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#76 2021-06-21 06:57:55

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 4,782

Re: Physics Topics

Seen as we've had discussion on Graviton or Gravity Waves I thought to post this news.

Astronomers saw the Same Supernova Three Times Thanks to Gravitational Lensing. And in Twenty Years They Think They’ll see it one More Time
https://www.universetoday.com/151581/as … more-time/

The un-cancelled LISA mission? NASA announced it would be unable to continue funding this mission

https://en.wikipedia.org/wiki/Laser_Int … ce_Antenna
The Laser Interferometer Space Antenna. Potential sources for signals are merging massive black holes at the centre of galaxies, massive black holes orbited by small compact objects, known as extreme mass ratio inspirals, binaries of compact stars in our Galaxy, and possibly other sources of cosmological origin, such as the very early phase of the Big Bang, and speculative astrophysical objects like cosmic strings and domain boundaries.

Previous searches for gravitational waves in space were conducted for short periods by planetary missions that had other primary science objectives (such as Cassini–Huygens), using microwave Doppler tracking to monitor fluctuations in the Earth–spacecraft distance. By contrast, LISA is a dedicated mission that will use laser interferometry to achieve a much higher sensitivity. Other gravitational wave antennas, such as LIGO, VIRGO, and GEO 600, are already in operation on Earth, but their sensitivity at low frequencies is limited by the largest practical arm lengths, by seismic noise, and by interference from nearby moving masses. Thus, LISA and ground detectors are complementary rather than competitive, much like astronomical observatories in different electromagnetic bands (e.g., ultraviolet and infrared)

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#77 2021-06-21 09:16:42

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

For Mars_B4_Moon re #76

Thanks for contributing to the Physics Topic (a) and (b) Thanks for the update on LISA !!! It is disappointing to learn that this important (as I see it) research instrument is going to have to wait for funding, but it's value seems to be recognized, so it should climb back to the top of the queue at some point.

While I'm thinking about it, thanks for all the topics you've brought back into view in recent times, and for the new items you've added to the mix.

This forum software lacks a simple way to indicate appreciation for contributions, and a post has the disadvantage of taking the author's place in the Active list.

I'll ask SpaceNut about the possibility of setting up a ThumbsUp Topic in Chat ... If we had such a thing, members could "vote" for posts without intruding on the flow of the topic.

(th)

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#78 2021-06-30 19:13:25

tahanson43206
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Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

I decided to toss a question into the Physics topic...

Adhesion and cohesion are properties of matter most closely associated with Chemistry, but I am interested in the Physics of the two.

Work has been done to show that Carbon can be arranged to have tensile strength nearly (but not quite) sufficient to support a space elevator above the Earth.   Apparently such an elevator can be constructed above Mars with existing materials.

However, ** this ** post is asking the question ... is adhesion potentially stronger than cohesion?

Most of the examples of answers that Google came up with have to do with water, which exhibits useful combinations of cohesion and adhesion that can be employed for various purposes.

There may be research on the power of electron bonds between atoms of various types, and I'd be interested in direction.

(th)

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#79 2021-07-01 17:55:41

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 26,803

Re: Physics Topics

The carbon bunky ball and nano tubes are the start of carbon products with graphene coming up into uses.

Carbon while it does conduct energy it is more of a resistive to its flow and disapates heat acrross its surface.

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#80 2021-07-28 13:13:47

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

https://www.yahoo.com/news/youtuber-bet … 00405.html

A YouTuber bet a physicist $10,000 that a wind-powered vehicle could travel twice as fast as the wind itself - and won
Aylin Woodward
Wed, July 28, 2021, 8:01 AM

What I ** really ** like about this story is the amazing creative thinking that led to this success.

Whoever had the insight to understand the principle behind this success is right up there with Void for creative thinking!

I am tempted to feel a tiny bit badly for the PhD who was so sure of himself, but on the other hand, his (unplanned) generosity is a wonderful teaching moment for thousands if not millions of others who may suffer from mental block.

