Search Results: " fundamental force? quantum eraser answer | space time | pbs digital studio"
All Most Recent Most Viewed-
09:27
Pancakes 201: Extra-fluffy, berry, chocolate and swirl recipes
296 views / 0 likes - addedThanks to CuriosityStream for sponsoring this video! For unlimited access to the worlds top documentaries and nonfiction series, enter the promo code ragusea when prompted and your membership is completely free for the first month: http://go.thoughtleader
-
05:41
These Places Have No Scientific Explanation!!
403 views / 1 likes - addedRadioactive lakes, rivers that can boil you alive, and lakes that turn things to stone these all sound like something straight out of a sci-fi fantasy, but theyre real places on Earth and today were going to take you there: Number 7. Shanay-Timpishka The
-
12:30
Top 10 Amazing Animals With Real Super Powers
425 views / 3 likes - addedTop 10 Amazing Animals With Real Super PowersIf you're new, Subscribe! http://goo.gl/djmfuXTop 5 Best is the #1 place for all your heart warming stories about amazing people that will inspire you everyday. Make sure to subscribe and never miss a single vi
-
04:04
Why Wolves Don't Chirp
400 views / 2 likes - addedCheck out Brilliant (and get 20% off) here: https://brilliant.org/MinuteEarth/Sounds that animals make can be really different, and it turns out that there's a reason why some species communicate with certain sounds.Thanks also to our Patreon patrons http
-
22:19
The Weird World in RGB
373 views / 1 likes - addedYou can support this channel on Patreon! Link below Have you ever wondered why the word looks so weird? Wait. Weird as in, like, all the time? Of course! We live in a weird world! But light, though! What about weird light? Ahhh, that's what this video is
-
10:56 Popular
GIANT KINDER BUNNY SURPRISE EGGS Unboxing! Opening Surprise Eggs Star Wars Kids Toys Review
1,375 views / 3 likes - addedGIANT KINDER BUNNY SURPRISE EGGS UNBOXING! Opening Giant Surprise Easter Bunny Kinder Surprise Eggs Disney Star Wars Kids Toys Review. Evren crack more Giant Kinder Bunny Surprise Eggs and Kinder Eggs Star Wars. Guess what Surprise Toys Evren discover thi
-
11:43
Last To Leave The FREEZING SNOW Wins | GEM Sisters
550 views / 10 likes - addedGEM Squad in this video we play Last To Leave The Freezing Snow Wins! This is our first time seeing snow. We went skiing in Brian Head Utah for our dad's birthday. The snow is so cold! Who do you think will win $1000. Should we do more last to videos? BOO
-
03:23 Popular
Do Juice Cleanses Actually Work?
1,066 views / 1 likes - addedJuice cleanses are all the rage. But do they actually provide any health benefits? Cristen explains. Learn more at HowStuffWorks.com: http://health.howstuffworks.com/wellness/diet-fitness/diets/what-s-the-big-deal-about-juice-cleanses-.htm Share on Facebo
-
08:06
Is There Any Cheese in Cheez Whiz? (And the Story of Kraft)
540 views / 0 likes - addedIf you happen to like our videos and have a few bucks to spare to support our efforts, check out our Patreon page where we've got a variety of perks for our Patrons, including Simon's voice on your GPS and the ever requested Simon Whistler whistling packa
-
15:44 Popular
Squishy Makeover: Fixing Your Squishies #15
2,449 views / 7 likes - addedHey guys! Today is another squishy makeover, obviously. I took on a couple really unique ones today. Actually kinda scary....and creepy. Plus one super basic one LOL. Which makeover do you like best?Also. The Koala issue that I mentioned about my LAST mak
-
18:56 Popular
Squishy Makeovers: Fixing Your Squishies #18
1,974 views / 7 likes - addedAD | Take 20% off when you shop at Arteza for the next 7 days using MORIAH20 at checkout https://arteza.com/moriahWelcome to another episode of squishy makeovers, where I transform ugly, used, old, dirty, cheap or unwanted squishies (donated by my subscri
-
05:51
You will never throw away these 12 food parts after watching this video!!
