General thread, soon to be reworked into separate threads

[Nilgiri]

 

[Anmdt]

Air-pressure driven engine; he has been working on that for several years. The latest one is a diaphragm based piston.
He might later add a pressure valve to provide steady pressure into the engine, thus providing a longer operation time.

 

[Anmdt]

Solar powered drone.

 

[Nilgiri]

 

[Test7]

Iconic radio telescope suffers catastrophic collapse​

This aerial view shows the damage to the Arecibo Observatory after its 900-ton equipment platform broke loose, swung into a nearby rock face, and smashed onto the radio dish below.

The Arecibo Observatory’s suspended equipment platform fell hundreds of feet and crashed through the giant radio dish.​

The Arecibo Observatory’s suspended equipment platform collapsed just before 8 a.m. local time on December 1, falling more than 450 feet and crashing through the telescope’s massive radio dish—a catastrophic ending that scientists and engineers feared was imminent after multiple cables supporting the platform unexpectedly broke in recent months. No one was hurt when the 900-ton platform lost its battle with gravity, according to staff at the observatory in Puerto Rico.

The telescope itself has been destroyed, although the full extent of the damage to surrounding facilities hasn’t yet been determined. Aerial photos show that the platform likely made a pendulous swing into a nearby rock face. Parts of it, including a large dome housing a complex reflector system, shattered near the dish’s center. Photos from the ground reveal that the tops of the three towers supporting the platform also broke off. People nearby reported that as the platform came down, it sounded like an avalanche, a train, or an earthquake.
“We can confirm the platform fell and that we have reports of no injuries. We will release additional details as they are confirmed,” says Robert Margutta of the National Science Foundation (NSF), which is in charge of the facility.

The iconic telescope has been in a precarious state since August, when an auxiliary cable supporting the equipment platform broke and fell through the radio dish, leaving a 100-foot-long gash in its reflective panels. The situation became more dire in early November, when one of the main cables supporting the equipment platform also snapped, leaving the telescope on the brink of a catastrophic collapse. Inspections revealed that other cables were showing signs of weakening and degradation, and over the last couple of weeks, engineers spotted ruptured strands and other signs of impending danger.
On November 19, NSF announced that it had decided to decommission the telescope and pursue options for a controlled demolition of the dangerous structure. That decision came after engineering firms evaluated the structure and predicted that the platform would collapse in the near future if it were not repaired.
With the risk of imminent collapse, authorities determined that it was too risky to send workers up on the platform or the towers to attempt repairs.

“If we’re worried about it falling, nobody should go up there or be there when it happens,” former observatory director Michael Nolan, now at the University of Arizona, told National Geographic at the time.
“As someone who was inspired as a child by the observatory to reach for the stars, this is devastating and heartbreaking. I’ve seen how the observatory to this day continues to inspire my island,” planetary scientist Edgard Rivera-Valentin of the Lunar and Planetary Institute said at the time. Rivera-Valentin tweeted today that they are "heart broken, sad, in mourning, and crying," following the observatory's collapse.
The NSF’s decision to decommission the telescope didn’t stop scientists and Puerto Ricans, for whom the telescope holds cultural as well as scientific value, to rally in support of the observatory. For decades, the facility has been a source of pride and inspiration for the island, and it has served as a crucial resource for local communities during natural disasters. Now, the crumpled telescope leaves a large, dangerous mess to clean up—and, perhaps, a site upon which to rebuild.

Anne Virkki, who leads the planetary radar team at the observatory, writes in an email: “We’ll need to start campaigning for rebuilding from today.

