The BBC have introduced a new, improved style of presenting the weather.
On their website, there no longer appears to be a proper 'Jack Scott'
weather map (Surface Pressure Chart), as per <https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfa cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel that
nobody was interested?
--
Ian
This is good
https://www.met.ie/forecasts/atlantic-charts/precipitation-pressure
On Wednesday, 7 February 2018 at 10:32:21 UTC, Ian Jackson wrote:
The BBC have introduced a new, improved style of presenting the weather.
On their website, there no longer appears to be a proper 'Jack Scott'
weather map (Surface Pressure Chart), as per
<https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfa
cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel that
nobody was interested?
--
Probably because the average <50 (or maybe less!) viewer of today hasn't
got a clue what its about.
Has anyone else noticed that organisations such as XCWeather,
Weatherwatch, and the Irish Weather Service (link above) are quite happy
to forecast 7 days ahead but the good old BBC (and for TV purposes the
Met Office) only ever do three?
On the contrary, the BBC weather app forecasts in 1 hour slots for 14 days ahead, which strikes me as an utterly pointless level of detail.
On Wednesday, 7 February 2018 at 10:32:21 UTC, Ian Jackson wrote:
The BBC have introduced a new, improved style of presenting the weather.
On their website, there no longer appears to be a proper 'Jack Scott'
weather map (Surface Pressure Chart), as per
<https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfa
cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel that
nobody was interested?
This is good
https://www.met.ie/forecasts/atlantic-charts/precipitation-pressure
On Wednesday, 7 February 2018 at 10:32:21 UTC, Ian Jackson wrote:
The BBC have introduced a new, improved style of presenting the weather.
On their website, there no longer appears to be a proper 'Jack Scott'
weather map (Surface Pressure Chart), as per
<https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfa
cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel that
nobody was interested?
The BBC do a "monthly outlook"
but they learnt long ago that long distance
forecasts are not accurate and always have warnings with them
On Wednesday, 7 February 2018 at 10:32:21 UTC, Ian Jackson wrote:
The BBC have introduced a new, improved style of presenting the weather. >>>
On their website, there no longer appears to be a proper 'Jack Scott'
weather map (Surface Pressure Chart), as per
<https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfa >>> cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel that
nobody was interested?
I've only just spotted this. The obvious comment is that that's the Met >Office's website, and nothing to do with the BBC (who don't even use the
Met Office's forecasts any more, but get them from an outfit called >Meteogroup). (Dis)credit where it's due.
Has anyone else noticed that organisations such as XCWeather, Weatherwatch, and
the Irish Weather Service (link above) are quite happy to forecast 7 days ahead
but the good old BBC (and for TV purposes the Met Office) only ever do three?
This is good
https://www.met.ie/forecasts/atlantic-charts/precipitation-pressure
On Wednesday, 7 February 2018 at 10:32:21 UTC, Ian Jackson wrote:
The BBC have introduced a new, improved style of presenting the weather.
On their website, there no longer appears to be a proper 'Jack Scott'
weather map (Surface Pressure Chart), as per
<https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfa
cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel that
nobody was interested?
--
Ian
On Mon 21/02/2022 08:57, Mike Cooper wrote:
This is good
https://www.met.ie/forecasts/atlantic-charts/precipitation-pressure
On Wednesday, 7 February 2018 at 10:32:21 UTC, Ian Jackson wrote:
The BBC have introduced a new, improved style of presenting the weather. >>>
On their website, there no longer appears to be a proper 'Jack Scott'
weather map (Surface Pressure Chart), as per
<https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfa >>> cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel that
nobody was interested?
--
Probably because the average <50 (or maybe less!) viewer of today hasn't
got a clue what its about.
Has anyone else noticed that organisations such as XCWeather,
Weatherwatch, and the Irish Weather Service (link above) are quite happy
to forecast 7 days ahead but the good old BBC (and for TV purposes the Met Office) only ever do three?
On 21/02/2022 09:59, Woody wrote:
Probably because the average <50 (or maybe less!) viewer of today hasn't
got a clue what its about.
Has anyone else noticed that organisations such as XCWeather,
Weatherwatch, and the Irish Weather Service (link above) are quite happy
to forecast 7 days ahead but the good old BBC (and for TV purposes the
Met Office) only ever do three?
I presume they can tell what pages people are looking at and decided that
the average viewer does not want the synoptic chart and might be confused
by it.
They can easily be viewed on the Met Office site.
https://www.metoffice.gov.uk/weather/maps-and-charts/surface-pressure
I am sure you can download the raw data if you wish to do your own forecasting. :-)
On 21/02/2022 08:57, Mike Cooper wrote:
This is good
https://www.met.ie/forecasts/atlantic-charts/precipitation-pressure
On Wednesday, 7 February 2018 at 10:32:21 UTC, Ian Jackson wrote:
The BBC have introduced a new, improved style of presenting the weather. >>>
On their website, there no longer appears to be a proper 'Jack Scott'
weather map (Surface Pressure Chart), as per
<https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfa >>> cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel that
nobody was interested?
If you're interested in just about every aspect of what the weather is
doing anywhere in the world, then the best website I've found is https://earth.nullschool.net/. This url centres on the UK: <https://earth.nullschool.net/#2022/02/21/2000Z/wind/isobaric/1000hPa/orthographic=-6.04,53.98,3226>
If you click on "earth" at bottom left, you can change the parameters of
what you're looking at. It's worth a play, but you may find yourself
spending rather a lot of time on the site!