315 views / 1 likes - addedIf you're tossing those leftover fruit parts in the trash, you could be missing out on some tasty flavors and powerful nutrients.Here are 11 food parts you should never throw away. 1. Watermelon seeds and rinds. Although they dont look like it, watermelon
-
15:51
Vincent Van Gogh's The Starry Night: Great Art Explained
151 views / 0 likes - addedGreat Art Explained totally unique merchandise available here - https://crowdmade.com/collections/greatartexplained Please consider supporting this channel on Patreon, thanks! https://www.patreon.com/user?u=53686503 Or if you prefer a one off donation - h
-
06:28 Popular
Bad Santa Pet Shark Attack! Magic transform into Christmas Present! Kid Prank Toy Shark eat Snack
1,249 views / 2 likes - addedBad Santa Pet Shark Attack Ryan and Daddy from Ryan ToysReview! Shark toy was hiding in the christmas tree and chase Ryan and his dad around the house transform them into Christmas Present! Kid Ryan also Prank the bad shark toy feeding him cookie snack wi
-
20:44 Popular
The Man Who Killed Millions and Saved Billions
1,533 views / 3 likes - addedYES, THIS IS A REUPLOAD. The original was age-restricted and demonetized. To support the channel directly, you can buy Snatoms: https://ve42.co/snatoms1 https://ve42.co/amzn or support on Patreon: https://ve42.co/pFritz Haber is the scientist who arguably
Featured -
04:40
Where Does Maple Syrup Come From? | Winter is Alive! | SciShow Kids
245 views / 0 likes - addedTeachers and parents: scroll down to check out the Next Generation Science Standards (NGSS) for this episode!Jessi and Squeaks are eating some pancakes and learning all about their favorite pancake topping: maple syrup! Learn how maple trees use air, wate
-
03:09
We don't know what a tree is (and this video won't tell you)
203 views / 0 likes - addedOffset your carbon footprint with Wren! They'll protect 5 extra acres of rainforest for each of the first 100 people who sign up at https://www.wren.co/join/minuteearth.It turns out that defining what is and isn't a tree is way harder than it seems.LEARN
-
04:23
Can Science Bring Vision to the Blind?
43 views / 0 likes - addedThis episode explores how new research and developing technology in brain implants may eventually pave the way to the treatment of complete blindness and bring vision to the blind. See how you can help more immediately by giving visual assistance to blind
-
12:37
8 Ways to Eat Instant Noodles | Around the World
443 views / 0 likes - addedDo you boil your favorite instant noodles and simply dump them into a bowl? If so, its time to elevate your approach. In the latest episode of Around the World, Great Big Story senior producer Beryl Shereshewsky sources eight instant noodle recipes from e
-
08:36 Popular
9 Futuristic Materials
780 views / 0 likes - addedLearn about some materials that seem like they should belong in science fiction, but actually exist today! Hosted by: Michael Aranda ---------- Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow ---------- Dooblydoo thanks go
-
07:18
Primitive Technology: Yam, cultivate and cook
592 views / 1 likes - addedPrimitive Technology: Yam, cultivate and cook Subscribe: http://bit.ly/subPT | Never miss a video! Enable ‘ALL’ Notifications! More videos, watch me build a natural Blower & Charcol next: http://bit.ly/2MuwEr5 Follow Primitive Technology:
-
02:16
Why Our Favorite Crops Live Fast and Die Young
527 views / 0 likes - addedTo start using Tab for a Cause, go to: http://tabforacause.org/r/minuteearth2 We mostly grow annual plants because they reliably produce energy-rich seeds, which we like to eat. Thanks to our Patreon patrons https://www.patreon.com/MinuteEarth and our You
-
16:51 Popular
Fixing The UNFIXABLE: Squishy Makeovers from "The Hopeless Bin"
1,576 views / 14 likes - addedHey guys! Today I am doing a video that was honestly DEMANDED by some people in my comment sections recently Many of you really wanted to see my attempt to "Fix The Unfixable," sooooo, here I go. This special episode of squishy makeovers will be me attemp
-
21:27
Should Airships Make a Comeback?
