Why do you say that the ecliptic intersects the equatorial plane at the vernal equinox and the bisector? Haven't they always crossed paths?

Because the vernal equinox and autumnal equinox are the intersection points of the ecliptic plane and the equatorial plane in the earth's orbit, in fact, the solar terms are more consistent with the Gregorian calendar, because the Gregorian calendar is based on the movement of the sun.

The ecliptic plane refers to the orbital plane of the earth revolving around the sun, and the intersection angle with the equatorial plane of the earth is 23 26'. Because the gravity of the moon and other planets affects the revolution of the earth, the position of the ecliptic plane in space is always changing irregularly. But in change, this plane always passes through the center of the sun at any time. The great circle where the ecliptic plane intersects the celestial sphere is called the ecliptic.

The ecliptic plane is the plane of the earth's orbit. Because the gravity of the moon and other planets affects the revolution of the earth, the position of the ecliptic plane in space is always changing irregularly. But in change, this plane always passes through the center of the sun at any time. The great circle where the ecliptic plane intersects the celestial sphere is called the ecliptic.

The equatorial plane refers to the plane where the equator is located in the geographical coordinate system (that is, when viewed from the earth), and the ecliptic plane refers to the orbital plane of the earth revolving around the sun. Because the earth axis is inclined and perpendicular to the equatorial plane, there is always a fixed included angle between the equatorial plane and the ecliptic plane, which is called the ecliptic angle (23 degrees and 26 minutes).

The equatorial plane refers to the plane where the equator is located in the geographical coordinate system (that is, when viewed from the earth), and the ecliptic plane refers to the orbital plane of the earth revolving around the sun. Because the earth axis is inclined and perpendicular to the equatorial plane, there is always a fixed included angle between the equatorial plane and the ecliptic plane, which is called the ecliptic angle (23 degrees and 26 minutes). The celestial equator is viewed in celestial coordinates, and you can regard it as an extension of the equatorial plane.

The horizon is only related to your local latitude, that is, where the great circle passes through. What's your local latitude and the angle between the horizon and the equatorial plane? If you stand at 3 1 degree n, the celestial equator is in the south of you (celestial equator can be counted as 0 degree latitude) and is not in the same plane with you. Polaris is in your north (not due north, of course), and the position of Polaris is the position where the earth axis points.