Arecibo Observatory suffers catastrophic collapse

The Arecibo Observatory’s suspended equipment platform fell hundreds of feet and crashed through the giant radio dish.

www.nationalgeographic.com

 

[Nilgiri]

Proud of my larger company....but it remain to be seen if its enough to take away more market share from GE (who is by far top dog because of 3 crucial things they invested in big time in the 90s that worked out super good for them) in long term:

Pratt & Whitney’s Geared Turbofan Is Poised To Emerge From The Pandemic In Great Shape

The Raytheon Technologies unit has used pandemic downtime to position for breakout commercial success once air travel recovers.

www.forbes.com

Investors have digested that part of the story. But there is another story unfolding behind the scenes that will become visible next year as commercial air travel begins recovering. That is the steady progress Pratt’s Geared Turbofan (GTF) engine is making. While the rest of the commercial aerospace sector was awaiting the end of the pandemic, Pratt & Whitney has utilized the downtime to position GTF for breakout success in the years ahead.

(more at link)

 

[Nilgiri]

I bet @Sinan already watched this heh.

 

[Nilgiri]

Really interesting aircraft for its time:

 

[Nilgiri]

I disagree with him about the folding blades (at the end) , I think its a good idea that can be tested and perfected.

A very good summary nevertheless on this technology's development in recent years.

 

[Bogeyman]

https://twitter.com/i/web/status/1338031097133731841

​

Tiny four-bit computers are now all you need to train AI​

AI can now train on tiny 4-bit computers

Powerful neural networks could soon train on smartphones with dramatically faster speeds and less energy.

www.technologyreview.com

 

[Anmdt]

Spontaneous synchronization:

Physics, never ceases to amaze people

Also physics: I am not stable along this axis so i will just randomly skip along;
Intermediate axis theorem:

Also physics, Your axis is not same as one, i will just rotate along that perpendicular axis and surprise you;
what we mainly owe helicopter maneuvers to: conservation of momentum

 

[Nilgiri]

Spontaneous synchronization:

Physics, never ceases to amaze people

Also physics: I am not stable along this axis so i will just randomly skip along;
Intermediate axis theorem:

Also physics, Your axis is not same as one, i will just rotate along that perpendicular axis and surprise you;
what we mainly owe helicopter maneuvers to: conservation of momentum

None of this surprises me heh....having worked with harmonics and resonances a lot.

The last lecture when he brings up stellar collapse at the end as special poignant point to angular momentum conservation was very well done.

There is of course another branch of physics also playing out here given the vastly higher energy density present at nuclear level that sustains the star for most of its lifetime. There is very small associated mass conversation all things considered compared to the full on harnessing of that mass during the collapse episode.

This also bears some carryover to exactly how neutron stars and blackholes "hold" residual energy from that collapse (that is not emitted during the nova or supernova)...in that their very physics at the nuclear level change drastically to accommodate this compared to what can exist in a more conventional physics model.

 

[Anmdt]

None of this surprises me heh....having worked with harmonics and resonances a lot.

The last lecture when he brings up stellar collapse at the end as special poignant point to angular momentum conservation was very well done.

There is of course another branch of physics also playing out here given the vastly higher energy density present at nuclear level that sustains the star for most of its lifetime. There is very small associated mass conversation all things considered compared to the full on harnessing of that mass during the collapse episode.

This also bears some carryover to exactly how neutron stars and blackholes "hold" residual energy from that collapse (that is not emitted during the nova or supernova)...in that their very physics at the nuclear level change drastically to accommodate this compared to what can exist in a more conventional physics model.

I knew the third one and applied that, not to great extends but it has a good use in floating offshore wind turbines, yet it still amazes me

The second one has emerged at some place, i wasn't acquainted with it and it took a while to find out the source is related to intermediate axis theorem,

The first one, i was surprised despite of being involved in vibration in all levels, observed it at an experiment and couldn't find the cause even if we checked damping at the system (was stable). the system was slowly being synced despite of the individual bodies were not coupled, except of the hydrodynamic coupling due to free-surface between them, well if i haven't watched those videos on YouTube probably i would never find the cause.
At the moment i know the cause but our solution was to skip that angle which triggers synchronization, and interpolate it from the nearest known angles. What is strange it doesn't appear in nonlinear simulations with similar boundary conditions and the same scale.
We know the system is stable at that angle and the individual parts do not sync, the phenomena just emerges when system is scaled down and placed into test basin .

