WHRM-DT

Actor Michael Douglas and writer/director Lena Dunham explore their family roots.

Christiane Amanpour leads discussions about world issues and interviews with global leaders.

The story behind David Attenborough's wildlife documentary series "Life on Earth," which changed his life forever.

How discoveries over the past 50 years have revolutionized people's understanding of the universe.

From Kenya to Mexico, people and wildlife find a harmonious balance in Earth's most vulnerable landscapes.

Chinese American photographer Corky Lee documents the celebrations, struggles and daily lives of Asian American and Pacific Islanders, assembling an astonishing archive of nearly one million images.

Muffy challenges Francine to be nice for one week; Arthur joins a gang.

Olive and Otto try to stop zeroes from disappearing; odd things happen to the Bears basketball team.

Martin encounters a lost colony of black-footed ferrets.

Corky is selected to make a presentation at school during a science day celebration, but humidity jeopardizes her project.

Lyla figures out how to do a magic trick with clues from Miss Emmaline; Luke finds a puppy.

Arugula and Carl go on an adventure as archaeologists; Carl spots a UFO on Mother's Day.

Things don't go as planned when Daniel and Dad Tiger spend the day together; Daniel and Mom's day together includes turning her old wagon into a trolley.

Jay and Lupe use wayfinding signs to track down Phoebe; Pete and Craig face an epic hoops battle on the courts.

Rudy feels angry when Abby asks him to share his toys, so his friends make a movie to show that sharing can be fun.

All aboard the Moo Moo Choo Choo; visiting great uncle Duper in the Windborhood; world's biggest whirligig blows away; helping great uncle Duper imagine how to build a new one.

Donkey babysits a baby yodel bird who won't take a nap; Donkey and Panda argue while playing superheroes.

Rosie and Javi get a new book, but it's in a different language; Rosie tries to form a club with her friends.

Ari grows impatient waiting for ketchup; Elinor, Olive and Ari have to figure out how to expand their clubhouse to fit all the new members of The Explorer's Club.

Alma, Eddie and Junior play a late-night game with Steggie; Alma decides she wants to play piano.

Molly uses Indigenous knowledge to spot a storm.

Mary Anning inspires Xavier and Yadina to continue working on a tricky art project; Charlie Chaplin helps Yadina cheer up Dr. Zoom.

Drywall paneling; cleaning a shower cartridge; using a lathe; turning a bowl.

Citrus-braised pork tacos; mild salsa tasting; piping bags; making churros.

A look at the history of nuclear weapons and how they've affected mankind.

Olive and Otto try to stop zeroes from disappearing; odd things happen to the Bears basketball team.

Muffy challenges Francine to be nice for one week; Arthur joins a gang.

Martin encounters a lost colony of black-footed ferrets.

Live news program produced out of BBC's Washington, D.C. bureau; host Sumi Somaskanda.

Co-anchors Amna Nawaz and Geoff Bennett and correspondents offer in-depth analysis of current events.

Port Washington, Wisconsin, sits on Lake Michigan, but has the easy charm of a New England seaside town. Charter fishing boats line the marina, pulling in salmon and more. A block west, downtown is the definition of Main Street, USA - friendly and postcard perfect! Port Washington, thank you for the perfect wrap for this season of Main Streets!

Luke joins Kurt Fogle - a Racine-based chef who got his start at Q&H Danish Bakery - to hand-fill and shape Wisconsin's state pastry from 18-layer Danish dough. Then he heads to Gills Rock at the northern tip of Door County, where Charlie's Smokehouse has brined and maple-smoked Lake Michigan whitefish using the same methods since 1932.

A famous crime author arrives in Brokenwood to give a reading of his latest novel and ends up falling victim to a murder portrayed in his book.

A whirlwind adventure and the return of arch-nemesis Moriarty lead John to believe that Sherlock is dead.

Exploring the long-term effects of the World War II incarceration of Japanese Americans by the U.S. government; intergenerational trauma.

Christiane Amanpour leads discussions about world issues and interviews with global leaders.

Port Washington, Wisconsin, sits on Lake Michigan, but has the easy charm of a New England seaside town. Charter fishing boats line the marina, pulling in salmon and more. A block west, downtown is the definition of Main Street, USA - friendly and postcard perfect! Port Washington, thank you for the perfect wrap for this season of Main Streets!

