1:11 props to the guy responsible for the text. that "cools" text changing from glowing orange to grey is a great detail!

@bdijkstra1982

6 жыл бұрын

I'd guess it was not a guy but a gal who did that.

@HeyKevinYT

4 жыл бұрын

It’s a *cool* detail

30 seconds that actually address the question start at 4:15

Santa will have to move.

@rock3tcatU233

6 жыл бұрын

Satan as well.

@kylebroflovski6382

6 жыл бұрын

These top comments are so stupid I love them! 😂

@dorukayhanwastaken

6 жыл бұрын

except when the magnetic poles flip, the geographic poles don’t. that means the north pole will always stay on north and santa won’t have to move!

@MichaelSHartman

6 жыл бұрын

It's about time. The cellar gets flooded every summer.

@devilsadvocate5411

6 жыл бұрын

You haven't checked a map lately have you? The north pole is an ocean now. Mandela effect

this subject is so interesting.. dang

@HB-jf6yq

6 жыл бұрын

George Gore Are you new?

@RangaBonsai

6 жыл бұрын

HB I've been here a while

@JohnJohansen2

6 жыл бұрын

George Gore Sciences are interesting!

I'm pretty sure that if a magnetic reversal starts happening, 50-5000 years is plenty of time to protect out electronics and take some precautions regarding the cosmic radiation.

@akrybion

6 жыл бұрын

Ivan Smirnov I garantee there will be people denying it.

@TheObsidianX

6 жыл бұрын

Seeing that we have only had electronics for less than 100 years your probably right

@patrickmccurry1563

6 жыл бұрын

You know what's great at protecting against cosmic radiation? Mass like an entire atmosphere. Surface background radiation would barely increase. You can't link these reversals up with global extinction events.

@daishi5571

6 жыл бұрын

What am I going to do with my Amiga ;-)

@Bodyknock

6 жыл бұрын

Patrick McCurry He never said it caused mass extinctions, just that radiation levels would increase and it would make life difficult for some current day satellites and electronics.

Because its Bi-polar? No? Ill stop

@HB-jf6yq

6 жыл бұрын

spartan300zx No.

@DizzyDisco93

6 жыл бұрын

+1

@greensteve9307

6 жыл бұрын

We have no flipping idea!

@Rob_V_W85

6 жыл бұрын

spartan300zx lol. That's one of those corny jokes that are so bad they are funny.

@justmechanicthings

6 жыл бұрын

I don't find your sense of humour attractive, that's for sure

I'm a bit surprised this didn't even mention the Sun as the probable cause of reversals.

@victorrosas7692

4 жыл бұрын

Solar storms

@Ali_lakhal

4 жыл бұрын

@@victorrosas7692 Solar storms are not that strong to do this, there is another effect on Earth

WTH!? At least I know ahead of time it's going to give me existential dread when I watch a Kurtzgesagt video, now I have to worry about that from SciSchow Space, too?

@sirisirih

6 жыл бұрын

Radix never tried some vsauce videos? Those are some pretty cool existential problem

@janpeternelj2309

6 жыл бұрын

Well that's science for you.

@anthonyrymer4391

6 жыл бұрын

Just do what more than half the human population does when things get hard and existential dread happens. Force yourself to believe in the illogical beliefs of religion!

@ervinm.5065

6 жыл бұрын

That exactly what I thought too

@kylebroflovski6382

6 жыл бұрын

Weapon Valhalla Have you ever even read a bible, or are you just jumping on the bandwagon that you've noticed everyone else on?

Terrific video! :) I'd like see more moon content personally. Thanks! ^-^

he is such a consistently good host, no BS and easy to understand

Thanks a lot. This video is amazing. Finally we understand what is this magnetic thing :-)

great stuff!!

I hope the switch happens while I am around to experience it.

@tilago

6 жыл бұрын

Raymo853 we will all immediately die.

@Knobulon

6 жыл бұрын

Raymo853 seeing as it takes thousands of years to happen. I dont think you will

@PeppoMusic

6 жыл бұрын

Raymo853 The process of reversal is rather slow though, give or take few thousand years. So theoretically, we would only experience a small diminishing of the magnetic polarity in a single human lifetime.

