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How Fast Is Earth Moving?
Space.com ^ | June 22, 2018 | Elizabeth Howell, Space.com Contributor

Posted on 09/11/2018 11:27:07 AM PDT by ETL

How Fast Is Earth Moving?

As an Earthling, it's easy to believe that we're standing still. After all, we don't feel any movement in our surroundings. But when you look at the sky, you can see evidence that we are moving.

Some of the earliest astronomers proposed that we live in a geocentric universe, which means that Earth is at the center of everything. They said the sun rotated around us, which caused sunrises and sunsets — same for the movements of the moon and the planets. But there were certain things that didn't work with this vision. Sometimes, a planet would back up in the sky before resuming its forward motion.

We know now that this motion — which is called retrograde motion — happens when Earth is "catching up" with another planet in its orbit. For example, Mars orbits farther from the sun than Earth. At one point in the respective orbits of Earth and Mars, we catch up to the Red Planet and pass it by. As we pass by it, the planet moves backward in the sky. Then it moves forward again after we have passed.

Another piece of evidence for the sun-centered solar system comes from looking at parallax, or apparent change in the position of the stars with respect to each other. For a simple example of parallax, hold up your index finger in front of your face at arm's length. Look at it with your left eye only, closing your right eye. Then close your right eye, and look at the finger with your left. The finger's apparent position changes. That's because your left and right eyes are looking at the finger with slightly different angles.

The same thing happens on Earth when we look at stars. It takes about 365 days for us to orbit the sun. If we look at a star (located relatively close to us) in the summer, and look at it again in the winter, its apparent position in the sky changes because we are at different points in our orbit. We see the star from different vantage points. With a bit of simple calculation, using parallax we can also figure out the distance to that star.

Earth's spin is constant, but the speed depends on what latitude you are located at. Here's an example. The circumference (distance around the largest part of the Earth) is roughly 24,898 miles (40,070 kilometers), according to NASA. (This area is also called the equator.) If you estimate that a day is 24 hours long, you divide the circumference by the length of the day. This produces a speed at the equator of about 1,037 mph (1,670 km/h).

You won't be moving quite as fast at other latitudes, however. If we move halfway up the globe to 45 degrees in latitude (either north or south), you calculate the speed by using the cosine (a trigonometric function) of the latitude. A good scientific calculator should have a cosine function available if you don't know how to calculate it. The cosine of 45 is 0.707, so the spin speed at 45 degrees is roughly 0.707 x 1037 = 733 mph (1,180 km/h). That speed decreases more as you go farther north or south. By the time you get to the North or South poles, your spin is very slow indeed — it takes an entire day to spin in place.

Space agencies love to take advantage of Earth's spin. If they're sending humans to the International Space Station, for example, the preferred location to do so is close to the equator. That's why cargo missions to the International Space Station, for example, launch from Florida. By doing so and launching in the same direction as Earth's spin, rockets get a speed boost to help them fly into space.

Earth's spin, of course, is not the only motion we have in space. Our orbital speed around the sun is about 67,000 mph (107,000 km/h), according to Cornell. We can calculate that with basic geometry. 

First, we have to figure out how far Earth travels. Earth takes about 365 days to orbit the sun. The orbit is an ellipse, but to make the math simpler, let's say it's a circle. So, Earth's orbit is the circumference of a circle. The distance from Earth to the sun — called an astronomical unit— is 92,955,807 miles (149,597,870 kilometers), according to the International Astronomers Union. That is the radius (r). The circumference of a circle is equal to 2 x π x r. So in one year, Earth travels about 584 million miles (940 million km). 

Since speed is equal to the distance traveled over the time taken, Earth's speed is calculated by dividing 584 million miles (940 million km) by­­ 365.25 days and dividing that result by 24 hours to get miles per hour or km per hour. So, Earth travels about 1.6 million miles (2.6 million km) a day, or 66,627 mph (107,226 km/h).

The sun has an orbit of its own in the Milky Way. The sun is about 25,000 light-years from the center of the galaxy, and the Milky Way is at least 100,000 light-years across. We are thought to be about halfway out from the center, according to Stanford University. The sun and the solar system appear to be moving at 200 kilometers per second, or at an average speed of 448,000 mph (720,000 km/h). Even at this rapid speed, the solar system would take about 230 million years to travel all the way around the Milky Way.