Luke joins Kurt Fogle - a Racine-based chef who got his start at Q&H Danish Bakery - to hand-fill and shape Wisconsin's state pastry from 18-layer Danish dough. Then he heads to Gills Rock at the northern tip of Door County, where Charlie's Smokehouse has brined and maple-smoked Lake Michigan whitefish using the same methods since 1932.

A famous crime author arrives in Brokenwood to give a reading of his latest novel and ends up falling victim to a murder portrayed in his book.

A whirlwind adventure and the return of arch-nemesis Moriarty lead John to believe that Sherlock is dead.

Arthur's not sure what to make of the new baby; D.W. considers running away to Button Island.

Oscar attends a gathering of Odd Squad scientists called Lab-Con at Odd Squad Academy.

Martin and Chris find out that Zach Varmitech plans to capture a black jaguar.

The kids learn what colors make up a rainbow just in time for a Mother's Day surprise.

Lyla and Luke clean Stu without a bath; Lyla and Ale find a way to protect the callaloo plants from stink bugs.

Carl and his friends clean up the Fuzzytown Park; Carl accidentally breaks the birthday present Sheldon planned to give his mom.

Daniel visits the post office and learns how letters are sorted and mailed, then sends a letter to Dad; Daniel and Dad Tiger surprise Mom with banana bread.

Phoebe and Jay accidentally get paint on the mail and have to decode addresses; Phoebe and Jay find their parents' box of memories.

Reporters Elmo and Abby offer strategies to Nursery Rhyme characters experiencing big feelings of excitement, nervousness and frustration.

Sammy and Benito find a way to communicate; Sammy makes plans for his mom's visit.

Donkey and Cousin Hodie figure out how to have fun in the rain; Donkey is patient while Cousin learns a new game at Grampy's Game Day.

Rosie finally gets the courage to go into the Fun House at the carnival, but then finds out she doesn't have enough tickets; Rosie goes to the pet store to get something for Crystal's new bunny.

The kids try to determine what the weather will be like for Animal Town's parade; Olive gets a bad case of the hiccups.

Alma finds a way for everyone to get books while the library is under renovation; Alma finds a doll in the park.

Molly must find her mom's plane keys so she can get home in time for Mother's Day; Trini spots a talking white bird.

David Suzuki explains to Xavier that by taking care of the earth, we take care of ourselves; Esther Martinez explains to Xavier and Yadina about how stories can connect people to their family histories.

Kevin gets a firsthand look at Nick Offerman's woodworking shop; home technology expert Ross Trethewey looks at a new device to track home energy usage in Future House; Richard shows what happens when one uses the wrong soap in the dishwasher.

South Carolina smoked fresh ham; spiral sliced bone-in ham; potato mashers; smashed potato salad.

A woman born in Vietnam searches for her American father; a man hopes to find the Texas cowboy who saved him when he was a child.

A man searches for the stranger who comforted him on Sept. 11; a man hopes to thank a fellow chaplain who helped him carry on.

Oscar attends a gathering of Odd Squad scientists called Lab-Con at Odd Squad Academy.

Arthur's not sure what to make of the new baby; D.W. considers running away to Button Island.

Martin and Chris find out that Zach Varmitech plans to capture a black jaguar.

Live news program produced out of BBC's Washington, D.C. bureau; host Sumi Somaskanda.

Co-anchors Amna Nawaz and Geoff Bennett and correspondents offer in-depth analysis of current events.

A panel of journalists provides reporting and analysis of the major stories emanating from the United States capital.

Events in Wisconsin.

On Christmas Eve 1969, an armed bank robbery interrupts celebrations at the police station and puts Gently, Bacchus and Coles on the trail of a violent gang of skinheads.

The team is plunged into an investigation following the shooting of an idealistic Freerunning champion.

As Van der Valk and the team continue to investigate, they are drawn into the world of drug smuggling.

Songwriters Kelly Willis, Brennen Leigh and Melissa Carper come together to create a unique sound with harmonies and melodies played on guitar, mandolin and bass.

Christiane Amanpour leads discussions about world issues and interviews with global leaders.

A panel of journalists provides reporting and analysis of the major stories emanating from the United States capital.

Events in Wisconsin.

On Christmas Eve 1969, an armed bank robbery interrupts celebrations at the police station and puts Gently, Bacchus and Coles on the trail of a violent gang of skinheads.

