Physics Discussion Thread

[Vayutuvan]

Have you read the story "The Gold-Bug" (IIRC) by Poe? It should go into math dhaga as well, I suppose.

[SaiK]

well if not gold, it can prevent tsunamis.. having those mangroves is good.

I meant "plants" as in industrial not as in trees

you took my moorkh levels way down! nevertheless, it would be interesting plant indeed!

[Neshant]

Have you read the story "The Gold-Bug" (IIRC) by Poe? It should go into math dhaga as well, I suppose.

what is the significance of it in this context?

[Vayutuvan]

xposting from India-US thread.

Recently my advisor (boss now) was telling me that he heard that Indian faculty and scientists working at IISc (tata insti at that time) and some other science institutions in India wanted to give employment to Jewish scientists who were persecuted by hitler's Germany during WW II but the proposal was shot by the powers that be - the British higher-ups who were anti-Semitic.

Absolutely correct, but it is a sad story. C.V. Raman in fact got Max Born to come to Bangalore which he did. The British authorities were very much against Raman, most of them were old school British engineers who had no clue of what had happened in Physics. They were virulently against Raman and
said Born was a B grade out of work fellow and yes anti-Semitic comments were made. Born had not gotten his Nobel yet. Born stayed in India in the late 30's and wrote several beautiful papers in the Proceedings of the Indian Academy of Sciences a journal that Raman started. Born also collaborated with N.S. Nagendranath a Raman student who soon after left to head the Board of Education in Bihar and did not do anything after that. In fact Born developed what is now called Born-Infeld theory in Bangalore. But soon after there was a huge falling apart between Born and Raman. I do not wish to go into the details of this, but you can read it in a biography of Raman called Journey into Light.
Born left for the UK I think in 1938. I once took out the first few volumes of the Proceedings of the Indian Academy of Sciences at IISc, they are falling apart and in pieces and carefully as the pages were fragile, made a copy of the Born and Born-Nagendranath papers. Eventually IISc did not give Born a position and he left for Edinburgh in 1937 or thereabouts. I surmise he also blamed Raman for the fiasco. Raman also eventually severed his links with IISc and was famously heard to say that he would grow the trees in RRL( Raman Research Labs) so tall that he would never be able to see the IISc campus across the road( now Sir C. V. Raman road).

http://en.wikipedia.org/wiki/Max_Born

What is even more sad is that Born wrote a classic undergraduate textbook called "Atomic Physics", he is very scathing of Raman when he talks of the Raman effect. He dismisses it in the book and says that a Russian discovered it before Raman. You can read it there it is a standard textbook and still published by Dover Press. It is hard to understand that a person who was befriended by Raman and taken out of Nazi Germany at personal risk and also someone who was shielded from the British authorities acts in this way. I understand Raman was a martinet of sorts but Born comes across as an ingrate who still kept his disagreements with Raman till his end.

Incidentally the singer Olivia Newton-John is the grand-daughter of Max Born. I however fear I went OT here, mods please delete this post if you find it not suited . Back to Gunjan Bagla.

[Amber G.]

In the early 20th century, some German scientist showed that it was possible to extract trace amounts of gold out of a few tons of sea water.

... trace amount adds up... there is about 20,000,000 TONS of gold (give or take a few thousand tons ) in oceans of earth (and this does not count much much more undissolved gold under a mile or so below the surface in the sea bed )..Just a cubic kilometer will yield about 15 gm (A 100Kmx100Kmx1Km will yield about 150 Kilos).

(Yes, famous Fritz Haber (The inventor of the Haber process) worked on research on the extraction of gold from sea water in an effort to help pay Germany's reparations following World War I - They found that concentration was still about 10,000 less than what they needed to to make the extraction workable)... (Also many people think are working on, say extraction of Uranium from sea water.. which has more concentration than gold)

How about microbes to "clean up" (accumulate) gold from water. The microbes can then be gathered and burnt to extract their gold content.

Some time ago I put a post about MIT scientists work on using microbes to eat up and cleanup radioactive water..)

[member_22733]

I have a question about Biot-Savart law (was working on a simulation that had to use this).

