Library of Congress
Library of Congress

15 Highlights from Carl Sagan's Archive

Library of Congress
Library of Congress

Recently, the Library of Congress acquired and began to digitize The Seth MacFarlane Collection of the Carl Sagan and Ann Druyan Archive, a compilation of the personal papers, books, and correspondence of noted astrophysicist Carl Sagan. Through more than a dozen books, as well as his groundbreaking 1980 television series Cosmos: A Personal Voyage—soon to be remade in March featuring equally awesome astrophysicist Neil deGrasse Tyson—Sagan used his wondrous spirit to urge people to look at the planet and our place in the universe in different, dynamic ways. Here are a few awesome things we found in the collection.

1. Home Movies of a Young Sagan

The video above shows a series of silent home movies, starting off with the young Sagan joking around while playing piano. Other clips—with appearances by his mother Rachel, his father Samuel, and his younger sister Carol—show Sagan horseback riding, on vacation, and documenting a family trip to the zoo.

2. The Evolution of Interstellar Space Flight

This wonderful drawing was created by pre-teen Sagan, and is a collage of proposed newspaper headlines from the future. One headline boasts of technological developments like atomic space ships that can travel 5 miles per second, while another imagined advertisement promotes “Interstellar Spacelines," encouraging people to travel to and inhabit a planet in another solar system called "Altair 8."

3. Wawawhack, the Rahway High School student newspaper, Vol. VI, No. 5.

This issue of Wawawhack, the Rahway High School student newspaper, contains a student spotlight section describing Sagan's accomplishments as a high schooler. “If you wish to gain information concerning anything,” the article says, “go to Carl Sagan.” The short piece also describes his ambition to become an astronomer when he grows up, lists his hobbies as reading and playing basketball, labels his pet peeve as “lettuce sandwiches,” and names his favorite song—“My Foolish Heart, the title song from the film adaptation of the JD Salinger short story “Uncle Wiggly in Connecticut.”

4. The sounds of Earth

This is Sagan’s personal copy of the gold-plated copper record disc that NASA produced in 1977 to accompany the Voyager 1 & 2 spacecraft into interstellar space for potential alien civilizations to discover. The disc includes 115 images of Earth cultures, natural sounds, music, and spoken greetings in 55 languages. The phrase “To the makers of music—all worlds, all times” is etched around the center of both sides. Also found in the archive is a 1986 birthday greeting to Chuck Berry by Sagan and his eventual wife Ann Druyan (Berry’s song “Johnny B. Goode” was included on the record), and a thank-you letter to famed ethnomusicologist Alan Lomax for helping compile the music for the disc.

5. The Pale Blue Dot

Sagan dictated many of his science-related thoughts and much of his official correspondence. This 4-minute audio recording is the abstract for his 1994 book, Pale Blue Dot, and ponders the primary concepts gained from the famous “Pale Blue Dot” photo taken, at Sagan's request, more than 4 billion miles from earth by the Voyage 1 spacecraft in 1990. “Consider that dot,” said Sagan, “That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.” The archive also includes the second of 20 drafts of Sagan’s book.

6. Diagram of all space and time

This diagram, drawn by Sagan in 1985, represents all of space and time. The X-axis illustrates past and future time, while the Y-axis illustrates scale from the minute size of electrons to the distance to the “M31” or Andromeda Galaxy. Note the relative size of the small box that represents the “Realm of Direct Human Experience” to the huge space given to the realms of Quantum Physics and Special Relativity, and also the ominously titled “Forbidden Zone.”

7. Jovian radio organisms

Throughout his later career, Sagan would keep a file composed of initial concepts for writing projects that piqued his interest that he called his “Ideas Riding” file—a play on the phrase “Ideas Writing.” In this one-page document, the astrophysicist contemplates the “very speculative idea” that large plantlike organisms on Jupiter could communicate using radio waves like “a vast sing-along or the noise leakage from an immense cocktail party.” Pretty trippy. Other documents from this file include everything from notes on the nature of the clouds on Venus to an observation about how whale songs sound like cello music to asking “why are clouds white?”

8. Briefing notes for President Carter and Vice President Walter Mondale

This handwritten note—on Watergate Hotel stationery—was used for a presentation by Sagan to brief then-President Jimmy Carter and Vice President Walter Mondale on concepts like the origin of life; the Voyager record; “cosmic catastrophes” like pulsars, quasars, and black holes; and CETI, or ”communication with extraterrestrial intelligence.”