Songwriters Kelly Willis, Brennen Leigh and Melissa Carper come together to create a unique sound with harmonies and melodies played on guitar, mandolin and bass.

A 1960 Ansel Adams Portfolio III: Yosemite Valley; a Persian Qashqai Gabbeh rug circa 1935; 1959 JFK's boxer shorts with signed photo.

Marine botanist Sylvia Earle and Fred Rogers snorkel off the Florida Keys.

Muffy challenges Francine to be nice for one week; Arthur joins a gang.

Martin encounters a lost colony of black-footed ferrets.

Benny's toy penguin is swept away by melting snow, transforming a day of sledding into an urgent rescue mission.

Lyla figures out how to do a magic trick with clues from Miss Emmaline; Luke finds a puppy.

Arugula and Carl go on an adventure as archaeologists; Carl spots a UFO on Mother's Day.

Things don't go as planned when Daniel and Dad Tiger spend the day together; Daniel and Mom's day together includes turning her old wagon into a trolley.

Phoebe, Jay and Lupe practice their fire safety plan when the fire inspector visits; Phoebe and Jay buy juice from Mr. Aguilar.

A streamlined way to sew 18-inch doll clothes; avoiding underarm seams; updating a basic jumper with a ribbon layout; creating doll clothes to mix and match.

Quilting big and fast with the passion flower design; dealing with big seams; creating large templates.

Visiting one of the smallest herbal botanical gardens in the U.S., which features plants for shade, traditional areas and more.

Craig Nutt's wooden chairs, tables and sculptures feature corn, butter beans and other vegetables as legs, stretchers and back rests.

Duck liver mousse with apples; sauteed duck breast with arugula salad and cracklings; vinaigrette; lemon mousseline.

Onion and potato gratin; rosemary chickpeas; pork chops with mushrooms and pickled pepperoncini.

Reggie Bush and his wife, Lilit, recreate Reggie's ultimate late night treat; a cocktail to shake things up.

Grilled hilltribe chicken with kua txob; the difference between fondue and fonduta; refreshing tomatoes with fontina sauce and cornichon dressing.

A flavorful tandoori salmon; favorite kitchen gadgets under $15; a tasting of yogurt; broiled smashed zucchini with garlicky yogurt.

Making cacio e pepe using only three ingredients; zucchini carbonara; spaghetti parsley with pesto.

A culinary tour of Vancouver's Chinatown; appetizers cooked with tea; dim sum; a Chinese dumpling mashup filled with Korean bulgogi; Grace Young's efforts to preserve New York's Chinatown; barbecue pork for Yangzhou fried rice.

Exploring fat's misunderstood role in the kitchen; cooking oils, storage tips and fat myths; what makes great olive oil; frying fish in peanut oil with a bold mayo smear.

Installing vinyl siding on the main house and ADU; revealing the ADU's framed layout; reviewing basement HVAC; installing a three-panel slider to connect indoor and outdoor living.

Lawn mowing basics; how to vet and hire a trustworthy contractor to avoid costly mistakes; installing a concrete paver walkway.

Luke joins Kurt Fogle - a Racine-based chef who got his start at Q&H Danish Bakery - to hand-fill and shape Wisconsin's state pastry from 18-layer Danish dough. Then he heads to Gills Rock at the northern tip of Door County, where Charlie's Smokehouse has brined and maple-smoked Lake Michigan whitefish using the same methods since 1932.

Port Washington, Wisconsin, sits on Lake Michigan, but has the easy charm of a New England seaside town. Charter fishing boats line the marina, pulling in salmon and more. A block west, downtown is the definition of Main Street, USA - friendly and postcard perfect! Port Washington, thank you for the perfect wrap for this season of Main Streets!

The evolution of La Crosse, Wis., including its people, politics, industries and higher education and medical institutions.

Phryne and Jack find buried treasure, pirate ghosts and murder in Queenscliff.

Oakley Wines enjoys newfound fame and welcomes a surprise visitor, while gala preparations take an explosive turn, putting the entire showcase at risk.

Prime Minister Thatcher faces mounting pressure after a key ally's sudden departure; a television appearance becomes a turning point for her political career.

A man dies on a bus after having a violent coughing fit, and police discover that the victim has multiple identities and a history of eco-terrorism; Detective Bea is warned off the case.

