What If You Traveled in Time?

if you traveled 10,000 years into the future what would planet Earth look like would most of its surface be covered in volcanoes or would it be frozen in ice what if you traveled even further to 1 million years in the future would all of the oceans have evaporated or would it have become one giant water world okay now what about 1 billion years would there be any humans left or would they have settled in other parts of the Galaxy this is what if and here's what would happen if you traveled 1 billion years into the future let's face it the chances of any humans being around to greet you when you arrive 1 billion years into the future are pretty low several key existential threats face the human race and if we want to be around in 1 billion years we'll need to endure them all we've seen how much we've struggled to come together just to survive a global pandemic so how do we have any chance of enduring the threats of climate change overpopulation Global nuclear war killer asteroids and comets Natural Ice Ages and the sun getting a whole lot hotter well let's take a look into the future and find out just under 10,000 years from now we're going to run into a big problem called the DECA millennium bug in the year 10,000 ad software encoding the ad calendar year won't encode dates with more than four decimals remember y 2K yeah it's just like that except hopefully we won't Panic as much this time around on the bright side in 10,000 years genetic differences and traits between humans will no longer be Regional traits like skin and hair color will be evenly distributed around the world maybe that will help us all get along finally 20,000 years into the future none of the current languages will be recognizable future languages will only contain 1% of the core vocabulary words of their present day counterparts 50,000 years from now will Mark a new glacial period for the Earth which will start a new Ice Age Niagara Falls will have eroded into Lake Erie completely and interestingly a full day on Earth will also increase by 1 second at this point in time so much more time for activities in 250,000 years the LOI volcano will rise above the water to form a new island in Hawaii and in 500,000 years it's likely that an asteroid with a diameter greater than 1 k ometer will hit Earth unless we can prevent it the resulting crater will be no less than 400 km across it will start fires all over the planet and make the air unbreathable so there's something to look forward to and in case that's not enough in 1 million years we'll likely have another super volcano eruption large enough to spew out 3200 cubic kilm of Ash it would produce enough lava to fill 75% of the Grand Canyon this would be similar to the Toba eruption that almost wiped out Humanity 70,000 years ago oh and the nearby star Beetle juu will have exploded into a Supernova by this time making it visible from Earth even during the [Music] daytime in 2 million ad Humanity will have settlements throughout the solar system this also means that if populations on different planets have remained separate humans may have evolved into other species adapted to their specific World in 10 million years a huge part of Eastern Africa will break off forming a new ocean basin in 50 million years Africa will collide with Eurasia closing off the Mediterranean Sea and a new mountain range will form between the two land masses this mountain range may include a mountain taller than Mount Everest out in space Mars will collide with its Moon resulting in it developing a ring system like [Music] Saturn's in 60 million years the Canadian and American Rockies will have eroded entirely in 80 million years all Hawaiian Islands will be below the water in 100 million years an asteroid similar to the one that killed the dinosaurs 66 million years ago will likely hit Earth one that is 10 km wide in 250 million years all of Earth's continents will be fused together like Pangia except this time it will be called Pangia Ultima but don't get too attached to it because in 400 to 500 million years Pangia Ultima will separate again in 500 to 600 million years a gamma ray burst will likely occur with within 6,500 Lighty years from Earth if it strikes Earth it could damage the ozone layer and trigger a mass extinction 600 million years from now the moon will be so far from Earth that total solar eclipses will no longer be possible and the sun's increasing Luminosity will have raised temperatures on Earth so much that it could halt plate tectonics movement in 800 million years carbon dioxide levels will drop dramatically and photosynthesis will no longer be possible free oxygen and ozone will disappear from the atmosphere and complex life on Earth will die and finally in 1 billion years the sun's Luminosity will have increased by 10% and the average temperature on Earth will be 47° C our atmosphere will feel like a damp greenhouse and our oceans will evaporate leaving just pockets of water at each of the [Music] poles when you arrive here in your time machine be mentally prepared to take it in a planet Earth that looks nothing like the one you remember the human race will be gone hopefully living its best life on some other far-off planet because of the intense heat lack of water and lack of breathable air Earth will be uninhabitable so you probably shouldn't stay too long so this marathon of what if episodes focuses on living in different eras in the history of the world world that trip into the future started out cool but by the end left me a bit sad for this planet once the most beautiful thing in the universe reduced to a dry lifeless Rock later on in the show we'll give you a different perspective on the history of Earth we'll travel 1 billion years into the past but right now let's take a pit stop on the way there and see what Earth was like just 300 million years ago who was living where your backyard is right now millions of years ago Earth looked very different all the continents were fused into one teaming with life both beautiful and terrifying when you think of prehistoric times you might picture a T-Rex rampaging through the jungle with its razor sharp teeth but even before the dinosaurs there were other giant creatures ruling the Earth yeah welcome to the peran period this epic started 300 million years ago back then our planet had one supercontinent Pangia surrounded by a world ocean called panthalassa the perian period began at the end of an ice age when temperatures were much cooler than today then during early peran days Earth warmed to a lush environment with a diversity of plants and a rapid