(th)

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#81 2021-08-02 16:03:38

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 2,235

Re: Physics Topics

An economist and a physicist discuss the unsustainable nature of economic growth.  Amusing and apt.
https://dothemath.ucsd.edu/2012/04/econ … physicist/


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#82 2021-09-07 09:22:49

tahanson43206
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Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

https://www.yahoo.com/finance/news/150- … 00248.html

A 150-Year Old Idea Could Lead To A Breakthrough In Space Travel
Editor OilPrice.com
Mon, September 6, 2021, 8:00 PM

According to Woodward, you can generate ~10 newtons of force for every kilowatt of electricity fed into the Mach Effect engines. Early applications would be in satellites used in chemical rockets to maintain orbits and alignment with the engines fueled by electricity, vastly extending their useful lifespans. Indeed, in this case, solar panels could provide all the necessary energy to power the drives.

Another interesting finding: The team has calculated that the smaller the device, the larger the force it can generate. So instead of scaling up, they hope that arrays of thousands of tiny MEGA Drives powered by a nuclear battery could one day be deployed to accelerate large probes into interstellar space. Indeed, the scientists claim that the drives are sufficient to power a human-crewed starship to nearby stars such as Proxima Centauri located some 4.25 light-years away from the sun and back in some reasonable fraction of the human lifetime.

This is the best writing I've seen so far on the subject.

The writer may not be a native English speaker.  The English is excellent, but I question the term "moot" when used with respect to atomic energy as a source of electricity.  However, the context may be the size of objects that might use this tool.  If objects are small, then solar panels for satellite positioning might make sense, and I would imagine that is where early funds to support further research may focus.

(th)

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#83 2021-09-07 13:46:22

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 2,235

Re: Physics Topics

TH: this is a fascinating topic (The Mach effect drive).  Definitely one to follow.  I don't quite understand the theory behind it, but it appears to be a propellantless propulsion concept, though not strictly reactionless.  If it can provide constant thrust irrespective of speed, then it is essentially a perpetual motion machine, because kinetic energy scales with v^2.  The energy would presumably have to come from somewhere, but apparently human beings don't have to pay for it.


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#84 2021-09-07 14:05:33

tahanson43206
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Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

For Calliban re #83

Thank you for commenting upon the article before you've had a chance to read it.  After you've read it, please  come back and share your insight.

The argument ** appears ** to be that the rest of the Universe participates in the process, and that the invention (if that's the right word) is a way of increasing the density (mass?) of matter when we pull on it, and decreasing the density (mass?) of matter when we push on it.  Apparently (and I am looking forward to correction as necessary) the process is very similar to the financial process used by major players with powerful computers who are able to catch tiny movements of stock price when they fall (so buy them) and then release (sell) when the price is infinitesimally greater.

I am told by FriendOfQuark1 that it is possible to live on the proceeds of activity along these lines.

(th)

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#85 2021-09-09 06:22:26

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 2,235

Re: Physics Topics

An interview with James Woodward here, that explains the concept in more detail.
https://medium.com/predict/james-woodwa … 384863ad50


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#86 2021-10-01 19:55:10

tahanson43206
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Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

https://www.sciencenewsforstudents.org/ … heat-space

Chen acknowledges that the team’s cooling device is small. And sometimes engineers have problems making experimental devices work when they try to enlarge them. One challenge to making the heat-shedding device bigger is that the chamber it’s in needs to be airless (a vacuum). Sucking all the air out of a larger chamber without making its walls crumple is tricky.

Another hurdle to enlarging the team’s device is cost, notes Chen. In particular, zinc selenide (the material the team used as the top of their cooling device) is quite expensive. But with further research, he says, engineers might find a cheaper substitute.

This research shows a way to emit radiation to space.

What is potentially interesting is that the method investigated works at (comparatively) low temperatures.

The current iteration is (apparently) limited in capability.

Never-the-less, for forum members who are obsessed with getting rid of nuclear plant excess energy, this might be attractive.