92 views / 0 likes - addedWill we see a new generation of airships roaming our skies? Head to https://www.odoo.com/r/veritasium to start building your own website for free.If youre looking for a molecular modeling kit, try Snatoms a kit I invented where the atoms snap together mag
-
49:35
How did consciousness evolve? - with Nicholas Humphrey
63 views / 0 likes - addedFind out how consciousness is generated in the human brain - and discover the evidence suggesting some animals are also sentient.Read Nicholas's book 'Sentience: The Invention of Consciousness' here: https://geni.us/eCGsWatch the Q&A here: https://www.you
-
15:38 Popular
I Painted My Clothes
744 views / 8 likes - addedHey Guys! Today I am trying something slightly different. I'm still painting on something....of course. BUT, today I am going to be painting on...my clothes? LOLI love jean jackets, so I thought it would be really cool to create a custom painted jacket. I
-
01:33
Vilnius and Lublin in Poland became the first two cities to connect through a virtual Portal
333 views / 0 likes - addedWelcome to PORTAL where Lithuania's capital, Vilnius and Lublin in Poland became the first two cities to connect through this virtual ‘bridge’! Born in Vilnius, Lithuania, PORTAL is a new wave community accelerator, aiming to bring people of d
-
05:17 Popular
How Much Does It Cost To Run For President?
6,160 views / 0 likes - addedThere’s a big difference between running for President and actually winning the election. So how much money will you need to have a decent shot at being Commander-in-Chief? Learn more at HowStuffWorks.com: http://people.howstuffworks.com/president.htm Sha
Featured -
04:26
What The Heck Is GDP?
642 views / 0 likes - addedGDP, GNP – what does it all mean? Jonathan explains what economists mean when they bring up these common economic indicators. Learn more at HowStuffWorks.com: http://money.howstuffworks.com/gross-national-happiness.htm Share on Facebook: Share on Twitter:
-
12:16 Popular
10 Most Beautiful Snakes In The World
2,737 views / 3 likes - added10 Most Beautiful Snakes In The WorldIf you're new, Subscribe! http://goo.gl/djmfuXTop 5 Best is the #1 place for all your heart warming stories about amazing people that will inspire you everyday. Make sure to subscribe and never miss a single video!#vir
-
08:42 Popular
HATCHIMALS SURPRISE EGGS OPENING Amazing Magical Animals Hatching Egg Little Live Pets ToysReview
1,223 views / 1 likes - addedHATCHIMALS SURPRISE EGGS OPENING Amazing Magical Animals Hatching Egg Little Live Pets Kid ToysReview. Thanks for joining Evren and Evren's mummy unboxing and playing with two Huge Hatchimals Eggs Surprise from Spin Master and the Little Live Pets Surpris
-
1:19:08
A Million Dollars vs A Billion Dollars, Visualized: A Road Trip
381 views / 0 likes - addedThere are lots of ways to compare a million to a billion, but most of them use volume. And I think that's a mistake, because volume just isn't something the human brain is great at. So instead, here's the difference between a million and a billion, in a m
-
17:21 Popular
How Pokmon 8-bit music was inspired by classical music
904 views / 2 likes - addedInstall Raid for Free IOS/ANDROID/PC: https://clcr.me/DavidBP_Dec22 and get a special starter pack Available only for the next 30 days Visit Christmas event page https://12daysofraid.plarium.com to get a chance to win amazing in-game and real life prizes
Featured -
03:21
Does It Pay To Cheat?
200 views / 0 likes - addedThanks Thryve for sponsoring the video. Get 50% off your gut health test at https://trythryve.com/MinuteEarthFor some birds, trying to cheat your neighbors into raising your babies is just as much work - and is no more successful - than doing it yourself.