--
Jeff
I wonder if the change in pressures being signified by how close together the lines run is actually explained any more? Surely its the simplest of concepts to grasp that the closer together the more the wind blows as high pressure is always trying to fill low.
I wonder if the change in pressures being signified by how close together the lines run is actually explained any more? Surely its the simplest of concepts to grasp that the closer together the more the wind blows as high pressure is always trying to fill low.
On 21/02/2022 12:06, Brian Gaff (Sofa) wrote:
I wonder if the change in pressures being signified by how close
together
the lines run is actually explained any more? Surely its the simplest of
concepts to grasp that the closer together the more the wind blows as
high
pressure is always trying to fill low.
Except that Coriolis forces mean the wind doesn't actually flow in the right direction to fill the low pressure!
On 21/02/2022 14:01, David Woolley wrote:
On 21/02/2022 12:06, Brian Gaff (Sofa) wrote:
I wonder if the change in pressures being signified by how close
together the lines run is actually explained any more? Surely its the
simplest of concepts to grasp that the closer together the more the
wind blows as high pressure is always trying to fill low.
Except that Coriolis forces mean the wind doesn't actually flow in the
right direction to fill the low pressure!
<pedant>I'm not sure 'force' is the right word there!</pedant>
Is it also so complicated to realise that warm air contains more water
vapour if it is in the area, but cold air lets it rain out?
Is it also hard to see that this interface is called the dew point and gthus ion the ground, if both are exactly the same, ie temperature and the dew point then its foggy damp ad wet as clouds form at ground level but the higher pressure stops all of that occurring.
I also wonder how much the public know about why weather systems spin
around? It is because the bits nearer the equator are moving faster and the drag forces a rotation. Cyclones one way anticyclones the other and each is reversed in the different hemispheres. Chaos reigns at the equator.
Weather even on these basic levels is interesting even before you invoke the sun angle and the tilt of the earth, reflectivity of te ground and
gasses that hold onto radiation.
Brian
On 21/02/2022 08:57, Mike Cooper wrote:
This is good
https://www.met.ie/forecasts/atlantic-charts/precipitation-pressure
On Wednesday, 7 February 2018 at 10:32:21 UTC, Ian Jackson wrote:
The BBC have introduced a new, improved style of presenting the
weather.
On their website, there no longer appears to be a proper 'Jack
Scott' weather map (Surface Pressure Chart), as per
<https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=
surfa cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel
that nobody was interested?
If you're interested in just about every aspect of what the weather
is doing anywhere in the world, then the best website I've found is https://earth.nullschool.net/. This url centres on the UK: <https://earth.nullschool.net/#2022/02/21/2000Z/wind/isobaric/1000hPa/ orthographic=-6.04,53.98,3226>
If you click on "earth" at bottom left, you can change the parameters
of what you're looking at. It's worth a play, but you may find
yourself spending rather a lot of time on the site!
On 21/02/2022 14:01, David Woolley wrote:
On 21/02/2022 12:06, Brian Gaff (Sofa) wrote:
I wonder if the change in pressures being signified by how close
together
the lines run is actually explained any more? Surely its the simplest of >>> concepts to grasp that the closer together the more the wind blows as
high
pressure is always trying to fill low.
Except that Coriolis forces mean the wind doesn't actually flow in
the right direction to fill the low pressure!
<pedant>I'm not sure 'force' is the right word there!</pedant>
On Mon, 21 Feb 2022 14:18:54 +0000, Java Jive wrote:
On 21/02/2022 14:01, David Woolley wrote:
On 21/02/2022 12:06, Brian Gaff (Sofa) wrote:
I wonder if the change in pressures being signified by how close
together the lines run is actually explained any more? Surely its the
simplest of concepts to grasp that the closer together the more the
wind blows as high pressure is always trying to fill low.
Except that Coriolis forces mean the wind doesn't actually flow in the >>> right direction to fill the low pressure!
<pedant>I'm not sure 'force' is the right word there!</pedant>
Enough force to blow off unattached items.
Woody wrote:
Has anyone else noticed that organisations such as XCWeather,
Weatherwatch, and the Irish Weather Service (link above) are quite
happy to forecast 7 days ahead but the good old BBC (and for TV
purposes the Met Office) only ever do three?
On the contrary, the BBC weather app forecasts in 1 hour slots for 14
days ahead, which strikes me as an utterly pointless level of detail.
(or more strictly still '*a* Coriolis effect' because there are others,
such as dropping a rock from a high enough tower causes it to land
slightly ahead of directly under the point where it was dropped, because initially it was travelling slightly faster through space and therefore overtakes that point).
Yeah, sure, :-), but, still being pedantic, that's not why storms spin,
which Brian has had a go at explaining elsewhere. AIUI, it should be
called 'the Coriolis effect', because AFAIAA there are no actual forces involved, just differences in linear velocity at different latitudes on
a rotating object such as the earth.
"Java Jive" <java@evij.com.invalid> wrote in message news:sv0cfu$2l5$1@dont-email.me...
(or more strictly still '*a* Coriolis effect' because there are
others, such as dropping a rock from a high enough tower causes it to
land slightly ahead of directly under the point where it was dropped, because initially it was travelling slightly faster through space and therefore overtakes that point).
Surely the lateral speed of the rock (relative to a stationary observer
out in space) remains the same as the earth's speed, no matter how much
the rock accelerates in a downward direction due to gravity and is decelerated by speed-dependent slowing due to air resistance.
On 21/02/2022 14:18, Java Jive wrote:
On 21/02/2022 14:01, David Woolley wrote:
Except that Coriolis forces mean the wind doesn't actually flow in
the right direction to fill the low pressure!
