[HN Gopher] Leonardo da Vinci's experiments explored gravity as ...
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Leonardo da Vinci's experiments explored gravity as a form of
acceleration
Author : PikelEmi
Score : 186 points
Date : 2023-02-17 09:51 UTC (13 hours ago)
(HTM) web link (www.caltech.edu)
(TXT) w3m dump (www.caltech.edu)
| thefoolofdaath wrote:
| IMHO, this is less surprising discovery about him considering
| this probing is around 300 years ahead of his time, and Da Vinci
| already has proof for concepts 500 ahead of his time.
| credit_guy wrote:
| > "What we saw is that Leonardo wrestled with this, but he
| modeled it as the falling object's distance was proportional to 2
| to the t power [with t representing time] instead proportional to
| t squared," Roh says. "It's wrong, but we later found out that he
| used this sort of wrong equation in the correct way." In his
| notes, da Vinci illustrated an object falling for up to four
| intervals of time--a period through which graphs of both types of
| equations line up closely.
|
| All lines look straight if plotted on a log-scale and drawn with
| a thick enough marker.
| lanosbdld wrote:
| Compare 2^t, where t takes values from [1, 2, 3, 4], with t^2
| over the same set of values. The results are closer than you
| might expect.
| pbj1968 wrote:
| This Leonardo is really going places.
| rerdavies wrote:
| One of the things that irritates me a little about Da Vinci is
| he gets disproportionate credit for inventing things that don't
| actually work. The list of things he invented that he actually
| got to work is vanishingly small.
|
| Even when claims are made that he is "prescient", there has
| never been, nor will there ever be a functional "helicopter"
| that looks like Da Vinci's helicopter.
| spaceman_2020 wrote:
| You always compare people against their contemporaries. Da
| Vinci has his reputation because he was exploring ideas far
| above and beyond his contemporaries, and because his breadth
| of knowledge and skills covered a wide swathe of subjects.
| ly3xqhl8g9 wrote:
| His killing machines seemed to work just fine [1], although
| some seem to go towards a more interesting counterpoint for
| when HBO will make the inevitable series _Da Vinci: The
| Machine_ , staring Leonardo di Caprio [2].
|
| [1] How Leonardo da Vinci made a living from killing
| machines, https://theconversation.com/how-leonardo-da-vinci-
| made-a-liv...
|
| [2] Leonardo's War Machines - The Italian Genius May Have
| Deliberately Sabotaged His Own Designs,
| https://www.warhistoryonline.com/history/leonardos-war-
| machi...
| quectophoton wrote:
| I have deep respect for these geniuses of the past.
|
| Imagine what they could have achieved if they have had access
| to modern tools, even "just" something like a graphing
| calculator[1].
|
| [1]: I like https://www.desmos.com/calculator
| kwhitefoot wrote:
| What Leonardo needed was staff. He needed to run a research
| institute and offload the implementation to people who were
| less easily distracted.
| mo_42 wrote:
| Yes! During his lifetime, he was mainly seen as an artist.
| He probably earned well but still magnitudes lower than
| what he would have needed to get something done. Just
| imagine if there would have been something like venture
| capitalists.
|
| I guess in terms of the big five, he was super-high in
| openness but no so high in conscientiousness. In today's
| world he would fit better because he could run an institute
| or a company.
| rerdavies wrote:
| Even better, imagine what he could have achieved if he had
| access to modern calculus!
| xeonmc wrote:
| Desmos? You mean a full-blown Turing-complete simulation
| platform[0]?
|
| [0] https://www.desmos.com/calculator/vjnhlumjiw
| anoncow wrote:
| That website is (chef's kiss) and I don't understand what
| it is about.
| ZiiS wrote:
| My worry is giving someone with da Vinci's thirst for
| knowledge Wikipedia and they may never have time to achieve
| anything.
| GuB-42 wrote:
| I actually think the tools and environment are more important
| that the genius.
|
| There are thousands, maybe millions of people with genius-
| level intellect, all capable of being the next Leonardo or
| Einstein. Out of them only a small fraction grew up in the
| right environment, usually wealthy families, but that's still
| a lot of people. The next, and I think most important
| requirement are the tool needed to make the discovery, or
| even just to know that a discovery is to be made.
|
| For example, if you don't have the tools needed to notice
| that the speed of light isn't infinite, special relativity
| makes no sense. General relativity requires even more tricky
| measurement, in fact it didn't came long after people noticed
| something was wrong with Newtonian mechanics.