 

[Nilgiri]

I knew the third one and applied that, not to great extends but it has a good use in floating offshore wind turbines, yet it still amazes me

Heh, well when you go out ice skating and pull your arms in when spinning, you can pirouette helluva fast if you dont watch out.

The second one has emerged at some place, i wasn't acquainted with it and it took a while to find out the source is related to intermediate axis theorem,

Hehe, it actually reminded me of a professor I once had when we worked on a satellite design project. One of my louder-brash project-mates kept venturing that we needed to make the reaction wheels bigger and beefier etc...and my prof finally got annoyed with him and just said "uhhh NO, you just make them able to spin FASTER!...SILLY!" ....i.e please recognise what is linear vs squared in the angular momentum rotational stability etc.

Basically getting something to spin incredibly fast relative to its mass, is perfect way to illustrate this like in that clip you posted. With little net gravity field, you can see principal axi easily when you simply impart the high rotational intensity...in effect the reverse of what reaction wheels do.

The first one, i was surprised despite of being involved in vibration in all levels, observed it at an experiment and couldn't find the cause even if we checked damping at the system (was stable). the system was slowly being synced despite of the individual bodies were not coupled, except of the hydrodynamic coupling due to free-surface between them, well if i haven't watched those videos on YouTube probably i would never find the cause.
At the moment i know the cause but our solution was to skip that angle which triggers synchronization, and interpolate it from the nearest known angles. What is strange it doesn't appear in nonlinear simulations with similar boundary conditions and the same scale.
We know the system is stable at that angle and the individual parts do not sync, the phenomena just emerges when system is scaled down and placed into test basin

So true, it is kind of counter intuitive at first glance, but there is sufficient transmission of the harmonics given each metronome concentrated harmonic w.r.t the system connecting them (in this case a plank on some cans, thus allowing fairly unconstrained energy interaction among a low population of items).

This is a more wide ranging phenomenon in the macro scale too...if you look at Resonant interactions at large, with the studies and works of poincare, hamilton, lagrange, fourier etc.

Take orbital resonances for example:

Looking at just Io and Europa for example (Any example will do, incl the planets themselves around the sun):

Shortest distance found between these two bodies (Io and Europa) in their respective orbits is roughly 250,000 km. At this point in time, they exert (due to their masses) about 4.5 *10^18 N on each other using Gmm/r^2.

If we look at Io, we find its centripetal force (mv^2 / R) due to jupiter is about 4.5X10^22 N.

So basically the latter is magnitude of 4 higher (10,000 times higher).

So a 0.01% relative force interaction (applied with enough consistency and time) is enough to achieve massive resonance lock.

(I did the numbers w.r.t distances, velocities and masses really quick without dbl checking so there is potentially an error somewhere , but the concept holds in general given magnitudes here I have explored before, trust me )

Can have a read here coming back to the metronome stuff:

http://www.math.pitt.edu/~bard/classes/mth3380/syncpapers/metronome.pdf

Coincidentally in that paper (given I just brought astronomy into the picture), Huygens (who was first to discover a moon of Saturn i.e Titan) was fascinated by the "ring of saturn", which are now known to be Rings and have a number of interesting resonant phenomenon given the presence of many many further moons within them too.

@Joe Shearer @VCheng @Sinan @Vergennes @xenon5434 @Kartal1 @Saithan @Saiyan0321 @Paro @Gautam @UkroTurk @Webslave @T-123456 @Madokafc @#comcom @Zapper et al.

 

[Saithan]

Awesome stuff. Some of it is wee bit above my level. I'm mostly at an anklebiter level

I find mini projects interesting. Projects that can lift up even the most rural communities a bit up and make life better for them.

The potential to give people more option and opportunities with energy.

