Talk:Inertia

message: If inertia is the same thing as mass, why don't we never call such a frame, a 'frame of mass', or 'massive frame'? --24.202.163.194 20:59, 31 December 2005 (UTC)
replies: text: Inside.  Archelon (talk) 19:20, 14 April 2015 (UTC)
thread_title:  Inertial frame 

message: Why does the caption read "Well, so far we've looked at the seat belts you use in your car when your doing 40 miles an hour"? Can't NASSA write? --61.69.3.155 (talk) 06:07, 7 February 2009 (UTC)
thread_title:  Caption 

message: This question is more generic than this particular article. In section "Mass and Inertia" there is the sentence "when the theory of relativity was not yet created". Is this the proper way to refer to it? The physics that the Theory of Relativity expresses were not created, but the theory itself was created. While the sentence is grammatically correct, it still feels wrong to say. Shouldn't it say something more like "prior to the formalization of TOR" or "when the TOR had not yet been expressed." -- The current phrase feels a bit like crediting Ben Franklin for "inventing" lightning. B-Con (talk) 00:31, 27 April 2009 (UTC)
replies: text: Hmm... I see what you mean.  As you say, the sentence is essentially correct as written, but I can see how confusion could arise.  And I'm not sure that it's accurate to say that a theory is "created", anyway.  "Developed" might be a better word or, as you suggest, "formalized" or "expressed".  To be honest, none of those feels just right, but I can't think of any others.  Of the three, "formalized" would be the most proper for an audience primarily composed of scientists but I think "expressed" might be the best one for Wikipedia.  I'm not going to change it just yet though.  I'd rather have another opinion or two first, and maybe even some more proposed words. -- edi(talk) 01:18, 27 April 2009 (UTC)
replies: text: I agree, it's hard to find the right word. I pondered it for a while as well before posting. I also agree on the use of formalized/expressed. I was going to make an edit, but figured I should ask to see if there exists standard protocol for this type of reference. It's surely an issue that comes up often and I'm sure (hope?) someone has an elegant -- or at least non-awkward -- method of dealing with it. I'll try to ask a math professor tomorrow. -- B-Con (talk) 05:40, 27 April 2009 (UTC)
thread_title:  "Invention" of Relativity 

message: I strongly suggest that this NASA video is removed immediately from the page. In one scene (at 1:26) there is the claim that "... because we are moving faster, we have a lot more inertia ...". This is of course a serious misconception and very misleading. That video is a shame for NASA. -- CHRV (talk) 23:04, 16 November 2009 (UTC)
replies: text: Just FYI: I removed the video some time ago. -- CHRV (talk) 22:36, 4 February 2010 (UTC)
thread_title:  NASA has been removed 

message: This article requires some media. A couple of explanatory pictures would be great. It's current format looks a bit dull.Ravi84m (talk)  —Preceding undated comment added 23:16, 6 April 2010 (UTC)
thread_title:  Media needed 

message: "Another profound, perhaps the most well-known, conclusion of the theory of Special Relativity was that energy and mass are not separate things, but are, in fact, interchangeable. This new relationship, however, also carried with it new implications for the concept of inertia. The logical conclusion of Special Relativity was that if mass exhibits the principle of inertia, then inertia must also apply to energy as well. This theory, and subsequent experiments confirming some of its conclusions, have also served to radically expand the definition of inertia in some contexts to apply to a much wider context including energy as well as matter."
I'm no physicist but isn't E = MC^2 General relativity?  —Preceding unsigned comment added by 88.104.105.223 (talk) 12:39, 23 October 2010 (UTC)
replies: text: I'm pretty sure that is in SR William M. Connolley (talk) 22:25, 24 April 2011 (UTC)
thread_title:  Last paragraph of Relativity section - isn't that GR rather then SR? 

message: I reverted  User:Kurtan, on the grounds that this isn't the place to be adding "novel perspectives". As far as I can tell, the Masreliez paper is exactly what it says - a novel perspective, not widely accepted or widely discussed. Which is to say, it looks fringe to me William M. Connolley (talk) 22:17, 24 April 2011 (UTC)
thread_title:  A novel perspective 

message: There is a simple experiment that can show that inertia has an extra component to it, than only mass.  Imagine two one-ton hunks of steel.  Shape one of them into a sphere, and the other one into a long rod (say 100 meters long).  Suspend both (separately) so that they can swing like a pendulum (the long rod horizontal to the ground).  Arrange to provide an impact-type of force to each mass (the same magnitude of force, of course).  On the side of the sphere opposite to its impactor, suspend an ordinary steel spherical ball-bearing ball, with a 1-millimeter gap between the ball and the sphere.  For the long rod, the impactor is set to apply force to one end of the rod.  At the far end of the rod we suspend another identical small steel ball with another 1-millimeter gap.  We can connect fine electric wires to all four suspended objects, and prepare a low voltage so that a circuit is completed when, say, the 1-ton sphere contacts the small bearing-ball.  Now trigger the two impactors so that both 1-ton masses are struck simultaneously with equal force.  The inertia of both objects must be overcome before they can move to hit/move the two suspended small steel balls.  We will be able to accurately measure any difference in the time it takes the electric circuits to close.
If the two large masses have identical inertia, despite their hugely different shapes, then both circuits will close simultaneously.  But in actual fact the sphere's ball will be contacted/moved first.  See, when a force impacts a mass, there is a compression-wave that moves through the mass at the speed of sound (which in steel can be 5000 meters/second, often faster in harder steels).  So, the far end of the 100-meter rod simply can't move at all, until that compression wave arrives (about 1/50th of a second) --while the compression wave in the sphere has much less distance to travel, so the whole sphere is more quickly affected by the applied force, than the long rod.  Therefore it logically follows that the long rod and the sphere have two different magnitudes of inertia --"the thing that must be overcome before an object can move as a whole"-- despite the large objects in this experiment having identical masses.  Which means, as initially stated, that the overall concept of inertia has an extra component to it (which mostly can be --and is-- ignored for ordinary everyday objects, but which should not be ignored if you really want to do accurate physics). V (talk) 22:09, 9 November 2011 (UTC)
replies: text: Your "extra component" is merely a difference in velocity and the way that you are proposing to measure it.  If, instead, you choose to measure the mass-average of the respective velocities then you find that both sphere and rod have the same speed at any instant.  Dbfirs 07:58, 19 February 2013 (UTC)
thread_title:  Another perspective 

