Up - Down; Around and Around

People on Earth pretty much know the difference between up and down.

In 5th grade, my teacher pretty much laid out the definition: "Down is toward the center of Earth. Up is away from the center of the Earth." This picture illustrates the meanings fairly well.

Picture credit: children-globe-istock.jpg

Children, where ever they are on Earth; jump up, then come down, or some one can throw them up and catch them when they come down.

We know what up and down are as Earth people, because we are born here and we live here. Some times people go into space, outside the Sky. As they orbit and look down, they get a sense of what Earth's perspective might be.

Earth's Perspective

Despite my mass,
weightless, I fall;
around,
and around,
and around.

Always falling.
Never dropping
down...

Down to the light,

down

to

the

Sun.

I've never been up in orbit, but express elevators can give you that "lost my stomach" thrill, and carnival rides too. And fast cars going over humps in the road, but that isn't always safe. So be careful.

a reply to: pthena
There is that pivotal moment in the Divine Comedy when the poet descends to the centre of the earth (just underneath Satan's tail), keeps on going in the same direction, and suddenly finds himself struggling upwards.
Which demolishes the theory that mediaeval man thought the world was flat.

a reply to: pthena

People on Earth pretty much know the difference between up and down.

Looking "back" from space there is no up or down. We call it that but more accurately its inward towards the surface, and outwards away from Earth.

a reply to: DISRAELI

demolishes the theory that mediaeval man thought the world was flat

Interesting. Seems like it was a strawman argument for war(literally and figuratively) propaganda.

James Hannam wrote:

The myth that people in the Middle Ages thought the Earth is flat appears to date from the 17th century as part of the campaign by Protestants against Catholic teaching. But it gained currency in the 19th century, thanks to inaccurate histories such as John William Draper's History of the Conflict Between Religion and Science (1874) and Andrew Dickson White's A History of the Warfare of Science with Theology in Christendom (1896). Atheists and agnostics championed the conflict thesis for their own purposes, but historical research gradually demonstrated that Draper and White had propagated more fantasy than fact in their efforts to prove that science and religion are locked in eternal conflict.
- James Hannam. "Science Versus Christianity?"

Myth_of_the_flat_Earth

Thank you. I didn't realize that.

a reply to: intrptr

Looking "back" from space there is no up or down.

If someone were to go straight up, with no lateral acceleration by which to reach orbital velocity, and then vertical lift ended, they would definitely know what down was. The old saying, "what goes up, must come down." comes into play. That was the wisdom applied up until people figured out how to reach orbital velocity (or so I've heard).

ETA

Escape velocity can keep vehicles going outward too. You are correct. Acceleration gives the feeling of gravity, but coasting away doesn't.

a reply to: pthena

What if the sun and the stars are moving around the earth. Then the earth would be up to the sun and the sun down to the earth.

Any model made of both Heliocentric and Geocentric design both hold to the same effects of the solar system. And the only way we could prove otherwise is to establish which is in the center, is to verify an absolute position to be completely still not moving at all. (which is pretty hard to do seeing everything in the solar system, as for that matter in the universe is moving). If we could find such a spot and use something to verify we are still, then and only then could we tell for sure which is correct Helio or Geo centric.

a reply to: ChesterJohn

What if the sun and the stars are moving around the earth.

That would effectively place Earth as center of the Universe, whether Earth itself was stationary. The Earth would be down to the sun, as in, if the sun dropped down, it would be headed for Earth.

I'm not an astrophysicist but, here are some numbers. If Earth were center, then:
Alpha centauri at a bit over 4 light years away would travel 25.13272 Light Years in 24 hours to make one orbit.

SDSS J122952.66+112227.8 at 53,000,000 Light Years from Earth would be traveling at 935,417 times the speed of light in order to orbit once in 24 hrs.

At speeds like that, relative to Earth, I doubt the stars would be visible at all.

a reply to: pthena

We had a discussion on another forum that the reason the stars are seen from the earth and not so much from deep space is because of our atmosphere.

The astronauts who went to the moon all commented on how they could not see any stars from the space craft and the surface of the moon. Just blackness, the earth which was close enough to see with out aid, even when they went behind the moon they could see not stars.

a reply to: ChesterJohn

I thought you were studying photography. Try a manual 35mm, like an old Pentax 1000. What f-stop and shutter speed should be used to photograph the moon at night? Daylight settings, because the moon is in daylight. No stars will be visible in the photo. Photos of stars are taken with much slower shutter speeds (more exposure time).

see: Examination_of_Apollo_Moon_photographs: Absence_of_stars

As for light pollution: When I was young and the closest source of light pollution was 50 miles away, the stars were so numerous and bright, the Milky Way so clear and crisp! Now days (nights), I'm lucky to see Orion, brightest constellation.

a reply to: pthena

Good explanation. I 'll accept that.

