A magnetic field is invisible ... marking the needle direction each time join the points to show the field lines The needle of a plotting compass points to the south pole of the magnet.

That is, unless you’ve got one of these nifty magnetic field visualizers developed ... time and produce an approximation of what the field lines would look like on its electronic paper display.

the angle at which magnetic field lines intersect the Earth. The turtles use these two pieces of information, which vary at every point on the planet's surface, as navigational markers that help ...

Bar magnets and horseshoe magnets are two of the most common shapes of magnet. The magnetic field is shown by lines with arrows that point from north to south. You can tell how old some coins are ...

As the time line at right shows ... Moreover, while a severe weakening or disappearance of the magnetic field would lay us open to harmful radiation from the sun, there's little evidence to ...