|
| Tools are in the general sense. Physical object like a
| computer or a good telescope, manufacturing techniques and
| even maths, think of the "shoulders of giants" thing.
|
| So it would be more like giving the graphing calculator the
| genius it needs rather than going back in time and giving the
| genius a graphing calculator.
| david927 wrote:
| Nicely said. Alan Kay talks a lot about this.
| rerdavies wrote:
| Umm.
|
| But the water droplets/sand particles do NOT form a straight line
| if you accelerate the jug. You have to decelerate the jug with
| exactly the right timing to form a straight line, not accelerate
| it. Nor do the beads in the Caltech video form a straight line,
| despite their dishonest attempt to arbitrarily impose a straight
| line on beads that are clearly not in a straight line.
|
| In the second diagram, which is alleged to be an attempt to plot
| acceleration due to gravity to the position of an accelerating
| water jug, the values [0,1,2,4,8] are marked on the x-axis, and
| [0,-1,-2,-4,-8] on the y-axis. Da Vinci then plots lines from
| [0,-8] to the points (0,0),(1,0),(2,0),(4,0),(8,0). Doing so
| doesn't really establish any sort of relationship between
| accelerating jugs and acceleration due to gravity, even allowing
| for an incorrect equation of motion for an accelerating object.
|
| Da Vinci spent most of his early career trying to sell military
| technology to potential patrons (largely if not completely
| unsuccessfully). One of the pieces of technologies he was trying
| to sell was a process for calculating improved artillery range
| tables (tables of elevation vs. range). He didn't manage to sell
| that either.
|
| The second diagram is more easily interpreted as a doodle that
| makes an unsuccessful attempt to scry a relationship between
| elevation and range for artillery pieces.
| s1artibartfast wrote:
| >But the water droplets/sand particles do NOT form a straight
| line if you accelerate the jug. You have to decelerate the jug
| with exactly the right timing to form a straight line, not
| accelerate it.
|
| You can make a right triangle via either acceleration or
| deceleration at the same rate as gravity. However, you can only
| make an Isosceles Right Triangle with acceleration
|
| Vertical position is a function of t^2. If you have constant
| horizontal velocity, you get a concave curve like this:
| https://www.wolframalpha.com/input?i=Y%3D-1x%5E2
|
| Accelerating the horizontal velocity leads to a triangle like
| this: https://www.wolframalpha.com/input?i=Y%3D-x
| SamBam wrote:
| Actually a constant horizontal velocity will make a straight
| vertical line of droplets under the jug. This is because the
| drops will have the same horizontal velocity as the jug.
|
| You can see that here:
| https://demonstrations.wolfram.com/TrajectoryOfABomb/
|
| At any time, the first bomb is always directly under the
| plane. This means all subsequent bombs will also be under the
| plane.
| SamBam wrote:
| > You have to decelerate the jug with exactly the right timing
| to form a straight line, not accelerate it.
|
| ---
|
| Edit: The quote above, and my original comment below, are
| wrong. The article is correct. Accelerating the jug at g will
| create a straight line.
|
| Corrected acceleration model:
| https://scratch.mit.edu/projects/805927382/
|
| Thank you hannasanarion for the correction.
|
| Indeed, this can be thought of intuitively (though it is
| slightly counter-intuitive): as the article says, if the jug is
| moving at a constant speed, the drops will actually make a
| vertical line under the jug. This is because each drop will be
| move with the same horizontal speed as the jug.
|
| A decelerating jug, as proposed above, would actually create a
| backwards line or curve. The drops at the bottom works actually
| be _ahead_ of the jug.
|
| An accelerating jug is the only way you can get the bottom
| drops behind the jug.
|
| ---
|
| My previous comment:
|
| Indeed.
|
| I was pretty sure this was correct, but wanted to model it to
| confirm. On a Chromebook right now, so Scratch was the easiest
| way to model and share:
|
| Accelerating jug (cat):
| https://scratch.mit.edu/projects/805898350/
|
| Decelerating jug: https://scratch.mit.edu/projects/805899100/
| hannasanarion wrote:
| In your program, each of the balls starts with zero
| horizontal velocity. This is not analogous to real life, in
| which the droplets from the jug will have the same horizontal
| velocity as the jug at the moment they detached. They
| shouldn't fall straight down, they should follow a ballistic
| arc. I don't have the skills to set up a simulation of this
| right now, but I wouldn't be too surprised if the total of
| those ballistic arcs forms a straight line.