Inside Out & Upside Down... Use To Be An Amazing And Funny Thing To Me As A Kid.. When Lucifer... Disguised As An Angel Of Light.. Revealed Them To Me.

He Knew Of The Wonders Of The Earth. And As A Kid... I DId Not.

Now... As An Adult (Not A "MAN" Yet)... I See Upside Down... Is An Amazing And Beautiful And Desirable Experience... More So With The Woman Of My Dreams. Only... Now... As An Adult... I Know... And Dream... But It Is Not Real. Lucifer No Longer Is My Angel Of Light. He Is An Absolute Devil. She... The Woman Of My Dreams... Is His. A Toy! It Is Pleasurable To Him. And She Is Submissive... In Everyway. But Never With Me. Always... She Is There... And I Am Tempted. But She Will Never Give To Me... My Perveted Dream. Upside Down... Is Her Head... Thrown Down... To Her Knees... To Worship... With Here Mouth... The Phallicy... Of The Devil. Inside Out...
Always.... At His Bidding...

Inside Out.... Is All That Is Inside Of Her Clothes... Hidden From Me... Out For Him... At His Bidding... Away From Me. I Wish... But... For Naught. For The Devil... Upside Down... And Inside Out... Is Dramatic.... Real... And Climatic. But... My Heart... Is Not Empty... It Beats With Jeaslousy And Anger. I Am Anguished... Always... Because... It Is Perpetual. My Mind Is Not Empty... Because It Dreams... And Dreams... But With Out Love. I Am An Disillusioned Pervert.

The End!

a reply to: pthena


While the cameras may be limited their eyes were not. Like I said even on the dark side as they passed they could not see not even off the shaded side of their space craft.

a reply to: ChesterJohn
A page to read by Brian Koberlein, Ph.D., Astrophysics, University of Connecticut

Can Astronauts See Stars In Space?

On the face of it, this might seem like a silly question. Of course we can see stars in space. We see stars more clearly from space than we do from Earth, which is why space telescopes are so useful. And yet, this question comes up again and again. Not just from moon landing skeptics and fringe science promoters, but from everyday folks who are sure they learned somewhere that stars can’t be seen in space.

Space shuttle frequent flyer James Reilly talks with The SpaceFlight Group's James Tutten about what stars look like in space.

A talking point often repeated is: The astronauts say they never saw any stars.
This, of course, isn't true and serves as another example of flawed thinking as Moon Landing Deniers continue to misinterpret the astronauts' statements.

a reply to: pthena

the shuttle is not in deep space as the Apollo moon visitors were. The shuttle is in a high altitude orbit still with some effects of or atmosphere affecting it.

a reply to: ChesterJohn

If you haven't watched the second video posted above, you may cut to the chase and start watching at around 6:30 of the video. At 8:00 the "Star Alignment Check" is described.

The shuttle is in a high altitude orbit still with some effects of or atmosphere affecting it.

The Hubble Space Telescope orbits at 539 km (335 mi) - 543 km (337 mi)

The air is so rarefied that an individual molecule (of oxygen, for example) travels an average of 1 kilometre (0.62 mi; 3300 ft) between collisions with other molecules.
. . .
In summary, the mass of Earth's atmosphere is distributed approximately as follows:
50% is below 5.6 km (18,000 ft).
90% is below 16 km (52,000 ft).
99.99997% is below 100 km (62 mi; 330,000 ft), the Kármán line. By international convention, this marks the beginning of space where human travelers are considered astronauts.
Thermosphere

From a space shuttle at 500 km above sea level, the 16 gas molecules per km^3 doesn't provide much of a holographic screen upon which illusionary stars are projected, for the bafflement of humans on Earth. Stars probably are objects far, far away, as opposed to light projections upon a screen.

a reply to: pthena

They are still in the spheres of Earth and not where there is absolute darkness.

a reply to: ChesterJohn



PIA10508: Tethys, satellite of  Saturn in Eclipse Sept. 25, 2008 by Cassini Orbiter

Around And Around... You Say!?!...

As A Kid It Was Wonderful When Lucifer The Masquerading Angel Of Light... Taught Me. Oh How I Delighted... And Needed More. Now... Around And Around Is Tormenting. Around And Around The World He Goes With My Dream Woman. Oh How I Cry........
Up And Down, All Around... To And Fro.... I Cry.