The Milky Way, too, moves in space relative to other galaxies. In about 4 billion years, the Milky Way will collide with its nearest neighbor, the Andromeda Galaxy. The two are rushing toward each other at about 70 miles per second (112 km per second). 

Everything in the universe is, therefore, in motion.

There is no chance that you'll be flung off to space right now, because the Earth's gravity is so strong compared to its spinning motion. (This latter motion is called centripetal acceleration.) At its strongest point, which is at the equator, centripetal acceleration only counteracts Earth's gravity by about 0.3 percent. In other words, you don't even notice it, although you will weigh slightly less at the equator than at the poles.

NASA says the probability for Earth stopping its spin is "practically zero" for the next few billion years. Theoretically, however, if the Earth did stop moving suddenly, there would be an awful effect. The atmosphere would still be moving at the original speed of the Earth's rotation. This means that everything would be swept off of land, including people, buildings and even trees, topsoil and rocks, NASA added.

What if the process was more gradual? This is the more likely scenario over billions of years, NASA said, because the sun and the moon are tugging on Earth's spin. That would give plenty of time for humans, animals and plants to get used to the change. By the laws of physics, the slowest the Earth could slow its spin would be 1 rotation every 365 days. That situation is called "sun synchronous" and would force one side of our planet to always face the sun, and the other side to permanently face away. By comparison: Earth's moon is already in an Earth-synchronous rotation where one side of the moon always faces us, and the other side opposite to us.

But back to the no-spin scenario for a second: There would be some other weird effects if the Earth stopped spinning completely, NASA said. For one, the magnetic field would presumably disappear because it is thought to be generated in part by a spin. We'd lose our colorful auroras, and the Van Allen radiation belts surrounding Earth would probably disappear, too. Then Earth would be naked against the fury of the sun. Every time it sent a coronal mass ejection (charged particles) toward Earth, it would hit the surface and bathe everything in radiation. "This is a significant biohazard," NASA said.


TOPICS: Astronomy; Chit/Chat; Science
KEYWORDS: astronomy; catastrophism; flatearthermorons; science; spaceexploration; trollthoughtworddeed; vanallenbelts
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To: ETL

All this movement is why a time machine would have to be a very, very fast spaceship. One miscalculation on speed and you’ll be millions of miles from earth.


61 posted on 09/11/2018 2:09:02 PM PDT by Blood of Tyrants (Democratic socialism is when the majority of people vote to steal your property.)
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To: DannyTN; LibWhacker
it’s all relative to the frame of reference.

Dear DannyTN,

Please don't be like so many other Flat Earthers that show up here. LibWhacker is trying to inform you that youtube video does not necessarily equal education, and in this case he is correct.

Physical laws of motion like Newtons laws, or Keplers planetary motion, work in an inertial frame. These laws, which start out as theory, get 'proven' or disproved by experiment and measurement.

We have known for hundreds of years now the planets orbit the sun because we can observe their motion, and predict their motions, using Keplers laws and Newtons laws.

Saying that it all revolves around the Earth, since as you say it all relative, would void all these laws. The other planets would no longer move in predictable fashion, and a great many other things we can observe and measure would be unexplainable. The mass of the Earth could never hold the mass of the sun in orbit for example.

62 posted on 09/11/2018 2:25:58 PM PDT by Magnum44 (My comprehensive terrorism plan: Hunt them down and kill them)
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To: ETL
Just sit back and enjoy the ride
63 posted on 09/11/2018 2:26:41 PM PDT by mikrofon (Patriots' Day BUMP)
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To: ETL

I wish I could find it, but there was an interesting article about our universe in motion. Basically the author said that all motion is relative and based on arbitrarily selecting a point and measuring motion from there.

With that in mind, it was asserted that picking earth as the point of reference was just as valid as picking any other point - thus the universe revolves around the earth.

He said it much better than I, but you get the gist.


64 posted on 09/11/2018 2:38:09 PM PDT by Crusher138 ("Then conquer we must, for our cause it is just")
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To: mikrofon

Lol!

