What is Sea Level?
Published on YouTube Nov 25, 2013: FREE FACT: An oblate […]
Date Posted:
November 27, 2013
Published on YouTube Nov 25, 2013: FREE FACT: An oblate spheroid is a special case of an ellipsoid where two of the semi-principal axes are the same size.
THANK YOU FOR A NON 10 SECOND VIDEO!!!!
When we say Mt. Everest is 8850m tall, how do we know what sea level would
be beneath the mountain? NEW VIDEO!
Wow! I never would have thought how much work has gone into this seemingly
intuitively simple concept – sea level!
Scientists of all kinds – the uncelebrated heroes of our civilization, just
doing their work.
This is amazing and how these videos should be. Imagine a 10 second video
which only says “Seal level is measured by scientists calculating gravity
if the mountain is not there. this calculation is programmed into GPS
satellites”
The only thing that stuck was that Gravity was stronger or weaker at
different points on the earth. Quick tell me where gravity is weakest so
that I can take my wife there have her step on a scale and tell her, “See
honey, you’re not fat!!!”
I don’t think I’ve ever put that much thought into sea level before. My
mind is kind of blown by this.
What if there was an identical version of mount Everest, but made of
osmium. Since it would have more of a pull on the water wouldn’t that make
its sea-level higher, and therefor shorter even though its identical.
I remember my father, a physicist, explaining this to me as a kid. He used
the geodetic model in his job, writing targeting programs for
intercontinental ballistic missiles.
Where do you take it’s base from? Sea level as defined by without gravity?
Sea level with gravity? The sea floor ( which is so variable it is useless
to measure against ) or the centre of the earth? (Which has more to do with
the region then the mountain itself)
Well it’s about more of the physics behind sea level, than facts about the
planet
Sea level is not the same everyplace?
Isn’t this more minuteearth content? Either way really cool video!
Isn’t this more minuteearth content? Either way really cool video!
Pesky continents moving around on the earth’s surface? Everything was
pretty awesome, up to that little error. Continents don’t move around. The
water does. Land masses spread apart as the earth is growing bigger and
bigger. But that’s another story. Otherwise, GREAT JOB! This is the best
explanation of the controversial sea level issue, on earth. Literally. This
makes history.
There is so much I don’t know that I wish I did. Thanks for making it one
thing less.
Longer video=great! Thanks!
Awesome video. Just one question: shouldn’t this be on the MinuteEarth
channel?
my mind is blown…..
Great video! Would you tell me how do you make your animations?
Whoa….very thought provoking. Didn’t realize how much of an elipsoid the
earth was.
Aren’t human beings such awesomely curious creatures?
Waaay over my head.
Great visual explanation of Sea Level (in case you didn’t already know).
Great visual explanation of Sea Level (in case you didn’t already know).
I don’t think I’ve ever put that much thought into sea level before. My
mind is kind of blown by this.
I did not understand your free fact. -_-
Just when you thought it was simple …
Funny how all these new media creations promote the old media they are
supported by. Is there anyone under 20 still reading? You know, paper (or
in this case: vocals) containing information that requires attention spans
way over a minute, without providing visual input.
(I’m old(er), so I’m allowed to be a slow fart!)
Defining what the sea level is might not be as simple as you think. This
three-minute video is most educational. Skip a few kitten pics today and
learn some geodesy instead.
Never knew that. Very awsem!
I did not realize that it was so complicated, i never thought it would take
a bunch if brilliant people to figure it out
Shouldn’t this be on MinuteEarth?
Everytime I watch these videos, I end up with more questions than answers.
Which is *exactly* why I love these videos!!
This is the most informative MinutePhysics I have seen. 100m differences in
sea level due to gravitic variations? I think I said ‘Wow!” and “That’s
wild!” half a dozen times while watching.
Okay, love the info, but dude talk a little slower! For some of us english
is a second language and it’s hard to keep up with all this new information
thrown at us! We gotta understand too mate :P
I seriously love this channel. If I teach physical science again I will use
the videos as part of my class. This particular one will be used in my
Earth science class next year.
i can read chinese do you mind putting the free fact in english please
*nice*
There are so many things I wasn’t aware of in this seemingly straight
forward concept.
Ok, this is really not as obvious as I thought! I guess 99% would answer
incorrectly on how this is calculated even if they had one hour to think
about it.
this is genius stuff give me some more sea level shit !
Aren’t ya glad you don’t have to do this kind of math to figure out what
pattern altitude you should use :)
Not as simple as I thought.
So… what is sea level?
I like this but that’s to fast
wow!
Sea level, how does it work?
do you first speak and then fast forward that a lill bit?
I feel like your voice changed, and it is hard for me to get used to. I am
not sure why this is just now on my subs.
Sometimes, a simple-seeming thing is really, really not.
Fascinating and astonishing. Thanks so much!
This kinda blows my mind.
This was a lot more complicated then I thought it would be 0.o
Chimborazo rules!!!
binary
Thumbs up if you’re studying geodesy currently!
O__O huh
So if the earth keeps spinning, will it become flat?
The 100 1s and 0s in hexadecimal: 930AAD5B2B6DA9D9622F3DCF2
I think it’s pretty much random
Chimborazo rocks!!!
What if you were at the bottom of Everest, that would be below sea level?
It’s a nice topic to discuss over dinner with your friends to show them how
smart you are.