<pedant>I'm not sure 'force' is the right word there!</pedant>
When I dabbled in physics many years ago "Coriolis force" was by
definition a fictional force so - unless the meaning has changed - it
seems an acceptable term in that context.
"Java Jive" <java@evij.com.invalid> wrote in message news:sv0cfu$2l5$1@dont-email.me...
(or more strictly still '*a* Coriolis effect' because there are
others, such as dropping a rock from a high enough tower causes it to
land slightly ahead of directly under the point where it was dropped,
because initially it was travelling slightly faster through space and
therefore overtakes that point).
Surely the lateral speed of the rock (relative to a stationary observer
out in space) remains the same as the earth's speed, no matter how much
the rock accelerates in a downward direction due to gravity and is decelerated by speed-dependent slowing due to air resistance. Or to put
it another way, the rock remains stationary relative to the ground in a lateral direction. That's assuming there's no wind - ie that the
atmosphere is rotating at the same speed as the earth and the tower.
Or am I about to learn something? Is the effect that you are describing
one that only exists because of the earth's atmosphere, or would it also
be true in a vacuum?
Clearly there are a lot of people on this group that <do> understand
weather and isobaric charts and thus probably the Shipping Forecast?
Slightly off line then could I recommend to those with such
understanding a book called 'Attention All Shipping' by Charlie
Connelly. He visits every SF area or at least as near as he can get to
them. Fascinating reading but just slightly tongue in cheek.
But see also my other post where I admit that I've always called the
Coriolis effect is actually classed as a fictitious force, I'd just
never heard it called that before.
Andy Burns wrote:
the BBC weather app forecasts in 1 hour slots for 14
days ahead, which strikes me as an utterly pointless level of detail.
I find that very handy.
On 10:37 21 Feb 2022, Jeff Layman said:
On 21/02/2022 08:57, Mike Cooper wrote:
This is good
https://www.met.ie/forecasts/atlantic-charts/precipitation-pressure
On Wednesday, 7 February 2018 at 10:32:21 UTC, Ian Jackson wrote:
The BBC have introduced a new, improved style of presenting the
weather.
On their website, there no longer appears to be a proper 'Jack
Scott' weather map (Surface Pressure Chart), as per
<https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=
surfa cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel
that nobody was interested?
If you're interested in just about every aspect of what the weather
is doing anywhere in the world, then the best website I've found is
https://earth.nullschool.net/. This url centres on the UK:
<https://earth.nullschool.net/#2022/02/21/2000Z/wind/isobaric/1000hPa/
orthographic=-6.04,53.98,3226>
If you click on "earth" at bottom left, you can change the parameters
of what you're looking at. It's worth a play, but you may find
yourself spending rather a lot of time on the site!
Lovely graphics. No forecast?
On 21/02/2022 16:04, NY wrote:
"Java Jive" <java@evij.com.invalid> wrote in message
news:sv0cfu$2l5$1@dont-email.me...
(or more strictly still '*a* Coriolis effect' because there are others,
such as dropping a rock from a high enough tower causes it to land
slightly ahead of directly under the point where it was dropped, because >>> initially it was travelling slightly faster through space and therefore
overtakes that point).
Surely the lateral speed of the rock (relative to a stationary observer
out in space) remains the same as the earth's speed, no matter how much
the rock accelerates in a downward direction due to gravity and is
decelerated by speed-dependent slowing due to air resistance. Or to put
it another way, the rock remains stationary relative to the ground in a
lateral direction. That's assuming there's no wind - ie that the
atmosphere is rotating at the same speed as the earth and the tower.
Theoretically, ignoring air-resistance, comparing the linear speeds of the rock and the point on earth's surface directly underneath where it is
dropped from, the rock has a larger radius of spin around the earth's axis
by an amount equal to the height of the tower, therefore when it is
dropped its linear velocity in the direction of earth's spin is slightly faster than the point on earth's surface directly underneath, so it will
land slightly ahead of it.
Well, I've never heard it called that, so my first reaction was to ask myself: "I wonder if he's confusing it with the centrifugal force, which, although it's just an inertial effect, is often called a fictional force, because it has the same units as a real force?"
"Brian Gaff (Sofa)" <briang1@blueyonder.co.uk> wrote in message >news:suvv85$g2$1@dont-email.me...
I wonder if the change in pressures being signified by how close together >> the lines run is actually explained any more? Surely its the simplest of
concepts to grasp that the closer together the more the wind blows as high >> pressure is always trying to fill low.
It's not entirely intuitive, the same as for contour lines on a map, but I'd >expect any children to be taught about contour lines (and probably isobar >lines) at school by the age of about 10.
But I wonder how many children of today have actually looked at an OS map,
as opposed to Google Map or Open Street Map) and have seen (and had
explained to them) contour lines.
Maps such as https://www.windy.com/?52.503,-2.648,6 take a different
approach and show the flow of wind (so their lines are roughly at 90 degrees >to isobar lines) which is easier to interpret in terms of speed and >direction.
The BBC have introduced a new, improved style of presenting the weather.
On their website, there no longer appears to be a proper 'Jack Scott'
weather map (Surface Pressure Chart), as per ><https://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfa >cePressureColour&fcTime=1517918400>
Is it there somewhere, and I can't find it - or do the BBC feel that
nobody was interested?
I was always confused when centrifugal force was described as fictional because it can definitely be felt and demonstrated. If you tie a weight
to a piece of string and whirl it round your head, you can feel a force acting outwards on your hand.