9. Letter to Brown University Admissions Office

This college recommendation letter was written by Sagan and sent to the admissions office of Brown University, endorsing a student named David Grinspoon for admission to the school. Sagan declares that Grinspoon “would rank in the upper one percent of the students in my introductory astronomy course at Cornell,” and notes that the young student is an “accomplished tennis and guitar player.” Grinspoon would eventually attend Brown, and would even get a second recommendation letter from Sagan—also in the collection—when he was trying to get into graduate school at the University of Arizona. Additional correspondence between the two includes a letter Sagan wrote to the undergrad asking him to help him find an astronomy book written by sci-fi author H.P. Lovecraft.

10. Viking Lander images of the surface of Mars

These photographs are Sagan’s personal copies of the images sent back to earth from the Viking lander in 1977. Sagan was obsessed with the Red Planet, and the collection also includes a photo of Sagan with a model of the lander taken in Death Valley, California.

11. Idea for Contact video game

Sagan wasn’t content working in just literature, academia, or television. In this document, he chews over how to create a video game that could teach astronomy “in a context as exciting as most violent video games.” The premise of the video game would involve creating a young galactic civilization “in order to help it before it destroys itself—which most of them generally do.” Ever the optimist, Sagan also considered how the video game could be a tie-in to his novel Contact, which would be published in 1985. The collection also includes a dictated first draft of chapter three and a full draft of the novel.

12. Candidate list of Why? books

Sagan connected with so many people thanks to his knack for making audiences easily understand some pretty difficult scientific concepts. This list from later in his life contains about 150 potential titles for a series of instructional books for children called “Why?” Some examples include “How High is the Sky?”, “Why Don’t I Feel the Earth Spin?”, “If a Baby Was Raised by Mutes, What Language Would it Speak?”, “Could there be an Undiscovered Number Between 1 and 2?”, and “Why is it Warm in Summer?”

13. Scientists tithe time to science education

Anticipating the contemporary lack of funding and support for potentially costly scientific endeavors, Sagan proposed that scientists themselves should donate ten percent of their time towards public education in science. As a way for these scientists to contribute to a better public understanding of science, Sagan suggests they should write articles in local newspapers, give public lectures, and hold open houses at observatories.

14. Lecture notes

Though he was the most high profile astrophysicist of his time, Sagan was still a university professor with coursework, exams, and research papers to assign. The collection give us a little look into just what it might have been like to be enrolled in—or to teach—one of his classes.

One document for the “Astronomy 490” course he taught at Cornell in the '80s features lecture notes written by Sagan himself, which encourage students to push their critical thinking between “what feels good versus what is true,” and explains that the course will follow the logical idiom “Post hoc ergo propter hoc.” One of the course’s final exams features an essay question asking students to describe the ways culture may change in the years following a major event involving UFOs, while another asks students to create a thought experiment for or against sun sign astrology.

For his 1965 “Astronomy 170” course at Harvard, his lecture notes outline topics such as the possibility of life on Mars and his desire to spend class time contemplating Saturn’s rings.

15. Correspondence between Sagan and a young Neil deGrasse Tyson

Perhaps my favorite discovery in the collection is a series of correspondence between Sagan—who was at the height of his popularity—and a young Neil deGrasse Tyson, an astrophysicist who has now taken over Sagan’s mantle in bringing popular science to the masses.

The banter starts with a letter from Sagan to Tyson—who was a senior at The Bronx High School of Science at the time—inviting the young man to visit him at Cornell and praising his decision to major in physics. Following their meeting and some time later, Tyson responds to Sagan informing him he has decided to attend Harvard because they have a larger astronomy department, to which Sagan cheekily responds that he’s sure Tyson has “not made a serious error in going there rather than Cornell.”

The formal friendship gives way to casual communication when Tyson send Sagan a letter about his first year as an undergrad at Harvard, and how he sublet an apartment in Cambridge for the summer so he could work full time at the Center for Astrophysics until school started up again. The pièce de résistance is a letter Tyson sent Sagan asking him how he would go about finding a publisher for turning a series of Q&A articles he wrote into a full-length book. The message includes a newspaper clipping about Tyson to remind Sagan of his accomplishments. It also features Tyson wearing a particularly goofy, but great astronomy-themed t-shirt.

The digitized collection is only in the preliminary stages, and the entirety of the documents from Sagan’s estate numbers in the hundreds more. If you’re as much of a Sagan fan—or science geek—as I am, let’s hope they put them online sooner rather than later.

