/sci/ - Science & Math

>rotation explanation
>uses a magnetic pendulum that stops working during a solar eclipse

>>9760246
People tend to explain underlying properties of higher order dimensions with one that can be intuitively explained by a familiar one

The ball and blanket analogy conveys the idea that a higher dimension affects a lower dimension, so it's a valid example

>>9760948
>it's a valid example

Except space-time is literally not a blanket you fucking pseud. It is something much more complex.

>>9761093

>>9761093
yikes

>>9760246
I agree that it's a bad analogy, but mostly because the whole idea of relativity is that the time component of your 4-vectors gets mixed in with your spatial components, and in typical metrics that you work with, the time-to-space mixing has the greatest impact on your results, rather than the space-to-space mixing (which are usually just some sort of R^3 coordinate change anyway).
But if you're "explaining" GR to laypeople, you can't possibly try to explain any of that in any meaningful way. Best you can try to do is give them the notion that "matter and light move along the easiest paths (geodesics if you want to throw some fancy terminology at them) in spacetime", which should be a fairly natural notion, and then "GR says spacetime is curved in the presence of matter". You're not trying to teach them how it really works, you wouldn't have the analogy at all if that were the case.

>>9761093
That's why it's called an analogy, retard

>>9761147
"Time components mixing" isnt really the crux here, but just the lack of typical invariants we consider universal. That is, we consider that distance and time is the same, and now our idea of simultaneous events really fails. But that only means that observers will disagree with certain shit, but you can still talk about what a particular observer can see, and he still sees motion in physical space and he could see how massive object changes the spatial geometry.

>>9760246
>aerodynamics explanation
>"we will ignore effects such as wind resistance"

>>9760246
>learning chemistry
>periodic table is written in comic sans

>>9760948
>explain gravity
>using gravity

>entropy explanation
>clean your room
Fuck that Peter Johansson guy

>>9761115
xkcd is the dark knight of stackoverflow.

>>9761093
>Earth is round, like this pool ball
>Earth am no pool ball, pseud

>>9760246
nice pepe, bump

>>9760246
>gravity explanation
>using a ball instead of a flat disk

>>9761115
love it

>>9761093
>pseud
Fucking kill yourself

>>9761093
>literally
No fucking shit. That's why it's a visual demonstration.

>>9760246
It's an easy way for normal people to visualize the effects of gravity on spacetime even though it's 2D.
I like to imagine a 3D square trampoline mat with the bowling ball inside, sucking/strectching the substance (energy) out of it to create it's mass.

>>9765658
Yes, that's quite difficult to show visually though.
To show it visually you pretty much need to use 2D because the "object" affected is space itself, so it can't be transparent, and if it is opaque then you can't see anything.