It says the force exerted on a charged particle is perpendicular to both the magnetic field and its velocity. Newton's third law says every action has equal and opposite reaction. Where is the reaction for the biot-savart action?

[SriKumar]

My two cents....
Taking a simpler version of the above, the scenario is: a particle with a charge 'q' is moving with a velocity 'v' in a magnetic field of strength 'B', experiences a force = F = qv x B.
If the force on the charged particle is the action, the reaction (i.e. an equal opposite force) will be felt by the device creating the magnetic field B (maybe a coiled wire, electromagnet etc.). Essentially the two magnetic fields, one being the original field 'B', and the other magnetic field caused by the moving charge, are pushing against each other. This is from what I can recall of 11th class physics. I may have missed something..

[member_22733]

Oh! I see. The moving charge itself creates a magnetic field that then interacts with the source of the initial magnetism. Wonderful.

[SriKumar]

Yes. In fact, the basic Biot-Savart's law is actually a statement of the strength of magnetic field generated by a moving charge (i.e. current). The full eqn. is below but briefly, it says, the strength of a magnetic field created by a current (which is = charge/unit time) is proportional to the current 'I', length of wire through which the current flows, and inversely proportional to the square of distance (r) from the moving current.

http://en.wikipedia.org/wiki/Biot%E2%80 ... d_curve.29

Essentially, your question was about...."what happens when you add another magnetic field to the case where you have a moving charge, and how do the two interact with each other".

[Amber G.]

Sri Kumar et al -

The "simple versions" of Newton's laws as given, are subjected, (as all laws are) to experimental verification... and are not "exactly" true (even in non-relativistic environment) in the strict sense.

For example stated as:

Actioni contrariam semper et qualem esse reactionem: sive corporum duorum actiones
in se mutuo semper esse quales et in partes contrarias dirigi.

To every action there is always an equal and opposite reaction: or the forces of two
bodies on each other are always equal and are directed in opposite directions.

(or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts-- OR.Forces always come in pairs, and the sum of the pair is zero.)

... This is generally true as we commonly see (in any physics book and problems) in mutual forces like gravitational force or electrostatic force.. But..

... if we consider the magnetic interaction between two moving charges, in the general case the forces do not add to zero. In such cases, relativistic effects and the momentum of radiation caused by accelerating charges must be included... even if don't consider relativistic effects, we do not have equal and opposite forces. (To be fair to Newton, he was NOT aware of magnetic forces on moving charges).

For example, here is the famous example, often given (first IMO by Feynman) to illustrate the point..

Consider two electric charges (say Q1 and Q2) moving with constant velocities towards a fixed point (say coordinate (0,0))- One along x-axis and other along Y-axis. Take the instant where Q1 is at (0,0) (and still moving), and is directly ahead of Q2 (which is at some distance from (0,0)).

The electric force on Q1 (due to Q2) is equal and opposite to the force on Q2 (due to Q1)

BUT ..

The magnetic forces (see LokeshC's B&S law) are NOT equal and opposite. (One force is, obviously zero while other is not)

(The "non-simple" way to describe Newton's third law ("Total Momentum of a closed system is conserved") is true (or easy to understand) even in relativistic form when all things are taken into account)

[member_22733]

^^^ Holy moly! I must have missed a lot of 12th grade physics. Why did I not think of this before.

[SriKumar]

Sri Kumar et al - The magnetic forces (see LokeshC's B&S law) are NOT equal and opposite. (One force is, obviously zero while other is not)

(The "non-simple" way to describe Newton's third law ("Total Momentum of a closed system is conserved") is true (or easy to understand) even in relativistic form when all things are taken into account)

THanks for the explanations with the moving charges. I did see something about the 'unequal' forces when I googled for the B-S eqn and forces on a moving charge, but did not dig too much into it since I interpreted his question as asking 'where was the reaction force being experienced', and I certainly did not focus on the directions. I'll look up the other eqn. thx.

[Vayutuvan]

LokeshC: What are you trying to simulate? Several different applications come to mind.