evolution of insect and animal life only as you probably know everything is Ever Changing on our Blue Marble over the next 50 million years Earth kept growing hotter and drier eventually the most deadly event in the history of our planet wiped out nearly everything that ever lived here scientists called this event the great dying and it was the most catastrophic mass extinction of the Earth has ever seen and the Earth has seen five of them but before we get to all this Doom and Gloom let me take you on an Epic Journey back in time here in the peran period some of the most incredible species that roamed our young Planet are about to emerge if you could time travel nearly 300 million million years into the past you'd land smack dab in the middle of the supercontinent Pangia Earth's smaller continents would have just finished colliding with each other to form this enormous land mass taking up onethird of the planet's surface there was likely less oxygen in the air than there is now but you still might be able to breathe oh and bring a jacket because it would likely be chilly with some areas averaging no more than a Brisk 4° C but don't worry things will soon start heating up by the end of the early peran the Ice Age was on its way out and Pangia was becoming a lush world plants and animals started to thrive this was a volcanic World violent eruptions changed the climate shaped the landscape and paved the way for evolution when giant swamp forests began drying out plant life had to adapt and so 290 million years ago Earth saw the very first seed bearing plants called gymnosperms these plants carried seeds on their cones and they spread across the superc continent like wildfire the ancient evergreen forest of the early peran was hiding something familiar just like today you could find cicas and beetles piercing and sucking on the plants and the cutest of them all cockroaches only these weren't the Cockroaches you know today these prehistoric Vermin were gigantic the size of birds but despite their size cockroaches never ruled prehistoric land and that's good news am I right no something much more fascinating was roaming Pangia the now extinct ancestor of primitive mammals dimetrodon this animal was as fascinating as it was terrifying encountering a dimetrodon would be quite a sight to behold this ancient lizard grew to 5 m long and weighed 225 kg it had a large sail running down its spine scientists think this sail helped the reptile regulate its body temperature soaking up water warmth during the daytime and dissipating excess heat during the cooler nights it would walk toward you like a crocodile and act like a total Menace dimetrodon was an apex predator of its time watch out for a mix of sharp and flat teeth that would slice you open and grind you up in the middle perian period other mammal-like reptiles took over the planet therapsids they had strong jaws with sharp teeth and a somewhat upright stance thanks to their legs being situated underneath their bodies therapsid reptiles varied from the 5 m long likely omnivorous dudosa surus to the five times smaller meing lops you could meet plenty more therapsids if you stuck around for another 20 million years during the middle perian period Earth kept getting hotter the average global temperature on Pangia grew to about 25° C and volcanoes were spitting greenhouse gases out into the atmosphere due to the changing climate sea levels were shifting but marine life found ways to thrive if you were to take a dip in the prehistoric super ocean you'd be swimming alongside ancient sharks and bony primitive fish many more complex marine species came and went as the environment kept changing in the late perian period you could have a friendly encounter with another reptile lystrosaurus these looked like a cross between a lizard and a pig but unlike all the scary prehistoric monsters out there lystrosaurus was a herbivore it was just 1 M long and had powerful front legs for burrowing soon another cute mamal likee lizard evolved the codon the codon looked like a giant rodent it was about 1 M long had whiskers and fed on small animals and insects now during this time something bad was brewing in the air a large amount of volcanic activity was displacing oxygen from the atmosphere scientists think there was as little as 10 % oxygen in the air compare that to 21% today you'd have a hard time breathing in that environment and the temperature kept rising and Rising with an average temperature of about 28° cus this Lush prehistoric world was turning into an oven all good things must come to an end and sadly this period came to a particularly brutal one about 252 million years ago about 90% of all plant and animal life was wiped out this tragic moment is called the Great dying and it was Earth's most devastating mass extinction event scientists still debate what caused this catastrophic Extinction most theories suggest it was the result of explosive volcanic activity as huge volcanic eruptions swept the continent massive amounts of Ash were Unleashed into the atmosphere so much Ash that it blocked out most if not all of the incoming sunlight and with no sunlight global temperatures dropped suddenly plants couldn't perform their photosynthetic processes and died off and without plants the very basis of their food chain animals soon followed things got worse before they got better because of all the carbon dioxide emitted during the volcanic eruptions global temperatures rose again and not just to where they were but higher much higher and this caused the super ocean to lose most of its oxygen and unable to breathe a majority of the perian sea animals perished eventually over 95% of marine species and More than 70% of land animals became extinct human beings have existed for 300,000 years and have managed to live in many unstable environments we've survived ice ages devastating pandemics and world wars but how would we fare even further back in time what about 400 million years ago when deadly marine life dominated our oceans and creatures on land were practically non-existent let's imagine your what if time machine happened to break down right at this moment trapping you in the devonian period What would life be like where would you live and how long could you last this is what if and here's what would happen if you lived in the devonian period Stroke of Luck our time machine stops you on land at this point in time 85% of the Earth was comprised of ocean only two supercontinents existed 600 million years ago gondwana and larusa gondwana had a massive mountain range similar to the Himalayas which slowly eroded