Naked Science Forum
On the Lighter Side => New Theories => Topic started by: Petrochemicals on 26/12/2018 23:16:27
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If i had a very very long rod in a negligable gravity atmosphere and i moved the one end of the rod in a mannor such as morse code for example, would this constitute an instantaneous data transmission senario? Is it akin to the quantum particle transmission that is also instantaneous. The rod would be moving in unison at a few mps but the data transmitted would be as fast as the rod is long.
https://www.sciencemag.org/news/2017/06/china-s-quantum-satellite-achieves-spooky-action-record-distance
Please do not say relativity !
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To paraphrase Isaac Arthur (who spoke on exactly this scenario), you aren't pushing on a rod: you are pushing on a collection of atoms which are pushing on another collection of atoms which are pushing on yet another collection of atoms and so on. That push travels as a wave through the material at a finite velocity (the speed of sound through the material, as Halc says).
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Yes but why do atoms resist the movement if there is no one around to hear it ? According to that analogy material movements would be limited to their sound wave speed, which, if you'll forgive me for saying, is utter drivel. The speed of movement through rubber is not the same as diamond. A stiff material would move only at a negligable speed, but would transmit the data far faster.
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Yes but why do atoms resist the movement if there is no one around to hear it ?
Because they have inertia.
According to that analogy material movements would be limited to their sound wave speed, which, if you'll forgive me for saying, is utter drivel.
The pressure wave moves at the speed of sound relative to the rod itself. The wave can certainly travel much faster relative to an outside observer. It still can't beat the speed of light, though. Length contraction and time dilation would prevent that.
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Nope they do not have inertia,
Without gravity, there would be no resistance to movement, no pressure. What is the pressure of the air in space.
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Nope they do not have inertia,
Without gravity, there would be no resistance to movement, no pressure. What is the pressure of the air in space.
Seriously? Did you seriously just say that?
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Like seriously dude, y'know like, yeah.
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Like seriously dude, y'know like, yeah.
Every object with mass has inertia. The rod has mass, so it has inertia. They teach that in elementary school.
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Nope they do not have inertia,
Without gravity, there would be no resistance to movement, no pressure. What is the pressure of the air in space.
Mass and inertia are intrinsic properties of an object and does not depend on the existence of gravity. If you want to get an object moving from a state of rest or bring it from a state of motion to one of rest you have to exert energy whether it is at the surface of the Earth or floating weightless in space. The only way gravity comes into play is if you are lifting the object upwards against it, or gravity is pressing the object against a surface so that friction between the surface and the object comes into play.
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The rod was at rest. :P :P
Gravity would give the atoms and there said electrons reason for resistance to acceleration, thus friction and the comressive rotation in the bonds should ensue.
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Gravity would give the atoms and there said electrons reason for resistance to acceleration
Gravity isn't necessary for that. Otherwise spacecraft would experience reduced inertia when they are far from sources of gravity such as planets or stars. That would make the acceleration due to their thrust very different from what existing equations predict. We would therefore not be able to safely land spacecraft on distant planets or moons using conventional physics. The fact that we have done that just fine for decades proves that inertia exists just as much in space as it does on Earth.