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24-08-2017, 10:51   #1
petemcewan
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SJCrothers,

Just an inquiry.


Quote:
II Critical phenomena in gravitational collapse

Starting with spherical spacetimes,



where dW dq2 + sin2qdj2, and {xm} = {t, r, q, j} are the usual spherical coordinates, Choptuik [5] investigated the gravitational collapse of a massless scalar field, f, which satisfies the Einstein-scalar field equations,
Why is the field expressed as a Scaler quantity and not a Vector quantity (having magnitude and direction ) ?
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24-08-2017, 10:56   #2
geared
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I think he ran off to troll other forums.
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24-08-2017, 11:02   #3
Hairyloon
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Quote:
Originally Posted by petemcewan View Post
Why is the field expressed as a Scaler quantity and not a Vector quantity (having magnitude and direction ) ?
Can you ask it in plainer English?
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24-08-2017, 12:11   #4
Jim Hardie
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This is Sheffield Forum not Stephen Hawking's drop box.
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24-08-2017, 12:30   #5
Hairyloon
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Quote:
Originally Posted by Jim Hardie View Post
This is Sheffield Forum not Stephen Hawking's drop box.
Are you suggesting that our members are incapable of advanced mathematics?

It may not matter if they are, if the OP is prepared to put in some work. There is no better way of properly understanding something than explaining it to another.
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24-08-2017, 15:05   #6
MEC176
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Quote:
II Critical phenomena in gravitational collapse

Starting with spherical spacetimes,

where dW dq2 + sin2qdj2, and {xm} = {t, r, q, j} are the usual spherical coordinates, Choptuik [5] investigated the gravitational collapse of a massless scalar field, f, which satisfies the Einstein-scalar field equations,

Er sorry cannot help you there but if you write into the Big Bang Theory
possible Sheldon may have the answer, Sarcasm loading.
and I’m sure with Einstein’s Theory of relativity you will manage a rhetorical
Sarcastic quiptic retort.
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24-08-2017, 22:46   #7
petemcewan
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Hairyloon,

I think what is in the question is as simple as it gets. Scalers are quantities which only have magnitude ,eg: volume. Vectors are quantities that have magnitude and direction, eg : force.
I'm puzzled how a scaler gets into the equation.

Last edited by petemcewan; 24-08-2017 at 22:48.
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25-08-2017, 16:16   #8
cressida
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gravity, black holes

...the planets are indeed a mysterious force to be reckoned with so better stay indoors if there is a full moon next to Uranus
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Last edited by cressida; 25-08-2017 at 16:17. Reason: sorry wrong thread
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25-08-2017, 16:42   #9
tinfoilhat
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Quote:
Originally Posted by Hairyloon View Post
Are you suggesting that our members are incapable of advanced mathematics?

It may not matter if they are, if the OP is prepared to put in some work. There is no better way of properly understanding something than explaining it to another.
Considering the amount of self confessed experts on here when I asked what I thought was a reletively straight forward question (for experts) on here, no two answers were the same.
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25-08-2017, 17:07   #10
The Joker
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Quote:
Originally Posted by cressida View Post
gravity, black holes

...the planets are indeed a mysterious force to be reckoned with so better stay indoors if there is a full moon next to Uranus
what if Uranus is so big it generates its own gravity ?
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25-08-2017, 17:10   #11
cressida
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There would have to be an internal investigation...obviously

.. the astrological alignments are a little challenging at the moment but wait for even more fireworks next year with Uranus doing his edge of chaos orbits.
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Last edited by cressida; 25-08-2017 at 17:23.
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25-08-2017, 17:14   #12
Hairyloon
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Quote:
Originally Posted by tinfoilhat View Post
Considering the amount of self confessed experts on here when I asked what I thought was a reletively straight forward question (for experts) on here, no two answers were the same.
That is probably the quantum effect...
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25-08-2017, 19:02   #13
horribleblob
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Quote:
Originally Posted by Hairyloon View Post
That is probably the quantum effect...
Do you mean the quantum leap of faith in the self-confessed experts here on SF?
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25-08-2017, 19:44   #14
mickey finn
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Quote:
Originally Posted by petemcewan View Post
SJCrothers,
Why is the field expressed as a Scaler quantity and not a Vector quantity (having magnitude and direction ) ?
Easy, because dW dq2 + sin2qdj2, and {xm} + dR4 - rT(vb) cos3e = {t, r, q, j}
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25-08-2017, 21:11   #15
Hairyloon
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Quote:
Originally Posted by horribleblob View Post
Do you mean the quantum leap of faith in the self-confessed experts here on SF?
I mean the idea of two contradictory things both being simultaneously true (at least until the wave function collapses): as in Schroedinger's cat being both alive and dead until the box is opened.
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25-08-2017, 21:18   #16
Alan Hartley
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How does the non vacuum of earth meet the vacuum of space?
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25-08-2017, 21:31   #17
Hairyloon
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Quote:
Originally Posted by Alan Hartley View Post
How does the non vacuum of earth meet the vacuum of space?
Gradually.

How does light propagate? Once upon a time that kind of question was fundamentally important to physics, but post Einstein, they have given up trying to model the real world, preferring instead the purity of mathematical models...
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25-08-2017, 21:41   #18
Alan Hartley
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Quote:
Originally Posted by Hairyloon View Post
Gradually.

How does light propagate? Once upon a time that kind of question was fundamentally important to physics, but post Einstein, they have given up trying to model the real world, preferring instead the purity of mathematical models...
Frankly I'm not impressed with how the scientific establishment, particularly the liars of NASA bat away doubters of their "facts" with complex mathematical equations. They're worse than a religious cult the way they reach for their book of numbers.
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25-08-2017, 21:50   #19
Hairyloon
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Quote:
Originally Posted by Alan Hartley View Post
Frankly I'm not impressed with how the scientific establishment, particularly the liars of NASA bat away doubters of their "facts" with complex mathematical equations. They're worse than a religious cult the way they reach for their book of numbers.
You won't find me arguing on that. Except for the use of the word "liars", which indicates deliberate dishonesty: I think they sincerely believe it.

Did anybody ever get an answer on the relativity question? Are we allowed to discuss it here or not?
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26-08-2017, 00:26   #20
petemcewan
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Hairyloon,

Your second paragraph. Are your referring to the General Relativity thread posted by SJC-that disappeared from the Forum ?

---------- Post added 26-08-2017 at 00:43 ----------

Quote:
Originally Posted by mickey finn View Post
Easy, because dW dq2 + sin2qdj2, and {xm} + dR4 - rT(vb) cos3e = {t, r, q, j}
Mikey Finn,

I beg your pardon. But it doesn't answer the question. Out of curiosity,where did you get the "cos3e " from ?
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