It needs a vacuum, so the cooling method may be attractive for space craft fitted with nuclear reactors.

(th)

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#87 2021-12-12 11:05:52

tahanson43206
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Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

http://hyperphysics.phy-astr.gsu.edu/hb … otime.html

Radiative Cooling Time
The rate of radiative energy emission from a hot surface is given by the Stefan-Boltzmann law .

The new topic just added to the forum is dedicated to considering cooling.

The scope of that topic includes both deep space as a sink, and the atmosphere of Earth as a source of thermal energy.

This post is about the energy imbalance of the Earth...

It appears that more energy is being retained by the Earth than is being radiated to space.

The result appears to be excessive free energy in the atmosphere, which leads to a variety of unwanted (though perfectly natural) effects on the humans who currently live on Earth.

The default response is to complain about the weather, and to repeat the assertion than no body can do a thing about the weather.

This post offers the perspective that an advanced civilization (human or otherwise) would not put up with the consequences of such an energy imbalance, however it was incurred.

Radiation to space is a remedy for the energy imbalance on Earth.

The fact is that Earth already radiates energy to space.  The fact that Earth can be seen from other bodies in the Solar System attests to that simple fact.

The logical space for augmented radiation to space would be the two poles.

Cooling of the poles is compatible with tradition, so further cooling would/should be accepted by all who study the problem.

I am proposing that we (humans) think about how to radiate more energy to space from the poles than we are currently doing, so as to achieve a balance of incoming energy (primarily from the Sun but also generated locally) and outgoing energy.

(th)

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#88 2021-12-12 13:32:23

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,803

Re: Physics Topics

Man has been the main factor in the ever increasing changes to earth eco systems where the temperature rise is not just showing in the air and its being seen on land and in the oceans as well.

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#89 2022-01-05 10:58:44

tahanson43206
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Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

https://www.msn.com/en-us/news/technolo … hp&pc=U531

The new magnesium isotope — called magnesium-18 — won't fill all the gaps in scientific knowledge about atoms, but the discovery will help refine the theories that scientists have developed to explain them, he said. In particular, the team's measurements of the products of the isotope's radioactive decay give new insights into the binding energies of electrons that orbit a nucleus, according to a summary of the research.

Atomic nuclei
Under normal conditions, pure magnesium is a soft gray metal with the atomic number 12, which indicates it has 12 protons — particles with a positive charge — in its nucleus. It's highly flammable, and the intense white light from a burning magnesium strip often dazzles students in chemistry classes.

The conditions that Calliban's fusion topic envisions may encourage temporary existence of isotopes of materials fed into the fusion chamber. A leading candidate is Tritium.

(th)

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#90 2022-01-23 11:35:46

tahanson43206
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Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

The Large Ship topics are inevitably leading toward confrontation with Rotational Artificial Gravity in space.

There are theories about how this might work, but (to the best of my knowledge) the human race has NO experience with rotational artificial gravity, except for accidental rolling that has (reportedly) occurred when equipment malfunctioned.

I will try to renew discussion of Rotational Artificial Gravity in the Physics topic, with the assertion that the American football ** may ** represent the peak of evolution of a shape capable of sustaining stable rotation along the Z axis.

If it can be shown that the American football is a favorable model for space craft intended to carry passengers from Earth to Solar System destinations, while providing artificial gravity for comfort and good health, then there is a possibility that the shape itself might generate human interest (in some segments of the human population), and funding for real-Universe experiments might be forthcoming.

The figure/equation of interest is h < 2.45r.  This equation was brought to our attention by Void, who found a video about Artificial Gravity that includes an assertion that includes this equation.

Edit: The human race ** does ** have experience with rotating objects in space.  The first American satellite, Explorer, was spin stabilized because that was the only technology available to Wernher Von Braun and his team at the time.

Numerous vehicles have been spin stabilized since 1958.

The opportunity awaits a group able to demonstrate sustained, stable artificial gravity in a structure moving in space with uncontrolled movement of masses from place to place inside the structure.