 

[Anmdt]

Can have a read here coming back to the metronome stuff:

http://www.math.pitt.edu/~bard/classes/mth3380/syncpapers/metronome.pdf

Seen it already, and i was never surprised to see those nonlinear terms are the convicts of the synchronization.

Heh, well when you go out ice skating and pull your arms in when spinning, you can pirouette helluva fast if you dont watch out.



Hehe, it actually reminded me of a professor I once had when we worked on a satellite design project. One of my louder-brash project-mates kept venturing that we needed to make the reaction wheels bigger and beefier etc...and my prof finally got annoyed with him and just said "uhhh NO, you just make them able to spin FASTER!...SILLY!" ....i.e please recognise what is linear vs squared in the angular momentum rotational stability etc.

Basically getting something to spin incredibly fast relative to its mass, is perfect way to illustrate this like in that clip you posted. With little net gravity field, you can see principal axi easily when you simply impart the high rotational intensity...in effect the reverse of what reaction wheels do.



So true, it is kind of counter intuitive at first glance, but there is sufficient transmission of the harmonics given each metronome concentrated harmonic w.r.t the system connecting them (in this case a plank on some cans, thus allowing fairly unconstrained energy interaction among a low population of items).

This is a more wide ranging phenomenon in the macro scale too...if you look at Resonant interactions at large, with the studies and works of poincare, hamilton, lagrange, fourier etc.

Take orbital resonances for example:

Looking at just Io and Europa for example (Any example will do, incl the planets themselves around the sun):

Shortest distance found between these two bodies (Io and Europa) in their respective orbits is roughly 250,000 km. At this point in time, they exert (due to their masses) about 4.5 *10^18 N on each other using Gmm/r^2.

If we look at Io, we find its centripetal force (mv^2 / R) due to jupiter is about 4.5X10^22 N.

So basically the latter is magnitude of 4 higher (10,000 times higher).

So a 0.01% relative force interaction (applied with enough consistency and time) is enough to achieve massive resonance lock.

(I did the numbers w.r.t distances, velocities and masses really quick without dbl checking so there is potentially an error somewhere , but the concept holds in general given magnitudes here I have explored before, trust me )

Can have a read here coming back to the metronome stuff:

http://www.math.pitt.edu/~bard/classes/mth3380/syncpapers/metronome.pdf

Coincidentally in that paper (given I just brought astronomy into the picture), Huygens (who was first to discover a moon of Saturn i.e Titan) was fascinated by the "ring of saturn", which are now known to be Rings and have a number of interesting resonant phenomenon given the presence of many many further moons within them too.

@Joe Shearer @VCheng @Sinan @Vergennes @xenon5434 @Kartal1 @Saithan @Saiyan0321 @Paro @Gautam @UkroTurk @Webslave @T-123456 @Madokafc @#comcom @Zapper et al.

Well i am glad to see another example in macro scale. Thanks for the information and the math.

 

[Anmdt]

It is know that Archimedes has shown a floating -submerged body overflows the liquid as much as its submerged volume,moreover subjected to a lift force related to its submerged volume*density of the liquid.
In 3th century BC, yet alone the advanced math(calculus), the proper math was available at limited stage.
Archimedes has discovered it with consistency/repetition of experiments and observation, however it can be proven mathematically too.
Archimedes principle of buoyancy can be mathematically proven by using 1st. Integral introduced by Leibniz-Newton*(17th century), 2nd. Divergence theorem introduces by Gauss (18th century) which is nearly 2 thousand years apart with Archimedes.

To describe in a more human way:
1. any point (infinitesimal are dA) on the submerged face is subjected to pressure P which acts along the normal of surface dA, integral of vertical component results in total buoyant force, while other axes are generally in balance.
2. Divergence theorem helps us to rewrite integrals defined on surfaces, as volume integrals.
3. Now, our integral is in form of volume integral with divergence of pressure field, of density x gravity along the volume for the vertical axis, which equals density x gravity x volume (submerged)

The conventional application is handy when one utilizes direct computation of the volume by hand, however if you have a surface which deforms or complex definitions, and need to compute total buoyancy and other inertial identities, discrete integral schemes which will not come handy with curved surface (also it would require a structured and well organized grid), whereas direct application of mathematical definition will be useful and robust. The direct application both saves time in computation (because it is a vectorized operation), and effort given (simplicity to compute by use of discrete elements ie. mesh,grid which is already present in computational domain).

