# When you sit down, it is the chair rising to you?

When you sit down, it is the chair rising to you?

If you live in Britain you would have seen the ad with prof Brian Cox saying that when you sit down it is the chair that is rising to you ~ due to general relativity.

Thing is if that’s true, then when I and someone on the opposite side of the planet sits down, the world would be expanding in both directions, and all directions of such movements?

What if I had robotic legs which are 100ft tall, or a thousand foot, or a million foot long, would the earth explode because two people with very long legs have sat down?

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No because the other person would and the Earth would move toward you.
The idea is that ALL things are relative to YOU.

{{yeah, yeah, it’s dumb, but they figure it suits the population}}

Lol yea, if the two or millions of people all moved at approximately the same time, and all with ultra long legs, then Huston we have a problem.

Perhaps it was not the best analogy for general relativity, but one has to ask if particles themselves know where they are in a manner of speaking, and hence it is just the act of measuring which is inaccurate?

It has nothing to do with accuracy or general relativity. The same thing happened with Newtonian mechanics.

It a question of where you place the coordinate system which you use to measure motion. You can place it anywhere you want.

that only shows how the chair or the person sitting down can be measured relatively, it doesn’t show that the person is specifically moving towards the chair or that the chair is specifically moving towards the sitter.

That’s because “specifically moving towards” makes no sense … it implies an absolute coordinate system somewhere in the universe. But a coordinate system is an abstraction which does not physically exist. It’s a concept that we overlay on top of physical matter.

I think Prof. Cox either was high or just wanting attention. I can see his point but uumm nooo. That would be saying that things do not grow , the world shrinks. I think more study and less imbibing.

That’s the impression that I got.

But if to be taken seriously, phyllo is right in that Relativity is an issue of chosen point of reference. Relative to you, the Earth moves toward you when you fall. But relative to the Earth, you fall toward it. It doesn’t really have anything to do with what reality is, but rather by which system you want to be measuring it.

Social and mental relativity are promoted for social effects (“everyone is their own god”), not for scientific or philosophical reasons.

I concur, but the point I was making however badly was that the chair is no more moving towards the sitter than vice versa.

I think the prof was trying to look clever but failed to achieve that. There’s a lot of mumbo jumbo in relativity and qm these days, and it lies in the metaphor e.g. a cat in a box isn’t in a state of living or being dead, because the box makes no difference, and the cat is either alive or it is dead.

Does this theory take into account planet rotation and or just revolving around the sun and moon revolving? I am now waiting to have my chair miss my butt. Too much booze does that but, now may I blame this theory??

Relativity doesn’t work on rotation. I’m afraid you’re going to have to blame your butt.

Are you being ironic on purpose? Because that’s literally relativity.

That’s not relativity, relativity doesn’t operate between proper nouns.

The chair and the butt are getting closer along a certain trajectory at a certain rate of speed. A tiny fly in the air between them may not be able to tell which is moving. An ant stuck to your butt would almost certainly percieve the chair moving towards them, just as we percieve the sun rising and moving through the sky.

Relativity deals with the math of the chair and the butt (and the ant and the fly), but it seems to me “Which one is moving” isn’t just a question of the math of their changing relative distances and speeds, it’s also a question of casuation. Your butt is moving, and not the chair. The reason is that the cause of this motion is your knees bending. Your knees bending gives a very simple mathematical explanation for why your butt would descend toward the chair, and it gives no explanation at all for why the chair (and the world) would be pulled toward your butt. Further more, we know that your knees are bending because you decided to bend them, and not because the world is pushing up at your feet and forcing them to bend; those would be two completely different experiences.

Relative to the other large objects in the known universe and their trajectory and position to each other, for the overwhelming part, your ass moved towards the chair. The chair only moved an infinitesimal fraction of your movement towards it, towards you.

In terms of acceleration your ass accelerated and deaccelerated much more than the planet.

→ Your ass moved towards the chair for the most part.

And thus your ass was retarded a little more.

Physics is weird man.

It gets weirder, much weirder.

I don’t even known that much physics but I know less calculus so it gets real incomprehensible real quickly. Thankfully, most things make intuitive sense without having to take an integral and since we’re in a relatively constant frame I rarely have to fail to solve a double integration.

The world is wide and wonderful. Sometimes you aren’t going to understand it all. Isn’t that part of the wonder?

I can’t see how the earth is moving at all, if for example we consider that it is ‘in position’ relative to all the forces which put it there so to say. then when you go to sit down that’s a different set of later events, and far larger forces would have been relatively moving the planet nearer to them, like the sun and all which makes the solar system take shape. if the act of sitting relatively moves all the particles of the earth, all the other particles in the universe would be making it stay in place.

or maybe relativity only exists when we observe a few particles, but doesn’t exist et al as we move towards the macroscopic scale of existence. after all, we can measure that with almost atomic accuracy?

Don’t know whats weird about physics. It’s just a bunch of fluids binded together by some magnetic force. My best guess is magnetism is an aether vortex. That is the part where it gets weird.

Pretty close to “right on”.