I predict (with only intuition available) chaotic behavior will take over any such structure after it is launched, and random movements are allowed to occur.

(th)

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#91 2022-01-25 13:25:56

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

I am continuing an investigation of the hypothesis that the American football may have evolved to become the most efficient possible shape to achieve stability in the Z axis while rotating in flight.

The article at the link below is short on math, but it does assert that the force of gravity is at work in guiding the path of the football from quarterback to receiver.  A detail that emerges is that the optimum rotation rate is 600 rpm.

https://interestingengineering.com/the- … ic%20shape.

This detail ** may ** be correct or it may not.  But if it ** is ** correct, I suspect it ** only ** applies to an object the shape and mass of an American football.

If the Large Ship of RobertDyck were shaped like an American Football, I am wondering what rpm would be needed to insure stability in flight.

RobertDyck has specified a desired rpm of 3, and a desired artificial gravity of Mars equivalent (about .4 Earth gravity).

I would appreciate someone with the needed skills and education evaluating the hypothesis and delivering an informed judgement for the result.

My reason for pursuing this is to try to find a shape/rpm solution that reduces the need for a complex force abatement system on Large Ship.

It is possible the current active membership of this forum does not possess the required education/skill level.  If there is a reader who is not already a member and who would like to help out, please read the recruiting topic and apply for membership.

In lieu of membership, if someone would like to provide advice/information, please write the NewMars Portal.

Edit later: The article at the link below is (apparently) much more productive:

https://www.nytimes.com/2020/10/16/scie … ysics.html

The author of this article reports on very high level analysis by a small set of physicists.  The work was done out of curiosity, and the article provides an overview of the results.  I came away from this article thinking that these folks might be willing to consider the Large Ship optimum shape question.

While drag is a major factor in the performance of an American football, it is less likely to be a factor in Large Ship stability.

Gravity is a factor in the flight of an American football.  It ** may ** be a factor in flight near Earth.

I note that the rotating spacecraft whose analysis was found and reported by SpaceNut intended to orient itself edge on to the path of movement around the Earth, in order to reduce drag.  The Large Ship design is intended to be oriented so the Z axis is always aligned with the center of the Sun, in order to maximize protection against Solar Radiation and particularly mass ejection events.

(th)

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#92 2022-01-25 23:17:38

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,952
Website

Re: Physics Topics

I dunno about such nuances. 

But there is a matrix of some 9 mass moments of inertia for any object.  The ones on the main diagonal are the principal  moments of inertia about the 3 axes.  The rest are the cross products of inertia,  which are zeroed by symmetry about the axes.  Spins are stable about the axes of max and min mass moments of inertia,  but not about the intermediate one.  If the cross products are nonzero,  spin is increasingly unstable.   That I remember from 50 years ago.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#93 2022-01-26 09:15:44

tahanson43206
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Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

For GW Johnson re #92

Thanks for taking up this challenging topic.  There may be a digital model that a student can run to experiment with those variables in "real" (simulation) time.

There are digital models of gyroscopic behavior on display in various YouTube videos.

It should be possible to build a digital model that anyone can run (assuming they have a modern computer).

I am (currently) pursuing the hypothesis that an American football is the product of an evolutionary process to find an object shape and physical characteristics that allow it to travel in a perfectly defined arc from passer to receiver.

Recent (heavy duty) research (by gents whose day jobs are at the highest levels of academia) revealed that the knobby surface of the rotating shape interacts with the atmosphere to very slightly modify the path.  The research revealed that there is a difference in performance between right and left handed passers, for example.

Your post #92 brings out the importance of symmetry in any rotating object.

RobertDyck has proposed sending water from place to place in the hull of Large Ship, to keep the rotating vessel in balance.

My expectation is that it will turn out water movement is ** way ** too slow for this application.

The speed of light is needed, and the speed of sound may be just barely sufficient.

Passengers are going to be moving about in the habitat ring.  Crew are going to be shifting supplies from one location to another.