washing sediments into the ocean these sediments provided Nutri nuut that allowed marine life to flourish giving rise to the devonian period okay enough background our first step for survival is to seek shelter in the early devonian period trees and plants had not yet evolved but there's lots of moss the land was Barren mars-like and surrounded by water you might need to get a little creative to build shelter if humans actually evolved in this period they would likely be naked with little material to make clothes or maybe we would develop a new fashion line made of moss seashells and Fishbones ooha La how devonian Chic speaking of Fishbones you'd want to be very careful about fishing many scary sea creatures would be happy to eat you like placoderms a species of armored fish with huge sharp Jaws that could easily make you bite-sized in the early devonian period placoderms were the apex predator and would grow up to 10 m let's say you got lucky and actually caught a fish without being eaten yourself in the process how would you cook it with no trees for fuel you'd have to find some very dry moss and start rubbing some rocks together luckily the climate was pretty warm meaning you wouldn't freeze at night but with very little kindling available you might be better off sticking to a raw diet of mollusks and other early arthropods you'd also have to move around a lot to keep finding these Critters so be prepared to do a lot of walking H I can see you're getting a little tired and bored of existing out there let's fast forward another 40 million years toward the late devonian period this period is also known as the devonian extinction but don't worry it could actually be a really good time for you Fearless traveler since by this point almost 79 to 87% of all existing species were wiped out but what could cause such a catastrophe scientists believe it was the evolution of plants vascular plants began dominating the environment including trees Ferns and flowering plants their Roots broke up the rocky ground and released nutrients and minerals in the water these nutrients fed algae which multiplied rapidly and produced greedy bacteria that fed on oxygen many regions of the ocean became anoxic zones and much of the marine life died off due to the lack of oxygen and with more air in the atmosphere some sea creatures slowly adapted and made their way way to shore so you can breathe easier knowing there are less predators in the water but look out for your new neighbors on land these land dwellers known as lobins were the early ancestors of amphibians and all four-legged vertebrates in fact the devonian period got its name from the fossils of lopin found in Devon England in 2004 a lopin fossil was found in the Canadian Arctic known as the the talic which is considered to be the species between fish and landd dwelling tetrapod it had a crocodil like head bony fins sharp teeth and a flat body almost 3 m long its fins had partial wrists allowing it to crawl on land so if I were you I would quickly hide if I saw a talic coming my way the other dominant species were cartilagenous fish with skeletons covered in you get IC cartilage these are the ancestors of sharks and Rays but you don't have to worry about sharks oh no there's something far bigger and scarier I'd keep my distance if you happen to see a Dunkle osus swimming around these were the deadliest predators of the devonian age with thick bony plates covering their skulls and razor sharp Jaws some would grow up to 10 m in Long length their jaws were strong enough to Chomp right through another Dunkleosteus with few fish left because of plants hogging the oxygen these placoderms were starving and desperate enough to eat each other so be very careful where you bathe with more trees and plants emerging in your environment you could finally create some helpful tools like Spears fishing hooks and rope you could improve your your diet and maybe become a vegetarian and you could fashion some new clothes that aren't so irritatingly itchy by the late devonian period you might even be able to build yourself a treehouse in the arch opterus the first tree on earth which grew up to 30 m tall with the trunk 3 m wide this may be nice for a while but if you think the devonian period is easy you might want to plan a hasty exit before the Cretaceous Period rolls around you know one of the big trends these days has women asking men how often we think about ancient Rome and surprisingly for women I guess it turns out that men think about ancient Rome quite a bit not me I mean what are the Romans ever done for us apart from the aqueducts and sanitation the roads the medicine the education the public health and the wine okay Mark me down as thinking about Rome some of the time here are another 7 Minutes of ancient Rome for you guys throughout history there have been many incredible civilizations that have shaped the way we live today one was ancient Rome a once Majestic and thriving City whose strong foundations live on to this day yet despite all its grandeur life as an average citizen in ancient Rome was hard and unforgiving what strange Customs did the Romans have what was the life expectancy of an average citizen and what did the Romans do for fun this is what if and here's what would happen if you lived in ancient Rome let's imagine you woke up some time between 27 BCE and 180 CE the Golden Age of Rome known in Latin by the Romans as Pax Romana or Roman peace this epic began when Augustus came into Power after his father the infamous Julius Caesar was assassinated with Augustus on the throne Rome began a period of Rapid development at its peak it was home home to over 1 million people it was a truly Golden Era of architecture science art entertainment and economic growth it was a time of peace and prosperity if you were Rich than okay so what's the catch well unless you were part of the 1% that controlled 16% of Rome's wealth life was tough as a citizen up to 50% of all Roman children died before the age of 10 and most adults were lucky if they lived long enough to see their 50s even though things were peaceful battles still happened and soldiers were in demand Roman armies at this point were largely made up of volunteers who were hoping for a better chance at life most soldiers came from the poorest social class and were stationed at the borders of the Empire where the most trouble was was expected as a soldier you were able to settle in the land where you were stationed once you retired and if you were particularly good with a sword or a bow you might be handpicked to join the Special Forces designed to protect the