# Where on Earth someone is

• B
• kent davidge
In summary: Without longitude (and with it local time), first, the altitude doesn't tell you latitude either.The azimuth just positions you somewhere on a circle that is centered on a point where the sun is directly overhead. A compass heading could position you on that circle.This is a good point - without longitude, you would not be able to orient yourself.

#### kent davidge

I saw the following question in Yahoo Answers,

How do you know where in our planet is a person located, knowing her height, length of her shadow and having a photograph of her on the unkown location, knowing day-month-year and time the photo was taken?

Is it even possible to know this?

If you have the time in UTC, sure.

kent davidge
russ_watters said:
If you have the time in UTC, sure.
But with what error bars?

If you have no orientation information (which way is North?), then there is quite a wide band of longitude+latitude solutions, mirrored on each hemisphere.

kent davidge
DrClaude said:
But with what error bars?
Accurate enough to navigate a ship in the 19th century...
If you have no orientation information (which way is North?), then there is quite a wide band of longitude+latitude solutions, mirrored on each hemisphere.
Good point; you would have to know the hemisphere, which maybe you could see from context in the photo.

kent davidge
russ_watters said:
Accurate enough to navigate a ship in the 19th century...
Not without a compass

My point is that at any given time, the same stick length will give the same shadow length at many points on the globe. If you have no information on the orientation of the shadow, there is not much you can say.

kent davidge
DrClaude said:
Not without a compass
Oh, you don't just mean the hemisphere. Yes, I see you're right; to get the longitude from the azimuth of the sun, you need the actual angle from north.

and...now that I think about it, without longitude (and with it local time) first, the altitude doesn't tell you latitude either.

kent davidge
The azimuth just positions you somewhere on a circle that is centered on a point where the sun is directly overhead. A compass heading could position you on that circle.

Edit: if the ground is not level, your navigation could be way off.

eudo and russ_watters
russ_watters said:
maybe you could see from context in the photo.
The one with the penguins in, perhaps.

nasu and jbriggs444

## 1. Where on Earth is the North Pole?

The North Pole is located at 90 degrees north latitude, in the Arctic Ocean. It is the most northern point on Earth and is covered by a layer of ice.

## 2. How can I find out my exact location on Earth?

You can find out your exact location on Earth by using a GPS (Global Positioning System) device or by looking at a map and identifying your coordinates in terms of latitude and longitude.

## 3. Where on Earth is the equator?

The equator is located at 0 degrees latitude and runs horizontally around the middle of the Earth. It divides the Earth into the Northern and Southern Hemispheres.

## 4. How do scientists determine the exact location of a place on Earth?

Scientists use a system of latitude and longitude to determine the exact location of a place on Earth. Latitude measures the distance north or south of the equator, while longitude measures the distance east or west of the Prime Meridian.

## 5. Can someone be in two different places on Earth at the same time?

No, it is not possible for someone to physically be in two different places on Earth at the same time. However, with the use of technology such as video conferencing, it is possible for someone to virtually be in two places at once.