In any case, if you want to solve for B (Magnetic Field) in an Magnetostatics (or only in situations where the current flow is weakly time varying) then take a general Electromagentics code that solves Maxwell's equations (Macroscopic should be fine if you are dealing with non-relativistic velocities and displacements are at least 9-10 orders of magnitude greater than Planck's length) from FLOSS (I don't have a link readily with me but you can check Scientific Linux distribution and see if they include some solver which can be driven through scipy/numpy endowed Python and possibly uses Octave for solving the linear system) which will obviate the need to roll your own code.

In the case of Magnetostatics, the approximation to B for your particular input as calculated by a Maxwell's equation solver would be same (within epsilon which you can chose) with the one you compute from Biot-Savart Law since Biot-Savart Law is a solution to Gauss's Law of Magnetism and Ampere's Law together which are the only two operative equations out of the four Maxwell's equations in case of Magnetostatics. As a by-product of the solve, one can get all reaction forces through post-processing the fields E and B.

From a computational perspective, you should roll your own code only if the following few conditions are satisfied:

1. Geometry is simple (especially if the problem at hand can be completely specified in a one of the common coordinate systems - Cartesian, Cylindrical, or polar)
2. You want to solve for the field at very few points and the field is fairly smooth
3. The medium is isotropic (constant Permeability and Permissivity in the domain)

Even then you may want to look at FLOSS codes as they are quite flexible and afford you the ability to model more physics than what you can with your own code. In the latter case, you have to keep on modifying your code as you include more physics into your model.

That was not an answer to your question. It might serve as an ansatz for others.

[Vayutuvan]

Srikumar: Please look in Wikipedia the following items:

Jifimenko's equations, Magentostatics, and of course Maxwell's equations.

[Vayutuvan]

LokeshC: HTH

EM simulation software

[negi]

^^^ Holy moly! I must have missed a lot of 12th grade physics. Why did I not think of this before.

Actually they taught classical mechanics in XIth grade and Electrostatics in XIIth but I don't think unless one is really curious types or had a brilliant teacher one would have at that time tried to think about connection between Newton's laws and Electrostatics . The closest was the typical comparison between the Gravitational force , electrostatic force and the weak force in one page of the text book.

[member_22733]

matrimc,

Here is what I can tell you: A somewhat crazy design for regenerative braking. I have used FEMM before, but needed a 3D finite element method to simulate it properly.

Long story short: Ended up looking at theory to try and derive the braking force and simulate it in an "indirect" way. One of the things I was looking at closely was B&S law and I ended up realizing that there was no "reactive" third law force to B&S force hence the confusion.

[Neshant]

Some so called Perpetual Motion machines.

According to the laws of Thermodynamics, they cannot exist. Though some of these machines may be incredibly efficient at conservation of momentum, they will eventually come to a stop due to friction. Nevertheless they are interesting.

I'm most fascinated with the first one - the Self-Flowing flask.

[Amber G.]

The "self flowing flask" video is nice, but it does not show the hidden pump (in the base) which is doing the work ..(IOW the video part is a bit fake)
(If you look carefully you may wonder why there is a mysterious pause after the water goes in (or why you see some bubbles that mysteriously appear)

[Neshant]

assuming there is no pump, what would stop the liquid from flowing in a loop endlessly.

would the liquid level in the flask eventually reach some level of equilibrium where the amount in the flask was insufficient to push the liquid entirely through the tube?

[Amber G.]

Assuming we are not talking about liquid helium near absolute zero (or other superfluid ) but just ordinary liquid in the flask(No capillary action - just a syphon). it will NOT work

For example wiki in Robert Boyle's page (http://en.wikipedia.org/wiki/Robert_Boyle says this ..

This is not possible in reality; a siphon requires its "output" to be lower than the "input".

Just try ... (Google gives, this You-tube: https://www.youtube.com/watch?v=-lTE3AQC_b0 to see if this really works.

(BTW, a good physics question is, why this will not work with liquids (as beer in the above video) where one can easily see that capillary action does seem to make this possible... a good physics question is, of course, why the level of liquid (beer) is higher in the narrow tube than in flask, in the first place.) ...

BTW, if you have not heard it before, check out what was proposed by the great Bhaskara in 12th century..Bhaskara's wheel

[SriKumar]

assuming there is no pump, what would stop the liquid from flowing in a loop endlessly.