@sayuas4293

6 жыл бұрын

+Peppo but didn't he say that there was evidence of 2 reversals in the span of only a few hundred years? Besides, they don't actually know how quick it happens. They just have speculation. Maybe it'll happen instantly. Though I'd rather have it take a few years so that we can have some apocalypse-ish fun.

@CJBurkey

6 жыл бұрын

He specifically said that those two were doubted, mostly because they take thousands of years to complete.

Anyone else notice that the last known pole switch happened approximately the same time Yellowstone erupted.....

@somemaycallthisjunkmeicall133

6 жыл бұрын

steveXracer Why not?

@ewoodley82

6 жыл бұрын

saardonyx correlation vs causation. However, it is still a valid observation and one that could bear some looking into, if it hasn't already been done, to see if there is a causative link between the two and any other massive geological shifts

@ewoodley82

6 жыл бұрын

steveXracer well neither is evolution. Funny thing about geology is its really easy to get indirect evidence if you know what you are looking for, so I am still waiting for a point

@ewoodley82

6 жыл бұрын

steveXracer you are not observing evolution, you are observing adaptation, which, yes leads to evolution, but is not itself evolution. Adaptation is more noticeable and happens under shorter time scales than evolution, which tends to be subtle, and takes a really long time relative to the reproductive frequency of the organism as it takes several viable adaptations or mutations to be passed to multiple succeeding generations

THANK YOU FOR THIS VIDEO! THIS VIDEO WILL HELP ME BECAUSE I HAVE A EXAMINATION TOMORROW :)

Thank you for summing up in 5 minutes what takes other channels a half hour to not even get it correct.

It's Amaaaaaazing....

My guess is that the earth's core spins, and tumbles, and depending on the sinking elements from above effects the rate of the tumbling. Changing the magnetic field.

The location of the north pole moves every year. There are sites that'll show you where it's been for the last 20 years or so. It's moved more than a thousand miles (but not all in one direction). It just wanders around.

But... What are some benefits from this magnetic flipping? & could smelting ore the way we do be effecting thing?

This is flipping awesome! Okay, I'll stop with the puns now

long time no see!

"Why Does the Earth's Magnetic Field Keep Flipping? Bla bla bla we don't know yet!" Well thank you for enlightening us!

@danbee6103

6 жыл бұрын

RashMatash Indeed.

@AstralTraveler

6 жыл бұрын

I can figure out nice explanation: flips of geomagnetic field can be caused by another strong magnetic field - like hypothetical Planet IX...

@somemaycallthisjunkmeicall133

6 жыл бұрын

Astral Traveler That’d affect the solar system, not just Earth..

@MariaMartinez-researcher

6 жыл бұрын

RashMatash The idea is piquing your curiosity, so you become a scientist, go and discover why in Earth they happen.

The problem with the studies that claim to show quick and recent reversals is that they have rather small datasets of limited locations, which would also be consistent with magnetic anomalies of the poles moving around a lot, but not really flipping. And they don't really flip, they weaken, move around, have also multiple weak poles which then coalesce into new ones.

Could we possibly use strong VLF waves to disrupt incoming particles and radiation? Been waiting for you guys to do an episode about this subject

Awesome

I might be the only one here to say thank you for saying "we don't know" about these intriguing questions we keep asking about the earth's magnetic field because as you said... these are all educated guesses by scientists and top professionals in their respective fields. And sometimes it takes a lot more time to get the right information than to speculate and give out the wrong information that would take years to clear once the right information is attained.

thanks

Would the other planets poles in our solor system reverse as well. Since mass attracts mass?

The idea of large amounts of magma moving would bering up this question. Do any of the Yellowstone eruption events line up with the past switches?

I think it's d4 orbital of iron. Geodynamo... Nickel recently had been shown to be vital as well. They did just find a gulf stream like structure in the outer core.

we kind of are in the middle of a reversal, theres a site that tracks the poles and you can see they are no where near where they should be.

I wonder and this is just a random thought.. could it be that the extinction of the dinosaurs was caused while in the middle of the flipping of the magnetic field(where it was basically nonexistent) and a massive solar flare occur'd. this could explain why lots of larger species died more surface area and also the smaller beasties would be in a deeper more shadier place usually.

How can one say that there won't be an apocalypse when the magnetic field disappears during a reversal? You can be sure that there will be an apocalypse if there's no wifi and we can't access new cat videos.

