HOW TOROIDAL PROPELLERS COULD IMPACT AERIAL + MARINE SECTORS...

[Fred Bloggs]

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.

 

[Carlos E.R.]

On 2023-01-28 13:50, Fred Bloggs wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

Interestingly, they don\'t show the claimed silence of the boat, but a
loud useless music instead.

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.

--
Cheers, Carlos.

 

[Anthony William Sloman]

On Saturday, January 28, 2023 at 11:50:32 PM UTC+11, Fred Bloggs wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

<snip>

There\'s always a vortex generated at a wing-tip. A toroidal blade doesn\'t actually have a tip have a tip so the idea looks plausible.

The publicity stuff doesn\'t show the stream line around the blades, which is a bit disappointing.

--
Bill Sloman, Sydney

 

[Fred Bloggs]

On Saturday, January 28, 2023 at 8:15:39 AM UTC-5, Carlos E.R. wrote:

On 2023-01-28 13:50, Fred Bloggs wrote:
This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/
Interestingly, they don\'t show the claimed silence of the boat, but a
loud useless music instead.

Scroll down further to the video of the triple outboard motor speedboat. It\'s impressive. If you look for the story on the Lincoln Labs site, they have some noise spectrum graphs.

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.
--
Cheers, Carlos.

 

[John Larkin]

On Sat, 28 Jan 2023 04:50:28 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.

Why is modern architecture so ugly?

We were walking around our neighborhood. The old houses are colorful,
graceful, rounded, decorated, human friendly. The new stuff is stark,
unfinished angular concrete slabs, grey, featureless boxes, repulsive.

No modern architect in 1000 around here dares design anything
beautiful or fun. And people buy and live in those monsters.

Designboom. We should blow it up.

 

[Fred Bloggs]

On Saturday, January 28, 2023 at 11:09:29 AM UTC-5, John Larkin wrote:

On Sat, 28 Jan 2023 04:50:28 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.
Why is modern architecture so ugly?

We were walking around our neighborhood. The old houses are colorful,
graceful, rounded, decorated, human friendly. The new stuff is stark,
unfinished angular concrete slabs, grey, featureless boxes, repulsive.

No modern architect in 1000 around here dares design anything
beautiful or fun. And people buy and live in those monsters.

Designboom. We should blow it up.

Blow this one up:

https://www.flickr.com/photos/universalpops/5651089045/in/photostream/

It was the architect\'s (??? he was not a formally educated architect IIRC) first and 2nd to last commission, which is no surprise. Inspired by a baked potato wrapped in foil- that\'s a deep one.

 

[Joe Gwinn]

On Sat, 28 Jan 2023 14:13:59 +0100, \"Carlos E.R.\"
<robin_listas@es.invalid> wrote:

On 2023-01-28 13:50, Fred Bloggs wrote:
This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

Interestingly, they don\'t show the claimed silence of the boat, but a
loud useless music instead.

Look farther down - there is a direct-comparison motorboat video, and
the difference is apparent. I would guess that the hum tone of
standard motorboat props is the blade-passing frequency. The prop RPM
is not specified that I saw. It will be a fraction of that of the
motor, which will be maybe 5000 rpm.

Also look at the bottom, to the video about toroidal drone aircraft
props. This explains where the idea came from. The part about tip
vortices implies that the hum is indeed the blade-passing frequency.

Joe Gwinn

 

[John Larkin]

On Sat, 28 Jan 2023 08:36:05 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

On Saturday, January 28, 2023 at 11:09:29 AM UTC-5, John Larkin wrote:
On Sat, 28 Jan 2023 04:50:28 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.
Why is modern architecture so ugly?

We were walking around our neighborhood. The old houses are colorful,
graceful, rounded, decorated, human friendly. The new stuff is stark,
unfinished angular concrete slabs, grey, featureless boxes, repulsive.

No modern architect in 1000 around here dares design anything
beautiful or fun. And people buy and live in those monsters.

Designboom. We should blow it up.

Blow this one up:

https://www.flickr.com/photos/universalpops/5651089045/in/photostream/

It was the architect\'s (??? he was not a formally educated architect IIRC) first and 2nd to last commission, which is no surprise. Inspired by a baked potato wrapped in foil- that\'s a deep one.

Tribalism suppresses thinking and inventing almost every time. People
are too social for the modern world. Peoples ability to think is
inverse on the number of eyeballs that are, or that they imagine, are
aimed at them.

