1 - first TED video is more easy to see here (add h por http):
2 - Curious like a person can say many words and say nothing. (in the video).
3 - I believe I understand geodescis and also like gravity curve the geodesic where travel the photons, ...
According to geodesic you consider that a point 3d xyz after a conversion o geodesical change from Euclidian to hyperbolic, ... the point xyz remain at same point 3d because you represent that point in a 3d coordenates without consider that hte geometry has changed.
An example: 10 is a mathematical value, but according by the base can to means 2 (binary), 10 (decimal), 16 (hexadecimal), ... but according you say only count that it's 10, by that you consider that 10 binary = ... = 10 hexadecimal and by that that 2 = .... = 16
Another example, light in universe travel by the geodesic, so near a mass the "straght line" without consider the mass is curved, really is straight but according to your geometry it would be curved and by that in a point would to be many parallels but really if you consider the so curved line light a "straght line" that change the geometry from euclidian to hyperbolic or another really only can to be 1 parallel in that point.
So wiithout consider that the geodesic is curved by gravity seem that the light is curved but knowing that mass curve the geodesic understand that really travel a "straght line".
4 - The TED video show a piece with more that one parallel that supposed parallels cannot to be parallels between theirs (1 common point) or only 1 parallel at any time and changing the geometry and by that the point xyz change.
Really the geometry in parallels and triangle is like a sheet of paper, draw a triangle or a parallel, know you can roll the paper in hyperbolic form and the parallel is only one, the point xyz change and the triangle adopt the adecuate form.
Please draw me more that 1 parallel in 1 point (withot the TED absurd form) or draw me a triangle with 2 angles of 90º, not affirm, draw me,
When I speak over cones I really speak over perimeter of cone without the base, this has 2 angles of 90º, and 1 more angle but the line that joint the 2 angles of 90º is equidistant to the other angle and by that is not straight and by that is not a triangle.
The example of the meridians in same form not is usefull because the line from equator is equidistant to the pole.
Thanks.
Another example:
According to relativity theory a man that travel in a rocket a hight speed the time go slowly (person 1).
So according to this in time x the rocket and another person in Earth (personn 2) consider time x, 1 year later in Earth (consider time present) occurs 2 things.
1 - present time is for person 1 and 2
2 - if we consider time x + 1 year the time is different by the 2 persons.
In same form a triangle or parallel in Euclidian geometry can to be represented in hyperbolic, ... but the position xyz change, not remains same in same form that in 2 the x + 1 year is not the same for both persons of the example or that 10 is not the same in binary that in decimal.
In the example of corals, ... the 2 sides of the coral or the worms only are paralels in a geometry according to that and the point is the same that in a flat Euclidian geometry when are parallels and the xyz point change and by that are not multiples parallels in a point because the point xyz always is the same, only change the geometry according to the movement of the worm.