In article <sv1413$tcq$1@dont-email.me>, NY <me@privacy.invalid> wrote:
I was always confused when centrifugal force was described as fictional because it can definitely be felt and demonstrated. If you tie a weight
to a piece of string and whirl it round your head, you can feel a force acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself - travel in
a straight line. The force *you* apply via the string makes it go round in
a circle. Stop applying that force are it will no longer circle you.
Jim
Jim Lesurf <noise@audiomisc.co.uk> wrote:
In article <sv1413$tcq$1@dont-email.me>, NY <me@privacy.invalid> wrote:
I was always confused when centrifugal force was described as fictional
because it can definitely be felt and demonstrated. If you tie a weight
to a piece of string and whirl it round your head, you can feel a force
acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself - travel in >> a straight line. The force *you* apply via the string makes it go round in >> a circle. Stop applying that force are it will no longer circle you.
Jim
<https://www.physicsclassroom.com/class/newtlaws/Lesson-4/Newton-s-Third-Law>
Newton's Third Law
"For every action, there is an equal and opposite reaction."
"The statement means that in every interaction, there is a pair of
forces acting on the two interacting objects. The size of the forces on
the first object equals the size of the force on the second object. The
direction of the force on the first object is opposite to the direction
of the force on the second object. Forces always come in pairs - equal
and opposite action-reaction force pairs."
Q: If centripetal force is real, what is its Third Law counterpart?
Is it real?
On 22/02/2022 14:42, Sn!pe wrote:
Jim Lesurf <noise@audiomisc.co.uk> wrote:
In article <sv1413$tcq$1@dont-email.me>, NY <me@privacy.invalid> wrote: >>> I was always confused when centrifugal force was described as fictional >>> because it can definitely be felt and demonstrated. If you tie a weight >>> to a piece of string and whirl it round your head, you can feel a force >>> acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself - travel in
a straight line. The force *you* apply via the string makes it go round in >> a circle. Stop applying that force are it will no longer circle you.
Jim
<https://www.physicsclassroom.com/class/newtlaws/Lesson-4/Newton-s-Third-Law>
Newton's Third Law
"For every action, there is an equal and opposite reaction."
"The statement means that in every interaction, there is a pair of
forces acting on the two interacting objects. The size of the forces on
the first object equals the size of the force on the second object. The
direction of the force on the first object is opposite to the direction
of the force on the second object. Forces always come in pairs - equal
and opposite action-reaction force pairs."
Q: If centripetal force is real, what is its Third Law counterpart?
Is it real?
When you whirl the string around there are 2 forces*. One is the string pulling the object. The other is the string pulling you. They are
equal and opposite.
*from the tension in the string.
Let's leave aside gravity, air resistance, interaction of damp string with the earth's magnetic field, the effects of last night's curry, ...
Robin <rbw@outlook.com> wrote:
On 22/02/2022 14:42, Sn!pe wrote:
Jim Lesurf <noise@audiomisc.co.uk> wrote:
In article <sv1413$tcq$1@dont-email.me>, NY <me@privacy.invalid> wrote: >>>>> I was always confused when centrifugal force was described as fictional >>>>> because it can definitely be felt and demonstrated. If you tie a weight >>>>> to a piece of string and whirl it round your head, you can feel a force >>>>> acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself - travel in
a straight line. The force *you* apply via the string makes it go round in >>>> a circle. Stop applying that force are it will no longer circle you.
Jim
<https://www.physicsclassroom.com/class/newtlaws/Lesson-4/Newton-s-Third-Law>
Newton's Third Law
"For every action, there is an equal and opposite reaction."
"The statement means that in every interaction, there is a pair of
forces acting on the two interacting objects. The size of the forces on >>> the first object equals the size of the force on the second object. The >>> direction of the force on the first object is opposite to the direction >>> of the force on the second object. Forces always come in pairs - equal >>> and opposite action-reaction force pairs."
Q: If centripetal force is real, what is its Third Law counterpart?
Is it real?
When you whirl the string around there are 2 forces*. One is the string
pulling the object. The other is the string pulling you. They are
equal and opposite.
*from the tension in the string.
Therefore 'Centrifugal Force' is real, not imaginary. QED
On 22/02/2022 16:41, Sn!pe wrote:
Robin <rbw@outlook.com> wrote:
On 22/02/2022 14:42, Sn!pe wrote:
Jim Lesurf <noise@audiomisc.co.uk> wrote:
In article <sv1413$tcq$1@dont-email.me>, NY <me@privacy.invalid> wrote: >>>>> I was always confused when centrifugal force was described as fictional >>>>> because it can definitely be felt and demonstrated. If you tie a weight >>>>> to a piece of string and whirl it round your head, you can feel a force >>>>> acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself -
travel in a straight line. The force *you* apply via the string makes >>>> it go round in a circle. Stop applying that force are it will no
longer circle you.
Jim
<https://www.physicsclassroom.com/class/newtlaws/Lesson-4/Newton-s-Third-Law>
Newton's Third Law
"For every action, there is an equal and opposite reaction."
"The statement means that in every interaction, there is a pair of
forces acting on the two interacting objects. The size of the forces on
the first object equals the size of the force on the second object. The
direction of the force on the first object is opposite to the direction
of the force on the second object. Forces always come in pairs - equal >>> and opposite action-reaction force pairs."
Q: If centripetal force is real, what is its Third Law counterpart?
Is it real?
When you whirl the string around there are 2 forces*. One is the string >> pulling the object. The other is the string pulling you. They are
equal and opposite.
*from the tension in the string.
Therefore 'Centrifugal Force' is real, not imaginary. QED
Neither of the 2 forces above is the mythical "centrifugal force".
