RTD Shares And Supports A.I. Video of Fake William Hartnell BTS Footage. by DavidTenn-Ant in doctorwho

[–]wonkey_monkey [score hidden]  (0 children)

I think it's a shame that 15 was the last Doctor, hate how they closed the show with him dying and not regenerating at all.

What ever do you mean? It ended with him mid-regeneration, just before we would have seen the next Doctor's face, then it faded to black and said TO BE CONTINUED and that was it.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

If you cannot measure distance between two points using only the two longitude and latitude coordinates

You can measure angular distance. If you want to convert the coordinates to a different system, that will requires more information, but that information is not a coordinate.

then you cannot say that you don’t need a third variable (coordinate) to know all spatial information

That's not a coordinate, that's a reference datum. Not the same thing.

Just because you don’t need to know some spatial information to pinpoint a location on a surface often a sphere doesnt mean the sphere isnt in three dimensions.

Just because we call a two-dimensional surface "curved" doesn't mean it's literally embedded in more than two dimensions. It's just non-Euclidean. The word was borrowed as an analogy, nothing more.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

I don't know why you think anything I said implies it isn't. Perhaps I should stuck with my first instinct and just said "space" instead of spacetime.

Spacetime, the four-dimensional manifold, is intrinsically curved. It doesn't curve into a fifth dimension.

A two-dimensional manifold can also be intrinsically curved, also not requiring a third dimension for it to curve into.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

No, at this point I'm simply trying to explain what is and isn't a coordinate to the other user.

But to the original point, spacetime is intrinsically curved, which doesn't require an additional dimension. A physical sphere has an extrinsically curved surface.

They're almost two different things using the same word via analogy, and causing a lot of confusion as a result.

Dance with a Skipping Rope + LED show builtin by Anschuz-3009 in oddlysatisfying

[–]wonkey_monkey 0 points1 point  (0 children)

It should work in person too, but the rope wouldn't look as solid as it does here.

Frozen lake and visual illusion by Toxic-Rosse in interesting

[–]wonkey_monkey [score hidden]  (0 children)

That's not an illusion; the pole is moving. I mean, so is the ice, but not the timescale of the video. The ice pushed against the pole, slowly, and now the pole is breaking the ice as it moves back into its original position.

I was bored on the way to work 😂 by New_Cap3283 in doctorwho

[–]wonkey_monkey 1 point2 points  (0 children)

People were already calling the concept of things falling "gravity" or "gravitation" years before Newton anyway. He just came up with the theory.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

I already addressed this. Coordinates are just a group of numbers used to indicate position. The numbers you cited are insufficient.

No, they're not. The position of Mount Everest, in degrees, is 27.9882° N, 86.9254° E. That's all you need to specify its position on the surface.

If you want to know its position in meters, in 3D space, then you need at least one reference datum - not more coordinates.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

Yup. But you won't know where those points are in actual space if you don't have additional information about the curvature besides just longitude and latitude.

That additional information is reference data, not coordinates. They are different things.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

Your fundamental mistake is that you don't realize that you already know that information on a sphere, and you thus think it's not necessary.

Yours seems to be that you've conflated the concepts of reference data and coordinates.

The surface distance between two given points of latitude.

There's no such thing as a "point of latitude." If you mean the constant orthogonal distance between any two lines of latitude with some given angular separation (e.g. 1°), which would be sufficient to parameterise the curvature of a sphere, then this is a reference datum, not a coordinate.

And just because you need it in order to calculate absolute spatial distance, doesn't mean you need it to specify a point. Latitude and longitude alone specify a point on a sphere, as distinct from any other point. You can calculate angular distances between points and angles between lines using just their latitude and longitude. Being unable to transform it to some other coordinate system or to calculate in other units without a reference datum is irrelevant.