-
11:44
4 Mysterious Extinctions from Earths History
209 views / 0 likes - addedNowadays, we're pretty confident about how the dinosaurs died out, but there are still other extinctions throughout Earth's history, some big, some small, that remain unsolved.Hosted by: Rose Bear Don't WalkSciShow is on TikTok! Check us out at https://ww
-
1:11:35 Popular
The Paint is Pink
818 views / 0 likes - addedBusy & Baby Beavers Present 70 Minutes Kids Compilation with "The Paint is Pink" in 3D. Kids will Learn Colors, 123s, ABCs, Shapes, Nursery Rhymes & More. The Paint is Pink (3D) 00:08 Princess 123s "I Can Count to 10" 02:16 Colors Chant FRENCH 05:
-
24:42 Popular
Businessman CALLS COPS on POOR GIRL, He Lives To Regret It | Dhar Mann
1,477 views / 2 likes - addedAccomplishing anything great takes time. Hi #DharMannFam, thanks for watching my video! For exclusive giveaways & more inspirational content follow me on Instagram here: http://bit.ly/2Kcbgs2 MOBILE APP App Store = https://apple.co/3nhvjapGoogle Play = ht
-
28:01
How Hidden Technology Transformed Bowling
240 views / 0 likes - addedBowling has been reinvented many times over the past seven thousand years but especially in the last 30. This is the fascinating physics of balls, oil, lane and pins. A portion of this video was sponsored by Salesforce. Go to https://salesforce.com/verita
-
05:46 Popular
SHOOTING ALIENS! Family Fun Game Night Challenges Surprise Toys Disney Cars 3 Mickey Mouse Clubhouse
838 views / 2 likes - addedALIENS SHOOTING GAME! Family Fun Game Night Challenges Disney Cars 3 Mashem Disney Mickey Mouse Clubhouse Surprise Toys. Thanks for joining Evren and Evren's family to unbox and play this Galaxy Shooting Game. The players has to shoot chosen aliens to gai
-
04:05 Popular
What Is 'Ranch' Flavor?
953 views / 0 likes - addedA plumber in Alaska invented a bizarre condiment that launched a multimillion dollar industry, and today ranch is the most popular salad dressing in the US. But what exactly is this stuff? Learn more at HowStuffWorks.com: http://recipes.howstuffworks.com/
Featured -
08:56 Popular
17 Jaw-Dropping Facts You Didn't Know About the Human Body
1,284 views / 2 likes - addedWhat do you know about your body? These 17Facts About the Human Body Will Send Chills Down Your Spine. These amazing facts may still behard toswallow, but you will absolutely beall ears tohear about them. Did you love science at school? Let's face it, onl
-
09:25
How Long Would It Take to Count to a Billion and What’s the Highest Anyone Has Counted?
637 views / 0 likes - addedIf you happen to like our videos and have a few bucks to spare to support our efforts, check out our Patreon page where we've got a variety of perks for our Patrons, including Simon's voice on your GPS and the ever requested Simon Whistler whistling packa
-
12:45
The Internet Is Running Out of Water
338 views / 0 likes - addedData centers are running out of water to cool their servers with. And they keep asking for more. Support me through Patreon: https://www.patreon.com/thehatedone - or donate anonymously: Monero: 84DYxU8rPzQ88SxQqBF6VBNfPU9c5sjDXfTC1wXkgzWJfVMQ9zjAULL6rd11A
-
08:29 Popular
Oldest footage of New York City ever
727 views / 1 likes - addedThe oldest and most incredible footage of New York City ever, including where the WTC would be built. With added maps carefully researched to show where the camera was. 28 shots of classic footage with a new twist and a new soundtrack. For more videos see
-
1:11:24 Popular
Learn the Alphabet Phonics
859 views / 0 likes - addedBabies & Toddlers Learn the Alphabet Phonics with this Fun & Colorful Busy Beavers Collection for Kids. Have Fun Learning the ABCs, 123s, Colors, Shapes, Nursery Rhymes & More. Alphabet Phonics Song (3D) 00:08 Surprise Eggs ABCs 03:17 Busy Bea
-
03:17 Popular
Dish Soap No Glue Slime, No Glue Fluffy Slime, No Glue,No Borax, No Shaving Foam, No Salt, MUST TRY
24.6k views / 20 likes - addedReal and Easy Dish Soap No Glue Slime Tutorial! If u have dish soap and face mask you can try the recipe easily!!The Best Ever Slime in no glue no borax slimes, I'll be testing out a slime that doesn't need borax, detergent, glue, corn starch and contact
-
1:11:40 Popular
Busy Beavers Long-Play Video on Color