See the site you quoted above:
<https://www.physicsclassroom.com/class/circles/Lesson-1/The-Forbidden-F-Word>
So what, then, is the force experienced by a finger
whirling a weighty object around on a string? The force is
undeniably transmitted by the string, but what is its name?
On 22/02/2022 17:06, Sn!pe wrote:
So what, then, is the force experienced by a finger
whirling a weighty object around on a string? The force is
undeniably transmitted by the string, but what is its name?
How about "the force on your finger that's keeping the weighty object whirling around on a string rather than flying off in a straight line at
a tangent"?
Robin <rbw@outlook.com> wrote:
On 22/02/2022 17:06, Sn!pe wrote:
So what, then, is the force experienced by a finger
whirling a weighty object around on a string? The force is
undeniably transmitted by the string, but what is its name?
How about "the force on your finger that's keeping the weighty object
whirling around on a string rather than flying off in a straight line at
a tangent"?
If we set our minds to it I'm sure we could think of something
better than that. How about "centrifugal force"?
In article <sv1413$tcq$1@dont-email.me>, NY <me@privacy.invalid> wrote:
I was always confused when centrifugal force was described as fictional
because it can definitely be felt and demonstrated. If you tie a weight
to a piece of string and whirl it round your head, you can feel a force
acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself - travel
in
a straight line. The force *you* apply via the string makes it go round in
a circle. Stop applying that force are it will no longer circle you.
On 22/02/2022 18:21, Sn!pe wrote:
Robin <rbw@outlook.com> wrote:
On 22/02/2022 17:06, Sn!pe wrote:
So what, then, is the force experienced by a finger
whirling a weighty object around on a string? The force is
undeniably transmitted by the string, but what is its name?
How about "the force on your finger that's keeping the weighty object
whirling around on a string rather than flying off in a straight line at >>> a tangent"?
If we set our minds to it I'm sure we could think of something
better than that. How about "centrifugal force"?
I've already told you the "centrifugal force" ain't real. I don't think I
can help you further.
On 22/02/2022 18:21, Sn!pe wrote:
Robin <rbw@outlook.com> wrote:
On 22/02/2022 17:06, Sn!pe wrote:
So what, then, is the force experienced by a finger
whirling a weighty object around on a string? The force is
undeniably transmitted by the string, but what is its name?
How about "the force on your finger that's keeping the weighty object
whirling around on a string rather than flying off in a straight line at >> a tangent"?
If we set our minds to it I'm sure we could think of something
better than that. How about "centrifugal force"?
I've already told you the "centrifugal force" ain't real. I don't think
I can help you further.
You can *say* that it isn't real, but everyday experience would disagree
with you. Just because someone says that black is really white doesn't automatically make it so.
"Jim Lesurf" <noise@audiomisc.co.uk> wrote in message news:59beb0d629noise@audiomisc.co.uk...
In article <sv1413$tcq$1@dont-email.me>, NY <me@privacy.invalid> wrote:
I was always confused when centrifugal force was described as fictional
because it can definitely be felt and demonstrated. If you tie a weight
to a piece of string and whirl it round your head, you can feel a force
acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself - travel
in
a straight line. The force *you* apply via the string makes it go round in >> a circle. Stop applying that force are it will no longer circle you.
Sure. And what name to you give to the outward (away from the centre) force that I experience while swinging the stone around my head, or the one which causes a light rotating weight to lift up a heavier one on the other end of the string? Physics needs to acknowledge these, rather than trying to
pretend they don't exist.
"Jim Lesurf" <noise@audiomisc.co.uk> wrote in message >news:59beb0d629noise@audiomisc.co.uk...
In article <sv1413$tcq$1@dont-email.me>, NY <me@privacy.invalid> wrote:
I was always confused when centrifugal force was described as fictional
because it can definitely be felt and demonstrated. If you tie a weight
to a piece of string and whirl it round your head, you can feel a force
acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself - travel
in
a straight line. The force *you* apply via the string makes it go round in >> a circle. Stop applying that force are it will no longer circle you.
Sure. And what name to you give to the outward (away from the centre) force >that I experience while swinging the stone around my head, or the one which >causes a light rotating weight to lift up a heavier one on the other end of >the string? Physics needs to acknowledge these, rather than trying to
pretend they don't exist.
If we set our minds to it I'm sure we could think of something
better than that. How about "centrifugal force"?
I've already told you the "centrifugal force" ain't real. I don't think
I can help you further.
Newton's Third Law
"For every action, there is an equal and opposite reaction."
"The statement means that in every interaction, there is a pair of
forces acting on the two interacting objects. The size of the forces on
the first object equals the size of the force on the second object. The
direction of the force on the first object is opposite to the direction
of the force on the second object. Forces always come in pairs - equal
and opposite action-reaction force pairs."
Q: If centripetal force is real, what is its Third Law counterpart? Is
it real?
On 22/02/2022 22:13, NY wrote:
"Jim Lesurf"<noise@audiomisc.co.uk> wrote in message
news:59beb0d629noise@audiomisc.co.uk...
In article<sv1413$tcq$1@dont-email.me>, NY<me@privacy.invalid> wrote:
I was always confused when centrifugal force was described as fictional >>>> because it can definitely be felt and demonstrated. If you tie a weight >>>> to a piece of string and whirl it round your head, you can feel a force >>>> acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself - travel >>> in
a straight line. The force *you* apply via the string makes it go round in >>> a circle. Stop applying that force are it will no longer circle you.
