Pigments, Planning Hubble's Rescue, and Flammable Fountains

Pigments are compounds that provide color to organisms and inorganic materials. Like dyes, their chemical structure causes them to absorb certain colors of light and reflect others, with the latter corresponding to the observed color. However, while dyes dissolve in liquid and chemically bind to molecules, pigments are suspended in a medium or require a binding agent to stick to surfaces.

> The oldest pigment in the geological record is pink and over 1 billion years old.

> Pigments create thousands of colors in nature, but which is the rarest?
> Because each pigment absorbs and reflects different colors, removing multicolor tattoos may require several different lasers.

Humans have used pigments for millennia, from natural ones found in cave art paints to synthetic colorants in modern cosmetics. In nature, pigments serve many functions, including capturing light energy for photosynthesis (chlorophyll), attracting pollinators and seed dispersers (flavonoids), carrying oxygen in the blood (hemoglobin), and protecting skin from ultraviolet radiation (melanin). Some organisms possess several pigments whose abundances can change, altering their appearance.

> Some of history's most famous paintings contain pigments made from animal blood, fermented waste, and incinerated skeletons.

> One historical pigment consisted of ground-up mummies and was consumed for its perceived health benefits.

> What pigments are responsible for bruises turning green and yellow?

Exposure to harsh chemicals, radiation, acidity, and other factors can degrade a pigment's molecular structure, causing its coloration to fade. By combining metals, salts, organic compounds, and other raw materials, vibrant, fade-resistant synthetic pigments have been developed, though some have relied on lead, arsenic, and other toxins. The need for nontoxic coloring agents has driven some research toward structural colors, in which nanoscale shapes, rather than chemical properties, affect the color-producing interactions with light.

> From lead paint to arsenic wallpaper, what is the deadliest pigment in history?

> Learn about the world's first synthetic pigment, created about 5,000 years ago.

> ... and why creating a perfect red pigment is likely impossible.

Discover more: 

> Fossilized pigments have helped scientists determine the color of dinosaurs.

> Take a tour inside the workshop that's handcrafted pastels from pigments for over 300 years.

> ... and visit a museum collection of over 3,000 pigments inaccessible to the public.

Keep learning by exploring all our findings on Pigments here.

News in Context

1440 brings you the knowledge and context behind the week's stories:

Google softened its ban on access to Google Search in schools that refuse to adopt its AI tools for students. (More)

> Watch how search engine usage has evolved since 1994, from AltaVista and Yahoo! to Bing and Google Search.

> See what people searched for most during Google Search's first 25 years.

NASA restarted discussions to save the Hubble Space Telescope, which is expected to fall to Earth in the 2030s. (More)

> Hubble needed rescuing shortly after it launched because its mirror wasn't polished correctly.

> From space missions and planets to stars and galaxies, explore galleries of photographs taken by Hubble.

Mars may be volcanically active, as evidenced by observations of volcanic gases emanating from its surface fissures. (More)

> The solar system's largest volcano is a Martian shield volcano the size of Poland.

> Volcanic fissures may be ideal places to look for life on Mars, as Earth features thriving ecosystems near similar underwater vents.

Americans in several states voted on ballot measures involving science, including protecting watersheds, funding conservation projects, and tackling pollution. (More)

> Research suggests most Americans value science, but this varies demographically and by political affiliation.

> Data centers may not have explicitly been on the ballot, but Americans' views on them have soured since January.

Research Spotlight

Like all great researchers, we love spending time learning about the latest breakthroughs across science and technology. Here's what we found this week.

A virtual Earth simulation may help scientists find life beyond our planet.

University of Washington | William Poor. Efforts to find extraterrestrial life have focused on exoplanets that can harbor liquid water, whose atmospheres scientists analyze in search of signs of molecules produced by living things. A new simulation identifies which atmospheric conditions can be explained without life, enabling scientists to better distinguish inhabited worlds from habitable ones. (More)

> The region where liquid water can exist around a star is called the Goldilocks zone.

> What molecules in exoplanet atmospheres would indicate the presence of life?

Carbon dots can be crafted to fluoresce in multiple colors for data encryption. 

American Chemical Society | Staff. Fluorescent materials typically emit a single color of light after absorbing more energetic light, such as ultraviolet radiation. Engineers created tiny carbon particles that can instead emit different colors based on their surface geometry, which can be adjusted. This characteristic has potential applications in sensors, data security, and anti-counterfeiting technologies. (More)

> Fluorescent probes have enabled scientists to simultaneously study multiple cellular processes.

> View a striking gallery of biofluorescent organisms that glow when exposed to ultraviolet light.

Changes in a species' body size may drive evolutionary change.

University of California, Riverside | Iqbal Pittalwala. In humans, a baby's head is large relative to its body at birth but becomes proportionally smaller as the baby matures. Similarly, some physical characteristics in certain organisms do not scale with their body size. A new theory suggests that more pronounced divergences can lead to deficits in certain traits, such as a tail not working properly, which can serve as the catalyst for evolution through natural selection over long periods. (More)

> There are five key mechanisms that drive evolution, including natural selection.

> How long does it take for a new species to emerge as a result of evolution?

Researchers use machine learning optimization techniques to find exoplanets.

California Institute of Technology | Katie Neith. Directly observing exoplanets is difficult because their light is much fainter than that of their host star. Researchers built a digital twin of the James Webb Space Telescope's primary camera to model stellar glare, which was then subtracted from images of planetary systems, enabling exoplanet detection with up to 15 times the sensitivity of standard methods. (More)

> Most exoplanets have been discovered by catching them eclipsing their host star.

> Explore a dashboard of the nearly 6,500 exoplanets discovered so far.

Etcetera

> Sometimes, you can fit every planet in the space between the Earth and the moon.

> The Arctic is leaking enough methane to create flammable fountains.

> If you want to be taller for your dating profile, take your measurements in space.

> The world's first traffic light exploded less than a month after its installation.

> In 2019, researchers confirmed that light can bounce off light—a seemingly impossible phenomenon predicted by quantum field theory.

> Why is the primary drive on Windows PCs named the C: drive and not A: or B:?

> Every day, about 1,800 weather balloons are launched worldwide.
 

> Alien-like ferrofluids enable you to see otherwise invisible magnetic fields.

> Female kangaroos have two vaginas and grow a third upon getting pregnant.

> How does a touch-screen device know where you tapped?

> The Himalayan mountain range has been growing taller for millions of years.

> View a historical gallery of electric vehicles from General Electric since the 1890s.