@SuperSMT

6 жыл бұрын

Because there is no evidence of past 'apocalypses' aka mass extinction events at the times of these reversals. And if one were to happen today, since they take thousands of years to occur (or at least a hundred), we would have plenty of time to prepare our electronics and satellite systems.

This is the question I wanted to ask my geology professor about.

Would 220v network would resist better, because less amps?

Perhaps all these flips stored in the ocean floor explain why there's been all of those problems for aircraft and ships in the Bermuda Triangle in the past.

The poles love to dance. So... cute... and terrifying XD

That's all still terrifying as all hell

So basically the plot of “The Core” in real life

Well, we are talking about relocating to Mars or the Moon and take their lack of magnetic fields in stride. Either, we need to worry about them more or worry about Earth less. I'm just going to live on a submarine. Let me know how it turns out.

@KriegsMeister27

6 жыл бұрын

is it going to be Yellow?

@GlenHunt

6 жыл бұрын

Nah, then we'd all have to live in it. I'm not great with large groups.

@Rikri

6 жыл бұрын

Uh... An artificial magnetic field that size might be a ridiculous idea, but maybe it's possible? There has to be better alternatives.

@patrickmccurry1563

6 жыл бұрын

Long term lack of magnetic fields allows solar wind to strip atmosphere away. That's probably what happened to poor Mars.

@David_Last_Name

6 жыл бұрын

+Glen Hunt The reason it's not much of an issue with potential humans on the Moon or Mars is because we aren't trying to transplant our entire CIVILIZATION there, only a few humans. We can provide extra shielding for a few humans and their habitats. It's much tougher to do for this for 7 billion people and their infrastructure over an entire planet.

If you look at the IGRF-10 (International Geomagnetic Reference Field, ver 10) and look at the time derivatives, you'll see that the strength of the primary term is decreasing fast enough to account for a reversal in (I forget the number, but I want to say 8,000 years) a geologically short period of time. The reversal looks like it is well underway. It is just kinda slow. Not geological timescale slow, but certainly civilization timescale slow.

I know that this is the space channel, but given that if every time the magnetic field is neutral the Earth gets barbecue doses of radiation, what about the existing life? any correlation to previously unexplained mass extinctions and/or drastic mutations in those given times?

@solarfluxman8810

6 жыл бұрын

Tests of correlations between extinctions and reversals are difficult for a number of reasons. Larger animals are too scarce in the fossil record for good statistics, so paleontologists have analyzed microfossil extinctions. Even microfossil data can be unreliable if there are hiatuses in the fossil record. It can appear that the extinction occurs at the end of a polarity interval when the rest of that polarity interval was simply eroded away. Statistical analysis shows no evidence for a correlation between reversals and extinctions.

I need a SciShow Kids video that explains the first 35 seconds of this video. I feel soooo dumb right now. "The magnetic North pole is actually the South pole of the earth's magnetic field. That's why it attracts the North Poles of magnets" Whuuuut?

I have read that the magnetic poles are moving towards each other, but how can two poles move closer? If I take two magnets and point one pole to the opposite one, it repeals, so how can they move closer to each other?

I got a movie idea. Get me Roland Emmerich.

Thanks for a very clear presentation. But don't we know more? The solid inner core rotates faster than the outer liquid core, which surely causes long vertical vortices running north/south in the liquid core. Being a conducting fluid, each vortex generates a magnetic field by the right-hand thumb-screw rule, because a vortex of electrical charge is a circular current. All the fields from all the vortices merge into the total planetary field. But the fluid rotates faster at the equator than the poles, so the north/south vertical vortices bend eastward in the middle, twisting the magnetic field tighter and tighter, as happens also on the sun, until it "snaps" and becomes twisted the other way. Is that NOT the explanation at some level? Or is it really that mysterious?

I'd be interested to see correlated evidence of damage to organisms during these shifts. I think we'd expect to find that.

You have not mentioned that when the ionosphere gets bombarded with charged particles it also creates a magnetic field capable of protecting life on the ground, although it would not be as good at it as the cores field.

I just came from my Garden..My brocolli is 3 feet tall. My lettuce is on 3rd harvest my berries are good and grapes are thriving. Bees are thriving, chickens are thriving..So blessed for this awesome growing season..St L Mo..hobby homesteader Checking in..and checking out. I am exhausted! GB our community and find a hard hat..it protects against hail hitting your noggin. That's my Boom..catch you survivors later. Many hugs

My father is in Merchant Navy, I paused the video and asked him what is bipolar magnetic reversal theory, he said yes after a pause, I thought he is joking, but dang he explained it to me and even to that we have studied calculations for it too.