A famous crime author arrives in Brokenwood to give a reading of his latest novel and ends up falling victim to a murder portrayed in his book.

When Edina loses a major fashion PR award to her archrival, she decides to rejuvenate her career.

A murder takes Oskar and Max's investigation into a world of underground gambling; Oskar's life is complicated by his feelings for Therese; Max questions if he and Clara are meant to be together.

Oakley Wines enjoys newfound fame and welcomes a surprise visitor, while gala preparations take an explosive turn, putting the entire showcase at risk.

Prime Minister Thatcher faces mounting pressure after a key ally's sudden departure; a television appearance becomes a turning point for her political career.

A man dies on a bus after having a violent coughing fit, and police discover that the victim has multiple identities and a history of eco-terrorism; Detective Bea is warned off the case.

An autographed first edition copy of Harper Lee's "To Kill a Mockingbird"; Titanic photograph and book; Rolex military watch.

Touring the "Mister Rogers' Neighborhood" television studio and meeting the staff.

Arthur's not sure what to make of the new baby; D.W. considers running away to Button Island.

Martin and Chris find out that Zach Varmitech plans to capture a black jaguar.

The kids learn what colors make up a rainbow just in time for a Mother's Day surprise.

Lyla and Luke clean Stu without a bath; Lyla and Ale find a way to protect the callaloo plants from stink bugs.

Carl and his friends clean up the Fuzzytown Park; Carl accidentally breaks the birthday present Sheldon planned to give his mom.

Daniel visits the post office and learns how letters are sorted and mailed, then sends a letter to Dad; Daniel and Dad Tiger surprise Mom with banana bread.

Phoebe and Jay accidentally get paint on the mail and have to decode addresses; Phoebe and Jay find their parents' box of memories.

A panel of journalists provides reporting and analysis of the major stories emanating from the United States capital.

Author Danielle Crittenden offers insight on how loss reshapes life and how to support those living through it.

Events in Wisconsin.

Social, political and economic trends of American agriculture.

General Howe takes Philadelphia, but the Americans' surprising victory over General Burgoyne at Saratoga encourages France to support the U.S.

Phryne and Jack find buried treasure, pirate ghosts and murder in Queenscliff.

Oakley Wines enjoys newfound fame and welcomes a surprise visitor, while gala preparations take an explosive turn, putting the entire showcase at risk.

Prime Minister Thatcher faces mounting pressure after a key ally's sudden departure; a television appearance becomes a turning point for her political career.

A man dies on a bus after having a violent coughing fit, and police discover that the victim has multiple identities and a history of eco-terrorism; Detective Bea is warned off the case.

An exploration of the 1936 Berlin Olympics, often considered to be the most controversial Olympics of all time, and how a boycott threatened the Nazi Germany's propaganda machine.

The team prepares for their first charity gala in three years in the castle's library, with some clay pigeon shooting, a three-course lunch and a big-ticket auction; the Carnarvons launch their own branded roses at the Chelsea Flower Show.

Sister Veronica weighs her future with the Order; Dr. Turner makes a final stand against the council's news before the maternity home closes; the Mullucks campaign for the rights of all thalidomide victims.

Becca and Rosaline reel from shock and seek solace in different directions as revelations about the circumstances surrounding Mary's death come to light.

Edmond reveals to Villefort that Heloise stole the vial of poison from him, the same poison used to murder the Marquise; Villefort confronts Heloise, threatening to expose her.

Simcoe plans to weed out rebel conspirators in Setauket through a political witch hunt; Ben is assigned to a secret mission.

Blues rock musician Gary Clark Jr. performs highlights from "JPEG Raw"; Black Pumas present selections from "Chronicles of a Diamond.".

An exploration of the 1936 Berlin Olympics, often considered to be the most controversial Olympics of all time, and how a boycott threatened the Nazi Germany's propaganda machine.

Sister Veronica weighs her future with the Order; Dr. Turner makes a final stand against the council's news before the maternity home closes; the Mullucks campaign for the rights of all thalidomide victims.

Becca and Rosaline reel from shock and seek solace in different directions as revelations about the circumstances surrounding Mary's death come to light.

Edmond reveals to Villefort that Heloise stole the vial of poison from him, the same poison used to murder the Marquise; Villefort confronts Heloise, threatening to expose her.