Or at school, to have your head dipped in the toilet by the jocks -.-
Seems to me to make more sense to measure height above sea level against a
uniform theoretical oblate spheroid of the seas rather than a theoretical
sea level accounting for gravity, at least for mountains. Why, for
example, would we have any interest in the height of Everest from a
theoretical gravity-influenced sea? The idea would be to have measurements
of two places that are more unambiguously comparable rather than to have to
correct for the effects of gravity on water that is not there.
I cant tell wether or not the ones and zeros mean anything because i dont
know how many bits run on it or if its talking about certain gravitational
forces on points of the earth
mind. blown.
Science is a lot more interesting now that I’ve been out of high school for
a few years and no longer study it as a subject.
The only thing that nags me a little bit is the fact that he says ‘Earth is
so non-spherical’. Sure, it is not a perfect sphere, but it is not by such
a small margin considering the fucking ridiculous magnitude of it that it
seems silly to later present Earth as an insanely irregular object.
Excellent!
In around 0:35 and 0:40, you said due to Earth is spinning, the equator
side is thrown out and polar sides are squashed in. I thought that Earth
may one day become totally flat due to the effect… Until I realized that
it would turn into debris before that even occured…
Calculating the height of the ocean from the gravitational model gives us
our estimate for the sea level. Then, will global warming (with the melting
glaciers) cause the sea level to rise enough such that it needs to be
adjusted?
This video does a good job of explaining sea level and how complicated it
can actually be.
I’m from Sri Lanka and I did not know that. Now I feel light-headed.
It’s nice to know people a lot smarter than me are doing extremely
complicated things to make my life more convenient, even if it’s just the
sea level.
I use this to fall asleep.
One of the best of his videos
Charlie Epps would know if it was random or not.
MY HEAD!!! IT HURTSS
Hey wait a minute….if a kilogram or pound is defined as a weight which
goes hand-in-hand with gravity, and gravity changes over different areas of
the Earth, wouldn’t that mean that the kilogram can vary slightly? I know
that the ‘official kilogram model’ is kept in Paris somewhere, but it would
change slightly when copies of this are distributed around the world. The
change would be barely discernable for the normal person, but there would
be some difference.
After seeing this, it’s almost a wonder that the GPS works so well.
science bitch!!
Unless � «VÊÛjvX�Ïs2 isn’t gibberish, it is random.
So mass creates gravity?
Wow. Go geodesists. That’s impressive
sooo good. #physics #sealevel
I knew the question “What is sea level?” was more complicated than first
assumed, but I didn’t even consider some of these.
2:42 in the morning. Cant… Stop… Watching… MINUTEPHYSICS!!!!!! D:
329 people hate ovals
What is sea level and how is determined.
Video: +MinutePhysics
Shouldn’t this by a MinuteEarth video? Maybe? Well… There is some
physics…
Wow, I’m so glad I watched this. I had no idea it was this complicated
I don’t think I’ve ever put that much thought into sea level before. My
mind is kind of blown by this.
Given that it seems mantle density’s effects on sea level can be so
extreme, a possible counter to catastrophic sea level changes due to the
effects of climate change could be to reduce the density in affected
locations enough to lower see level by a corresponding amount. Obviously
something requiring engineering beyond our current
abilities…perhaps…but definitely allowed by the laws of physics. Very
interesting indeed!
Wow! That was amazing. I really learned something new. :) Thanks.
no they weren’t random because they are binary code so it made something,
right?
but the dead sea is a sea but it is -417 sea level, explanation please?
The author of that book needs to understand what information is.
Those 1’s and 0’s look pretty random to me, then again, my brain is trained
to spot random. Although mathematics may reveal that it is not random at
all, as you sometimes need advanced software to detect true randomness.
Centrifugal? Really? I would understand if just a stranger made that
mistake, but physics channel?
Dang its pretty cool that Denver got its name “the Mile High city” for
being exactly a mile higher than sea level.
has anyone found out what is the 0s and 1s are?
This guy needs to shut his loud mouth, how would you even know there is a
difference in km of the radius of the earth, did you go and measure it, no,
so its based on faith. Secondly lets say its true, that is not enough km to
even notice anything, and to even think to draw it anything but a sphere
when representing the earth is stupid
I still don’t get it.
Clicked on this thinking the answer was obvious.
Mind blown!
For everyone who may be arguing about if the Earth is actually being thrown
out by inertial forces instead of Centrifugal. The answer is: No.
In physics, inertia is a property of matter in which an object retains its
state of rest or its velocity along a linear path assuming it is not acted
upon by an external counter-force.
Centrifugal force is the outward force on a body of mass that is rotating
on its axis.
Parts of the Earth are indeed being effected by inertial effects, but that
does not affect the Earth as a whole, because the Earth spins at different
rates of velocity everywhere.
All parts of the Earth are indeed affected by Centrifugal forces, and even
you. In fact, get out of your chair right now, hold your arms up as if you
were flexing, and start spinning. Seriously, try it. Oh my god, you should
have seen yourself, because you looked so stupid. Wow, that was mean. I am
sorry. Anyway, did you feel how it got harder and harder to keep your arms
inward as you spun faster and faster? That is because of Centrifugal force:
You are the rotating body of mass and your arms are more outward than any
other part of your body (at least I hope so) from the center, so they will
move outward a bit more than they are now, or at least try.