Emperor or maybe to climb the ranks as a gladiator they were treated like celebrities well at least the ones that survived with a large portion of the men away from home working as soldiers women gained more autonomy during this period serving important roles as City councilors lawyers teachers and more some women were even Gladiators however the men in the family still had the privilege of handling the matters of property and finance most of the poor lived in cheap wooden houses many of them lived in the city slums where crime was rampant you might find the emperor augustus' police force or cohortes Urban a patrolling some parts of the city but generally the poorer areas were Lawless and dangerous whether you were a soldier philosopher or Senator most Romans ate a similar diet of bread cheese grapes nuts olives and meat if you could afford it you could eat out at one of the many bakeries in the city to wash things down you'd have the option of thick milk watered wine or fruit juice that doesn't sound too bad to me after lunch many Romans went to the bath house to swim play sports bathe or get a massage and dinner was just a few hours later around 4:00 or 5:00 p.m. in the afternoon okay where do I sign up while many Romans had this luxury a large portion of them were slaves or clients for Rich families in this Patron client system people were sold and forced to help with all kinds of work from hard menial labor to highly skilled jobs like teachers accountants and doctors if they were lucky their patrons would give them a good dinner and they would go home with pockets full of food and if they did really well they would eventually be freed some poor people were desperate enough to sell their children in times of hardship speaking of hardship if you needed to use the washroom you could visit one of Rome's public toilets housing over 10 toilet seats out in the open oh that's intimate these weren't exactly the cleanest toilets and instead of toilet paper Romans had a stick with a sponge at the end that they would share uh I'll stick with my bedet please oh and when it was time to clean up many Romans used urine from humans or animals to decontaminate surfaces treat infections and even to wash their laundry it might sound strange but Ura in urine breaks down into ammonia a strong cleaning agent found in most cleaning supplies today and if you happened to get sick with epilepsy you might be prescribed some gladiator's blood or liver to consume uh thanks but no thanks Doc if you managed to save up a little money you could go shopping at the Tran Market the first ever mall in the world or if you were craving more excitement why you not in the how about a chariot race at the circus Maximus or an epic Gladiator battle maybe some theater and for the budget-minded there were plenty of public executions to go around okay power up the what if time machine because today you're traveling back to witness the most radical changes ever known in Earth's history you'll watch our planet give birth to strange new animals and see continents taking shape we're going to the time that defines our existence the Paleozoic Era but how would your body react to the new climate what kind of creatures would you eat and how hot would the planet get this is what if and here's what would happen if you live in the Paleozoic Era the Paleozoic Era began 530 million years ago when the earth woke up from an ice age the era lasted for 289 million years but you might not even last 5 minutes in this climate but hey if you're as resilient as the life in these Waters you just might stay alive in these oceans life has the perfect space to begin and like all great things it started small good luck trying to find a meal 543 million years ago all life on Earth lived below a thick layer of mud on the sea floor but don't get out your Lobster bib yet the only things you'll find here are microbes ooh so chewy your menu won't be getting any bigger for a few million years until the Cambrian explosion the big event that would Kickstart life on Earth the cyano bacteria would pump more oxygen into the atmosphere making it easier for you to breathe so take a deep breath and enjoy life on this doomed [Applause] continent During the tivis period 485 million years ago you would watch North America and Europe merge to become the super continent known as gondwana now grab your parka because as this land mass moves over the South Pole a massive Ice Age would spread across the globe under the water jawless fish would roam the sea dominating the ocean algae and sponges would begin living on coral reefs and back on land the first plants would take root but 80% of the life in Shallow Seas would die as sea levels plummet when the new Ice Age [Music] begins starting about 444 million years ago you would see the glaciers melt this event would create a climate similar to what we have now the ocean would be full of sea scorpions the size of dogs so look out these opportunistic Predators make confuse you with [Music] dinner in the devonian period three continents blanketed the planet 419 million years ago much of earth's land mass remained underwater you would need to live near the shoreline to harvest the resources you need to stay alive since trees would be covering the world for the first time you could build shelter and even start a fire and with the soil rich in nutrients you could begin to farm plants but while you would rule the land as an apex predator the ocean would belong to the early sharks and they look hungry [Music] travel back 358 million years ago and you would see life near the equator would Thrive while the rest of the world would experience deadly temperature changes the first reptiles would start appearing look out for that ofadon they can grow almost three M tall even dragonflies can have wingspans of 75 centimet well one of those could feed you for a while okay all the changes we saw have led to this event the peran period about 299 million years ago almost every land mass on Earth had merged into the supercontinent known as Pangia this massive land stretched from pole to pole with vast deserts in the center the wild temperature changes would kill amphibians but don't worry you wouldn't be alone here the aops would Tower over you standing 2 m tall this lizard-like creature devoured its prey whole if you keep out of its way you might enjoy the new oxygen levels thanks to more trees sprouting up everywhere but you would see a violent end to this period whether it's meteors exploding volcanoes or methane clouds 96% of all life on Earth would die out the highest Extinction rate ever known I never