Why did it take 100 years approximately for the idea of energy to be accepted

In summary, it took over 100 years for the scientific community to accept that energy is directly proportional to velocity squared, despite it being able to be taught in a simple 1 hour lesson in high school. This is because early natural philosophers, such as Newton, Leibniz, and Descartes, had different ideas about the fundamental "quantity of motion". Newton's belief that energy was proportional to momentum delayed the acceptance of Leibniz's idea that it is proportional to the square of velocity. It was not until French physicist Émilie Du Châtelet conducted experiments measuring the depth of impressions left by dropped balls in clay that the concept of kinetic energy being proportional to velocity squared was widely accepted.
  • #36
FactChecker said:
But there are complications. When two equal balls collide head on and both stop dead, that seems to prove that there is nothing like "energy" that is conserved.

PS. If it wasn't clear to Newton, it is not that obvious.
Do you think that they were approaching momentum and energy with conservation in mind?
 
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  • #37
anorlunda said:
Do you think that they were approaching momentum and energy with conservation in mind?
Some people find it hard to empathise with other people's ignorance. It's just amazing how little the Scientists of the Enlightenment actually knew, compared with what we have found since.
"Conserve" is what you did with your food supplies over winter, in those days.
 
  • #38
sophiecentaur said:
Some people find it hard to empathise with other people's ignorance.
...
That's almost word for word what I told my sister last week.
Of course, being an 'old' man, I was wise enough not to argue with her.

One of my greatest thought experiments, and conversations, kind of mirrors what you just said:

Om; "I wonder, if the moon hadn't been tidally locked, if people would have realized the world was round, a tad bit sooner?"
Some person I at one time respected; "They were stupid. Of course the world is round."
I suppose, the next time I see him, I should ask him to prove the world is round.

ps. Anyone remember Cyrus? He posted something posted by Carl Sagan today, about the first guy to figure out the world was round. I really enjoyed it. 300 BC.
I think that is what brought up this memory.

pps. I think I've gone off topic. So, as always; Ok to delete, infract, and ban.
 
  • #39
anorlunda said:
Do you think that they were approaching momentum and energy with conservation in mind?
I am by no means a student of the history of physics, so I do not know what they were really thinking. But I could understand if they were reluctant to recognize a need for any new concept for moving objects such as "energy" that was different from momentum.
 
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  • #40
OmCheeto said:
I suppose, the next time I see him, I should ask him to prove the world is round.
If I lived then, I would have confidently and stubbornly believed that:
1) The world is flat.
2) There are obviously different rules for the Moon, Sun, and stars that float in the sky -- different from things on Earth that fall to the ground.
3) Fire is one of the four elements. It escapes when something burns.
I would know those things because I could see those facts with my own eyes.
 
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  • #41
My own "Why did it take so long" relates to flying. After 100 years of hot air ballooning we still didn't appear to understand that birds soar in thermals.
 
  • #42
FactChecker said:
If I lived then, I would have confidently and stubbornly believed that:
1) The world is flat.
2) There are obviously different rules for the Moon, Sun, and stars that float in the sky -- different from things on Earth that fall to the ground.
3) Fire is one of the four elements. It escapes when something burns.
I would know those things because I could see those facts with my own eyes.
Which would have been the best way to be about 'new things' in Science. It is essential that a change should be very hard to institute and that there should be many hurdles to jump before the establishment accepts a new idea. If it fails the first time round, it will be discovered again; what's a few decades of waiting, compared with even more time wasted when a phoney new idea is accepted?
You could just have been lucky, back then, to have been in the company of someone clever enough (or you could have been the one) and could actually associate yourself with a 'big step'.
In these modern times there is much more chance of being involved with Earth shattering new stuff - as long as you are bright enough to get the entry qualifications for such work. But, of course, no one has a cat's chance of getting far on their own, from scratch. There is an exception to that. Andrew Wiles was the sole worker on proving Fermat's Last Theorem. After his first dodgy proof, he locked himself away for several years with secret work and then came up with a good version. One man on his own - but that was Maths and he didn't need an LHC to get his result. (Read Simon Singh's book; excellent)
 
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  • #43
One might as well ask about the history of relativistic mass. It was coined in 1906, shown to be unnecessary and unhelpful in 1908, and today it's the Energizer Bunny of bad ideas.

The short answer is that in the XVIII century there was no concept of "energy". The concept was "vis viva" and it conflated the ideas of kinetic energy and momentum. Much of the debate was whether it was proportional to velocity or velocity squared. But very little of this would be recognizable to the modern student of mechanics - most of what we call "classical physics" was developed during the Great Quantification (my invention) from 1825 to 1865 or so. Asking why it took 100 years to sort this out is like asking why it took 200 years to get from Mozart to Debussey.
 
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  • #44
Vanadium 50 said:
One might as well ask about the history of relativistic mass. It was coined in 1906, shown to be unnecessary and unhelpful in 1908, and today it's the Energizer Bunny of bad ideas.

The short answer is that in the XVIII century there was no concept of "energy". The concept was "vis viva" and it conflated the ideas of kinetic energy and momentum. Much of the debate was whether it was proportional to velocity or velocity squared. But very little of this would be recognizable to the modern student of mechanics - most of what we call "classical physics" was developed during the Great Quantification (my invention) from 1825 to 1865 or so. Asking why it took 100 years to sort this out is like asking why it took 200 years to get from Mozart to Debussey.

Nice, Vanadium 50 (that element has one of the most persuasively beautiful names ever) -- I think we can all subtain in the recognition that Isaac Newton was a giant of intellect -- c'mon we're all bright guys here (and that includes the gals) but I presume to suppose that none of us here will claim to be a better pianist than Beethoven.
 
  • #45
sysprog said:
I presume to suppose that none of us here will claim to be a better pianist than Beethoven.
That is probably correct for the older members, I know some young men who have not yet accepted their real limits and for whom the sky is the limit. Women seem to start off with a realistic and mature attitude that many men have to wait many years for. (Those young men also tend to believe that they are immortal, can base jump and cycle up one way streets.)
 
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  • #46
sophiecentaur said:
That is probably correct for the older members, I know some young men who have not yet accepted their real limits and for whom the sky is the limit. Women seem to start off with a realistic and mature attitude that many men have to wait many years for. (Those young men also tend to believe that they are immortal, can base jump and cycle up one way streets.)
excellently good insights in a rather not overly long post -- yep -- back in '75 when I was 17 playin' Mario in my Mom & Dad's VW rabbit, although I was probably a bright guy, I was definitely effing stupid as eff to go about driving like/ [as if/were] 90 was parking speed, and everyone was immortal [I'm not much of a theist but I have more than zero faith) --

oh yeah and even then I knew (and continue now to know) "don't drive drunk" --

your thoughts are much appreciated -- Beethoven was by just about all competent concurrent accounts the most astonishingly best pianist of the few decades in which he lived -- whoever you are- well you're clearly a very bright person - not that that you require any ego massage, and (to me at least) more importantly, you seem to be a nice person ...
 
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