Carole King - I Feel The Earth Move (under my feet)


65 posted on 09/11/2018 2:39:09 PM PDT by ETL (Obama-Hillary, REAL Russia collusion! Uranium-One Deal, Missile Defense, Iran Deal, Nukes: Click ETL)
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To: glennaro

Thanks - She’s in west NC - Sylva area so they’ll get a lot of rain but I think they’ll be alright.

For all the east coasters (1 million+) being evacuated I do wonder where they’ll go? That’s a lot of motel rooms, I guess you just keep driving west til you find one.


66 posted on 09/11/2018 2:42:34 PM PDT by Tunehead54 (Nothing funny here ;-)
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To: DannyTN
Yes, the sun wobbles as the earth goes around it (has nothing to do with relativity, afaik).

And we can use earth as a frame of reference (has a little more to do with relativity).

But a look at the equations of orbital motion tell us what is really going round what.

Is the earth going around the sun as it is yanked along by the sun in its approx 600 million mile orbit around the sun? Or is the sun going around the earth as it wobbles along in its approx six foot long "orbit" around the earth (I'm assuming a wobble of approx one foot either way)? Could the earth even fit inside that "orbit?" No.

So the equations of orbital motion give us a way to distinguish a real orbit from a six-foot-long imaginary orbit (it's a real wobble, that's for sure, but that's all it is), as if we needed it.

67 posted on 09/11/2018 2:48:55 PM PDT by LibWhacker
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To: ETL

Too fast to get off. Try it and you’ll get a road rash like nobody’s business!


68 posted on 09/11/2018 3:11:15 PM PDT by TigersEye (This is the age of the death of reason.)
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To: Magnum44

Well at least you presented an argument.

I agree that the idea that the sun and the universe revolving around the earth throws a monkey wrench into the way we understand things. But I think most of the laws would work the same regardless, except that we would have no explanation of why everything revolves around the earth.

We have mass to explain all the other motion. The other planets would still predictably move around the son according to the mass based laws of gravity as we understand them. But why would the earth be pinned and the Sun and the rest of the universe revolve around it? Certainly not because of mass.

I was really hoping that someone would explain why the video claimed the need for dark energy would go away.

And I don’t appreciate being called “other Flat Earthers”. I’m not a flat earther. That was a term generated by evolutionists to discredit creationists. I never claimed to agree with the video. And while I do believe in scripture the oldest book in the Bible, Job, speaks speaks of the earth being round and that God hung it upon nothing.


69 posted on 09/11/2018 4:02:06 PM PDT by DannyTN (uit)
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To: ETL

It makes for really tough navigation of my time machine.


70 posted on 09/11/2018 4:18:22 PM PDT by GingisK
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To: Blood of Tyrants

Didn’t some NASA geek miss a decimal point calculating a conversion from English units to metric, ruining a trip to Mars a while back and resulting in a loss of a space probe?

Rocket surgery is hard!


71 posted on 09/11/2018 5:24:57 PM PDT by outofsalt (If history teaches us anything, it's that history rarely teaches us anything.)
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To: LibWhacker; Magnum44

The video is “The Genesis Theory - (Part 1)”

The part about the Heliocentric model begins 2 hours into the video and the next 30 minutes is pretty interesting.

The first video is 3 hours, the 2nd is 5 hours. The third video he apparently never made.

He says at the beginning that he intends to first introduce creationist concepts, then a number of scientific theories that are not discussed much. And he intends to pull those theories together into a unifying picture that presents an alternate cosmology that supports creation.

He spends about an hour and a half introducing creationist views, using scripture and a lot of Kent Hovind clips as well as others. Then he introduces some Flood information and some Egyptian creation myths.

Two hours in, he gets into the astronomy, with challenges to the heliocentric model. Presents the claim that cosmic background radiation indicates the earth is at the center of the universe. Then he pulls out some Eric Dollard and Tesla.

3 hours of material, I’m sure it’s target rich. Hey but so is science. For every hole you might be able to shoot in this guy’s presentation, I’m sure I can pull out past episodes of scientific global warming/cooling/warming/cooling/warming, pithdown man, blood letting, historical medical treatments of female hysterics, scientific geoupthink and ridicule of theories eventually proven correct, etc.