Fresh water will be flowing from where-ever it is produced to the cabins, and used water will be flowing from cabins to where-ever it is to be processed.

I working ship in flight, full of passengers and crew, will be a dynamic environment that must be kept in constant symmetry to prevent out-of-control perturbations that could easily overwhelm the fragile metal structure holding such a vessel together.

Your trusty slide rule ** may ** be up to the challenge of determining if a foot ball shape is ideal for Large Ship.

Mass can be estimated at 5,000 tons for the purposes of the exercise.

Recently (either Void or SpaceNut) found a video about artificial gravity that contained the assertion that the length of the Z axis with respect to the radius of a rotating object determines stability.

The video included this expression: h < 2.45r

The video itself contained an error.

However, it should be possible to determine if the 2.45 number has any relationship to Real-Universe physics.

Have you ever heard of it? Can you work out what it might have come from?

I would deduce that an object of infinite length in the Z axis would be stable in that axis.

Therefore, I would expect that an object with Z greater than 2.45r would be stable.

Can you find (or work out) a proof, one way or the other?

Do you have an acquaintance who dabbles in this sort of mechanical engineering, and who might be interested in considering the problem?

(th)

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#94 2022-01-26 14:05:50

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

SearchTerm:Doppelganger

The term Doppelganger has unfortunate connotations, for the purpose I have in mind.

This post is about the instantaneous mass movement echoing that may be necessary to insure a rotating space vessel remains in trim at all times.

An aircraft needs to adjust trim as passengers move about.  The larger the aircraft the less adjustment is needed.

However, an aircraft is interacting with the mass of the atmosphere at a rate that allows the aircraft to remain aloft.

The aircraft is forcing air molecules down (in normal flight) to exactly balance the pull of gravity on the vehicle.

A rotating passenger space vessel will have no equivalent mass against which to interact.

In anticipation of the need that may become clear, for instantaneous mass equivalent shifts on the opposite side of a rotating space vessel, I am launching ** this ** post to invite thoughtful evaluation of the possibility.

Edit: Movement ** in ** the Z direction should produce no change of momentum with respect to the rotation problem to be addressed.

In the case of Large Ship, that movement would be across the width of the passenger habitat ring.

(th)

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#95 2022-01-26 19:18:55

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 26,803

Re: Physics Topics

A football has an aero dynamic shape as its going to cut through the air and have lift due to the curved shape starting small and getting wider as it get closer to the center where the hand will grab it. The opposite shape is achieved since it must be thrown in either direction.
The grip release is why it spirals and wobbles as the arm is move forward to make the pass.

The imbalance of a rotating space ship is akin to a washing machine with the close bunched up onto one side of the tub. Is that mass that causes it to vibrate in the out of round as it spins.

Much like the tub depth the rotating of a single ring will as its width gets wider have more effect as mass is shifted from center center towards any direction. Its when that mass gets bunched up like at eating time in a mess hall that the imbalance will happen. Keep that bunching towards the inside of the ring and along the center will make it have less effect.

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#96 2022-01-26 19:33:49

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

For SpaceNut re #95

Thanks for another terrific real-Universe example of what our two intrepid spacecraft designers are facing!

Earlier you gave the excellent example of a wheel that must be balanced perfectly, in order for it to serve for thousands of miles.

Your example of a washing machine is inspired!  I can relate to that immediately, although I don't remember specific instances of out-of-balance conditions, I definitely ** do ** recall them having happened.

I think you are optimistic about how much mass will cause noticeable effects ...

There are MANY examples of space craft that have been launched with rotation as a part of the flight plan.

It seems to me that the experience of the engineers who achieved success with those systems would be greatly beneficial to RobertDyck and to kbd512, as they try to design huge rotating vehicles.

The folks designing the orbiting hotel for LEO that was reported in the forum recently must surely be thinking about rotational stability.

If mass is out of round in the Large Ship, I expect that it will be noticeable even if the amount is just a few kilograms out of 5,000 tons os system mass.  The idea that we (humans) can build and rotate a ship of that size without handling mass distribution with precision seems to me overly optimistic.