Well, there are 'frictional' type of losses. The viscosity of the liquid would absorb energy in whichever direction it flows....similar to how friction absorbs energy of an object moving on a surface. This 'drains' the (kinetic) energy of the system ....in other words, viscous losses would not translate to a potential energy that can be 'recovered' later as a kinetic energy and keep the liquid moving. Also, there is friction between the flowing liquid and the walls of the tube, container....again energy 'lost' to the system. I know....LCE ....etc. it goes somewhere. Not sure where it goes...perhaps viscous losses result in a local increase in temperature.

would the liquid level in the flask eventually reach some level of equilibrium where the amount in the flask was insufficient to push the liquid entirely through the tube?

If I may...I think you might be assuming that the liquid in the larger tank weighs more (true) and therefore ought to 'push' the liquid in the smaller tube upwards since this weighs lesser. The thing to note is that the weight of the liquid in the larger tank is supported to a good extent by the walls of the tank. It is not entirely directed at the tube at the bottom. Note that the liquid applies a pressure everywhere (in direct proportion to its height) in its container..walls, bottom everywhere-Pascal's law. This pressure is a result of the weight of the liquid. The levels of liquid in the tank and tube will be the same at equilibrium.

The only force that the liquid in the smaller tube will experience from the liquid in the larger tank is the pressure at the bottom times area of the opening connecting the larger tank to the smaller tube.

[SriKumar]

(BTW, a good physics question is, why this will not work with liquids (as beer in the above video) where one can easily see that capillary action does seem to make this possible... a good physics question is, of course, why the level of liquid (beer) is higher in the narrow tube than in flask, in the first place.) ...

Not clear on what is being referred to as 'will not work'. Assuming it is perpertual flow of liquid in the system...... energy in a closed system is constant, and frictional losses bleed off energy and heat up the system, gradually reducing the kinetic energy. AS to why the beer is higher in the tube....to be frank the result was surprising to me. I could see that the portion of the beer higher than the 'expected' level of beer was not liquid beer...seems to be froth/foam of some sort. I suppose it foam/froth floating on 'actual' beer? I dont know much about capillary effect but the diameter of the tube seems to be too large for any significant level of capillary effects to pull up the fluids significantly.

Added later: I suppose the above beer+foam experiment is akin to doing the same test with 2 liquids, one with a lower density and one with a higher density? The lower density liquid will be at a higher level as it would be 'sitting' on top of the higher density liquid.

[member_22733]

Basically a perfectly reversible system can be a perpetual motion machine. If any form of energy is extracted out of it then its perpetual motion is going to stop.

All boils down the second law of Thermodynamics. Perfectly reversible closed systems have zero entropy increase. If there is the slightest bit of energy loss (usually in the form of radiation), then it will not be recoverable (unless faster than light physics is possible ). When the entropy increases, the perpetual motion decays. Once something is radiated out of the closed system, you are never going to recover it as you can never catch up with it.

So trick with finding flaws with perpetual motion machine is to look for sources of radiation (or heat). Friction, turbulence, EM radiation source (coil moving abruptly around a magnet) etc can be good starting points.

[johneeG]

BTW, if you have not heard it before, check out what was proposed by the great Bhaskara in 12th century..Bhaskara's wheel

Excellent! Thank you! I didn't know about this. The simplicity of the idea is excellent. BTW, why mercury? Weight?

[johneeG]

Basically a perfectly reversible system can be a perpetual motion machine. If any form of energy is extracted out of it then its perpetual motion is going to stop.

All boils down the second law of Thermodynamics. Perfectly reversible closed systems have zero entropy increase. If there is the slightest bit of energy loss (usually in the form of radiation), then it will not be recoverable (unless faster than light physics is possible ). When the entropy increases, the perpetual motion decays. Once something is radiated out of the closed system, you are never going to recover it as you can never catch up with it.

So trick with finding flaws with perpetual motion machine is to look for sources of radiation (or heat). Friction, turbulence, EM radiation source (coil moving abruptly around a magnet) etc can be good starting points.

The problem seems to be to find ways to store energy (and carry it around easily) after it has been created. Capacitors and batteries seem to do it but are only used at small scale. So, is there anyway to store energy for few weeks after it has been created?

[Amber G.]

