straight line in what coordinate ssytem

reality isn't a coordinate system

geocentric, or cartesian, etc

oh ok, so oh a sphere you can go in a straight line

in a spherical coordinate system

ok well that'sa diff coordinate system

so ya i understand you now

well you'd have to leave the surface to go in a straight line

but you can follow a line of longitude

ya you can just walk on teh surface

you have to technically use spherical trig

but that works as well

over short distances, that's teh same as a 2D surface

correct fore everyone it rises at an azimuth of 90

yep

This one's complicated to visualize

east is based on your local point where you stand, and parallel to your line of longitude

@jeremy yes if you travelled at an initial heading of east, you'd eventually cross teh equator, that would effectively put you in the same path as an orbit with the inclination of your latitude

https://planetary.s3.amazonaws.com/assets/images/z_changeover/20130125_vandenberg-launch-trajectories.png

but that's if you're stuck to the surface

light rays are not stuck to the surface they come from the sun

@AstralSentient well wait lemme think

b/c i think you would

if you set your initial heading as east, and never adjusted it again, didn't look at a compass

your magnetic heading wouldnt' stay east

at the start?

or throughout the journey

well you'd need a compass to do that

which i guess is dead reckoning still

but imagine you start on a heading of 90 and never 'turn' left nor right

eventaully your magnetic heading will change

you wuoldn't follow a line of latitude in that case

@jeremy and past it

and south of it, then you'd return back to where you started

would you cross the equator at an angle, or would you be parallle with it, in your opinion?

@AstralSentient if you maintain a compass heading ya

@jeremy if you end up at the equator, and then kept going, you'd also go past it, and circle back to where you started

just like an orbit

it's like that image i posted

why

if you crossed it at an angle you'd keep that angle

@jeremy orbital spacecraft is the best example of this

they start at a certain azimuth then don't change

@AstralSentient only if you made adjustments to stay ON a magnetic heading of east

@jeremy what else do you doubt with the globe model?

ok it's easy

check out this diagram

https://planetary.s3.amazonaws.com/assets/images/z_changeover/20130125_vandenberg-launch-trajectories.png

@jeremy you'd circumnavigate

why wouldn't you go all the way around

@jeremy why would it go south to the equator then suddenly stop

@jeremy he just stopped teh lines at teh eqautor, continue them, where do they go

travelling on the surface of teh globe ya leads to a circle around teh globe, but light doesn't stick to the surface of the earth like someone walking

yes but that doesn't mean if i see a light source east of me, that it originates at the equator

^^^

That just makes no sense

what does that even mean originates at teh equator

no it rises in the east

no that's the error

taht's a projection of travel

but light doesn't travel along the surface of the earth

if you're stuck the globe east takes you to the earth but light isn't stuck to the globe

the sun? it's not stuck to the surface of the earth that's for sure

and it doesn't travel like someone walking on the surface

lol what's a freeze frame/

@jeremy draw lines that go east, that aren't stuck to the surface of the globe,

then they don't go to the equator

@AstralSentient i tried, he can't visualize a tangent, vs a line taht follows the globe surface

@jeremy Do you understand now/