1,262 views / 0 likes - addedThis Busy Beavers Long-Play Video Teaches Babies & Toddlers Colors with the Baby Beavers Version of "Pink Flower Song". Kids will Have Fun Learning Colors like "Pink", "White" & "Purple", along with Shapes, ABCs, Nursery Rhymes & More. Click H
-
04:36 Popular
Let It Go (Disney's "Frozen") Vivaldi's Winter - The Piano Guys
1,253 views / 3 likes - added► Get our latest album "UNCHARTED" here: http://hubs.ly/H04ZSnT0 ► WE'RE ON TOUR! http://goo.gl/fmybn0 ► DOWNLOAD THIS SONG: http://goo.gl/gbXiHb ► GET THE SHEET MUSIC: http://goo.gl/TcNZzB ________________________ ► Also Order "Uncharted" here: ► iTunes
-
14:48
The Fourier Series and Fourier Transform Demystified
153 views / 0 likes - addedWatch over 2,400 documentaries for free for 30 days AND get a free Nebula account by signing up at https://curiositystream.com/upandatom and using the code "upandatom". Once you sign up you'll get an email about Nebula. If you don't get one, contact the c
-
1:00:24
Explosive chemistry - with Andrew Szydlo
38 views / 0 likes - addedDiscover the evolution of explosive chemical experiments, with the maestro of chemistry Andrew Szydlo.Sign up as a YouTube Channel Member to watch the Q&A here: https://youtu.be/XCeDrmFgrewThis Discourse was recorded at the Ri on 29 February 2024.Go on a
-
05:24
3 Brand New Colors That Scientists Discovered
654 views / 1 likes - addedFor millennia, we mostly had to make do with natural pigments and dyes, but in the last 300 years or so, chemical synthesis has revolutionized the colors of our world. We're conducting a survey of our viewers! If you have time, please give us feedback: ht
-
12:53
Unsolved Math Mystery - What's The Largest Sofa That Can Fit Around a Corner?
437 views / 0 likes - addedSign up to Brilliant to receive a 20% discount with this link! https://brilliant.org/upandatom/Recommended course: Advanced Geometry Puzzles https://brilliant.org/courses/advanced-geometry-puzzles/Mathematica Notebook and animations can be found at the bo
-
03:38
When Tree Planting Goes Wrong
68 views / 0 likes - addedSpecial thanks to the Society for Ecological Restoration and its global partners for their support during this production; and to the Convention on Biological Diversity, which is part of the United Nations Environment Programme. Thanks to Kingsley Dixon a
-
03:38
How Do Some Waves Get SO Big?
227 views / 0 likes - addedGet 10% off all orders with code MINUTEEARTH now through May 31. After that, code is valid on 6" and 8.5" only. Shop now on https://bit.ly/MinuteEarthGlobes.All over the world, giant wave breaks appear because of underwater geology that supercharges their
-
04:52 Popular
The Science Of Hay Fever... Are Parasitic Worms The Cure?
784 views / 0 likes - addedHay fever has an awful habit of ruining what should be the nicest time of the year. But what is it? And why is it called ‘hay fever’? Kate explores the science of allergies, and hunts through the research for a cure. Subscribe for more from Kate: http://b
-
27:19
What The Prisoner's Dilemma Reveals About Life, The Universe, and Everything
47 views / 1 likes - addedThis is a video about the most famous problem in Game Theory, the Prisoners Dilemma. Head to https://brilliant.org/veritasium to start your free 30-day trial, and the first 200 people get 20% off an annual premium subscription.If youre looking for a molec
-
03:44
Why Exercise Is Hard
381 views / 0 likes - addedThanks to the University of Minnesota for sponsoring this video! http://twin-cities.umn.edu/Because exercise isn't essential for short-term survival, we don't exercise enough, so we need to reincorporate purposeful physical activity into our lives.Thanks
-
1:12:01 Popular
"Super Christmas" Songs | Jingle Bells, Santa Claus | Christmas Songs for Kids | Children's Songs
1,641 views / 0 likes - addedThis Kid's Christmas Compilation is Stuffed Like a Stocking with Xmas Carols, Colors Songs, Shapes Learning Videos & Busy Beavers "SUPER CIRCUS 3D" Clips. Children will Love the Christmas Classics Like "Jingle Bells", "'Twas the Night Before Christmas" &
-
16:43
Why it took 379 pages to prove 1+1=2
153 views / 0 likes - addedSign up to Brilliant to receive a 20% discount with this link! https://brilliant.org/upandatom/ Hi! I'm Jade. If you'd like to consider supporting Up and Atom, head over to my Patreon page :) https://www.patreon.com/upandatom Visit the Up and Atom store h