I just re-read this wonderfully written and horrifying book

https://www.amazon.com/Guns-Last-Light-1944-1945-Liberation/dp/1250037816

It\'s astounding how savage the Germans were because they believed
Hitler and their peers and hated non-German speakers. Putin is very
much like Hitler.

 

[Fred Bloggs]

On Saturday, January 28, 2023 at 12:10:14 PM UTC-5, John Larkin wrote:

On Sat, 28 Jan 2023 08:36:05 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

On Saturday, January 28, 2023 at 11:09:29 AM UTC-5, John Larkin wrote:
On Sat, 28 Jan 2023 04:50:28 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.
Why is modern architecture so ugly?

We were walking around our neighborhood. The old houses are colorful,
graceful, rounded, decorated, human friendly. The new stuff is stark,
unfinished angular concrete slabs, grey, featureless boxes, repulsive.

No modern architect in 1000 around here dares design anything
beautiful or fun. And people buy and live in those monsters.

Designboom. We should blow it up.

Blow this one up:

https://www.flickr.com/photos/universalpops/5651089045/in/photostream/

It was the architect\'s (??? he was not a formally educated architect IIRC) first and 2nd to last commission, which is no surprise. Inspired by a baked potato wrapped in foil- that\'s a deep one.

Tribalism suppresses thinking and inventing almost every time. People
are too social for the modern world. Peoples ability to think is
inverse on the number of eyeballs that are, or that they imagine, are
aimed at them.

I just re-read this wonderfully written and horrifying book

https://www.amazon.com/Guns-Last-Light-1944-1945-Liberation/dp/1250037816

It\'s astounding how savage the Germans were because they believed
Hitler and their peers and hated non-German speakers. Putin is very
much like Hitler.

I find some of that impossible to believe. Berlin in particular was probably the most cosmopolitan city in Europe, people came from all over Europe to do business in Berlin. The city was huge in geographical extent as well as population. This was all prior to the fascism fiasco.

 

[John Larkin]

On Sat, 28 Jan 2023 09:59:19 -0800 (PST), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

On Saturday, January 28, 2023 at 12:10:14 PM UTC-5, John Larkin wrote:
On Sat, 28 Jan 2023 08:36:05 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

On Saturday, January 28, 2023 at 11:09:29 AM UTC-5, John Larkin wrote:
On Sat, 28 Jan 2023 04:50:28 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.
Why is modern architecture so ugly?

We were walking around our neighborhood. The old houses are colorful,
graceful, rounded, decorated, human friendly. The new stuff is stark,
unfinished angular concrete slabs, grey, featureless boxes, repulsive.

No modern architect in 1000 around here dares design anything
beautiful or fun. And people buy and live in those monsters.

Designboom. We should blow it up.

Blow this one up:

https://www.flickr.com/photos/universalpops/5651089045/in/photostream/

It was the architect\'s (??? he was not a formally educated architect IIRC) first and 2nd to last commission, which is no surprise. Inspired by a baked potato wrapped in foil- that\'s a deep one.

Tribalism suppresses thinking and inventing almost every time. People
are too social for the modern world. Peoples ability to think is
inverse on the number of eyeballs that are, or that they imagine, are
aimed at them.

I just re-read this wonderfully written and horrifying book

https://www.amazon.com/Guns-Last-Light-1944-1945-Liberation/dp/1250037816

It\'s astounding how savage the Germans were because they believed
Hitler and their peers and hated non-German speakers. Putin is very
much like Hitler.

I find some of that impossible to believe. Berlin in particular was probably the most cosmopolitan city in Europe, people came from all over Europe to do business in Berlin. The city was huge in geographical extent as well as population. This was all prior to the fascism fiasco.

Do you believe this?

https://en.wikipedia.org/wiki/Holocaust_victims

 

[Fred Bloggs]

On Saturday, January 28, 2023 at 1:13:42 PM UTC-5, John Larkin wrote:

On Sat, 28 Jan 2023 09:59:19 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

On Saturday, January 28, 2023 at 12:10:14 PM UTC-5, John Larkin wrote:
On Sat, 28 Jan 2023 08:36:05 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

On Saturday, January 28, 2023 at 11:09:29 AM UTC-5, John Larkin wrote:
On Sat, 28 Jan 2023 04:50:28 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.
Why is modern architecture so ugly?