***
In your Post #95 you noted the football shape ...

I am proposing that shape for Large Ship because the Z axis may be  longer than 2.45r.

h < 2.45r was the mathematical relationship in the video that you commented upon recently.

I think that Void found the video and posted a link.  You and I have both commented, and it may be that others have as well.

The claim in the video was that stability of a rotating object is stable if Z is greater than 2.45r

At any rate, that is how I interpreted it, since the graphic itself contains a self-evident error.

An object with an infinite Z would be stable.

The question to be resolved is where that 2.45r figure comes from, and how it can be verified.

My guess is that a football is stable in flight because it follows the h ? 2.45r rule.

(th)

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#97 2022-01-26 19:44:22

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

To SpaceNut .... re football dimensions:

The rule of thumb published in the video that Void found was 2.45r as the "magic" length

https://www.dimensions.com/element/american-football

American Footballs have a short diameter of 6.68”-6.76” (16.9-17.2 cm) and length of 11”-11.25” (28-29 cm), resulting in circumferences of 21”-21.25” (53-54 cm) on the short axis and 28”-28.5” (71-72 cm) in the long. The mass of a American Football is between 14-15 oz (400-425 g) with a pressure between 12.5-13.5 psi (86.2-93.1 kPa
).
Drawing of a American Football showing dimensioned analysis of the diameters and circumferences

Taking 17 cm diamether and 28 cm length, then r is 8.5 cm

2.45 * 8.5 >> 20.825

This is less than the regulation length of 28 cm.

This appears to support my interpretation that the rule of thumb should read: h > 2.45r

The video has the relationship in reverse.

28 / 8.5 is 3.3

From this I deduce that if Large Ship has a ratio of 3.3 between length of the central shaft, and radius of the habitat ring, the vessel will be stable.

The scientific article I found about football operation indicated that a small amount of precession around the Z axis should be expected and it cannot be eliminated, so I would expect something similar to be observed when Large Ship spins up.

(th)

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#98 2022-01-26 19:54:47

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 26,803

Re: Physics Topics

The shape of a football is so that it will glide through the air otherwise we would throw bricks.
The length to to the shape is about balance and less about the ratio of diameter to length.

The fact that RobertDyck's plan to has multiple decks which if the non moving mass is on the outside which is the greenhouse and water we already have a more stable ring as the people moving mass is on the inner deck where we need less mass shift due to the gravity that is more the further you go from the center on the outer wall of the ring.

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#99 2022-01-27 07:49:55

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

For SpaceNut re #98

The American football evolved from the original shape as players demanded better equipment.

The European Rugby football is likely to have been the starting point for evolution of the American design, and the Rugby ball is NOT thrown.

It is possible the history of the American football is available for study. 

I am pursuing the hypothesis that the design of the American football is optimized for stability in the Z axis, in addition to the other important factors that players want and need.  You've certainly started along a helpful path, by thinking about aerodynamic shape, and features of the surface that help with grip.

In the design I am proposing, the habitat ring could be identical to the one proposed by RobertDyck.  It would fit inside the shape of the vessel at the center of the Z axis.  The shell for a space vessel doesn't need to be curved like a football, but it ** does ** need to have enough strength to be able to carry force loads from the prow and from the stern of the central shaft.

The advantage of the football shape is it's potential market value.

American football franchises are potential sponsors.

We've talked recently about $2,000,000 for a flight model of Large Ship.  An American football franchise could afford to invest $2,000,000 in an experiment to test the Large Ship concept in a model.  It would be a minor adjustment to package Large Ship in a football shape, if the sponsor can show advertising video.

Another potential sponsor just occurred to me .... The Goodyear Blimp is still flying over large football events ...

The heart of the issue I am working here is stability along the Z axis.

It is easy to get distracted by other aspects of football design.

(th)

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#100 2022-01-27 08:28:38

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,070

Re: Physics Topics

For SpaceNut re History of Evolution of American Football...