Sure. And what name to you give to the outward (away from the centre) force >> that I experience while swinging the stone around my head, or the one which >> causes a light rotating weight to lift up a heavier one on the other end of >> the string? Physics needs to acknowledge these, rather than trying to
pretend they don't exist.
Perhaps it'll turn out to be something like Laithwaite's examination of gyroscopes.
"Robin" <rbw@outlook.com> wrote in message news:7dc991c1-c662-483b-ff15-c208d9af361b@outlook.com...
On 22/02/2022 18:21, Sn!pe wrote:
If we set our minds to it I'm sure we could think of something
better than that. How about "centrifugal force"?
I've already told you the "centrifugal force" ain't real. I don't
think I can help you further.
You can *say* that it isn't real, but everyday experience would disagree
with you. Just because someone says that black is really white doesn't automatically make it so.
On 22/02/2022 22:16, NY wrote:
"Robin" <rbw@outlook.com> wrote in message
news:7dc991c1-c662-483b-ff15-c208d9af361b@outlook.com...
On 22/02/2022 18:21, Sn!pe wrote:
If we set our minds to it I'm sure we could think of something
better than that. How about "centrifugal force"?
I've already told you the "centrifugal force" ain't real. I don't
think I can help you further.
You can *say* that it isn't real, but everyday experience would disagree
with you. Just because someone says that black is really white doesn't
automatically make it so.
What about suction? A vacuum doesn't suck. A vacuum isn't anything, so
how can it suck?
Things *seem* to be hard, though, in fact, they are made of atoms which
are mostly empty space. They seem to be hard due to the electrostatic repulsion between their electron fields.
On 23/02/2022 08:27, Jeff Layman wrote:
On 22/02/2022 22:13, NY wrote:
"Jim Lesurf"<noise@audiomisc.co.uk> wrote in message
news:59beb0d629noise@audiomisc.co.uk...
In article<sv1413$tcq$1@dont-email.me>, NY<me@privacy.invalid> wrote: >>>>> I was always confused when centrifugal force was described as fictional >>>>> because it can definitely be felt and demonstrated. If you tie a weight >>>>> to a piece of string and whirl it round your head, you can feel a force >>>>> acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself - travel >>>> in
a straight line. The force *you* apply via the string makes it go round in >>>> a circle. Stop applying that force are it will no longer circle you.
Sure. And what name to you give to the outward (away from the centre) force >>> that I experience while swinging the stone around my head, or the one which >>> causes a light rotating weight to lift up a heavier one on the other end of >>> the string? Physics needs to acknowledge these, rather than trying to
pretend they don't exist.
Perhaps it'll turn out to be something like Laithwaite's examination of
gyroscopes.
It took me a while to find this, but here it is for anyone interested. https://www.rigb.org/explore-science/explore/video/engineer-through-looking-glass-jabberwock-1974
On 22/02/2022 22:16, NY wrote:
<grin>
You can *say* that it isn't real, but everyday experience would disagree
with you. Just because someone says that black is really white doesn't
automatically make it so.
It depends on the dictionary.
One synonym of Black is Dark
One synonym of Dark is Dim
One synonym of Dim is Pale
One synonym of Pale is Light
One synonym of Light is Bright
One synonym of Bright is White
QEDÂ :-)
Jim
On 23/02/2022 08:27, Jeff Layman wrote:
On 22/02/2022 22:13, NY wrote:
"Jim Lesurf"<noise@audiomisc.co.uk>Â wrote in message
news:59beb0d629noise@audiomisc.co.uk...
In article<sv1413$tcq$1@dont-email.me>, NY<me@privacy.invalid>Â wrote: >>>>> I was always confused when centrifugal force was described as
fictional
because it can definitely be felt and demonstrated. If you tie a
weight
to a piece of string and whirl it round your head, you can feel a
force
acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself -
travel
in
a straight line. The force *you* apply via the string makes it go
round in
a circle. Stop applying that force are it will no longer circle you.
Sure. And what name to you give to the outward (away from the centre)
force
that I experience while swinging the stone around my head, or the one
which
causes a light rotating weight to lift up a heavier one on the other
end of
the string? Physics needs to acknowledge these, rather than trying to
pretend they don't exist.
Perhaps it'll turn out to -be something like Laithwaite's examination of
gyroscopes.
It took me a while to find this, but here it is for anyone interested. https://www.rigb.org/explore-science/explore/video/engineer-through-looking-glass-jabberwock-1974
On Tue, 22 Feb 2022 20:08:17 +0000, Robin <rbw@outlook.com> wrote:
If we set our minds to it I'm sure we could think of something
better than that. How about "centrifugal force"?
I've already told you the "centrifugal force" ain't real. I don't think
I can help you further.
What about "centrifugal reaction"? The centripetal force, whether
we're talking about interplanetary gravity or string, is a real force
applied at right angles to the straight line the object would follow
if it was left alone. The object's inertial reluctance to follow the
force is a reaction to it that feels like an outward force to whoever
or whatever is actually applying the inward one.
The fact that the force is at right angles to the direction of travel
of the object and thus neither speeding it up nor slowing it down
means that no energy is being added or subtracted because no mass is
being moved in the direction of any force, which is why in the absence
of any other forces the rotation could continue forever.
It's not rocket science...
On 23/02/2022 12:04, Indy Jess John wrote:
On 23/02/2022 08:27, Jeff Layman wrote:
On 22/02/2022 22:13, NY wrote:
"Jim Lesurf"<noise@audiomisc.co.uk> wrote in message
news:59beb0d629noise@audiomisc.co.uk...