A couple points: * I wonder if there is any correlation between how the Earth's magnetic field is created (and flips) vs. how the Sun's magnetic field is created (and also flips at a regular 22year cycle). Both are charged fluids, Earth's charged fluid just flows slower... * Due to the increase in ionizing radiation (both solar and cosmic) making it to Earth's surface (and thus the biosphere) when the magnetic field is weakest during a flip, I wonder if any flips can be correlated to mass die-offs and/or evolutionary bursts.

I've wondered if there's any relation to our place within our oscillation around the galaxy. If it correlated with how the solar system's electromagnet output interacts with varying concentrations and relative direction/flow of cosmic dust. It's a theory I'm working on called electromagnetic star migration.

@thephilosopher7173

Жыл бұрын

Props to you for thinking outside of the box! This video is hypocritical because it states theories as if they're facts while discrediting anyone who thinks otherwise, while also saying that we don't know what we just said were actually facts in the first place. lol

1:25 just want everyone to know I walked along that bridge and walked around there. It’s in Iceland btw

But HOW would it flip? I mean the process can't be instant. Would it involve movement of matter? Would the core flip?

Wow; so much speculation!

I wonder - is there a way of telling if this is actually happening when it would be happening? Can we observe or measure this process when it will be going on?

@rubbers3

6 жыл бұрын

I'm not going to go into conspiracy theory mode or say deny climate change, but would it be possible, that it's slowly happening right now and it's why there is climate change? Or maybe it's the human action that started the shift?

@akrybion

6 жыл бұрын

rubbers3 I guess we would be easily able to spot it with our technology, as we can measure the magnetic field. And I doubt climate change is causing it, because the climate changed over time more periodicly that the magnetic field shifted (I'm no expert though)

@rubbers3

6 жыл бұрын

I don't mean that the climate change is causing the shift, only the vice fersa - the shift, weakening the magnetic barier heats up the earth. I doubt it myself, but who knows? But your point about being able to measure magnetic field is quite good and quite obvious, I don't know why I didn't thought about that. Maybe because of how many times he said in the video that "we don't know why it's happening" xD

@akrybion

6 жыл бұрын

rubbers3 I think some of our satellites also locate themselves with the magnetic field, so once it shifts they might go haywire (though I'm not sure if I'm mixing something up). Don't know if the climate change thing works, but maybe if all the icecaps melt and as he said, the new weight distribution somehow effects the iron, though I really doubt this will generate enough energy to cause a shift. The oceans are very miniscule in a planetary scale. Though maybe this is all a very fragile equilibrium.

@sezzac155

6 жыл бұрын

rubbers3 I have come across that particular theory that the switching of the magnetic fields is influencing climate change. And we could be in the beginning/middle of one. I don't think it triggers climate change all the time as I think climate change is still primarily human made. But the magnetic fields could definitely be a factor if we are indeed in the process of a flip. I thought that this video would touch on that but then I also was one of the people who thought it had more of a stable pattern of occurrences.

this guy has a great voice

Magnetic field lines point from the magnetic north to the magnetic south pole. You did it the other way around in your illustrations of earths magnetic field.

@solarfluxman8810

6 жыл бұрын

I concur that his arrows are pointing backwards as you said. I would add that the arrows should point from magnetic north to magnetic south external to the magnet, and from magnetic south to magnetic north internal to the magnet.

Lots of ideas as to why the poles might flip. What about the sun's magnetic field? Or interactions with the other planets? Watching a guys flip a magnetic field by pushing it into a bigger magnet south to south. Unno. Just makes yeh think! :)

What about tectonic plates movement..?

ITS NOT JUST THE MAGNETIC FIELDS THAT ARE FLIPPING.WITH THE ICE MELTING ON THE NORTH POLE,& THE ICE INCREASING ON THE SOUTH POLE WE CAN EXPECT FIRST A WOBBLE,THAN A ROLLING OVER ON ITS SIDE, SHIFT. THIS HAS ALSO HAPPENED IN THE PAST.