We were walking around our neighborhood. The old houses are colorful,
graceful, rounded, decorated, human friendly. The new stuff is stark,
unfinished angular concrete slabs, grey, featureless boxes, repulsive.

No modern architect in 1000 around here dares design anything
beautiful or fun. And people buy and live in those monsters.

Designboom. We should blow it up.

Blow this one up:

https://www.flickr.com/photos/universalpops/5651089045/in/photostream/

It was the architect\'s (??? he was not a formally educated architect IIRC) first and 2nd to last commission, which is no surprise. Inspired by a baked potato wrapped in foil- that\'s a deep one.

Tribalism suppresses thinking and inventing almost every time. People
are too social for the modern world. Peoples ability to think is
inverse on the number of eyeballs that are, or that they imagine, are
aimed at them.

I just re-read this wonderfully written and horrifying book

https://www.amazon.com/Guns-Last-Light-1944-1945-Liberation/dp/1250037816

It\'s astounding how savage the Germans were because they believed
Hitler and their peers and hated non-German speakers. Putin is very
much like Hitler.

I find some of that impossible to believe. Berlin in particular was probably the most cosmopolitan city in Europe, people came from all over Europe to do business in Berlin. The city was huge in geographical extent as well as population. This was all prior to the fascism fiasco.
Do you believe this?

https://en.wikipedia.org/wiki/Holocaust_victims

That goes back to mass insanity from womb exposure to heavy metal pollution from super-excessive coal burning.

Read some Barbara Tuckman and see if the Swiss don\'t have a worse track record of anti-Semitism than pre-Nazi Germany. https://en.wikipedia.org/wiki/History_of_the_Jews_in_Basel

 

[Carlos E.R.]

On 2023-01-28 18:04, Joe Gwinn wrote:

On Sat, 28 Jan 2023 14:13:59 +0100, \"Carlos E.R.\"
robin_listas@es.invalid> wrote:

On 2023-01-28 13:50, Fred Bloggs wrote:
This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

Interestingly, they don\'t show the claimed silence of the boat, but a
loud useless music instead.

Look farther down - there is a direct-comparison motorboat video, and
the difference is apparent. I would guess that the hum tone of
standard motorboat props is the blade-passing frequency. The prop RPM
is not specified that I saw. It will be a fraction of that of the
motor, which will be maybe 5000 rpm.

Ok, yes, that\'s better. I missed it.

Still, marine life cares about the noise inside the water, and that is
still missing.

Also look at the bottom, to the video about toroidal drone aircraft
props. This explains where the idea came from. The part about tip
vortices implies that the hum is indeed the blade-passing frequency.

Yes, that is interesting.

--
Cheers, Carlos.

 

[RichD]

On Saturday, January 28, 2023 at 5:42:18 AM UTC-8, bill....@ieee.org wrote:

On January 28, Fred Bloggs wrote:
https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

There\'s always a vortex generated at a wing-tip. A toroidal blade doesn\'t
actually have a tip have a tip so the idea looks plausible.

What makes a prop faster than a paddle wheel? The paddle
wheel is a direct application of Newton\'s third law.

Rocketry, you know?

--
Rich

 

[Ricky]

On Saturday, January 28, 2023 at 1:10:14 PM UTC-4, John Larkin wrote:

On Sat, 28 Jan 2023 08:36:05 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

On Saturday, January 28, 2023 at 11:09:29 AM UTC-5, John Larkin wrote:
On Sat, 28 Jan 2023 04:50:28 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.
Why is modern architecture so ugly?

We were walking around our neighborhood. The old houses are colorful,
graceful, rounded, decorated, human friendly. The new stuff is stark,
unfinished angular concrete slabs, grey, featureless boxes, repulsive.

No modern architect in 1000 around here dares design anything
beautiful or fun. And people buy and live in those monsters.

Designboom. We should blow it up.

Blow this one up:

https://www.flickr.com/photos/universalpops/5651089045/in/photostream/

It was the architect\'s (??? he was not a formally educated architect IIRC) first and 2nd to last commission, which is no surprise. Inspired by a baked potato wrapped in foil- that\'s a deep one.

Tribalism suppresses thinking and inventing almost every time. People
are too social for the modern world. Peoples ability to think is
inverse on the number of eyeballs that are, or that they imagine, are
aimed at them.

I just re-read this wonderfully written and horrifying book

https://www.amazon.com/Guns-Last-Light-1944-1945-Liberation/dp/1250037816

It\'s astounding how savage the Germans were because they believed
Hitler and their peers and hated non-German speakers. Putin is very
much like Hitler.