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15 Scientific Reasons Spring Is the Most Delightful Season

Summer, winter, and fall may have their fans, but spring is clearly the most lovable of the four seasons. Not convinced? Here are 15 scientific reasons why spring is great:


road and field on a sunny day

Spring marks the end of blistering winter and the transitional period to scorching summer. In many places, the season brings mild temperatures in the 60s and 70s. People tend to be most comfortable at temperatures of about 72°F, research shows, so the arrival of spring means you can finally ditch the heavy winter layers and still be comfortable.


sunny sky

Following the spring equinox, days begin lasting longer and nights get shorter. Daylight Saving Time, which moves the clock forward starting in March, gives you even more light hours to get things done. Those extra hours of sun can be a major mood-booster, according to some research. A 2016 study of students in counseling at Brigham Young University found that the longer the sun was up during the day, the less mental distress people experienced.


blue bird on branch

Many animals migrate south during the winter, then head north as temperatures rise. For relatively northern regions, there is no better indicator of spring than birds chirping outside your window. Their northward migration can start as early as mid-February and last into June, meaning that throughout the spring, you can expect to see a major avian influx. In addition to the satisfaction of marking species off your bird-watching checklist, seeing more of our feathered friends can make you happy. In 2017, a UK study found that the more birds people could see in their neighborhoods, the better their mental health.


Baby squirrels

Many animals reproduce in the spring, when temperatures are warmer and food is plentiful. Baby bunnies, ducklings, chipmunks, and other adorable animals abound come spring. Studies have found that seeing cute animals can have positive effects on humans. For instance, one small study in 2012 found that when college students looked at cute images of baby animals, they were better at focusing on a task in the lab. Being able to watch fluffy baby squirrels frolic outside your office window might make spring your most productive season of the year.


flowers hanging outside of a house

In 2015, a pair of public policy researchers discovered a hidden upside to "springing forward" for Daylight Saving Time. It reduced crime. When the sun set later in the evening, the study published in the Review of Economics and Statistics found, robbery rates fell. After Daylight Saving Time started in the spring, there was a 27 percent drop in robberies during that extra hour of evening sunlight, and a 7 percent drop over the course of the whole day.


child with rainbow umbrella jumping in puddle

Warmer temperatures mean you can spend more time outside without freezing your feet off, which is great for mental health. Across the seasons, research has found that taking walks in nature slows your heart rate and makes you more relaxed, but some research indicates that there is something special about spring's effect on your brain. A 2005 study from the University of Michigan linked spending 30 minutes or more outside in warm, sunny spring weather to higher mood and better memory. But the effect reverses when spring ends, since being outside in the warmest days of summer is usually pretty uncomfortable.


woman writing in a park

That same University of Michigan study found that spending time outside in the sunny spring weather isn't just a mood booster, it actually can change the way people think. The researchers found that being outdoors broadened participants' minds, leaving them more open to new information and creative thoughts.


leaves budding in spring

Spring brings green growth back to plants and trees. Depending on where you live, trees may begin sporting new leaves as early as mid-March. That successful spring leaf growth ensures a cool canopy to relax under during the hot summer—a hugely important factor in keeping cities comfortable. According to researchers, vegetation plays a big role in mitigating the urban heat island effect. When trees release water back into the air through evapotranspiration, it can cool down the areas around them by up to 9°F, according to the EPA.


tulip bulbs

It's amazing what a little sun can do for plants and grass. Through photosynthesis, plants convert sunlight, carbon dioxide, and water into food, releasing oxygen in the process. That means as plants start to grow in the spring, they pull carbon out of the atmosphere, providing an important environmental service. Plants take in roughly 25 percent of the carbon emissions humans produce, absorbing more than 100 gigatons of carbon through photosynthesis each growing season. Because of this, the amount of carbon dioxide in the atmosphere drops each spring and summer. (Unfortunately, it rises in the winter, when most plants aren't growing.)


wooden box full of fresh produce

Many vegetables and some fruits are harvested in the spring. 'Tis the season to get your local asparagus, greens, peas, rhubarb, and other fresh produce. Getting more fruits and vegetables into your diet isn't just good for the body; it's good for the soul. A 2016 study of more than 12,000 Australians found that when people increased the amount of fruits and vegetables in their diet, they felt happier and had higher rates of life satisfaction. If they increased their intake by eight portions a day (a tall order, we know) the psychological gains were equivalent to the change in well-being people experience when they go from being unemployed to having a job, the researchers found.