realized how dangerous the peran period was not a lot of firsthand accounts available to read about it now if you enjoyed that trip through the Paleo zoic era well in a couple of weeks we'll have a new video coming out taking a deeper dive into the Cambrian Period the first real explosion of multicellular life on Earth be sure to hit subscribe and you'll be notified the moment the video comes out okay enough about the Permian and the Cambrian we all know why you came here today the Carboniferous period yeah let's take a trip into this period the one that birthed Pangia just remember to take an oxygen regulator a sweater and a giant fly swatter you'll see what I mean over 300 million years ago before the age of giant dinosaurs Earth was covered with giant insects imagine a world where dragonflies are the size of crows and millipedes are as long as cars welcome to the Carboniferous period why were insects so enormous during during this time what did oxygen have to do with it and why did these insects go extinct this is what if and here's what the Earth looked like in the age of giant insects the Carboniferous period was one of the most transformational periods in the history of Earth the planet's land masses were beginning to form the supercontinent of Pangia extensive swamps and warm humid forests dominated the landscape and giant insects weren't the only huge creatures roaming the planet there was also a vast array of marine life like early forms of sharks and a giant amphibian that would reach up to 6 ft long now enough talking let's travel back in time 300 million years ago and dive in the Carboniferous age now the first thing you'd probably notice would be the giant insect likee creatures one of the most iconic was the Mega nura this insect resembled a modern-day dragonfly except with a major twist it had a wingspan of up to 75 cm yeah scarier than that though it was carnivorous hunting down other insects and small amphibians oh hopefully it doesn't come for you so that thing is in the sky but on land you'll have the arthr plura this milliped like creature could grow up to 2 and 1/2 M long luckily it wouldn't go after you it preferred munching on decomposing vegetation hey before we talk more about these giant insects there's another giant issue we need to worry about and that's our planet's ecosystems and how important it is to help them stick around till the end of this video to check out an inspiring project from the folks over at Planet wild another creepy looking insect was the pulos Scorpius this was a giant scorpion that mostly roamed the sampier areas of Earth they could grow 70 cm long there were also giant cockroaches that grew to 10 cm and mayflies with 45 cm wingspans so it's safe to say that you'd have a lot to watch out for when you're wandering around in this period but the question is how did these insects get so big anyway well you may have noticed as you've been hanging around in the Carboniferous age you feel a lot more energetic and alert maybe you've had an easier time running around this has to do with the oxygen levels in your current world research has estimated that the atmospheric oxygen levels were as high as 35% during this period compare that to the 21% we breathe today oxygen was one of the key factors in the gigantism found in insects at the time but why would this make them so giant insects breathe differently from other creatures insects don't have a circulatory system to transport oxygen instead it gets delivered directly to their tissues through through a network of tiny tubes called the trachea and the more oxygen in the atmosphere the bigger these insects are but there might be more reasons why the insects grew to this size another theory suggests that the insects were forced to grow so large due to oxygen toxicity yeah as amazing as oxygen is you can have too much of a good thing too much oxygen in your body can create what's known as free radicals these are unstable molecules that can damage your cells and even damage your DNA in the case of our insects they were forced to grow this big otherwise they'd suffer oxygen toxicity growing larger would slow down the rate of oxygen absorption making it harder to suffer from too much oxygen and the same could happen to you the longer you hang out in this period the higher oxygen levels will cause you to experience nausea respiratory issues and even some effects on your nervous system now insects were arguably the stars of this age but they weren't the only things to experience massive change during the Carboniferous period this time was known as the coal age that's because of the extensive coal beds that formed after ancient forests decade these coal beds are one of our main sources of energy we're still using them today and a lot of the fruits and veggies you find in the grocery store may be descendants of plants from over 300 million years ago the Carboniferous period saw the evolution of the first seed bearing plants creating more diverse ecosystems than we'd ever seen before wait what's that over there kind of looks like a dinosaur oh hey little guy turns out this wasn't a dyo just one of the first first reptiles to ever appear but if you stick around a couple of million more years we'll enter the Mesozoic Era which was known as the age of dinosaurs speaking of change the atmosphere was another part of Earth that evolved during this period Earth had a lush greenhouse-like climate when you first arrived warm and humid temperatures to support the swampy forests we've been mucking about but as the period progressed over for millions of years the climate transitioned to what's known as an ice house Earth State the temperature would get significantly lower and ice sheets would begin to form mainly in the southern hemisphere but why did this happen well as we've been exploring this crazy period earth's land masses have been slowly coming together to form a supercontinent known as Pangia and when land mass is this big start to move it can seriously affect ocean currents wind patterns and Global Climate now the rainforests have collapsed which has led to a decline in the fauna and vegetation that were previously booming and with the rainforests in Decline well that means oxygen levels are being reduced before you know it our massive insects start dying and going extinct without the higher levels of oxygen available to support their size well these giant insects can't survive the lower oxygen levels and a drier climate have created a habitat better suited for smaller insects also happening at this point early reptiles are starting to take over making the