| SamBam wrote:
| You're totally right. Adding in the ball's horizontal speed
| makes the article's statement correct: you do have to
| accelerate the jug by g in order to get a straight line.
|
| Corrected model:
| https://scratch.mit.edu/projects/805927382/
| [deleted]
| coda_ wrote:
| That's what I thought as well... But I think what the diagram
| isn't showing is that the drops are actually moving
| horizontally to the left at the speed that the jug was moving
| at the time the drop left the jug. This means each one is
| moving to the left slightly faster than the one before it...
| And as they fall this creates an increasing horizontal distance
| between them... The line is kept at a constant angle due to the
| fact that the earlier drops are falling downward slightly
| faster than the later drops. The horizontal and vertical
| difference between the adjacent drops maintains a 1 to 1 ratio.
| josefresco wrote:
| Just finished reading Leonardo da Vinci by Walter Isaacson. Was a
| very good read, learned a lot about da Vinci that I was never
| taught or discovered on my own.
|
| https://www.goodreads.com/book/show/34684622-leonardo-da-vin...
| actinium226 wrote:
| ^ I also just finished it. Really loved it. Really loved how
| Isaacson allowed himself to interject here and there with his
| own thoughts and his own appreciation of daVinci. I felt like
| it really highlighted some of the unique aspects of the man.
|
| I also came to appreciate some of the artwork and now I can
| look at the Mona Lisa and have my own thoughts on the work.
| electroagenda wrote:
| Domingo de Soto (1494-1560) also indicated that gravity produced
| accelerarion way earlier than Galileo Galilei.
| orwin wrote:
| Da Vinci's work on water's management and hydrolics ultimately
| pushed us through the technological wall the Romans hit, that
| lead toward waterworks and the first industrial revolution.
| p1mrx wrote:
| Would it be correct to say that you feel gravity/weight because
| the ground is accelerating upwards in your local reference frame,
| and your body's inertia resists that acceleration?
| samstave wrote:
| So... this is a really interesting comment to me.
|
| Years ago when I was really into [various philosophies] and
| [secret society]...
|
| They stated that gravity actually _pushes up_ but it is mass
| and movement that counteract gravity 's push
|
| it was the vibrations of cymatics and sound that could counter-
| act mass on gravity and take advantage of gravity pushing up...
| and this is how the ancients knew to move/manipulate matter in
| space...
|
| This is what Tesla alludes to through 3/6/9 vibrations, and how
| Ed Skalnanin built the coral castle.
|
| Its all about changing harmonious vibrations, and both
| Skalnanin and the Egyptions had interesting vibratory circular
| tools which are missing parts, but basincally from spinning
| them they could manipulate the vibratory frequency of matter
| such that their mass didnt effect gravity and took advantage of
| gravity's push...
|
| So the idea was to think of mass as the inverse of gravity when
| the frequencies are not sync'd..
|
| I know it science-fiction, but its fun to think about.
|
| I think the more interesting effect to look at is centrifugal
| forces. I think that _everything_ spins because a constant
| turning (warping) of space-time (gravity pushing) 'UP' is how
| mass stays 'co-herent' 'co-hesion'
|
| Think of superconductive levitation. Slow the spin of an object
| "in-motion" and it can levitate...
|
| What if rather than through temperature control on manipulating
| the rotation of Atoms, you could use sound to levitate
| objects.. (seen the frog levitating in ultra-sound...
|
| The conspiracy idea is that it is mapped out in certain stone
| carvings for the frequency.
|
| Like the Rose church, which has Cymatic [atterns carved into
| its walls, which tell you the frequencies used...
|
| Think of how certain alloys are made under magnetic fields, and
| ceramics. Imaging forging an alloy under both a magnetic field
| & a cymatic frequency.
|
| I love this conspiracy theory as its a great foundation to
| science-fiction writing as well.
| p1mrx wrote:
| I don't see how any of that follows. If the ground is
| accelerating upwards, then making an object levitate would
| require stopping that acceleration. Even with scifi magic,
| that problem sounds more difficult than "blocking gravity" in
| one location.
| hgsgm wrote:
| When you _aren 't_ moving you feel pressure due to you and the
| planet trying to free fall into each other to make a black
| hole, or at least pass each other in very close orbit, but
| being blocked by the repulsion of your electrons vs your
| shoes'/floor's/ground's.