Google came up with a great (significant) number of citations about this topic ...

The citations appear to support my guess that the American football evolved from Rugby, which evolved from a pig bladder.

The point I am trying to make, and which I hope will eventually prove useful, is that while Rugby does not involve throwing a ball (to the best of my knowledge - correction requested), the American sport developed that variation.  The result was the pressing need for a ball that would fly true, in addition to providing all the other services you've mentioned, such as being easy to grip.

Here is a preliminary set of Google snippets:

In the 1860s and 1870s, once Richard Lindon developed a rubber version of the pig bladder for rugby players — basically a frame underneath the leather encasing that kept the ball's firm, oval shape — and a pump to inflate it, then American football players started to use the same to maintain the shape of their ...

Feb 1, 2019
Super Bowl History: Why Are Footballs Shaped Like That? | Time

People also ask
How did American football get its shape?
A football is a prolate spheroid, and it's shaped that way because that's also the shape of an inflated pig's bladder, which is what the first footballs were made of. ... But as the football evolved — and was constructed of cowhide and rubber — it got even more prolate, which made it easier to carry and easier to throw.

How the Football Got Its Shape | TIME.com - Ideas

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Who came up with the shape of the American football?
When did the shape of the football change?
How has the American football ball changed over time?

How the NFL Football Got Its Shape | Live Science
www.livescience.com › 32808-nfl-football-spheroid-origins
Sep 8, 2010 · The truth is that the American football's unique contour is an evolution of history more than design. Technically shaped, at least roughly, as a ...

How Did the Pigskin Get Its Shape? | Arts & Culture - Smithsonian ...
www.smithsonianmag.com › arts-culture › how-did-the-pigskin-get-its-sha...
Oct 5, 2012 · American football may have evolved from soccer and rugby, ... The unique shape of the ball was somewhat formalized in the early 20th century ...

The Evolution of the Football - SportTechie
www.sporttechie.com › the-evolution-of-the-football
Aug 15, 2014 · In the early 1900s, the ball was given a more aerodynamic shape, hence the modern football. The prolate spheroid shape was designed to help ...

The History of the Football – The Actual Ball | Mental Itch
mentalitch.com › the-history-of-the-football-the-actual-ball
American football has a rich history, and its shape has been modified several times up till now. The sport was evolved in the 19th-century collegiate system ...

Why a football is shaped the way it is | 11alive.com
www.11alive.com › why-guy › why-is-an-american-football-shaped-like-that
Jan 29, 2020 · Why is an American football shaped like that? ... The shape of the ball itself has a history that goes more than 100 seasons.

The Evolution of the Football - Popular Mechanics
www.popularmechanics.com › adventure › sports
Feb 1, 2018 · In a century and a half since the first game of American football, ... the early days of the game, when the odd size and shape of early ...

The Evolution of the Football | Sutori
www.sutori.com › story › the-evolution-of-the-football--deUyZTXeom7U...
The History of the Football. The football was created by Walter Camp. He is known as the father of the american football. He invented the football in the ...

How the Football Has Changed Since 1869 - Scout Life magazine
scoutlife.org › Features
Officially, the shape is known as a “prolate spheroid.” 1941. football-1941. Wilson became the official manufacturer of NFL footballs and has been ever since.

American football - Wikipedia
en.wikipedia.org › wiki › American_football
Early history. American football evolved from the sports of rugby and soccer. Rugby, like American football, is a sport where two competing teams vie for ...

If this forum includes a member who is a marketing genius, I'd welcome a thoughtful analysis of the potential sponsorship of a Large Ship model to be tested on orbit, if the Large Ship designer is willing to accept the proposition that the American football shape will insure stability of the vessel in the Z axis.

I am arguing that the evolution of the American football has delivered a shape that is optimal for Large Ship, not because it is aerodynamic, or because it is easy to grip, but because it flies as true as an arrow from passer to receiver, without significant (ie, destructive) perturbation along the Z axis.

(th)

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