I wonder if magnetic pole swapping could have anything to do with enough counter electromotive force building up over time, enough to actually push the molten iron around and flip the field.

Hey SciSchow, what are your thoughts on the "flat earth" theory?

Try adding something large in our solar system traveling opposite to this systems planetary rotation. Another planet perhaps, rotation would be around 3,400-4100 year rotation. Probably closer to 3,699. Causing eractic wobble to planets as the mass entered our system.

Anyone else hate that woman in the state farm ad that plays before videos? Let the guy fix the leak, it’s just soldering a new piece of pipe, then repairing the drywall.

@SueMead

6 жыл бұрын

So, there are people who don't use _Ad Block Pro_ out there? Wow. No, not spamming. Just sayin'.

@anthonycaruso1781

6 жыл бұрын

Sue Mead Lots of people who use ad block disable it for certain channels to support shows they like. If EVERYONE used ad block then there would probably be no scishow.

@epatman07

6 жыл бұрын

jay west haha I’ve always thought this exact thing.

@AGoldSoldier

6 жыл бұрын

Anthony Caruso No, there would still be scishow. They have patreon supporters, you know....

@otaku3OBSESSION

6 жыл бұрын

Haha KZread Red beats Ad Block

so would it change due to and increased incidence in earthquakes? tsunamis? like tectonic plate shifting?

@xHaniffax

6 жыл бұрын

nevermind, you touched on this.

If I flip the pizzas Mr. Aziz will flip out

We're not due for one because we haven't had one for a while, we're due for one because we have lots of minor magnetic poles popping up and screwing with our van allen belts. Also, with the main (normal) poles moving so much, and apparently picking up speed, wouldn't it be possible that the poles would just move around the world to their new locations, instead of disappearing and later reappearing?

So we don't know how, why, what, or when. So nice to hear 'I don't know' when the answer is 'I don't know'.

Haha the poles be like North Pole: hey wanna switch? South Pole: Nah maybe 1000 more

Are the magnetic flux lines drawn backward in the graphic or am I mixed up?

@heinet

6 жыл бұрын

The Earth's magnetic field shields us from corpusucular radiation (charged particles), but does nothing to shield us from electromagnetic radiation (light) which is what causes sunburns, but this episode lists heightened sunburn risk as a consequence of a diminished magnetic field which isn't the case.

@solarfluxman8810

6 жыл бұрын

Tom, you are correct. They are drawn backwards.

The grid going down is apocalyptic in itself. A lot of people would die from that alone.

Reed says Earth's magnetic field weakens during the reversals. Would that alter the molecular clock calculations? Like, increase the probability of increased mutation rates?

Mention was made that meteorites might cause the effect. Did the magnetic fields switch at the K-T event?

(4:03) It's that "other living things" that we'd have to worry about, because if the [not necessarily cultivated] crops fail due to electromagnetic radiation damaging their DNS, the vertebrates that depend on them would be in trouble. Not necessarily a mass extinction, but mass starvation would be a possibility.

Someone's playing with our magnetic poles.

Yep

A Magnetic field moving near iron or other metal orientates the metal by magnetic induction. Therefore it's more likely that a chain effect is occurring between the sun and the earth. And the sun is effected by other stars or by the galactic singularity.

The current weakening of Earth's magnetic field, and the magnetic north currently running away from Canada towards Siberia at 100's kilometres per year, has what to do with a reversal? SWARM satellites currently in orbit to measure the decline of the magnetic field, means how long do we have? Governments know of this, and thank you for bringing it forward. I've mapped out the magnetic north movement for years now, and it is currently around the year 2018-2019 that the MNP will be on the same side of the planet as the MSP. The rise in the global temperature "Global Warming" imho is the decline of our fields as described in the video to protect us from the harmful rays.

Before the north goes south we all have gone south. The moment the earth's magnetic field weakens enough, we lost our deflector of radiation.

SciShow - Do pole flipping events line up with extinction or mutation events in the geological record?

I always thought it was a sudden flip. So basically if it does take thousands of years to complete a flip, imagine thousands of years of random electronic failure. They would probably be so cheap.

Aren't magnetic field lines supposed to be directed from north to south?

I was concerned about how the flip would effect animal’s abilities to navigate the world, but if it takes so long then I guess they’d be able to adapt in time

@thephilosopher7173

Жыл бұрын

This comment didn't age well, look at the culmination of news reports on migratory animals, and the surprise of how fast the magnetic field of Earth is changing.