Flowers in a vase

After months spent conserving energy, flowers bloom in the spring, once they sense that the days have grown longer and the weather has turned warmer. That's good for humans, because several studies have shown that looking at flowers can make you happy. A 2008 study of hospital patients found that having flowers in the room made people feel more positive and reduced their pain and anxiety [PDF]. Another study from Rutgers University found that when participants were presented with a bouquet of flowers, it resulted in what scientists call a "true smile" a full 100 percent of the time. Seeing flowers had both "immediate and long-term effects" that resulted in elevated moods for days afterward, according to the researchers [PDF].


woman tying shoes in flower field

While it's important to keep moving no matter what the weather, research shows that working out can be more beneficial if you do it outside. A 2011 study found that, compared with an indoor workout, exercising outdoors in nature increased energy levels, made people feel revitalized, and decreased tension, among other positive effects. People who worked out in the fresh air also tended to say they enjoyed the experience more and would be likely to repeat it, suggesting that using nature as your gym might help you stick with your exercise regimen. While those benefits probably extend to winter, too, it's a whole lot easier to stomach the idea of a run once the weather warms up.


dew on grass and a daisy

Flu season in the U.S. typically lasts through the fall and winter, usually peaking between December and February and tapering off during the spring. The seasonal change is in part because of dry air. Cold temperatures mean a drop in humidity, and indoor heating only makes the air drier. This lack of moisture in the air can dry out your skin and the nasal cavities, leading to nose bleeds, irritated sinuses, and a greater risk of getting sick. Since the mucus in your nose is designed to trap viruses, when it dries up, you're more likely to catch something nasty, like the flu. As the weather warms up and becomes more humid throughout the spring, that mucus comes back. As the season wears on, not only can you lay off the body lotion, but you can probably put away the tissues—if you don't have spring allergies, that is.


windows open on a red house

Temperate weather makes it easier to get the fresh air you need. Opening your windows and allowing the breeze in serves as an important way to ventilate indoor spaces, according to the EPA. A lack of ventilation can lead to an unhealthy concentration of indoor pollutants from sources like cleaning product fumes, certain furniture and building materials, and stoves (especially gas ones), posing a threat to your health and comfort. Winter brings the highest rates of indoor pollutants like nitrogen oxide, a 2016 study of unventilated stove use in homes found. Spring brings the perfect opportunity to throw open those windows and doors and get the air moving again.


woman enjoying sitting in the sun

Sunlight triggers your body to produce the vitamin D, which keeps your bones strong. At northern latitudes, it's extremely difficult to get enough sun exposure naturally to maintain healthy vitamin D levels during the winter—even if you did want to expose your skin to the elements—but that starts to change during the spring. One Spanish study found that in Valencia (which shares a latitude with Philadelphia, Denver, Baltimore, Kansas City, and several other major U.S. cities), people only need 10 minutes outside with a quarter of their bodies exposed to the spring sunshine to get an adequate daily dose of vitamin D.

A version of this story originally ran in 2014.

8 Ways to Tell If Someone Is Lying to You

Sociopaths and narcissists may believe they have lying down to a science, but it turns out there are a lot of little clues that reveal even the most sophisticated level of mendacity. If you want to catch a liar in their tracks, look for the following "tells," courtesy of father and daughter Dan and Lisa Ribacoff, credibility assessment experts and advanced certified polygraph examiners based in New York. They use their skills in criminal investigations, business matters, family and relationship issues, and other areas; you might have seen them on TV. Dan is also a private investigator.

The Ribacoffs use a mix of psychology, body-language analysis, expert interview skills, and polygraph tests to determine whether someone is lying. A polygraph is a combination of medical devices that monitor any physiological changes, particularly heart rate, blood pressure, respiratory rate, and perspiration rate, that an interview subject undergoes during an interview. To begin this process, the examiner conducts a pretest interview, asking questions that should be easy for the subject to answer, such as name and age. This establishes a "baseline" of normal autonomic responses to benign questions. They may also do a "stimulation test" in which the subject is asked to lie consciously. Changes from the baseline may indicate deception—though that interpretation is up to the examiner.

The accuracy of polygraph tests has been questioned by numerous critics, including the American Psychological Association. Guilty people have passed them, and innocent people have failed them. But they're just one factor in the Ribacoffs' assessments, which are based mostly on reading people, not polygraphs.