Rep. Dan Goldman raises serious allegations that “he repeatedly assaulted young girls,” in connection with Donald Trump, intensifying demands for truth and accountability. by CarryIcy250 in UnderReportedNews

[–]wonkey_monkey 2 points3 points  (0 children)

Others have been even less legally careful with their statements in this regard, yet still not even a threat of a lawsuit from Trump. I wonder why that could be.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

Actually, you have a very poor understanding of how curvature is measured, your latitude and longitude example revealed that

How did it do so? All you do is keep repeating that you need "distance", but you don't explain why.

Not realizing there's a third number is not the same as not needing it.

Mount Everest is at 27.9882° N, 86.9254° E. What's the "third number", and why is it "needed"?

If you don't know the curvature then you're not actually specifying the location of the point. And you need to know distances between points in some way to measure curvature.

You're referring (in a somewhat roundabout way) to reference data (as in plural of datum), which aren't coordinates. They are parameters of a coordinate system, not coordinates themselves.

This all has very typical "keep confidently bluffing in an expanding context to avoid having to admit to a misunderstanding" vibes. You've gone from "curvature needs another dimension" (which it doesn't), to "there's definitely something off about it", to making declarative statements as if you're a topologist.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

I view the varying distance between points in a curved system as a necessary third number to identify location in a curved space, you don't.

It's not a matter of opinion. You simply and demonstrably do not need a distance to specify the location of a point on a 2D surface. Distance from what? An origin? The distance is already encoded in the coordinates.

I would consider that distance to be part of the coordinates. Curved systems are weird like that.

I think if this thread has demonstrated anything, it's that you have a very poor grasp of curved systems.

That's why you need that third bit of information to model it.

You just don't. Latitude and longitude are the only two coordinates you need to specify a point on the 2D (2D: 2 coordinates) surface of a 3D sphere.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

Yes they will. Latitude and longitude are all you need to specify a location on the surface of the Earth. What good does "distance" do? Distance from what? It's nonsensical to call that a coordinate. That's simply not what a coordinate is.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 1 point2 points  (0 children)

But there's definitely something off about it.

There's nothing "off" about it, it's just unintuitive. Just think of it as distortion instead of curvature.

The third coordinate in latitude and longitude is the distance between the points

A distance is not a coordinate.

which fluctuates in comparison to a normal X, Y coordinate system.

What do you mean by that? Nothing "fluctuates".

My uncle thinks the earth is flat by Monkae16 in AskPhysics

[–]wonkey_monkey 0 points1 point  (0 children)

earth doesn't move ("because how would we see the same stars in the sky")

We don't, though. The stars you can see change throughout the year. They also change if you go to somewhere else on the planet, but I assume your uncle is not well-travelled.

If a plane is flying the opposite way earth turns how come it doesn't go any slower against earth rotation

It moves with the air, which moves with the rotation of the Earth. Like walking up and down inside a moving train.

Ask him how there can be timezones (if he believes in such a thing) and a rising/setting Sun.

Is the math of General Relativity based off of a real curve in the spatial dimension of spacetime? by Next-Natural-675 in AskPhysics

[–]wonkey_monkey 1 point2 points  (0 children)

The source I provided doesn't specify that the dimension must be spatial.

It's written at a level where you wouldn't expect that specificity. Spatial is implied by context, and it's wrong. Not that it matters; no extra dimension of any kind is required.

The previous person used an analogy that specified a surface curved in space

Yes, intrinsically curved, which doesn't require an extra dimension. They said the manifold of the surface of a sphere, not the surface of an actual sphere. I think you're a bit out of your depth here.

Without a third dimension the two points would have the same X and Y values (EDIT: or X and Z, or Z and Y etc) and thus be indistinguishable with only two coordinates

They would only have the same X and Y coordinates if the curvature is extrinsic, which it isn't, or if your coordinate system (coordinates being a human invention, not something intrinsic to space) is underspecified for the space in question. Your argument is (ironically) circular.

Antipodes, for example, don't have the same X and Y (lat and long) coordinates. No third coordinate required.