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What Is Earth's Gravity ? | Secret Of Earth - Duration: 22:05.
Minster design stream weather
Alien landscapes and bizarre phenomena
Is the most complex system we know of in the universe
that planet
Is earth and we are only beginning to unlock its secrets
On planet earth there is an invisible force
governing everything
It gave me enough energy to be able to go through all the loops and twists and turns of this amazing track
It's called gravity a
Phenomenon occur me eights the planet wielding secret power over the continents and oceans
plants and people
But in a remote part of North America
some of it has turned up missing and
It could be gone forever
If I suddenly turn off gravity we would be flung into outer space
Without gravity there would be no you and there would be no me the case of the missing gravity
On this planet called Earth something strange is happening
Gravity a fundamental force of nature is actually missing in some places
In fact Canada's Hudson Bay has lost a lot of gravity more than almost anywhere else on the planet
It is a mystery tied to one of the most important forces and the cosmos
Gravity is the glue that holds the universe together
Gravity is assisting us and in all of the actions and things that we do as human beings
Without gravity there would be no
Galaxies there would be no stars
It would be no planets
There would be no you and no me
For over a half century
scientists on earth have been on a mission to solve the case of the missing gravity and
What secrets it might reveal about the planet?
It is a quest that has taken them to one of the most remote outposts along the Hudson Bay
Churchill Manitoba
No roads lead here
The only way in is by train was small aircraft
The sub Arctic community of only 600 people is the polar bear capital of the world
Tourists flock here in the summer and fall when the massive white beasts move inland off the melted ice
But for much of the year
Churchill is a desolate town
where winter temperatures can dip to minus 30 degrees Fahrenheit and
The modes of transportation are snowmobile and dogsled
We're in Churchill in northern Canada, one of the world's largest gravity lows
The missing gravity in the Hudson Bay region is so large that you can observe it from space
Understanding would cause this bizarre abnormality in the Hudson Bay
requires decoding the secrets of gravity on earth and in the universe
Gravity is an attractive force that causes any two objects with mass to be pulled toward each other
This force is stronger for more massive objects and it's stronger the closer you are to that object and that's the way gravity works
So really big things like planet Earth have lots of gravity that pulls everything towards this center
The rocks forming this cliff here
Attract me gravitationally, but I don't feel an attraction toward them instead
I'm firmly planted on earth here because Earth's mass pulling me down is so much greater than the mass of those rocks
Pulling me to the side
The earth like all planets was formed when gravity
Pulled together bits of rock dust and gas over millions of years
gradually forming a speeder
Gravity holds the earth together and keeps it orbiting around the Sun
To understand how important to gravity is. Let's turn it off
If you suddenly turn off gravity, we would be flung into outer space at a thousand miles per hour
The power of gravity isn't just reserved for shaping the universe
Humans sometimes harness it for thrill
Here I am on the accelerator ride at Knott's Berry Farm in Southern California and
This incredible roller coaster is going to show us the amazing power of gravity
Here I go
And now gravity is gonna take me down
And the rest of the ride is powered by nothing but gravity
So I got accelerated to 80 miles an hour and then launched nearly vertically
So I was doing work against gravity
Got to the top of the track and then gravity dropped me down
Gravity gave me enough energy to be able to go through all the loops and twists and turns of this amazing track
Since the mass of an object determines how much gravity it has
things weigh more on massive planets
On gigantic Jupiter the 180 pound human would weigh about 470 pounds
But on the surface of the earth smooth the same human would shed a lot of weight
The moon's gravitational attraction is less than that of Earth. It's about six times less
So a given person who weighs say a hundred and eighty pounds on earth would only weigh 30 pounds on the moon
It's the same amount of mass that person is still the same person
But he or she is being pulled down on the moon only one-sixth as much as on earth
Back on earth the effect that mass of an object has on gravity
would expose an ancient secret in
the Hudson Bay region of Canada
in the 1960s
Scientists began taking the first global measurements of the Earth's gravity field using simple ground instruments
This is a relative gravity meter
Essentially, it measures the differences between gravity
Spot where it's known and where you want to measure
So these meters are typically placed wherever you want to observe gravity that could be out on the ice that could be on rock
For the early measurements in the Hudson Bay. The gravity meter was lowered to the bottom Hudson Bay
These gravity meters picked up an anomaly a peculiar change in gravity
This change was due to a layer of rock from the Earth's crust
That was missing
It was about as thick as the length of three football fields placed in zone to end zone
Scientists also noticed strange land features surrounding the Hudson Bay
These physical signs pointed to a possible culprit a
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climate catastrophe of epic proportions
The disappearance of gravity in the hudson bay region of canada has troubled scientists for decades
They're on a hunt to find out what happened to it and what this might mean
Since the late 1960s
Scientists had noticed weird geological features along the shoreline of the bay
the bedrock had deep gouges and grooves that look like they've been made by some colossal force a
plausible theory about the missing gravity surfaced
20,000 years ago earth was suffering through its last ice age the