It's funny to think that the single most solid thing we can think of is basically a lava lamp too, with lots of liquified aspects to its makeup.

What about solar cycles? Could they switch the poles because they already affect the magnectic feilds? Makes sense to me since the sun is the most massive object and core of the solar system.

I think scientists need to think about the amount of energy our star throws at us and the interactions between the earths magnetic field and the solar wind, the highly charged particles could be charging the earths core or the magnetic field of the sun directly affecting the planets magnetic field orientation.

Wait.. If you sync this theory/phenomenon with continental drift, can we safely say that said irradiation of living organisms speed up their specialization?

Start building lead houses and cover power grids with lead. Grab boron and find something to do with it. Learnt in physics they absorb radiation really good

My main question is, is this Earth Pole Shift scientifically safe to humanity? Is there any bad effects to this planet while it's changing for about thousands of years? Would it slightly be dangerous to go outside? Alot of questions that need to answer...

Imagine going to space and using a magnet lol

I don't understand why the field would have to die down at all. It currently is moving in a circle around the actual north pole. Why, when it flips, wouldn't this spiral just move out towards the equator while spinning then slowly approach the other side and then rotate around the pole on the other side for a few hundred thousand years. Just like a spinning top but instead of a spinning top on a surface falling over and stopping on it's side on the surface, it just passed through and rotated around to the underside of that surface and spun there for a while. Actually I think more like a gyroscope in space. What's the reasoning for thinking that the power of the magnetic field should become weaker in anyway? I feel like someone should try to make a large ball generate a magnetic field just from super hot fluids inside it, and then again with a solid metal ball in the middle of the ball, and see if there's a way to figure out which part is generating the magnetic poles. If the thing inside is really generating the magnetic fields how is the generation stopped when it's reversing, when the things generating the magnetic field are still in motion? Wouldn't it be easier to assume that the thing generating the magnetic field is actually changing direction inside the planet? If the solid metal ball inside the planet could be moving around and spinning independent of the outside layer. As it spins the ball of metal inside planet could just flip around slowly and point the magnetic field in a different direction. I assume it's slowly rotating like a top inside probably going a very tiny bit slower than the outside layer. A gyroscope stuck in hot mud but still spinning ever so slowly, because the mud is spinning around the gyroscope as well but at a different pace. Just like the atmosphere is moving slowly around the earth but of course it's not keeping up with the spin of the planet so it seems like it's always moving east. The inside of the planet could be doing something similar.

Could the eruption of super volcanoes have any effect on the switching of poles ?

@mrboomward

3 жыл бұрын

I think that would count as a big mass redistribution/lots of magma coming up so probably.

These changes are so random it looks like they're governed by quantum physics! 😮 That's it! I just figured it it! As a bonus, I found evidence of quantum effects on macroscopic objects!

@RizzRiderEUC

6 жыл бұрын

L Galicki Band Grade-A confirmation bias

@noblereflex8332

6 жыл бұрын

Lol

@amphibiousone7972

6 жыл бұрын

Okay, that's a funny!

So, the presumed double pole flip 41000 years ago happened around the same time that Neanderthals went extinct and when the oldest known cave paintings were created? There are some other interesting things from that period that I can't recall right now. Possible connection? I'm sure someone has already thought of this... ;)

@wezul

6 жыл бұрын

You may want to read the Neanderthal Parallax, a series by Robert Sawyer, which addresses this and a few other interesting coincidences. OUTSTANDING fiction trilogy by one of my favorite authors. :]

The back to back is another large body in a different orbit that might be too close to Earth and flips us the on the return it flies ppl s us back. But I do believe the object pulling on us, it would cause earthquakes, volcanoes, and possibly earth crust displacement.

If we don't assume Earth's core to be perfectly symmetrical, could it be the Dzhanibekov effect writ large? There's some cool demonstrations of it from the ISS, where spinning objects flip over seemingly at random, without ceasing to spin. en.wikipedia.org/wiki/Tennis_racket_theorem

So... how do we stop it

There are three theory about how earth gravity actually work.the earth has magnetic feild and it creates a gravity second theory is the more the mass of a planet the more it can bend the space and so that the result is any objects are pull from the center of the earth and third theory is the earth is flat. Which one is correct ?