a weapon but as the enrichment % decreases, the amount of uranium needed to create a fission reaction increases.

Weapon State: There are two types of nuclear weapons - tactical and strategic. Iran does not have the technical rocket capabilities to produce a strategic nuclear weapon - those capable of striking anywhere on the globe. However, North Korea has provided Iran the rocket, fuel and guidance capabilities to produce a tactical weapon - these small, highly mobile battle-field capable weapons would be able of strike distances up to 3000 kilometers (central Europe, southern Russia, India). In combination with Iran's current ballistic missile capabilities - Iran could easily place a tactical weapon anywhere in the MidEast. The Fatah-1 hypersonic ballistic missile, unveiled in 2023, is reported to have high velocity, is maneuverable within and outside the atmosphere, and has the ability to evade most anti-missile defense systems. These could be armed with a nuclear warhead.

Having studied North Korean weapon capabilities for The Paris Contagion, I took away one learning - one cannot expect to 'bomb away knowledge' from any country. Iran has many talented and well-educated nuclear scientists and engineers. Removing infrastructure through attack simply slows the overall development processes, the brains remain and with their alliances with other nuclear-capable countries - it would not take long to re-establish a viable Iranian weapons program.

The information above was compiled from various Wikipedia and open-file CIA, IAEA and US military sources. The internet is a powerful and sometimes skewed source of information - combine several sources to confirm or refute claims.

"Mankind invented the atomic bomb, but no mouse would ever construct a mousetrap" Albert Einstein

May your summer days be bright - your winter days be easy - enjoy some BBQ with friends - celebrate each other.

Just a reminder for our readers - we always provide the reference to the information shared - it's usually in a link. Make sure you click on the link if you're interested in learning more about the subject.

AI is never used in the design, construction or editing of our newsletters.

We'll be back next month with another installment. Be well, be kind. CA