Prunella receives a Braille copy of a book; Arthur and D.W. watch immature television shows.

Odd Squad must figure out how to control the temperature of two dragon eggs after the power goes out in headquarters.

Martin and Chris try to touch a hummingbird; the brothers utilize hummingbird powers to prevent Gourmand from cooking chocolate-covered hummingbird egg snacks.

As a hurricane approaches, the Hunter kids learn about preparation and safety, moving furniture inside and checking their emergency supplies.

Lyla and Stu help out when the neighborhood garbage truck malfunctions; Lyla and Louisa take a ride on the city bus and accidentally lose Stu.

Sheldon can't wait for Carl to play his favorite beach game; Lotta and her friends search for Lotta's lost blanket.

Daniel and O play post office; Jodi uses things in nature to make a homemade boat.

Phoebe plans a birthday surprise for Grandma; Phoebe and Jay must tend to the bell pepper in the garden.

Rudy is afraid of getting a shot at the doctor's office, so Nina and Abby play pretend to show what the visit will be like so he can feel less scared.

The Treeborhood celebrates a parranda; the Wombats try to stay awake on New Year's Eve.

Panda is sad when an exciting holiday is over; Rockstar Penguin asks Donkey and Panda to make up a new dance.

Rosie puts on a concert when Tia is unable to get tickets to see her favorite singer; Rosie loses her first tooth, and prepares to welcome both the Tooth Fairy and the Tooth Mouse.

Ronald, a meticulous, rule-following pig, and Roxy, a free-spirited musical hedgehog, explore the "wows" of one of America's most extraordinary places -- Sequoia National Park.

Alma and Eddie open a mofongo food truck but run out of time to make the mofongo; Alma challenges André to scooter races to prove she is faster.

Molly must find her mom's plane keys so she can get home in time for Mother's Day; Trini spots a talking white bird.

Edmund Hillary explains to Xavier that even the most courageous adventurers ask for help when they need it; Yadina prepares for a special birthday performance with the help of Celia Cruz.

Tom is in Cincinnati to create a simulated wainscoting out of base cap molding; NASA astronaut Mike Foreman shows off a few space tools; Richard helps a homeowner get enough hot water for his children's bath time.

Skillet pizza Margherita; traditional and enameled cast iron skillets; chocolate chip skillet cookie.

A 1960 Ansel Adams Portfolio III: Yosemite Valley; a Persian Qashqai Gabbeh rug circa 1935; 1959 JFK's boxer shorts with signed photo.

From folk art and marionettes to tiny furniture, exploring the world of tiny objects and the artists who create them; featuring the International Folk Art Market, Leandro Gomez Quintero, Mark Murphy, Alexander Girard and Gustave Baumann.

Odd Squad must figure out how to control the temperature of two dragon eggs after the power goes out in headquarters.

Prunella receives a Braille copy of a book; Arthur and D.W. watch immature television shows.

Martin and Chris try to touch a hummingbird; the brothers utilize hummingbird powers to prevent Gourmand from cooking chocolate-covered hummingbird egg snacks.

Live news program produced out of BBC's Washington, D.C. bureau; host Sumi Somaskanda.

Co-anchors Amna Nawaz and Geoff Bennett and correspondents offer in-depth analysis of current events.

A Cartier Art Deco Tutti Frutti clutch circa 1925; a Carl Kauba cowboy bronze circa 1900; a Sumerian cuneiform tablet.

The Ways is a collection of language and culture stories from Native communities around the central Great Lakes that explores traditional ways, and those of today. The series supports educators in meeting the requirements of Wisconsin Act 31.

The town of Natchez, Miss., confronts the tension between preservation and truth as it wrestles with race, memory and identity.

Becca and Rosaline reel from shock and seek solace in different directions as revelations about the circumstances surrounding Mary's death come to light.

Port Washington, Wisconsin, sits on Lake Michigan, but has the easy charm of a New England seaside town. Charter fishing boats line the marina, pulling in salmon and more. A block west, downtown is the definition of Main Street, USA - friendly and postcard perfect! Port Washington, thank you for the perfect wrap for this season of Main Streets!

Christiane Amanpour leads discussions about world issues and interviews with global leaders.

A Cartier Art Deco Tutti Frutti clutch circa 1925; a Carl Kauba cowboy bronze circa 1900; a Sumerian cuneiform tablet.