BTW, if you have not heard it before, check out what was proposed by the great Bhaskara in 12th century..Bhaskara's wheel

Excellent! Thank you! I didn't know about this. The simplicity of the idea is excellent. BTW, why mercury? Weight?

JohneeG, from what I know, in all probability, Bhaskara used this example to illustrate silliness ( impossibility) of such machines. They may be good enough to fool those who are not good at math (or are not careful to find obvious mistakes in arguments). One can not construct such machines in practice to useful work and that is not too hard to understand.

[Amber G.]

.. If I may...I think you might be assuming that the liquid in the larger tank weighs more (true) and therefore ought to 'push' the liquid in the smaller tube upwards since this weighs lesser. The thing to note is that the weight of the liquid in the larger tank is supported to a good extent by the walls of the tank. It is not entirely directed at the tube at the bottom. Note that the liquid applies a pressure everywhere (in direct proportion to its height) in its container..walls, bottom everywhere-Pascal's law. This pressure is a result of the weight of the liquid. The levels of liquid in the tank and tube will be the same at equilibrium.

The only force that the liquid in the smaller tube will experience from the liquid in the larger tank is the pressure at the bottom times area of the opening connecting the larger tank to the smaller tube.

Very good explanation. Thanks.
(Water level in the tube will be same level as flask - does not depend on the diameter of the tube)

[johneeG]

JohneeG, from what I know, in all probability, Bhaskara used this example to illustrate silliness ( impossibility) of such machines. They may be good enough to fool those who are not good at math (or are not careful to find obvious mistakes in arguments). One can not construct such machines in practice to useful work and that is not too hard to understand.

Did Bhaskara clearly stated that he was attempting to illustrate the impossibility of making such machines? If not, its just your opinion based on speculation. Anyway, how can one prove the impossibility of making perpetual motion machine? If one design does not work, one can always claim that a better design will work.

I think you (not Bhasakara) missed a basic logic: one cannot prove the non-existence conclusively. Non-existence is an assumption when existence is not perceived by the seer.

Existence can be positively proved by direct observation. Non-existence (I.e impossibility) cannot be conclusively proved.

So, your idea that impossibility can be proved is itself silly.

So, I am going to assume that Bhaskara actually tried to build a working perpetual motion machine. The fact that this design was copied by many other cultures shows that this design was seen as very good. Further, Bhaskara may have been inspired from ancient work on such machines. Mahabharatha mentions huge wheels being setup when a new city was established by Yuddhishtira. What are these wheels for? It doesn't mention.

This Bhaskara wheel might be useful in generating electricity.

[csaurabh]

JohneeG, from what I know, in all probability, Bhaskara used this example to illustrate silliness ( impossibility) of such machines. They may be good enough to fool those who are not good at math (or are not careful to find obvious mistakes in arguments). One can not construct such machines in practice to useful work and that is not too hard to understand.

Did Bhaskara clearly stated that he was attempting to illustrate the impossibility of making such machines? If not, its just your opinion based on speculation. Anyway, how can one prove the impossibility of making perpetual motion machine? If one design does not work, one can always claim that a better design will work.

I think you (not Bhasakara) missed a basic logic: one cannot prove the non-existence conclusively. Non-existence is an assumption when existence is not perceived by the seer.

Existence can be positively proved by direct observation. Non-existence (I.e impossibility) cannot be conclusively proved.

So, your idea that impossibility can be proved is itself silly.

So, I am going to assume that Bhaskara actually tried to build a working perpetual motion machine. The fact that this design was copied by many other cultures shows that this design was seen as very good. Further, Bhaskara may have been inspired from ancient work on such machines. Mahabharatha mentions huge wheels being setup when a new city was established by Yuddhishtira. What are these wheels for? It doesn't mention.

This Bhaskara wheel might be useful in generating electricity.

Wtf is this? Impossibility is real. 2+2 = 5 is impossible. In mathematics ( unlike sciences ), proofs of possibility or impossibility are absolute.

Physically going beyond the speed of light is impossible according to the current knowledge. If a different picture of the universe arises, then perhaps we can go beyond that barrier, but until then, it is still impossible.

Perpetual motion machines are just silly. The wheel mechanisms were devised by con artists as a scam in various parts of Europe in 18th-19th centuries. No need to think much about this.