Build-up of snow and ice created the Laurentide Ice Sheet a two mile thick glacier that spanned most of present-day
Canada
It depressed the crust of the earth and made it sort of stretch outward and squeeze out the sides meaning there was less their
gravity isn't as strong there because some of the rock was squeezed out the
Continent-sized glacier appeared to be The Smoking Gun
But in the 1990s new GPS surface instruments picked up something else
After the mega glacier melted the Earth's surface began to slowly rebound
the phenomenon is known as
post-glacial rebound
But the amount of gravity recovering from the last ice age
Only added up to about one third of the total amount missing
So there has to be something else
Something much bigger going on in the Hudson Bay to have caused this gravity depletion
And it's not the only place where gravity is low
In space the gravitational field is extremely small
That's because gravity becomes weaker the farther apart one object is from another object
In
This microgravity environment astronauts appear to be floating inside a spacecraft
But they're actually in a constant state of free fall or weightlessness
Astronauts don't drop to the floor because the floor is also falling
So you have the optical illusion that there's no gravity in your space capsule, but actually there's plenty of gravity
You're just falling at the same rate as the capsule. Therefore a weightlessness is an optical illusion
Created by the fact that gravity pulls
objects at the same rate
In low gravity space the human body experiences all sorts of side effects
An astronaut experiences muscle atrophy and loses 1% of bone mass per month
Muscle mass
starts changing our bones start deteriorating so consequently one of the things that astronauts hate the most
Is that they have to work out two and three hours a day to try and keep that body mass
With less gravity
moisture from the bloodstream accumulates in the spinal discs
Which can lengthen the spine almost two inches in
Fact spacesuits are sewn larger to accommodate the stretch
now the interesting aspect about that too is when we're in space all
The fluids move up around your head in your brain in your face area
and one of the things that the astronauts complain about is their faces getting rounder and fatter and
You can't see any facial gestures
While the weak gravity field in space has a profound effect on humans the
gravity on earth
influences everything big and small
The case of the missing gravity near Churchill along the Hudson Bay of Canada
Reminds us how central this force is to life on planet Earth
It sets invisible limits on even the tallest things in the natural world
I'm standing here among a bunch of California redwoods and
Some redwoods can be the tallest trees in the world almost 400 feet high
Now they can't get much taller than that. And that's because the downward force of gravity
Caused by the earth makes it hard for water to go up toward the tops of the trees
Even mountains have a secret height limit set by gravity
Mountains on earth can't become arbitrarily high because eventually Earth's gravity is going to be pulling on them so much
That they'll sink in Earth's crust
On earth our tallest mountain Everest reaches five and a half miles high
On Mars where gravity is roughly 1/3 less powerful the largest mountain Olympus Mons
rises three times higher into the sky
All creatures on earth have evolved to deal with Earth's particular gravitational pull
Look behind me that animal right there weighs about three and a half tons
So gravity affects them, but look at their legs, they're like tree trunks they support all of this massive weight
They don't grow much larger than that because they need to be able to move
They need to be able to forage and find food in
Fact no land animal on earth even a dinosaur has ever grown larger than 100 tons
but underwater
whales can grow to almost twice that weight
Whales in the ocean can use buoyancy of the water to support themselves. They've gotten around the conundrum of
gravity
Around the globe animals have been shaped by Earth's gravity
In the Hudson Bay could they provide a clue to what made the gravity disappear?
During the years scientists have been studying this gravity anomaly they've seen the weather change drastically
Global warming now keeps the bay ice-free for longer periods
shortening the polar bear season to hunt for food and
Threatening its very existence
It turns out that the melting of sea ice also has the power to change the planets gravitational field
March 17 2002
NASA and the German Space Agency launched grace the Gravity Recovery and climate experiment
The satellites take the most precise measurements of the Earth's gravity field that will provide crucial information about any
changes in the planet's oceans
geology and climate
Grace is a dual satellite system made up of two satellites in the same polar orbit one satellite is
140 miles behind the other satellite and they're constantly measuring the distance between them using a very precise radar system
Suppose that grace flies over a very heavy object like a mountain represented by this rock
The gravity of that mountain will pull the two grace satellites towards it which will decrease the distance between the satellites
conversely if grace flies over a region like Hudson Bay where gravity is weaker that
Will result in an increase of the distance between the two satellites
For five years grace orbits the earth 15 times a day at an altitude of over 300 miles
As the satellites monitor very a shion's of mass within the earth
They uncover a long-held secret about the missing gravity in the Hudson Bay
Something that has been welling deep inside the planet for hundreds of millions of years
In the Hudson Bay of northern Canada
The case of the missing gravity has been an unsolved scientific mystery for over half a century
Scientists knew that an ancient ice sheet had deformed the rock in the Hudson Bay leading to some of the gravity loss
But that couldn't account for most of the missing gravity
Then in 2007
Scientists got a new view from space
The grace satellites generated the most detailed maps ever made of births gravitational field