message: What is the speed of inertia?  — Preceding unsigned comment added by 77.103.166.101 (talk) 19:48, 4 November 2013 (UTC)
replies: text: What is this "+ s"  and "- s" phenomenon?  I've never heard of it.  See Special relativity.  Dbfirs 09:55, 8 December 2013 (UTC)

text: So could I detect the gravitational potential from a distant spaceship, and use this effect to communicate at speed "c + s"?  Dbfirs 08:45, 12 December 2013 (UTC)
thread_title:  How fast is inertia? 

message: I've just reverted this definition:
:Inertia is the tendency of an physical object to remain in the state of rest, motion and direction until that object is exposed to some external unbalanced force. (provided by user:Priyank Koul)
In the interests of open discussion, I'm not entirely happy with the previous definition that I reverted to.  Can anyone improve on it?  What definition do the best sources use?  Dbfirs 06:36, 13 July 2014 (UTC)
thread_title:  New definition 

message: I think we need an expanded section describing how iniertia may arise,
Mach-ian, from distant masses in the universe, or any other acceptable
theories as to how it arises.
Spope3 (talk) 14:36, 20 November 2016 (UTC)
replies: text: Apologies that it has taken 3 years for a response to your request. Isaac Newton is credited with being the first to observe the phenomenon we now call inertia, and to describe it in his First Law of Motion, one of science’s physical laws. His First Law is sometimes called the Principle of Inertia. In asking for information about how inertia arises you are asking for something more fundamental than Newton’s Laws of Motion. I am happy with the notion that we have nothing more fundamental than Newton’s Laws of Motion, and that we aren’t able to explain how inertia arises. Dolphin (t) 02:43, 16 November 2019 (UTC)
replies: text:  The law of inertia originated with Aristotle who justified it by saying that if a body is in motion there is no reason for it to stop and similarly if it is at rest. His argument was repeated by DesCartes and others. I can give references if anyone is interested.JFB80 (talk) 05:19, 16 November 2019 (UTC)

text:  My mistake - Newton was not the first to observe the phenomenon we now call inertia. Thank you for providing that correction. Dolphin (t) 12:07, 16 November 2019 (UTC)
thread_title:  Origins of Inertia 

message: Hello fellow Wikipedians,
I have just modified one external link on Inertia. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
*Added archive https://web.archive.org/web/20070129111002/http://etext.library.adelaide.edu.au/a/aristotle/a8ph/ to http://etext.library.adelaide.edu.au/a/aristotle/a8ph/
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
Cheers.—InternetArchiveBot (Report bug) 17:27, 13 November 2017 (UTC)
thread_title:  External links modified 

message: The following text and quotation appears in the section “Theory of impetus”:
:Shortly before Galileo's theory of inertia, Giambattista Benedetti modified the growing theory of impetus to involve linear motion alone:
The cited source is: Giovanni Benedetti, selection from Speculationum, in Stillman Drake and I. E. Drabkin, Mechanics in Sixteenth-Century Italy University of Wisconsin Press, 1969, p. 156. On 22 Oct the following comment was appended from an IP address: The citation for this passage appears to be incorrect.  It is not on p. 156 of Drake and Drabkin, and apparently not anywhere in the book.
I will erase the comment from the article as this Talk page is the appropriate place to deal with it.
The same text, same quotation and same cited source also appear in the article Theory of impetus. Dolphin (t) 23:50, 22 October 2022 (UTC)
replies: text: I've put the comment into a  template. You can add a link to the talk page to that. StarryGrandma (talk) 23:54, 22 October 2022 (UTC)
thread_title:  Theory of impetus 

message: The last figure (currently) in the article seems only distantly related to the concept of rotational inertia, contrary to the claim of its caption. The figure shows a ball moving in a straight line but describing a curved path in a rotating frame of reference.
The figure also appears towards the top of the article on Coriolis force, where it seems helpful. Maybe someone just copied the figure to this article on inertia? In any case, the figure fails to help me understand the concept of rotational inertia.
Being pretty ignorant on this subject, I'm hoping a more expert person will consider replacing or removing the figure. DavidHolmes0 (talk) 19:57, 21 December 2023 (UTC)
replies: text: I have now deleted the gif, attempting to be bold. DavidHolmes0 (talk) 16:36, 24 December 2023 (UTC)
thread_title:  unhelpful animated figure for "Rotational inertia"