Credibility assessment is not built upon a single tell but a combination, Dan tells Mental Floss: "There's not one verbal or non-verbal cue that is going to be the absolute indicator [of a lie]. It's a process of collecting pieces to the puzzle and putting that puzzle together."

Read on for tips to identify when someone might be lying to you.


A common habit for a person obfuscating the truth is to put physical distance between themselves and the person they're lying to, particularly if they're being questioned. "Sitting back and stretching your legs out is trying to gain distance between you and the interviewer," Dan says. Crossing one's arms, a defensive posture, is also a potential sign of duplicity.


Because lying activates the limbic system, whose goal is to keep you calm under stress, liars may have a hard time sitting still. "It's like the popcorn maker pops its lid [in your mind]," Dan says. "You do things to burn off nervous energy, like pick off imaginary lint, rub your arm—self-soothing behaviors such as moving or fidgeting." Lisa tells Mental Floss that "rubbing your neck or playing with hair" are also signs of potential deception, particularly if someone does it right after they lie to you.


man in suit avoids eye contact

Eye contact is intimate, vulnerable—and lots of liars can't hold a gaze when they're working up a mistruth. Lisa says she's found that examinees will often maintain eye contact "right up until they give the answer they're lying about." The polygraph usually reveals physiological changes that suggest the person is lying. There are other reasons that a person might not make eye contact, such as being on the autism spectrum or having certain psychological disorders, but Dan says the baseline of normal behavior is established for each individual subject. What examiners look for is a change or departure from the person's unique baseline.


A liar will not directly say they haven't done something wrong; they'll answer with a dodge, a question back at you, or a nonsequitor. Not answering directly is an immediate alarm bell to Dan. An innocent person will usually just say "no" when asked if they've done something wrong. "A guilty person has a hard time saying no," Dan says. When they don't answer the question, you might sniff out a lie.


Hand pointing

Another surefire trick of the treacherous is to over-explain. "They hard sell it to you, they go off on tangents, they ramble," Dan says. "They give you unimportant information." Or, they'll shift the blame onto someone else.

Dan, who lends his expertise to The Steve Wilkos Show, recently assessed a situation where an employee of a hotel was accused of stealing money from a hotel room. He polygraphed the entire hotel security staff, because it involved taking money from a safe that only they would have access to. When Dan questioned the accused employee, the man proclaimed his innocence and shifted the blame to his manager, Kara, and another employee named John. "When I said, 'Did you take the money?' he said, ‘I didn't take the money, it's that goddamn Kara, she's constantly favoring this one guy John because she grew up with him, and he's her boy,'" Dan recalls.

But John passed the polygraph, while the employee—who was guilty—failed it.


Liars also tend to change the story every time they tell it. In a recent case, Dan interviewed a man who was charged with stealing from his workplace and selling the items. He claimed to Dan that a security guard at the company had actually committed the crime. He even mentioned that he'd run into the security guard recently at a party. But conveniently, the man didn't know the guard's name or have his phone number. Lisa put him through a second interview, asking him the same questions, and "suddenly he knows the security guard's name and has his number," she says. This spelled a lie to Dan, and the polygraph results backed up his assessment.


"If the story doesn't make sense, it's usually not true," Dan says. In a recent case, a wife had agreed to take a polygraph at the request of her jealous husband, who had found numerous texts between her and a coworker on her phone. At first she told Dan that she and her colleague were merely friends who texted a lot, but that nothing physical happened between them. But as the polygraph went on, she added their communications went on for three years … and then confessed that they included nude photos of her.

She failed the polygraph—but then agreed to a second one, during which she denied having sexual contact with the friend. After she failed that test too, she admitted she had kissed the friend. (Even without these confessions, her body language throughout both tests was telling, Dan says; she was distraught and trembling. "I felt really bad for her," he admits. "I knew it wouldn't end well.")

"There's a saying: If it doesn't add up," Dan says, "it's usually because the truth wasn't in the equation."


Close-up of perspiring, tense, frowning young blonde woman

You breathe shallower when you lie, your face flushes, and you may begin to sweat. In addition, Dan says, "You lick your lips because digestion stops when fight or flight kicks in." Of course, these symptoms can also happen if you are genuinely afraid or have issues with authority, but according to Dan, this is where that valuable baseline of behavior helps an examiner determine if you were already nervous when you walked in.

Dan has one more tip that's useful no matter how astute your observational powers are: Get the person talking. He suggests approaching your line of questioning as an interview rather than an interrogation. "When I interview you, I let you talk," he notes. "In an interrogation, I'm doing the talking to get you to confess."


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