Which can be applied as:
total buoyancy force =
sum of (fluid static pressure at center of element x derivation of surface normal along vertical axis (vertical component of the normal vector) x area of element )

*However there could be earlier definitions of integral, they are credited for the completeness of application.

 

[Joe Shearer]

Heh, well when you go out ice skating and pull your arms in when spinning, you can pirouette helluva fast if you dont watch out.



Hehe, it actually reminded me of a professor I once had when we worked on a satellite design project. One of my louder-brash project-mates kept venturing that we needed to make the reaction wheels bigger and beefier etc...and my prof finally got annoyed with him and just said "uhhh NO, you just make them able to spin FASTER!...SILLY!" ....i.e please recognise what is linear vs squared in the angular momentum rotational stability etc.

Basically getting something to spin incredibly fast relative to its mass, is perfect way to illustrate this like in that clip you posted. With little net gravity field, you can see principal axi easily when you simply impart the high rotational intensity...in effect the reverse of what reaction wheels do.



So true, it is kind of counter intuitive at first glance, but there is sufficient transmission of the harmonics given each metronome concentrated harmonic w.r.t the system connecting them (in this case a plank on some cans, thus allowing fairly unconstrained energy interaction among a low population of items).

This is a more wide ranging phenomenon in the macro scale too...if you look at Resonant interactions at large, with the studies and works of poincare, hamilton, lagrange, fourier etc.

Take orbital resonances for example:

Looking at just Io and Europa for example (Any example will do, incl the planets themselves around the sun):

Shortest distance found between these two bodies (Io and Europa) in their respective orbits is roughly 250,000 km. At this point in time, they exert (due to their masses) about 4.5 *10^18 N on each other using Gmm/r^2.

If we look at Io, we find its centripetal force (mv^2 / R) due to jupiter is about 4.5X10^22 N.

So basically the latter is magnitude of 4 higher (10,000 times higher).

So a 0.01% relative force interaction (applied with enough consistency and time) is enough to achieve massive resonance lock.

(I did the numbers w.r.t distances, velocities and masses really quick without dbl checking so there is potentially an error somewhere , but the concept holds in general given magnitudes here I have explored before, trust me )

Can have a read here coming back to the metronome stuff:

http://www.math.pitt.edu/~bard/classes/mth3380/syncpapers/metronome.pdf

Coincidentally in that paper (given I just brought astronomy into the picture), Huygens (who was first to discover a moon of Saturn i.e Titan) was fascinated by the "ring of saturn", which are now known to be Rings and have a number of interesting resonant phenomenon given the presence of many many further moons within them too.

@Joe Shearer @VCheng @Sinan @Vergennes @xenon5434 @Kartal1 @Saithan @Saiyan0321 @Paro @Gautam @UkroTurk @Webslave @T-123456 @Madokafc @#comcom @Zapper et al.

Ooooh.....my head aches!

I read HISTORY, for Heavens sake.

 

[Saithan]

Ooooh.....my head aches!

I read HISTORY, for Heavens sake.

I went Economy I'm waiting for the "Beautiful Mind" moment... any minute now...

It is know that Archimedes has shown a floating -submerged body overflows the liquid as much as its submerged volume,moreover subjected to a lift force related to its submerged volume*density of the liquid.

I had about Archimedes back in my teenage time while taking diving classes and the exam for my CMAS certificate...

Well Myth Busters did contribute a bit later on

 

[Saithan]

Some of the stuff we're working with atm. SMART energy management in office buildings.

How advanced is this stuff in Turkey ?