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Everything posted by J.C.MacSwell
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Electron - electron collisions
J.C.MacSwell replied to Moontanman's topic in Modern and Theoretical Physics
Thanks Strange, Mordred -
Electron - electron collisions
J.C.MacSwell replied to Moontanman's topic in Modern and Theoretical Physics
Besides the speeds and energies involved, any remarks on the difficulty of getting point like masses to collide? -
Entanglement and "spooky action at a distance"
J.C.MacSwell replied to geordief's topic in Quantum Theory
What is spooky about a gyroscope? Everything is local. -
That's not just money burning a hole in your pocket....
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I am certainly far from anything close to expert on this, but it was my understanding that quantum spins were intrinsic. You seem to be saying that anything that is capable of having classic spin cannot have intrinsic (quantum to me, interchangeably) spin. Is that what you are saying or claiming? Is it accepted as correct?
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You're going to let others sail off first, then put a patch over one eye and chase them down?
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We would probably struggle to survive back then, but so did they, our ancestors. We still have our adaptive systems that evolved, in part, through that time...including the ones that helped make us unfit (physical fitness unfit) from our lifestyle, such as ones that recycle (atrophy) muscle we don't use. They would help us adapt to the varied conditions we might encounter, or not, depending on our inherent survival fitness for those conditions. Maybe 10,000 years from now we might not get so unhealthy from excessive time spent in front of a computer...we can probably all help speed this process up by not exercising regularly, especially for those that have Doctors recommending that they in particular should do so.
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As long as it didn't increase the drag on the train from interference you would get a very slight gain for your effort, when a train happened to go by.
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Right. But the quantum spin is not classic. Generally speaking when discussing subatomic particles doesn't "spin" refer to quantum spin, and not to any movement associated with kinetic energy?
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He refers to quantum spin as not having kinetic energy because it is not the same as classical spin...and you get from that he thinks classical spin has no kinetic energy...that's not obtuse?
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...off to the basement to get some exercise in the "weight room"
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That's awesome Janus. There should be a slight effect from which way it is spinning. So walking one way would have some different effects from the other depending on your speed.
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It assumes the "scale invariance of empty space". What is the current model based on? Have there been some effects assumed to be present due to the expansion? What are they with respect to empty space? Or am I misinterpreting?
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It might be useful to try. When you are unable to do so in a manner consistent with physics it can give you some incite into why. IIRC this was part of Einstein's thought process.
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You probably know that it is close to, but not exactly 1%. What formula do you think would be appropriate here? And why?
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A not so small discrepancy in Relativity of Simultaneity
J.C.MacSwell replied to Truden's topic in Relativity
You do understand logic must be based on a set of assumptions? The point where the doors stop into each other are spatially separated from the points of opening. The doors can be open when the stops are closed with respect to other frames. There is nothing logically inconsistent with this...unless you use an assumption that is inconsistent with SR. -
A not so small discrepancy in Relativity of Simultaneity
J.C.MacSwell replied to Truden's topic in Relativity
Based on what assumptions? Based on SR? Or based on your belief that the rigidity of the door geometry in one frame must hold in another? How good is your logic? Is it good enough to work with a set of assumptions that you are not comfortable with? -
A not so small discrepancy in Relativity of Simultaneity
J.C.MacSwell replied to Truden's topic in Relativity
In the set up and sequence we are discussing, there are just two doors and they each just close then open once. This occurs simultaneously in the barn frame...and sequentially in the ladder frame. The red dot touching event is coincident with the simultaneous opening/closing of the doors in the barn frame. (it lasts the duration of the closed doors) In the ladder frame the back door opens and closes ahead of the approaching ladder and later the front door closes then opens behind the back of the ladder. The red dot touching event happens part way between the two, completely after the first and completely before the second. Movements of all intermediary points occur in succession, such that the "rigid" door/connection systems from the barn frame are distorted in the ladder frame. I know that is counterintuitive, might seem like it does not make sense...but welcome to SR. -
A not so small discrepancy in Relativity of Simultaneity
J.C.MacSwell replied to Truden's topic in Relativity
In the ladder frame the connection/touching near the hinge (red points) happens halfway between the time the back door opens then closes, and when the front door opens then closes. It will seem like the system connecting the doors is quite flexible, even if it isn't in the barn frame. -
A not so small discrepancy in Relativity of Simultaneity
J.C.MacSwell replied to Truden's topic in Relativity
The guy on the ladder simply won't have time to propose to the girl in the barn...I will give you that ...but the hinge still touches with respect to all frames if it does in any. -
A not so small discrepancy in Relativity of Simultaneity
J.C.MacSwell replied to Truden's topic in Relativity
The error is your thinking the hinge area cannot be closed when the ladder is midway in it's path through the barn, given that you set it as an assumption in the other frame. -
A not so small discrepancy in Relativity of Simultaneity
J.C.MacSwell replied to Truden's topic in Relativity
If you would kindly provide a drawing with both doors open, ladder sticking out each end, and the hinge joining the doors touching closed halfway between them you can save us the trouble. -
A not so small discrepancy in Relativity of Simultaneity
J.C.MacSwell replied to Truden's topic in Relativity
It happens with the ends of the ladder sticking out each door, one about to be shut, the other already shut and reopened. -
A not so small discrepancy in Relativity of Simultaneity
J.C.MacSwell replied to Truden's topic in Relativity
Why not? That event takes place in that frame if it takes place in any...just not at the same times with respect to that frame as either door is closed. (nether door is closed at the same time in that frame)