[Vayutuvan]

JohneeG: A very simple scientific thing to do.

Build one with the help of bhAskarAchAryA's drawings. Right down your setup in excruciating detail so that others can reproduce it just from the description. At this point know how is good enough. Once a large number of people reproduce the results independently, the search for know why can start.

First observation of phenomenology, next controlled experimentation and description of the setup and independent verification and then comes how to harness and control.

[Yayavar]

It would be nice to know if Bhaskara was in earnest or was demonstrating that such solutions are silly. Any references to the latter? That would be a much higher level of scientific understanding that was 'rediscovered' only after Carnot (iirc)

[Yayavar]

Adding to above... from what I can find Bhaskara actually thought that this machine would run on its own; and this gave rise to the frenzy in Europe for perpetual motion machines. Did not find any reference indicating that Bhaskara thought the machine was impossible or that he considered perpetual motion machines an impossibility. (All this through Google chacha so the eventual source could be one person's interpretation)

[member_22733]

johnee garu,

One thing I "believe in" (as there is no real proof of it) is the second law of thermodynamics, and also the law of conservation of energy. You can think of entropy as an "inverse of energy content". If you design a system that goes from one state to another with zero loss of energy, you have "something" that is perpetually moving. The moment it starts leaking energy (i.e. entropy increase) you end up losing whatever energy there is in the system. And you know it will start leaking energy when you try to extract it for whatever "work" you are planning to do with it. The useful energy soon goes to zero (max entropy state), and then your machine stops or breaks down. There is no miracle here, no silliness. The math is surprisingly simple and easy to follow.

Here is something interesting I discovered while I was trying to understand Relativity and Thermodynamics:
The fact that entropy decrease is never possible in a closed system is one of a very fundamental nature. You can take any equation that describes the physical process and reverse time in it and you will get a mathematically and physically valid situation. The only way that we know that time is "increasing" is that entropy keeps increasing as time increases. This is why I believe that time-travel backwards is not possible (not proved yet, so my conjecture). The reason is when you travel "backward" in time, you are going into a "hotter" universe than the one you are currently in. You are traveling from a state of high entropy to a state of low entropy, and that I am conjecturing is impossible. There must be a conjecture that closed-time-like curves (CTCs) are impossible in Quantum-Gravity. I am sure someone would have thought of that by now.

Somehow there exists a deep link between time and entropy increase. For example: What it tells me is that there is no part in the universe that a process will be running backward in time according to its physical description. Which means, every particle, every atom, every "body" (including a black hole and a particle of light) must have its entropy increasing. The rate of increase maybe local, but the phenomenon of entropy increase is global. Global and local as defined by relativity. Near a blackhole time would pass much more slowly than outside. All it means is the process of entropic decay is slower near that region, but it IS happening and at some point of time in the far far future from our reference frame, that black hole will attain its maximum entropy state (which according to Hawking results in a particle that is of Planck Mass after a few million-billion-trillion years). Remember Max Entropy: Max decay, lowest possible energy.

In a non-Quantum Mechanical world, there is nothing called "free-energy", although there are all sort of crazy "scientists" running around trying to figure out free-energy, time travel etc. "free-energy" comes from the fact that Quantum Mechanics and relativity combine in a narrow sense and create this mathematical convinience of particles appearing and disappearing simultaneously. This is due to fluctuations of the field and a field = particle in QM. There is no way anyone is going to extract it and use it.

[SriKumar]

LokeshC mian,
please go ahead with your explanations for JohneeG's comments on perpetual motion machine. But I suspect this may be your first engagement with JohneeG
So, just to give you some idea of what might lie in store.....JohneeG sahab is sceptical about some theories of rocket propulsion..... (JohneeG bhraata, kshamyataam, kshamyamtaam. I do not want to re-start this debate )

Disclaimer: It is possible JohneeG has changed his mind on this, in which case I stand corrected.
But, I have to say I do owe JohneeG garu one..... Thanks to a question he raised about a post of mine (again, physics thread), I was able to nominally and marginally correct my stance barely in time as the resident adhyaapak came by, admonished the ignorance at display and clarifed the point
(minor edits made...this thread was in GD forum for prior discussions and brought outside recently...).