And revealed something astonishing
The missing gravity in the Hudson Bay of Canada was caused not just by the coal of the Ice Age
But also by searing heat from the depths of the earth
Hundreds of miles beneath Earth's surface
7,000 degree molten rock continuously rises in all's in a process called mantle convection
We can see convection in a pot of water boiling on a stove
As it's heated it expands it becomes less dense
So it rises when it gets to the top it cools off contracts and becomes more dense
So it sinks this convective process is the same in the mantle except. It's a lot slower
Mantle convection on earth occurs in cycles
in many places its rising or upwelling
But under the Hudson Bay the flowing rock and the mantle is sinking or downwelling
In hudson bay. It just so happens that in that particular spot. The mantle is going down because it's more dense
This is dragging every feature of the earth with it downward which ends up reducing gravity
Mantle convection is essentially permanent. There is effectively going to be no into this on a human time scale
After over 60 years the case of the missing gravity in the Hudson Bay region of Canada
Has finally been solved
Scientists now have a deeper understanding of how changes in the gravity field can reveal hidden secrets about the planet
Above and below its surface
The quest has even led to the discovery of other gravity anomalies that expose threats to the global population
The 2005 Amazon drought left a gravity anomaly because there wasn't as much water as expected on the ground
we also see that gravity is decreasing over most of the ice sheets on the planet and
This is because those ice sheets are melting and sliding into the ocean primarily because of the co2 that we're dumping into the atmosphere
The journey to unravel this secret of the earth
Shows how the elusive force of gravity has left its mark on
mountains and continents
trees and animals
It's an essential part of the entire universe and something we could not live without
You
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Khloé Kardashian's Family Is 'Jokingly' Giving Tristan Thompson a Hard Time, Source Says - Duration: 3:21.
The KarJenners love to joke around! Now that Tristan Thompson is back in Los Angeles with Khloé Kardashian, the couple is regularly hanging out with her family for the first time since the NBA player's alleged infidelity came to light
"He is spending time with her family," a Keeping Up with the Kardashians source tells PEOPLE, adding that the KarJenners "have jokingly been giving him a bit of a hard time
Like, 'we are watching you!' " "But otherwise, everyone is being respectful and focusing on catching up with Khloe," the source adds
"Khloe is so happy being a mom. Everyone just wants her to stay in this happy bubble for as long as possible
" The source also says that "Khloé had the perfect celebration" on Wednesday in honor of her 34th birthday
"She wanted a more quiet dinner party with family and friends. She was very happy
She is having fun being back in L.A," the insider continues, adding that "she seems happy with Tristan too
" Kim Kardashian West and Thompson certainly seemed like they were ready to put the past behind them during the party, as the KKW Beauty mogul asked the NBA player to unblock her from social media
Thompson blocked Kim after she spoke out against him after his cheating scandal erupted in April just days before Khloé was due to give birth to the couple's daughter True
"All right guys, what do you think? It's Khloé's birthday, should I ask this guy to unblock me?" she asked
"For Khloé's birthday it's only right," he said. "I got you." Taking out his phone, Thompson pulled up Kim's profile on his Instagram feed
"There's no going back now," he said, as he unblocked her. While the new parents seem to be doing well in the wake of the cheating scandal, a source previously told PEOPLE that the reconciliation didn't go over well with the KarJenner clan at first
Despite that, the insider said the family members "respect her decision." "Everyone knows Khloé plans on staying with Tristan, so things have been civil so far," the source continued
"They still have opinions about Tristan's bad behavior, of course, but no one wants to upset Khloé
"
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Joanna Gaines' Love for Husband Chip's 'Dorkiest' Accessory Is Relationship Goals - Duration: 2:38.
Chip Gaines's one statement accessory is the "dorkiest" thing about him, according to his wife, Joanna
The Fixer Upper contractor may be spotted most days donning work boots and a Magnolia Farms hat as he renovates houses for the couple's company, but his off-duty outfit comes with one notable addition
"Honestly on the weekends, Chip really does wear this set of binoculars. It's like harnessed on his chest," Joanna, who just welcomed their fifth child, a boy named Crew, reveals in an interview with KMOV
"It's the dorkiest thing, but I love it." RELATED: Chip Gaines Recalls the Ill-Fated Mexico Trip That Had Joanna Threatening, 'You Have Three Days to Get Back to Texas, or This Relationship Is Over' The HGTV stars' four older kids — Drake, 13, Ella, 11, Duke, 10, and Emmie Kay, 8 — like the promise of adventure their dad's binoculars represent when they hit the road as a family, Joanna says
"He will be driving in his truck, and whether it's a road trip or it's on our way out into the country, he will always stop if he sees anything," Joanna explains
"Whether it's trash and he thinks it's a deer, or if he sees a raccoon or a coyote, he always pulls over and all the kids go, 'Ooh dad's found something
'" And I am always like, 'Chip, let's get there. We gotta go. But he always stops and pulls out his binoculars
" RELATED: Fixer Upper Almost Got the Axe from HGTV! See the Hilarious Clip that Saved the Show Chip may not possess his wife's enviable sense of style, but his weekend hardware does represent what she says she loves most about him: his adventurous spirit
"I think what I love is that is authentically who he is. He's a discoverer. He's an explorer, and I think, I'm thankful for that
"
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