The Ways is a collection of language and culture stories from Native communities around the central Great Lakes that explores traditional ways, and those of today. The series supports educators in meeting the requirements of Wisconsin Act 31.

The town of Natchez, Miss., confronts the tension between preservation and truth as it wrestles with race, memory and identity.

Port Washington, Wisconsin, sits on Lake Michigan, but has the easy charm of a New England seaside town. Charter fishing boats line the marina, pulling in salmon and more. A block west, downtown is the definition of Main Street, USA - friendly and postcard perfect! Port Washington, thank you for the perfect wrap for this season of Main Streets!

D.W. doesn't want another pet after her bird, Spanky, dies; Buster's too busy to spend any time with Arthur.

Owen and Ohio provide backup on a case, so they can have a pizza party; an unlucky coin is accidentally released to the public.

A Creature Quiz challenge question about the differences between a crocodile and an alligator turns into a Crocogator contest.

Benny's toy penguin is swept away by melting snow, transforming a day of sledding into an urgent rescue mission.

Lyla struggles to sleep and tries to figure out what is wrong with her sleep routine; Lyla tries to do her own hairstyle.

Carl blames Nico when his special crayon breaks and Nico blames Carl when his drawing rips; Lotta tries to learn to play the alto saxophone.

The Tiger Family goes to the restaurant for taco night; Music Man Stan comes to school for a musical story with the class.

Phoebe and Jay set a new record for the longest paper airplane fight; Phoebe and Jay learn how to build a stable pillow fort.

Reporters Elmo and Abby offer strategies to Nursery Rhyme characters experiencing big feelings of excitement, nervousness and frustration.

The Wombats track down a scary-weird sound that has frightened Carly, CeCe and Clyde; the Wombats become Hopping Helpers for a day.

Donkey and Panda must complete hard challenges to earn badges for Try Scouts; Donkey and Duck Duck teach Bob Dog a new game.

Things get out of control when Rosie starts a pet-sitting business; Rosie plays with a rock from Javi's rock collection.

Elinor and her friends play Hide-and-Go-Seek but are unable to stay hidden from the Goat twins; an owl inspires Elinor's costume for Costume Day.

Alma cheers up Lucas after he misses out on a trip to the Statue of Liberty; Alma and Andre help Dona Carmen with a recipe.

Molly faces big obstacles while training for a cross-country ski race; Molly and her family lose their lunch when a seal sneaks onto their boat and steals their food during a fishing trip.

Bruce Lee helps Xavier and Brad realize that no matter how angry they get, they are in charge of what their body does; Sonia Manzano shows Yadina that telling stories can help manage big feelings.

Tom and Kevin use scrap wood to create an end grain cutting board in Build It; Scott installs surface-mounted downlights in a living room; What Is It?; Roger discusses the best ways to keep mice out of the house.

Garlic fried chicken; budget-friendly Dutch ovens; crispy Parmesan potatoes.

Actor Michael Douglas and writer/director Lena Dunham explore their family roots.

Lucy Worsley investigates what really happened to the two princes who disappeared in 1483.

Owen and Ohio provide backup on a case, so they can have a pizza party; an unlucky coin is accidentally released to the public.

D.W. doesn't want another pet after her bird, Spanky, dies; Buster's too busy to spend any time with Arthur.

A Creature Quiz challenge question about the differences between a crocodile and an alligator turns into a Crocogator contest.

Live news program produced out of BBC's Washington, D.C. bureau; host Sumi Somaskanda.

Co-anchors Amna Nawaz and Geoff Bennett and correspondents offer in-depth analysis of current events.

Jamie Chung, Cyndi Lauper and Danny Trejo retrace the journeys of their immigrant ancestors.

Research into the ancestry of singer Lea Salonga and actress Amanda Seyfried reveals relatives who survived heart-wrenching ordeals.

President Trump's unprecedented challenges to the Federal Reserve and what it means for the economy; tracing the battle between Trump and the Fed as the central bank steers the economy through an increasingly precarious moment.

The team prepares for their first charity gala in three years in the castle's library, with some clay pigeon shooting, a three-course lunch and a big-ticket auction; the Carnarvons launch their own branded roses at the Chelsea Flower Show.

How discoveries over the past 50 years have revolutionized people's understanding of the universe.