Why Does Approaching the Speed of Light Affect Mass and Time?

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Discussion Overview

The discussion revolves around the effects of approaching the speed of light on mass and time, focusing on concepts from relativity, including relativistic mass, energy-mass equivalence, and the implications for spacetime curvature. Participants seek to clarify these concepts and their mathematical foundations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about why mass increases and time slows down as one approaches the speed of light, seeking simpler explanations.
  • Another participant questions how energy converts to mass, indicating a lack of understanding of this relationship.
  • Some participants reference the equation E=mc² to explain that mass is a form of energy, suggesting that mass increases with energy concentration.
  • Concerns are raised about the use of classical mechanics equations like F=ma in the context of relativity, with one participant arguing that they are not applicable.
  • There is a discussion about the distinction between relativistic mass and invariant mass, with one participant asserting that while relativistic mass increases, invariant mass remains constant.
  • One participant proposes that the increase in energy translates to an increase in mass, questioning whether this affects the curvature of space through which the object travels.
  • Another participant challenges the notion of increasing mass, arguing that relativistic mass is misleading and suggesting it is merely a mathematical construct to align relativistic equations with Newtonian forms.

Areas of Agreement / Disagreement

Participants express differing views on the concept of relativistic mass, with some supporting its validity and others questioning its usefulness and existence. The discussion remains unresolved regarding the implications of these concepts on spacetime curvature and the interpretation of mass in relativistic contexts.

Contextual Notes

There are limitations in the discussion regarding the definitions of mass, the applicability of classical mechanics in relativistic scenarios, and the mathematical interpretations of curvature tensors. These aspects remain open to interpretation and clarification.

semidevil
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so I"m just reading about physics for fun these days, and I"m still trying to understand the concept of relativity.

So why does mass get higher and time for me go slower as I approach the speed of light? I know this has to do with the concept of relativity and frame of reference, I"m trying to grasp the basic concept of it.

anyone care to explain to me in simpler terms?

thanks
 
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I hope someone posts an answer to that question soon. How does energy get converted to mass? I've never quite understood myself. If I come across anything I'll post it.
 
Basically, these things happen because of the math.

Here are some hints that should lead you to your answers:

Posted by Semidevil:

So why does mass get higher...as I approach the speed of light?

[tex]F=ma[/itex]<br /> <br /> <blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> Posted by Semidevil:<br /> <br /> So why does ... time for me go slower as I approach the speed of light? </div> </div> </blockquote><br /> [tex]\gamma = \frac{1}{\sqrt{1-\frac{v^2}{c^2}}}[/tex]<br /> <br /> Let me know if you need some more explanation.[/tex]
 
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Oxymoron said:
Basically, these things happen because of the math.

Here are some hints:
[tex]F=ma[/itex][/tex]
[tex] <br /> This is a pretty bizarre hint, since it's the basis of classical Newtonian mechanics and has nothing to do with relativity.[/tex]
 
Posted by Baryon:

How does energy get converted to mass? I've never quite understood myself.

The famous [tex]E=mc^2[/tex] equation tells us that mass (or matter) is energy. The way I like to think of it is this: Matter (which has mass, always!) is what you get when you "squeeze" a whole lot of energy into one place - and I mean a lot of energy. Doing the opposite (that is, breaking the matter up as opposed to putting it together) "spreads" the energy out again.

Notice that [tex]E=mc^2[/tex] implies that a body at rest has energy which contradicts the Newtonian view of motionless bodies. This leads me to mentioning the fact that you must understand the difference between rest mass and invariant mass. This leads you to the following Special Relativistic form of [tex]E=mc^2[/tex]:

[tex]E = \frac{m_0c^2}{\sqrt{1-\frac{v^2}{c^2}}}[/tex]
 
This is a pretty bizarre hint, since it's the basis of classical Newtonian mechanics and has nothing to do with relativity.

Yeah, maybe it was too cryptic.

Obviously [tex]F=ma[/tex] or better yet: [tex]F=\frac{d(Mv)}{dt}[/tex] will not work in SR because Mass is not considered constant. Instead one must correct with the Lorentz factor (my second hint) which you can read about here:

http://en.wikipedia.org/wiki/Relativistic_mass"
 
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Oxymoron said:
The famous [tex]E=mc^2[/tex] equation tells us that mass (or matter) is energy. The way I like to think of it is this: Matter (which has mass, always!) is what you get when you "squeeze" a whole lot of energy into one place - and I mean a lot of energy. Doing the opposite (that is, breaking the matter up as opposed to putting it together) "spreads" the energy out again.

Notice that [tex]E=mc^2[/tex] implies that a body at rest has energy which contradicts the Newtonian view of motionless bodies. This leads me to mentioning the fact that you must understand the difference between rest mass and invariant mass. This leads you to the following Special Relativistic form of [tex]E=mc^2[/tex]:

[tex]E = \frac{m_0c^2}{\sqrt{1-\frac{v^2}{c^2}}}[/tex]


So the increase in energy is translated to an increase in mass. Does that mean that the space that the object is traveling in becomes more curved?
 
baryon said:
So the increase in energy is translated to an increase in mass. Does that mean that the space that the object is traveling in becomes more curved?

Note that while the relativistic mass of an object increases, its invariant mass stays the same.

As far as curvature goes, the curvature tensor itself is usually considered to be a coordinate-independent object, which exists independently of any particular coordinate system. So the object is not considered to be a "different" object when viewed by a moving observer or a stationary observer, it's considered to be the "same" object. This means that the curvature, considered as a tensor, is considered to be the same regardless of velocity.

The curvature tensor at a location in space is not just one number - it consists of 4x4x4x4 = 256 numbers, many of which, however, are constrained to be the same because of symmetry.

However, components of the curvature tensor will vary depending on one's coordinate system. I.e. the values of these 256 numbers will change when one changes one's velocity. They change in a "standard" manner - this is in fact the definition of a tensor quantity, that its components will change in a "standard" manner when one changes coordinates.
 
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mass doesn't actually increase as you approach the speed of light. Its pretty misleading the way people say it. What increases is relativistic mass which is rly nothing like rest mass. Relativistic mass is a vector (I think i remember seeing some picture of an ellipsoid) and doesn't really exist. its gamma * mass (where gamma is[tex]\gamma = \frac{1}{\sqrt{1-\frac{v^2}{c^2}}}[/tex]) and in my opinion is just used to make relativistic equations look like their Newtonian counter-parts. For example, instead of [tex]F = \gamma ma[/tex] you can use [tex]F = m_ra[/tex] (btw that example might be completely wrong, don't really remember if there is a relativistic force equation but it still shows my point).
 

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