In article<sv1413$tcq$1@dont-email.me>, NY<me@privacy.invalid> wrote: >>>>>> I was always confused when centrifugal force was described as
fictional
because it can definitely be felt and demonstrated. If you tie a
weight
to a piece of string and whirl it round your head, you can feel a
force
acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself -
travel
in
a straight line. The force *you* apply via the string makes it go
round in
a circle. Stop applying that force are it will no longer circle you.
Sure. And what name to you give to the outward (away from the centre)
force
that I experience while swinging the stone around my head, or the one
which
causes a light rotating weight to lift up a heavier one on the other
end of
the string? Physics needs to acknowledge these, rather than trying to
pretend they don't exist.
Perhaps it'll turn out to -be something like Laithwaite's examination of >>> gyroscopes.
It took me a while to find this, but here it is for anyone interested.
https://www.rigb.org/explore-science/explore/video/engineer-through-looking-glass-jabberwock-1974
I was still at university at the time of his infamous Christmas lecture
and remember well the outrage (tinged with pity for the death of his
academic reputation). He ignored the way calculations using no more than Newton's laws explained the way the gyroscopes behaved. Apparently just didn't want to believe those who could do the sums.
Science is supposed to welcome challenges to established beliefs, yet the Royal Institution took the unprecedented decision of banning the TV
broadcast of that set of Christmas Lectures without even considering the ideas put forward.
On 23/02/2022 14:01, Robin wrote:
On 23/02/2022 12:04, Indy Jess John wrote:Given that Einstein showed that Newton's Laws didn't cover all possible circumstances, it was a bit unfair to pillory Laithwaite for suggesting
On 23/02/2022 08:27, Jeff Layman wrote:
On 22/02/2022 22:13, NY wrote:
"Jim Lesurf"<noise@audiomisc.co.uk>Â Â wrote in message
news:59beb0d629noise@audiomisc.co.uk...
In article<sv1413$tcq$1@dont-email.me>, NY<me@privacy.invalid>Sure. And what name to you give to the outward (away from the centre) >>>>> force
wrote:
I was always confused when centrifugal force was described as
fictional
because it can definitely be felt and demonstrated. If you tie a >>>>>>> weight
to a piece of string and whirl it round your head, you can feel a >>>>>>> force
acting outwards on your hand.
Newton's Laws state that a moving item will - if left to itself -
travel
in
a straight line. The force *you* apply via the string makes it go
round in
a circle. Stop applying that force are it will no longer circle you. >>>>>
that I experience while swinging the stone around my head, or the one >>>>> which
causes a light rotating weight to lift up a heavier one on the other >>>>> end of
the string? Physics needs to acknowledge these, rather than trying to >>>>> pretend they don't exist.
Perhaps it'll turn out to -be something like Laithwaite's
examination of
gyroscopes.
It took me a while to find this, but here it is for anyone interested.
https://www.rigb.org/explore-science/explore/video/engineer-through-looking-glass-jabberwock-1974
I was still at university at the time of his infamous Christmas lecture
and remember well the outrage (tinged with pity for the death of his
academic reputation). He ignored the way calculations using no more than
Newton's laws explained the way the gyroscopes behaved. Apparently just
didn't want to believe those who could do the sums.
the same thing.
Science is supposed to welcome challenges to established beliefs, yet
the Royal Institution took the unprecedented decision of banning the TV broadcast of that set of Christmas Lectures without even considering the ideas put forward.
On 23/02/2022 11:40, Max Demian wrote:
Things *seem* to be hard, though, in fact, they are made of atoms which
are mostly empty space. They seem to be hard due to the electrostatic
repulsion between their electron fields.
OT, really, but perhaps you know something about this area. I've often wondered about the physical characteristics of elements - their hardness
(in the solid state. How hard is solid Oxygen?!), their MP and BP, and
their density. Exactly what determines these, and can physics predict
what these values of an element would be?
"Roderick Stewart" <rjfs@escapetime.myzen.co.uk> wrote in message news:5ovb1h1ihspn90lh3ak555tieakat8mlnc@4ax.com...
On Tue, 22 Feb 2022 20:08:17 +0000, Robin <rbw@outlook.com> wrote:
I've already told you the "centrifugal force" ain't real. I don't think
I can help you further.
If you work in a chemistry lab, you may want to separate a solid
precipitate from a liquid in which it is is suspended. You do this by
placing a test tube of it in a device like a small spin-drier which
rotates it at very high speed so the bottom of the test tube spins
outwards while the neck of the tube is held in place in the rotating mechanism. A force causes the precipitate to gather at the bottom of the tube.
This device is called a centrifuge. Is it a misnomer? Should it be
called a centripete? Did early scientists make a mistake with their
physics when they were naming the device?
On 22/02/2022 22:16, NY wrote:
You can *say* that it isn't real, but everyday experience would disagree<grin>
with you. Just because someone says that black is really white doesn't
automatically make it so.
It depends on the dictionary.
One synonym of Black is Dark
One synonym of Dark is Dim
One synonym of Dim is Pale
One synonym of Pale is Light
One synonym of Light is Bright
One synonym of Bright is White
QEDÂ :-)
Jim
On 23/02/2022 12:50, Jeff Layman wrote:
On 23/02/2022 11:40, Max Demian wrote:
Things *seem* to be hard, though, in fact, they are made of atoms which
are mostly empty space. They seem to be hard due to the electrostatic
repulsion between their electron fields.
OT, really, but perhaps you know something about this area. I've often
wondered about the physical characteristics of elements - their hardness
(in the solid state. How hard is solid Oxygen?!), their MP and BP, and
their density. Exactly what determines these, and can physics predict
what these values of an element would be?