landscape way more difficult for the [Music] insects if time travel is possible why haven't we met a single time traveler yet and if we did meet one how would we know they weren't faking it what would their time machine look like and how would it operate would there be a set of rules for time travelers to follow and what would happen if they decided to break them this is what if and here's what would happen if you met a time traveler in 1998 a gentleman by the name of John ttor arrived from the future or so he said in his timeline as he claimed General Electric had managed to invent time travel in the year 2034 he even showed and described his time traveling device in great detail and then ttor vanished as abruptly as he appeared did he finish his mission or was he real at all how could we know if we were able to prove that someone has traveled from a different time it would be very cool for science although it might overwrite Albert Einstein's theory of relativity Einstein approached time as a fourth dimension space is a three-dimensional spectrum that provides us with length width and height time offers Direction together they form A Spacetime Continuum and it can be affected by gravity according to Einstein's theory of relativity gravity is a curve in SpaceTime and technically because space and time are one gravity could Bend time as well as space but you'd need something really really big to notice any changes in the movement of time if you somehow managed to get yourself close to a black hole like Sagittarius A you'd be experiencing time at half speed compared to people on Earth this is because Sagittarius A packs a mass of 4 Million Suns into an indefinitely dense Point creating a very strong gravitational field around it another another way to travel in time is to move really fast the closer you get to the speed of light the slower time passes for you if you were a passenger on a train that somehow could travel at 99% of the speed of light for every year you spent on the train 223 years would have passed back at the station that would make you a time traveler into the future but what about traveling back in time just like John Tor said he did Tor claimed that this little machine is what made time travel possible in any direction the c204 as he called it allowed him to manipulate gravity with the help of two micro singularities that were packed inside it also had gravity sensors to lock the machine and time traveler in a fixed place in space ttor had this machine installed in a car pretty much like the good old time traveling DeLorean did but it would only take him as far as 60 years from his time how would you know that Tor was actually traveling in time and not just making it up proving that someone really is a time traveler might be even harder than time travel itself Time Travelers could make predictions about the future show their futuristic technology or even undergo some genetic testing to support their story maybe the best way to prove time travel is real would be to take you with them on their next adventure of course there are easier ways to prove the possibility of time travel in 2009 the world famous theoretical physicist Steven Hawking threw a party not just any party but one to which only future time travelers were invited Hawking didn't send off invitations until after the party he believed that if travelers from the future arrived before the invitation was released that would prove that time travel will become possible one day he sat there waiting for hours but nobody showed up that doesn't mean time travel is impossible there is a chance that time travelers from the future will learn to use wormholes or bridges in SpaceTime we haven't seen one of those yet but the theory of general relativity predicts that they exist the biggest problem with wormholes is that they're microscopic and collapse too quickly for a human traveler to go through but maybe the reason nobody attended Hawkings party is that time traveling might not be that precise maybe the guests from the future did arrive but they were too late for the party or maybe going back in time is strictly prohibited for Time Travelers because if they do they might change their timeline completely perhaps they're just trying to avoid the risk of spreading any diseases from the far future onto us or maybe the information about time traveling is so highly classified that only a few people would be trusted with it maybe traveling back into time isn't possible after all maybe time can only move forward and never backwards maybe John Tor was one big lie we have a few more years until 2034 to find out in a way we already have time travelers In Our Lifetime astronauts on the International Space Station are moving at 8 km/s this makes them age slower although the difference is measured in hundreds of a second but if you're listening you're invited to a reception for Time Travelers hosted by Steven Hawking the party will take place at the University of Cambridge United Kingdom on June 28th 20 n no RSVP required that's Steven Hawking he sure was a Scamp wasn't he you know one thing we didn't mention about traveling back in time is that if you're an English speaker like I am well you could really only go back about 450 years before you're unable to communicate with the other English speakers of the day that's because it was around the time of the Great Vowel Shift that's when people started pronouncing their vowels differently before this time eyes were were pronounced like e and U's were pronounced like O's so the words sounded completely different but they were mostly the same words we'd be completely lost but okay this is the point in the show where I usually tell you about our merch store yeah you can buy shirts like this so that you can look super cool and knowledgeable and so your friends can come up to you and say oh no way I know that what if show you like it too amazing anyways no pressure but if you want to look cool shop. underknown do.com that's where you get imagine a time of scientific and mathematical Innovation magic and fertile land irrigated by the great Nile River ancient Egypt was a successful and intelligent civilization that lasted for 3,000 years what do you think your life would be like if you were an Egyptian during this time period and let's pretend it's a good period no droughts locusts plagues or famine for you what kind of food would you eat how were women treated and did slaves build the pyramids this is what if and here's what would happen if you lived in ancient Egypt ancient Egyptians believed in strict social structure depending on the class or