[member_22733]

JohneeG sahab is somewhat sceptical that rockets work in vaccuum.

Dont want to troll anyone , but here is a story:
Long time ago, over copious amounts alcohol and ganja an artist friend figured out a new form of propulsion: Balloon Propulsion. Logic goes like so: Earth rotates 1800km/h. Get on a balloon, hover above the earth and go from point A to point B at 1800km/h.

I told him that we were so "high" at that time, that just closing your eyes will get you from point A to point B at speed of light. Anything is possible... onleeee.

[Vayutuvan]

Probably you were not doing Gin and grass and so lived to tell the tale. Those two are supposed to be fatal if consumed simultaneously. No idea of the veracity. Is it an urban legend?

[member_22733]

No it's the truth, I believe, the combination can make you nauseous or dead. I just don't quite remember much of that day and what any of us consumed that day. I do remember that balloon idea though

[Yayavar]

btw, the reference to Bhaskara's wheel made me think if there are other 'machines' that are known to have been used in ancient/medieval India? Spinning wheel is another. Was the thrust towards mechanical devices mainly from European medieval ages?

[member_22733]

yayavar:

This is OT, I dont know the appropriate thread for it. I will xpost if I find one.

I have been looking at reasons why Europe advanced suddenly out of the "medieval times". The reason is based in violence, scarcity and necessity, and also being at the right place at the right time. Most of Europe developed war machines (torturing devices, weapons etc), and had knowledge on construction of advanced machinery for the purpose of war.

This was a lucky accident, as it was a left over push from the Greko-Roman Bryzantine era (in which Europeans were r-a-p-e-d). These empires were built on expansionist philosophy. This is also the root of the "love" that many western folks have about the Greeks. The other thing is Bryzantine empire protected Europe from Islamic onslaught, it was a buffer zone. The left over Roman Jews/Christians/Pagans fighting against their more violent cousins.

Bryzantine empire was in the "right place at the right time for Europe", i.e. they were doing crusades at that time which meant they will murder every malsi follower on their way to Jerusalem. Crusades played an important role in the development of long distance maritime trade and shipping.

Now in the process, the Bryzantine folks did something amazing (and IMO this is where we indics lost out) they collected knowledge from the Middle east, which was collecting knowledge from India and elsewhere. They also started collecting knowledge from Central Asia and "old"-Europe. Bryzantines are known to have preserved and respected the old European civilizations. But as "colonizers" of Europe, they changed the elites of Europe with various favors (just like our Macaulayites of today).

Bryzantine empire thus became a knowledge center, an archive of ancient knowledge and also collected large number of students and artists in the process. By the time Bryzantine empire fell to the Ottomans, they were already weak compared to the European center that was developing in the west. Europe thus inherited the scientists and the artists and it became a "melting pot" of the ideas that came from as far away as India and China. Europe also inherited the Bryzantine war machine, Greko-Roman realpolitik and intelligence gathering structure which was perfected by the Bryzantines. Euopeans were also buffered and protected from Malsis in their most weakest moments by the Bryzantine empire.

Europe is also far colder than the Mediterranean. Which means Europe was more inclined to develop clustered and isolated population, i.e. Cities. Innovations that can support more people will result in more people coming together (if you know what I mean). Urbanization also creates an idea market that can never be beaten in villages. European elites were fascinated with new "knowledge" and sponsored scientists and artists to study them. This went on until Rome became supreme again (through the Vatican) and Europe fell into their "dark ages" for about 800 years.

Renaissance pulled them out of it and they started to recover old Bryzantine/Greek/Roman knowledge and build on it. By this time, India was still largely rural and was never "plugged in" to the enormous churn that was going on in Europe. We had excellent knowledge centers, but we never had the need to "explore, integrate and innovate". If we had a Bryzantine invasion or had been a war obsessed knowledge gathering center, we might have been an extremely powerful entity by now. Whether Indic philosophies would have survived it or not is another question.

We were self-absorbed, just like much of Europe and the west is today. Then came the Islamic barbarian onslaught and the fall of the India. The rest, as you know is history .

BTW: I do not know of knowledge flow "INTO" India anywhere in History, if anyone knows about it please make me aware of it.