-
25:04
Causing An Avalanche To Explain How They Work
35 views / 0 likes - addedAvalanches are beautiful, majestic, and completely terrifying this is a video all about the science of avalanches. Head to https://brilliant.org/veritasium to start your free 30-day trial, and get 20% off an annual premium subscription.A massive thank you
-
08:56
The Rubber Band: Holding It Together Since 1820
688 views / 0 likes - added→Subscribe for new videos every day! https://www.youtube.com/user/TodayIFoundOut?sub_confirmation=1 →How "Dick" came to be short for 'Richard': https://youtu.be/BH1NAwwKtcg?list=PLR0XuDegDqP2Acy6g9Ta7hzC0Rr3RDS6q Never run out of things to say at the wate
-
20:24
The Impossible Problem NO ONE Can Solve
85 views / 0 likes - addedGet Nebula using my link for 40% off an annual subscription! https://go.nebula.tv/upandatomRecommended shows:Is Math Invented or Discovered? https://nebula.tv/ismathinvented Becoming Human https://nebula.tv/becominghuman?ref=upandatomWhat is Code? https:/
-
31:33
The Oldest Unsolved Problem in Math
63 views / 0 likes - addedDo odd perfect numbers exist? Head to https://brilliant.org/veritasium to start your free 30-day trial, and the first 200 people get 20% off an annual premium subscription.If youre looking for a molecular modeling kit, try Snatoms, a kit I invented where
-
17:59
A Hobbyist Just Solved a 50-Year-Old Math Problem (Einstein Tile)
126 views / 0 likes - addedSign up to Brilliant to receive a 30-day free trial + a 20% discount with this link! https://brilliant.org/upandatom/Recommended course: https://brilliant.org/courses/beautiful-geometric-explorations/Hi! I'm Jade. If you'd like to consider supporting Up a
-
26:33
The Algorithm That Transformed The World
159 views / 0 likes - addedThe Fast Fourier Transform is used everywhere but it has a fascinating origin story that could have ended the nuclear arms race. This video is sponsored by 80,000 Hours. Head to http://80000hours.org/veritasium to sign up for their newsletter and get sent
-
1:12:13 Popular
Days Of The Week Song & More | 3D Baby Rhymes, Learn Colors For Kids, ESL Toddler Learning Videos
1,352 views / 1 likes - addedToddlers & Preschoolers Learn the Days of the Week with a Brand New 3D Video starring Billy, Betty, Mr. Alligator & Silly Monkey doing different activities. This Collection will help Kids Grow Up & Teach them the Months of the Year, Expressing Emotions &
-
1:12:13 Popular
Watch Me Fish | Dance Hits 4 Kids | Children's Learning Songs, Edutainment by Busy Beavers
1,185 views / 0 likes - addedKids, it's Time to Dance! Busy Beavers new Hit Song "Watch Me Fish" will make your Little Ones Sing & Dance with Fun Lyrics & a Catchy Tune. Babies & Toddlers will Have Fun in Front of this Compilation while Learning Colors, ABCs, Nursery Rhymes & More Ed
-
08:28
Wardruna - Lyfjaberg (Healing-mountain) Official music video
94 views / 1 likes - addedVideo produced by Ragnarok Film – https://www.ragnarok-film.com Original lyrics and English translation: Lyfjaberg Sal din hug og lat den ri og renna Med blinde augo vil du vegen finna Djupt du dreg anden inn – let tankar svinna Langsamt slepp
-
10:33
TELEVISION: HOW IT WORKS 1952 CORONET INSTRUCTIONAL FILM CATHODE RAY TUBE ORTHICON XD39134
235 views / 0 likes - addedWant to support this channel and help us preserve old films? Visit https://www.patreon.com/PeriscopeFilm Visit our website www.PeriscopeFilm.com This black-and-white educational film from 1952, “Television: How it Works” was created with educa
-
19:26
What Happens If A Star Explodes Near The Earth?
134 views / 0 likes - addedPeople have witnessed supernovae for millennia, but what threat do they pose to life on Earth? This video is sponsored by Brilliant. You can get started for free, or the first 200 people to sign up via https://brilliant.org/veritasium get 20% off a yearly
-
34:29
What Does IQ Actually Measure?
218 views / 0 likes - addedIQ is supposed to measure intelligence, but does it? Head to https://brilliant.org/veritasium to start your free 30-day trial, and the first 200 people get 20% off an annual premium subscription.If youre looking for a molecular modeling kit, try Snatoms a
>> View fundamental force? quantum eraser answer | space time | pbs digital studio web videos