trade you were born into your life would be vastly different the hierarchical Pyramid of social status and wealth was composed of slaves and servants tenant Farmers Specialists like sailors and soldiers educational professionals and finally the elite who would you be at the bottom of the social pyramid were slaves they came from foreign lands but were not of a single race and while they could negotiate their contracts they were still bonded laborers and worked in exchange for food and shelter at the very top of the pyramid was the ruler who reigned over everyone there were 300 rulers throughout ancient Egypt's existence while we call them pharaohs today that wasn't their actual title in ancient Egypt rulers did not necessarily have to be men or Egyptian but they were seen as divinely aons between the gods and the people life would be drastically different depending on your gender like many ancient civilizations Egypt had strict gender roles but you still had the same legal rights women could only own property and live alone if they chose to however marriage was seen as a social and economic necessity no matter your gender so if you lived in ancient Egypt you'd probably be married and have a brood of children you would live in a house built of mud bricks with a stone oven and pits dug into the ground for food storage if you were an elite family then lucky you as a nobleman or woman you would be waited upon by your servants after a breakfast of bread and fruit the man of the house would take his Chariot down to his estate on the banks of the Nile after touring the grounds and maybe meeting with the estate overseer about the year's Harvest you might take a quick nap once you're rested you would meet up with a friend to hunt wild fowl on your estate at home as a a woman you would spend the day supervising plans for a banquet before the banquet begins you would Adorn yourself with gold and semi-precious stones to further show your wealthy status now you're ready to greet your guests as they arrive in chariots and litters which were wheeless enclosures carried on the shoulders of servants nobleman or woman you Feast on Geese duck fish ox and gazelle followed by grapes figs dates and melons once the party is over you head to bed while your servants clean up life as a farmer is not nearly as Grand if you're a man you spend the day working in the fields and tending to cattle or ducks on tax day you would pack up some of your Harvest and bring it to the temple as payment for the land land if you're a woman you spend the day grinding wheat making bread and raising children for food you mainly eat bread beer garlic and if you're fortunate a little bit of meat maybe you're neither part of the elite or a farmer but a pyramid Builder you wouldn't be a slave but you would live a life of hard labor you would be one of 10,000 devoted workers since it took 30 years to build one pyramid you would probably work on the same Monument for your entire [Music] life which would be shorter than your fellow ancient Egyptians because of all that hard labor at least you get to eat meat regularly and get an honorable burial once you die no matter your status you would worship several thousand gods and for fun you would play board games such as men or Senate to pass some free time overall the quality of your life would drastically depend on your ruler and the time period there were three periods of prosperity and two periods of instability during this civilization fear of famine caused by droughts or locusts was a constant threat but you'd still have better luck living a good life in ancient Egypt than you would in the Middle Ages this is the world 200 million years ago no cell phones electricity or even other humans would you be able to survive in this new world could you get yourself a pet dinosaur wait dinosaurs are here okay maybe this won't be so bad this is what if and here's what would happen if you were alive 200 million years ago the world was pretty different during the late Triassic period one of the most notable differences is this right here this is Pangia a supercontinent containing different parts of today's world there's Australia down south North America in the Northwest and Eurasia in the East all interconnected it would take you a while but in theory you could walk from California to France you won't see the Hollywood Walk of Fame or see the Eiffel Tower as they don't exist yet what would you see the first thing you'd notice as you're traveling across Pangia are all the dinosaurs running about you won't have to worry about dinosaurs such as the Delong that weigh only 11 kg they won't pose much of a threat but watch out for the melanorosaurus who has a height of 12 m and would find you to be a tasty snack scientists say that the late Triassic period was the dawn of the first dinosaurs dinosaurs of all sizes would be everywhere you'd also see some other crazy creatures you've never seen before and some that may remind you of animals you see today this species known as the drepanosaurus with its reptile-like skin and arched back might be one of the first versions of birds to ever exist the Triassic period was an incredibly important 50 million years of evolution a time with not a lot of competition between species since just prior to this period 70% of Earth's creatures were wiped out in a mass extinction event many of the animals at the time were able to thrive and grow without having to be constantly wary of other Predators the further you travel Inland into Pangia you'll notice the massive weather changes the outer edges of the supercontinent may be full of lush forests and green grass but the further you go in that begins to change scientists suspect that much of P Anga was a dry desert Wasteland that's because the land mass was so large that the interior wouldn't have received the cooling effects of the ocean speaking of which the ocean known as panasa surrounded all of Pangia and covered 70% of Earth's surface this ocean was extremely deadly it could easily produce super hurricanes and monsoons and due to its massive size they could gain enough momentum to hit Pangia with potentially fatal weather Pangia was just beginning to separate 200 million years ago if you were able to stick around a few million more years for the Jurassic period That's when you'd truly see dinosaurs Thrive imagine if you could take in all of human history in the blink of an eye well from the first steps out of the slime to the first steps on the moon that's exactly where we are in Cosmic terms but in that short amount of time we've done quite a bit what would you see if you