I'm not by any means an expert (!), but maybe liquid and gas forms of
atoms are just as hard as solids, but the molecules dodge about a lot!
I don't think that physics (actually physical chemistry) can accurately predict the properties of the elements, so chemists roughly predict them
from their position in the Periodic Table, and relation to other elements.
If you work in a chemistry lab, you may want to separate a solid precipitate >from a liquid in which it is is suspended. You do this by placing a test
tube of it in a device like a small spin-drier which rotates it at very high >speed so the bottom of the test tube spins outwards while the neck of the >tube is held in place in the rotating mechanism. A force causes the >precipitate to gather at the bottom of the tube.
This device is called a centrifuge. Is it a misnomer? Should it be called a >centripete? Did early scientists make a mistake with their physics when they >were naming the device?
There is only that one force, gravity, towards
the earth.
Maybe they did. It wouldn't be the first time. They got electric
current the wrong way round after all, and by the time the truth was discovered it was too late to rewrite all the textbooks.
There are lots of things that are or were called the wrong things, and sometimes changed later in an attempt to reduce confusion, sometimes successfully and sometimes just causing more. For example, "superhet" circuitry is from "supersonic heterodyne" because supersonic used to
mean having a higher frequency than we can hear. Then there's the "drop-frame" method of recording TV signals on film, though it
actually drops fields, because the meanings of those words has
changed, and then there's the requirement to buy a licence to watch
"live" television, which usually isn't live at all in the sense that
I've always understood it. I'm sure you csn think of more examples.
Rod.
Did they? I thought I'd seen Laithwaite expounding his theories on gyroscopes. The RI was very wrong if it censored him by banning the
broadcast after it had been recorded.
On 23/02/2022 16:13, NY wrote:
Did they? I thought I'd seen Laithwaite expounding his theories on
gyroscopes. The RI was very wrong if it censored him by banning the
broadcast after it had been recorded.
One of the things I found while hunting for the gyroscope lecture said
that the lectures were not broadcast *at the scheduled time*, but there
was no mention of when it was actually broadcast. You probably saw it
when it was broadcast later.
On 23/02/2022 16:13, NY wrote:
Did they? I thought I'd seen Laithwaite expounding his theories on
gyroscopes. The RI was very wrong if it censored him by banning the
broadcast after it had been recorded.
One of the things I found while hunting for the gyroscope lecture said
that the lectures were not broadcast *at the scheduled time*, but there
was no mention of when it was actually broadcast. You probably saw it
when it was broadcast later.
I can't comment on that at first hand because in the 1970s I was in a
flat with no TV.
https://www.rigb.org/explore-science/explore/video/engineer-through-looking-glass-jabberwock-1974
I'll have a look at that later. Oddly enough, Ref 4 on the Wiki page
about Laithwaite is for that lecture, but leads to a "not found" at the
RIGB website. However, search for "looking glass" on that page, and it
turns up that, and the other Christmas lectures, by Laithwaite.
The Wiki page notes that "Laithwaite later acknowledged that gyroscopes behave fully in accord with Newtonian mechanics". It adds, however, "To
this very day, research is conducted to account for the physics behind gyroscopic effects, directly pointing to Laithwaite's work as
motivation." See <https://iopscience.iop.org/article/10.1088/1361-6404/abce88/meta>.
In article<sv5a8u$pne$1@dont-email.me>, Jeff Layman <jmlayman@invalid.invalid> wrote:
https://www.rigb.org/explore-science/explore/video/engineer-through-looking-glass-jabberwock-1974
I'll have a look at that later. Oddly enough, Ref 4 on the Wiki page
about Laithwaite is for that lecture, but leads to a "not found" at the
RIGB website. However, search for "looking glass" on that page, and it
turns up that, and the other Christmas lectures, by Laithwaite.
The page shows here on a lite browser some black rectangles where video access might be expected and a message saying I have been "banned permanently! With an link to 'vimeo'. Who I've never used so far as I know. Weird! Maybe yt-dlp can make sense of it?
It gets even more confusing when isotopes are considered - hydrogen, deuterium, and tritium, have a different MP and BP. I'd be interested to
know if any physicists have ever considered looking at physical
properties of elements in respect of their atomic structure and bonding
(I very much doubt it!).
But I did copy the Abstract to paste into this message: ABSTRACT The
forced precession of a symmetrical gyroscope is studied for the
particular case in which the axle of a flywheel is pivoted by a hinge
joint and follows a horizontal circular path of a given radius. The aforementioned setup appears in the so-called Laithwaite engine, the
detailed mechanics of which are still an enigma. Instead of applying Lagrangian equations, Newton's second law is applied to the rotating gyroscope with respect to its center of mass. Three novel Euler
equations are developed that are much longer than those found in
textbooks. In this mechanical system, which is characterized by one
degree of freedom, the main nonlinear governing equation is identified
and then MATLAB code is developed to obtain and visualize the numerical solution. Under particular conditions that ensure small oscillations of
the gyroscope's axle (a maximum oscillation of eight degrees in the lean angle) near the horizontal plane through the pivot, a linearization is performed and is successfully compared with the aforementioned nonlinear numerical solution. The computer program facilitates the understanding
and calculation of physical quantities such as the internal forces and moments, support forces and power transmission from the drive motor. In particular, it is shown that, for a hinge joint, the period of
oscillation differs from that of a rotating pivot, which is crucial to
the debate about whether such an engine may produce a net thrust, or
not. A relevant paradox is resolved.
Yours, for what it is worth.
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