|
| When you are falling, you are feeling the air that is hitting
| you because it is not falling, causing the electron effect
| above, and your guts feel weird because your brain is noticing
| that nothing is pushing on them anymore.
| boomboomsubban wrote:
| A recent discussion on the topic
|
| https://news.ycombinator.com/item?id=34764318
| dboreham wrote:
| Speaking of Leonardo: I noticed that the Mona Lisa has a new much
| better (more transparent) protection glass, at least new since I
| last visited a few years ago. It makes it imho more worthwhile to
| go see it. Also pro tip, go in February -- there's only a
| moderate crowd, not a crazy dense throng as in the summer.
| actinium226 wrote:
| Here's another pro-tip: there are other "copies" of the Mona
| Lisa which, IMHO, are more interesting to look at than the
| deeply varnished one on display at the Louvre. The Prado Mona
| Lisa is one I particularly like.
| s1artibartfast wrote:
| I would think that individuals from antiquity would understand
| that an object rolling down hill picks up speed, or a rock
| dropped from higher hits harder.
|
| The existence of acceleration aspect may not have been novel, but
| measuring the rate seems to be the novel part
| tbarbugli wrote:
| isn't indeed easier to measure a rolling object going down from
| a ramp? measuring water falling from a jar while moving the jar
| sounds very complicated.
| n4r9 wrote:
| I may be missing something here, but there's a conceptual leap
| from "the acceleration produced by gravitational force" to
| "gravity as a form of acceleration".
|
| Da Vinci certainly appears to be exploring the former. The latter
| was Einstein's great insight. I don't see much in the article to
| persuade me that da Vinci was equating gravity and acceleration
| in the way Einstein did, and so the title seems a little too
| suggestive.
| coldtea wrote:
| > _I don 't see much in the article to persuade me that da
| Vinci was equating gravity and acceleration in the way Einstein
| did_
|
| Thinking of the effect on speed of things falling down as
| acceleration (as opposed to constant), and even coming up with
| a formula, is already a bridge between these two things.
| Gregaros wrote:
| No, it is not at all a bridge to Einstein's 'gravity and
| acceleration are equal', which is "the gravitational force is
| physically indistinguishable from any acceleration", which
| has to do with changing to relatively accelerating reference
| frames.
|
| The insight of da Vinci's here is anticipating Newton, not
| Einstein. And yes, this is already an accomplishment, but not
| the outlandish one the article would imply.
| coldtea wrote:
| Hence "a bridge". It's not Einstein's result, but it's
| moving towards Netwon (and eventually that) from older
| ideas about the behavior of things "falling" (such as
| proportional to their weight and constant speed).
| razor_router wrote:
| agreed, there's no evidence is there that suggests Da Vinci was
| equating gravity and acceleration in a similar way to Einstein
| mannykannot wrote:
| Indeed; this seems to be an extreme example of what might be
| called the "whig history of science", which interprets the past
| in the light of what we know today, attributing, to historical
| figures, modern concepts which they surely never even conceived
| of, and which would undoubtedly baffle them until they had been
| brought up-to-date with current knowledge.
|
| https://en.wikipedia.org/wiki/Whig_history
| valvar wrote:
| > attributing, to historical figures, modern concepts which
| they surely never even conceived of, and which would
| undoubtedly baffle them until they had been brought up-to-
| date with current knowledge.
|
| I don't think that's quite what Whig history is. The
| Wikipedia article doesn't seem to imply that, either. If
| there was a "Tory history", I think this case would be more
| like that, as it presents a past figure as being more
| enlightened (while Whig history typically does the opposite
| in order to extol progress).
| mannykannot wrote:
| Yeah, I'm not certain about the analogy, and I'm basing it
| more on how I have seen the phrase used in other places,
| but my cursory search did not dig them up. IIRC, the
| complaint is that, in order to present history as the
| steady progress towards what they regarded as an
| enlightened present, Whig historians attributed influential
| and powerful historical figures with liberal motives and
| goals. Tory historians might have attributed them with
| illiberal motives and goals that were sometimes thwarted
| (leading to what they regarded as a suboptimal present),
| which might well be more plausible in general.
|
| Looking a little further into the article, I see it
| mentions a whig history of science that ignores failed
| theories and dead ends, and I would agree that this is not
| the same as attributing _successful_ theories to people who
| probably did not hold them, though the latter does also
| tend to present science in 'march of progress' terms.