Ironic, that you mention Hitler, but not a more recent example, very much like Hitler. Yes, we are talking about Trmp. Putin has learned from the master.

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Ricky]

On Saturday, January 28, 2023 at 12:09:29 PM UTC-4, John Larkin wrote:

On Sat, 28 Jan 2023 04:50:28 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.
Why is modern architecture so ugly?

We were walking around our neighborhood. The old houses are colorful,
graceful, rounded, decorated, human friendly. The new stuff is stark,
unfinished angular concrete slabs, grey, featureless boxes, repulsive.

No modern architect in 1000 around here dares design anything
beautiful or fun. And people buy and live in those monsters.

Designboom. We should blow it up.

More terrorist talk from the bomb. It\'s one thing to digress a topic, but really? You change from saving wildlife to blowing up buildings?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Anthony William Sloman]

On Sunday, January 29, 2023 at 4:10:14 AM UTC+11, John Larkin wrote:

On Sat, 28 Jan 2023 08:36:05 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

On Saturday, January 28, 2023 at 11:09:29 AM UTC-5, John Larkin wrote:
On Sat, 28 Jan 2023 04:50:28 -0800 (PST), Fred Bloggs
bloggs.fred...@gmail.com> wrote:

This is arriving just in time for the shipping sector. Shipping noise is killing ocean marine life. And for what? So mindless uneducated consumers can buy a bunch of cheap junk from China that all ends up in North American landfills.

https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

IMO is decades behind the times.

https://gcaptain.com/imo-moves-to-curb-shipping-noise-that-threatens-marine-life/

Not really, they don\'t move much at all.
Why is modern architecture so ugly?

We were walking around our neighborhood. The old houses are colorful,
graceful, rounded, decorated, human friendly. The new stuff is stark,
unfinished angular concrete slabs, grey, featureless boxes, repulsive.

No modern architect in 1000 around here dares design anything
beautiful or fun. And people buy and live in those monsters.

Designboom. We should blow it up.

Blow this one up:

https://www.flickr.com/photos/universalpops/5651089045/in/photostream/

It was the architect\'s (??? he was not a formally educated architect IIRC) first and 2nd to last commission, which is no surprise. Inspired by a baked potato wrapped in foil- that\'s a deep one.

Tribalism suppresses thinking and inventing almost every time. People
are too social for the modern world. Peoples ability to think is
inverse on the number of eyeballs that are, or that they imagine, are
aimed at them.

I just re-read this wonderfully written and horrifying book

https://www.amazon.com/Guns-Last-Light-1944-1945-Liberation/dp/1250037816

Of course it is written from the tribal American point of views - the high American casualties are lauded as evidence of the aggression of the American generals, rather than as evidence that they wasted their troops in ill-judged assaults.

> It\'s astounding how savage the Germans were because they believed Hitler and their peers and hated non-German speakers.

They were losing the war. That does make for savage fighting.

> Putin is very much like Hitler.

Putin is nothing like Hitler. For one thing he is much less well-read, and the nationalist nonsense he spouts doesn\'t include any racist twaddle.
For another there\'s nothing in his history about getting support from foreign millionaires comparable withe the financial support Hitler got - early on - from Henry Ford.

--
Bill Sloman, Sydney

 

[Anthony William Sloman]

On Sunday, January 29, 2023 at 12:01:28 PM UTC+11, RichD wrote:

On Saturday, January 28, 2023 at 5:42:18 AM UTC-8, bill....@ieee.org wrote:
On January 28, Fred Bloggs wrote:
https://www.designboom.com/technology/toroidal-propellers-quiet-efficient-alternatives-aerial-marine-sectors-01-27-2023/

There\'s always a vortex generated at a wing-tip. A toroidal blade doesn\'t
actually have a tip have a tip so the idea looks plausible.

What makes a prop faster than a paddle wheel? The paddle
wheel is a direct application of Newton\'s third law.

Rocketry, you know?

A propellor is no less an application of Newton\'s third Law. It just produces fewer unnecessary vortices in the medium it acts on. A toroidal propellor seems to generate even fewer.

A rocket generates force by accelerating (and discarding) its own mass. A propellor generates force by accelerating the mass of the medium in which it is immersed.

You\'d better re-read those first year lectures.

--
Bill Sloman, Sydney