# What's it like if I were standing on earth's axis?

1. May 2, 2010

### Exists2Wonder

Hi I am new to this forum and I am not even studying physics nor currently taking any classes in my old age. But I had a thought last night whilst tossing in my sleep and the question arose to my mind about what it would be like if I went to the North Pole and stood dead center aligned exactly standing on the earth's physical pivoting axis point? If at night I stood there looking up at the stars I would guess that I would just see them spinning in a circle directly above me (imagine a line drawn staight through and connecting the earths north and south poles axis). I know standing on the street in say NYC and looking up at the starts I watch the pattern as how the stars move across the sky. The centrifigual forces acting upon me (us) in NYC are not the same I would guess as if I were standing directly on the north or south poles pivot axis right? Would that change the physical behavour or properties of things as we normally know or feel them in the middle of the earths (like standing at the equator where the velocity of us spinning through the air space is much greater than the same person standing exactly on the earths's north pole rotating axis)?
Hope you get the jist of my question here. Makes me wonder. (like a spinning phonograph record spinning at 33RPM, the velocity of the outer grooves are traveling at a much higher rate of speed than the inner grooves of same record. But the entire record can be said to all be spinning at the same speed. Different parts of that record platter are using up and exhibiting different energy levels or physical properties). Just wondering. Do the laws of physics say explaning gravity or other properties change or get modified at the earth's axis vs at the equator spinning (energy levels obviously are different to be rotating at the same rate but at different velocities.

Also just thinking about another question that arises based on what I've heard about traveling at high speeds (like Einstein's theory if an astronaut took off into space at the speed of light and came back a year later, he would have aged one year but the everyone on earth would have aged many more years). So if speed slows down time and therefore aging, do we live longer if we are located by the equator (where rotational speed is moving us much faster through space) than if we were up at the north pole axis pivot turning at a turtles pace?

Thanks!

Last edited: May 2, 2010
2. May 2, 2010

### PhanthomJay

yes, this is correct.
that's right, in fact, there is virtually no centripetal force acting at the poles
yes, but only slightly, since the gravity force overwhelms the centripetal force by a great amount (you weigh just a tiny bit less at the equator than you do at the north pole, about 0.3% less).
Careful about the twin paradox...the twin travelling near lightspeed would practically not have aged at all upon his return. Astronauts returning to earth have aged a wee wee wee bit less than if they had not made the journey....but you really have to travel at a significant fraction of lightspeed to note any difefrenvce.

3. May 2, 2010

### Redbelly98

Staff Emeritus
Hello Exists2Wonder, welcome to Physics Forums. Since this is not a homework exercise, I have moved your post out of the Homework & Coursework subforums.
Yes, the strength of gravity would be different at the north or south pole but not by much. A person will weight half a percent less at the poles than at the equator, so 1/2 pound lighter for a 100 lb person, 1 lb lighter for a 200 lb person, etc.
It's an incredibly tiny effect, and will depend on the strength of the gravitational field as well as the speed. The time factor is much much less than the 1/2 percent figure that applies to the weight of a person. According to this article, astronauts on one of the Apollo missions aged about 3 ten-thousandths of a second during their trip:

http://www.time.com/time/magazine/article/0,9171,839785,00.html

And here we are talking about staying on Earth, so while I'm not expert enough to calculate that it would not be anything a person could notice, without using sensitive measuring instruments.

4. May 2, 2010

### Exists2Wonder

Thanks for replying with some info on these wonders of mine PhanthomJay and Redbelly98.
I really put out these questions to spur thought on it but I still wonder, if I built a house right on the north pole actual dead center pivoting point of the earth axis and lived there, due to the differences of these forces (and other factors) I wonder if I might observe strange phenomena or occurrences not seen nor witnessed by the majority of the living population living more towards the middle regions of the earth. I have no idea if ever there was any expedition team up or down at the axis poles specifically to investigate this question(s) or not. So I wonder on. (P.S. - I really cannot afford to build a house right on the north pole even if the land were free and unclaimed! But maybe some government or research team can! :-) )
PS- I mean located smack dead center on the pole axis. Not near it or slightly off of it, right on it. I wonder if certain everyday (therefore common sense) physical, electrical, paranormal, whatever behavours that we humans have come to expect and know in everyday average middle of the earth life might exhibit surprising different behavours at that spot (dead center on axis that is). Mixing solutions of chemicals, compounds, whateever done right there, might they have different outcomes and properties than when same procedured are done in NYC middle earth)? just wondering of course but interesting to send a team up there to experiment (like they do in space -e.g. - making more perfect ball bearings or some such for example).