traveled 1 billion years into the past did Earth ever look like a giant slush ball how far back would you have to go to see the first humans and are we already going extinct this is what if and here's what would happen if you went 1 billion years into the [Music] past in a sense we're alltime Travelers we travel into the future at the rate of 1 second per second but if you want to go backward in time you'll need to go faster than the speed of light that's according to Einstein or maybe your time machine would jump through wormholes a hypothetical tunnel that connects two different points in SpaceTime however you decide to travel through the jumbled mess of time you'll see the effects and then the causes of the most powerful forces that shaped our world you might leave wondering how many times did the earth freeze as you watch History unfold or refold or whatever you you might be surprised at the toll Humanity has taken on this planet in such a short amount of time if you start in 2021 and move backward you would watch the sixth mass extinction event happening right now known as the hallene extinction we are currently living through one of the most destructive periods of our time caused by human activity as humans destroy coral reefs and rainforests the numerous wildlife and plants that depend on these ecosystems die with them according to the international Union for the conservation of nature 67% of endangered species could be extinct in 100 years and since most of these extinctions are undocumented we won't even know about what we've lost until it's gone maybe not even then visit the 18th and 19th centur and you could watch the pollution created by the Industrial Revolution reversed back into the Smoke Stacks cities would shrink down and return to their Roots as rural farmlands while this would let you see the explosion of the human race in terms of population and pollution if you want to retrace our first steps you'll need to go back farther tour the planet 200,000 years ago and you would Witness the arrival of our species Homo sapiens jump back 7 million years to Northern Chad and the oldest known species of humans could stroll right by you known as theanthropos jadensis this mysterious Link in our chain looked aplike but was the first to walk upright he seems friendly enough but travel to 60 millon years ago and you'll see the first primates emerge from the humid rainforests of Asia okay step back to 65 million years ago and you'd find yourself under the giant asteroid that created a global Extinction event the impact caused a tsunami and filled the air with dust and debris the crash also set off massive volcanic eruptions across the world with the sun blacked out and the land flooding the last of the dinosaurs died out but without this event mammals like us may never have taken over the planet go back 130 million years and you'll see the first flowers bloom as you travel 200 million years back in time you'll witness the breakup of Pia the mass of land that will become the continents as the land breaks apart the lava eruptions will be so massive they kill almost 80% of the species on Earth okay keep going back another 20 million years and watch the first early mammals small and nocturnal crawl around in the dark and if you go back to 230 million years ago you could watch the early dinosaurs walk for the first time on two legs before that can happen though the Earth has to go through what would be known as the great dying also called the perian extinction 95% of all species on Earth died but you could also watch the earth's land masses come together to form Pangia now you could take a walk from Argentina to China but things get interesting around 375 million years ago you would watch watch marine animals walking onto land for the first time maybe you would see a talic which looks like a salamander mixed with a fish this strange creature would later evolve into mammals and amphibians but just like every species you saw before this growth doesn't happen without a cost and now we're at the first Extinction event the or division Extinction occurs when ice sheets spread from the polar caps into the oceans almost 70% of all sea life died off during this planewide freeze over 460 million years ago okay keep going back and you could see how life started underwater called the Cambrian explosion the lineage of most of the species on our planet today can be traced back to this Milestone but but scientists are still unsure how this unique event happened between 635 and 850 million years ago the earth froze over twice once for almost 60 million years and the next time for 15 million years one Theory suggests that the Earth was only covered in a thin film of ice allowing the sun's Rays to seep through and plant the SE Seeds of Life Below but go back 1 billion years in history and you'll be surprised to find well not a lot during this time red algae are forming spores to reproduce cells are coming together to form larger organisms life on Earth is microscopic and not very threatening but nothing has been more vicious to our planet in such a short amount of time as humans but maybe humans will set things right eventually there could be a change in our planet or our hearts that might set our future on a different path or maybe like the dinosaurs and neandertals we would just be replaced by something else so let's take our time machine and find out what if you traveled 1 billion years into the future well that's a story for another what [Music] if okay that's it for today's tour a tumultuous twirling Tempest traversing the terrain and time of terrafirma hope you enjoyed we'll be back soon with another what if if you traveled 10,000 years into the future what would planet Earth look like would most of its surface be covered in volcanoes or would it be frozen in ice what if you traveled even further to 1 million years in the future future would all of the oceans have evaporated or would it have become one giant water world okay now what about 1 billion years

Channel: What If

Views: 688,581

Keywords: what if, science documentary, earth, hypothetical scenario, free documentary, david attenborough, Exoplanets, science channel, science TV, TV show, live stream, cosmos, space, space documentary, astrobiology, interstellar, many worlds, are we alone in the universe, space discovery, science, educational, asteroids, asteroid, asteroid impact, space time, time travel, travel dimension, time continuum, time machine, traveling through time, time travel machine, how to travel through time

Id: KoEHQ-UuKwE

Length: 73min 6sec (4386 seconds)

Published: Fri Sep 29 2023