| syntaxfree wrote:
| A conservative history would emphasize more the contingency
| of the scientific process and the fact that it wasn't
| inevitable that we'd get where we got.
|
| Extending this: the Whig story on contemporary science (sp.
| as it affects policy) is that this is the best science
| because scientists have been improving it forever, while
| the conservative story is that maybe the scientists are
| wrong now, they've so often been wrong in the past.
| lucideer wrote:
| You're right but upon reading the article it does seem to
| actually be a form of Whig history - the article attributes
| the actual first work on this to Galileo (not Einstein), so
| while the headline is misleading, the article content seems
| to simply be surprised someone in the 14th century could be
| aware that gravity causes objects to accelerate at all.
|
| The idea that the Galileo in being the first to formalise
| an equation for precise calculation of acceleration was by
| extension the first in history to conceptualise that
| acceleration occurs at all is a severe infantalisation of
| all scientists who preceded him.
| n4r9 wrote:
| Like the other reply I question whether this is an example of
| what's in your wiki article. However I have often wondered
| why something like Democritus' atomic model of the universe
| is given such praise when it probably had very little going
| for it at the time, and now I know the terminology for this
| phenomenon, so I am grateful for that :)
| samstave wrote:
| I call BS on this particular account of a Vinci ;;
|
| He was millennia ahead of his time, and I personally believe
| he had an understanding of physics but was existing in a time
| where the tools available to his understanding were what was
| lacking.
|
| This guy predicted eddy-based hydrodynamic in the cardio
| vascular system before "human biology" was considered a
| science.
|
| Look at da vinci's designs for the eddy-hydro-pump system...
|
| Maybe he was a time traveling engineer who needed to plant
| seeds of knowledge in our past on this timeline to ensure
| advancement and growth of Humanity.
| hummus_bae wrote:
| Early on in my physics career, my supervisor asked me to keep
| in mind "it's about speed, not velocity" when doing
| calculations. In general a force is a change in momentum, i.e.
| a change in speed. Acceleration is a change in speed relative
| to some frame. It's quite possible that da Vinci may
| unknowingly have seen gravity as an acceleration (as in my
| example above) and taken the next step to seeing it as a change
| in speed.
| red_trumpet wrote:
| Well, thinking of gravity as a force is Newtonian mechanics,
| which was also not available to da Vinci.
| globuous wrote:
| Which was in itself the genius of this newton guy. It's one
| thing to realise that objects falling accelerate. It's
| another to realise that F=ma, and that this can model objects
| falling as well as a bunch of other things. Surely da Vinci
| wasn't lucky enough to have an apple fall on his head ? :)
| photochemsyn wrote:
| Someone has already incorporated this into the wiki entry for
| historical development of gravitational theory, which may or
| may not be entirely justified:
|
| https://en.wikipedia.org/wiki/History_of_gravitational_theor...
|
| That's an interesting article, including some challenges to
| Aristotle's views and gravity-related concepts introduced by
| Indian and Islamic scholars of the 6th - 12th century eras or
| so.
| wolverine876 wrote:
| > Someone has already incorporated this into the wiki entry
| for historical development of gravitational theory, which may
| or may not be entirely justified: > https://en.wikipedia.org/
| wiki/History_of_gravitational_theor...
|
| Isn't that a core problem with Wikipedia? I don't understand
| why its reputation on HN improved, a few years ago, from
| 'infotainment but a symbol of mis-/disinformation' to 'source
| of truth'.
| lamontcg wrote:
| Yeah, this is just high school Newtonian physics where we
| should have all learned the concept of gravitational
| acceleration.
| olddustytrail wrote:
| Inevitable pedantry: his name is Leonardo, not "da Vinci".
|
| "da" means "from", or in this sense "of". So just as you might
| say "Jesus of Nazareth" you say "Leonardo of Vinci".
|
| You would never say something like "...and Of Nazareth said...",
| so likewise it's weird to say "da Vinci invented..."
| alecst wrote:
| I asked an Italian native speaker about this and she said she
| calls him "da Vinci." She has a PhD in linguistics, and in
| general she's pretty precise with her language. She doesn't
| seem to see anything wrong with it. Just as a datapoint.
| dokem wrote:
| You're wrong because everyone in the English speaking world
| refers to him as da Vinci which means da Vinci is the name that
| refers to the person Leonardo. That's how names and language
| work. Now back to playing with my LEGOs.
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