The more I think about this, the more I want to go to the north pole axis and stand myself personally right on the mark. In this day and age I am sure they can pinpoint the exact spot of the rotational axis precisely and tell me where it is. I am curious to see how I would feel if I stood right on the spot and observe any sensation(s) not observed nor felt in the middle of the earth from where I am accustomed to. While others want to go on a vacation to see the great pyramids, or the grand canyon and stuff like that... I now want to go to the physical north pole axis to experience it! :-) Of course the likelyhood of this for me is probably 0. :-( But I wish someone else can do it and report back one day!

Last edited: May 2, 2010
5. May 2, 2010

### Staff: Mentor

There is no reason to believe there would be anything noticeable/interesting happening at the pole due to the rotation and in any case, the ice over the north pole moves so you wouldn't be able to build a house on it anyway.

6. May 2, 2010

just a quick ?, wouldn't the time lapse view of the stars be more of a Spirograph? the tilt of the the axis to it's orbit around the sun would make the stars appear to slow or stop then continue right?

7. May 2, 2010

### pallidin

Dang North Pole igloo's anyway. My address keeps changing.

8. May 2, 2010

9. May 2, 2010

### Exists2Wonder

Yes I know, I thought about the ice problem. My comment(s) about building my house up there were in jest. I know in most probability that it would not be feasible. :-) Anyway I am sure in this day and age we can get a team up there at the exact point (bring me along with you) and at least try to be able to stay on that axis spot long enough to experience anything from it. It may be unfeasible to do due to the constant moving of ice but I think some team with the proper resources should try. Up there I wonder how light and electro magnetic phenomena or any other physical properties we've come to expect in middle earth life might manifest themselves however slightly different. Anyway, just a dream wonder. Maybe one day if man is still alive in the future we will have some of the answers.

10. May 2, 2010

### Exists2Wonder

Yes your are correct on that the earth axis does tilt and change and is not fixed. It does vary (wobble) from what I understand from our books that teach us. But I am only speaking of the spinning of the earth on its access points. I was not concerning the varying tilt of the axis in space as it is spiining. I was just proposing for intellectual thought and ideas provoked by asking my question which just came to me in the middle of the night while sleeping. I remembered the dream state this morning so got curious about what it would be like if you could stand right on that rotational axis of the earth. That's all.

11. May 2, 2010

### Staff: Mentor

No, to earth the stars appear like a fixed-sphere around us and the earth rotates inside it. The shape of the path the stars take is due to the rotation only. If you were on the north pole and took a long exposure picture, you'd see this except that it would be centered directly above you:

http://www.astronomy.org/programs/seasons/pictures/08shi-ncp-1988-sm.jpg
Sure, it could be done, but since it costs money, scientists would need a reason to believe they would find something worth the cost of the expedition. And since there is no reason to believe that there would be anything interesting to observe, there is nothing to justify such an expedition.

12. May 2, 2010

### Staff: Mentor

Good point - that wobble would produce a "spirograph pattern" over a couorse of thousands of years.

13. May 2, 2010

### Redbelly98

Staff Emeritus
And in summer you'd just see the sun in the sky ... not noticeably changing altitude during the course of a single day, and circling all the way around the horizon.

14. May 2, 2010

It was the precession I was thinking of, I figured it would be noticeable over the course of a yr. Polaris though does seem to move about an elliptical path due to the tilt and it being about 1/2* off axis.

Exists2wonder, the magnetosphere poles don't line up on the axis, so to experience any effects from the magnetic poles you'd be in a different location.

15. May 2, 2010

That's OK, I hadn't ever thought about it till you asked and then it was a mental exercise taking a bit too much into account.

16. May 2, 2010

### Staff: Mentor

I was talking about precession too, but with a period of 26,000 years, you certainly couldn't notice a difference in one year.
Circular, to be more precise.

17. May 2, 2010

I thought 'oblate spheroid' was the technical term (tidal forces)

ooops you're right, 360* over 25,800yrs or just about 50secs of arc per yr.

18. May 2, 2010

### Redbelly98

Staff Emeritus
Huh? Stars appear to have circular orbits (neglecting precession) simply because the Earth is spinning on it's axis. Tidal forces, and the fact that the Earth isn't a perfect sphere, have nothing to do with it. You could stand on a rotating cube and stars would still appear to have circular orbits.

19. May 2, 2010

I thought that the tidal forces also effected the axis as well, so that the tilt varies and that would make the path to be not a perfect circle.

20. May 2, 2010

### nucleus

Exists2Wonder

I have been to both geographical poles many times and can assure you that there is nothing noticeable different than elsewhere on earth, except all directions is either north or south, depending on which pole you are at.

If you have lots of money there are tours to both poles. There is a permanent station at the South Pole. The South Pole moves approximately 10m a year and is recalculated each year.

http://en.wikipedia.org/wiki/Amundsen-Scott_South_Pole_Station