So both sides are target rich. Try to keep the discussion logical and to the facts.


72 posted on 09/11/2018 7:34:11 PM PDT by DannyTN
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To: outofsalt
Good memory!

Metric mishap caused loss of NASA orbiter

73 posted on 09/11/2018 7:34:49 PM PDT by Sawdring
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To: ETL; brytlea; cripplecreek; decimon; disndat; KoRn; Grammy; steelyourfaith; Mmogamer; dayglored; ...
NASA says the probability for Earth stopping its spin is "practically zero" for the next few billion years... What if the process was more gradual? This is the more likely scenario over billions of years, NASA said, because the sun and the moon are tugging on Earth's spin. That would give plenty of time for humans, animals and plants to get used to the change. By the laws of physics, the slowest the Earth could slow its spin would be 1 rotation every 365 days. That situation is called "sun synchronous" and would force one side of our planet to always face the sun, and the other side to permanently face away. By comparison: Earth's moon is already in an Earth-synchronous rotation where one side of the moon always faces us, and the other side opposite to us.
The process at work there is called the tidal transfer of momentum; the rotation of the Earth slows as it pushes the Moon away, and the Moon, being about 1 percent the mass of the Earth, did the same until it ran out of rotational momentum. A satellite in retrograde orbit, by contrast, gets pulled down toward the parent body.

The Sun, though more distant, is doing the same to the Earth, with about half the effect that the Moon once had (when the Moon was tidally transferring momentum, the Moon was pushing the Earth away, as the Earth was and continues to do to the Moon) because of its much greater mass. Similarly, the Sun contributes about 1/3 of the tides, which is a real squirt of lemon juice into the eye of anyone who takes the book "Rare Earth" seriously.

At some point, if the Earth continues to push the Moon away, there will be a bad crazy period as the Moon slips the surly bonds of Earth, because the process won't be instantaneous, due to the slower velocity of the Moon as it rises in average distance in its orbital path.

Thanks ETL. Ping to the APoD list, along with the Catastrophism list.



74 posted on 09/11/2018 10:55:28 PM PDT by SunkenCiv (www.tapatalk.com/groups/godsgravesglyphs/, forum.darwincentral.org, www.gopbriefingroom.com)
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To: ETL
Yeah, well, it is that sudden cessation of spin, where we all go flying that will be the pits.

That and all that ocean water sloshing around.

Best to be in orbit or on an airplane when it stops spinning. Slamming the brakes on at 1,000 mph could be painful.

75 posted on 09/11/2018 11:33:49 PM PDT by doorgunner69 (no mntion whast)
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To: ETL

Good read. Thanks for posting it, ETL.


76 posted on 09/11/2018 11:53:52 PM PDT by octex
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To: outofsalt

Yep. http://articles.latimes.com/1999/oct/01/news/mn-17288


77 posted on 09/12/2018 5:43:19 AM PDT by Blood of Tyrants (Democratic socialism is when the majority of people vote to steal your property.)
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To: DannyTN

Most people don’t have time to view 3 hour videos just to try to pick them apart. Why do you want others to do this ‘work’ for you? Similarly to LibWhacker, I have got other things on my plate. And while there are still mysteries to Gods great universe, nothing from Big Bang and the physics we know is incompatible with creation theory, as long as you don’t try to lawyer Gods word.


78 posted on 09/12/2018 5:52:58 AM PDT by Magnum44 (My comprehensive terrorism plan: Hunt them down and kill them)
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To: ETL

Asimov wrote a murder mystery short story about this effect.

https://en.wikipedia.org/wiki/The_Billiard_Ball


79 posted on 09/12/2018 7:07:13 AM PDT by Conan the Librarian (The Best in Life is to crush my enemies, see them driven before me, and the Dewey Decimal System)
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To: DannyTN

“Indicating the earth may be the center of the Universe.”

I do not know about physics but philosophically speaking, in an infinite universe the center is wherever you are because all interior points are an equal distance from the edge. Thus you are always in the center, no matter how far you travel.


80 posted on 09/12/2018 7:24:27 AM PDT by Fai Mao (There is no rule of law in the US until The PIAPS is executed.)
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