BrendanS
Well-Known Member
Better get the mast checked out for temporal stresses
<hr width=100% size=1>Utinam logica falsa tuam philisophiam totam suffodiant
<hr width=100% size=1>Utinam logica falsa tuam philisophiam totam suffodiant
A trip around the world
- Thread starter Badger
- Start date
jimi
Well-Known Member
from a fixed point in space as the earth spins then the mast and the keel would describe a series of spirographs with sometimes the keel being the furtherst away object and the mast the nearest. So I hypothesise that the distance is equidistant when viewed from a point in space
<hr width=100% size=1>.. whit way roon should it be again ..
<hr width=100% size=1>.. whit way roon should it be again ..
BrendanS
Well-Known Member
From a sufficiently large distance, the movement of the earth spinning, and that of the earth around the sun, and the sun through the galaxy, and the galaxy through the universe, would make any such measurement of differerence between mast and keel meaningless.
You'd also have to define fixed position. If absolutely fixed, the movement of all of the above would take the fixed position out of range of know instruments to measure the difference in a tiny amount of time. If you fixed the position as above the pole, and the yacht was sailing around the equator, you could still measure the difference.
<hr width=100% size=1>Utinam logica falsa tuam philisophiam totam suffodiant
You'd also have to define fixed position. If absolutely fixed, the movement of all of the above would take the fixed position out of range of know instruments to measure the difference in a tiny amount of time. If you fixed the position as above the pole, and the yacht was sailing around the equator, you could still measure the difference.
<hr width=100% size=1>Utinam logica falsa tuam philisophiam totam suffodiant
MainlySteam
Well-Known Member
Now Brendan you as a fan of physics know better than that /forums/images/icons/smile.gif!
If you were that far away you could not know that the yacht had sailed around the world yet. The nearest galaxies are around 200,000 light years away so you will have to wait 200,000 years before one can say what sort of pattern the yachts mast would describe from that distance (or 13.8 billion years or something I think it is to the currently furtherest known galaxy) and the significance of that.
One can make a prediction now of the significance to someone looking back at the yacht's motion through space based on our current understanding of the laws of physics, which is incomplete. But one cannot claim that the motion will be insignificant. What will be seen in 200,000 years time by someone far away looking back to today will be set against the laws of physics as understood by the observors at the time of the observation. We cannot make a prediction of the significance of the yachts motion to them from our current vantage point in time and knowledge.
For example, the civilization looking back at earth from afar may have just developed some theory of physics that depends for its experimental proof upon some very small motion differential between one part of a solid body and another part of the same body being measured. So there they are gazing out into space with their super telescope in 200,000 years time (to us)and spy earth as it was 200,000 years ago (to them) and lo and behold they see a yacht sailing around it. The physicist says to himself, ahha, if I measure the track of the top of the mast and the track of the boat in my frame of reference that will provide the data for my experiment.
So unknowingly, some sailor who has not the first idea about physics and is long dead becomes the focus of an important physics experiment to the inhabitants in another galaxy in 200,000 years time, and the different tracks of his mast and hull become milestones in experimental physics.
Guess you are probably the only one left awake after reading that Brendan /forums/images/icons/cool.gif.
Unphysically yours
John
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If you were that far away you could not know that the yacht had sailed around the world yet. The nearest galaxies are around 200,000 light years away so you will have to wait 200,000 years before one can say what sort of pattern the yachts mast would describe from that distance (or 13.8 billion years or something I think it is to the currently furtherest known galaxy) and the significance of that.
One can make a prediction now of the significance to someone looking back at the yacht's motion through space based on our current understanding of the laws of physics, which is incomplete. But one cannot claim that the motion will be insignificant. What will be seen in 200,000 years time by someone far away looking back to today will be set against the laws of physics as understood by the observors at the time of the observation. We cannot make a prediction of the significance of the yachts motion to them from our current vantage point in time and knowledge.
For example, the civilization looking back at earth from afar may have just developed some theory of physics that depends for its experimental proof upon some very small motion differential between one part of a solid body and another part of the same body being measured. So there they are gazing out into space with their super telescope in 200,000 years time (to us)and spy earth as it was 200,000 years ago (to them) and lo and behold they see a yacht sailing around it. The physicist says to himself, ahha, if I measure the track of the top of the mast and the track of the boat in my frame of reference that will provide the data for my experiment.
So unknowingly, some sailor who has not the first idea about physics and is long dead becomes the focus of an important physics experiment to the inhabitants in another galaxy in 200,000 years time, and the different tracks of his mast and hull become milestones in experimental physics.
Guess you are probably the only one left awake after reading that Brendan /forums/images/icons/cool.gif.
Unphysically yours
John
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chas
Well-Known Member
Pedant\'s Paradise
Do you sail round the equator or along it? And if you did, would'nt you bump into bits like S America and Africa?
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Do you sail round the equator or along it? And if you did, would'nt you bump into bits like S America and Africa?
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