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quawa99
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Is everything we know relative or is there something absolute in this universe?
quawa99 said:Is everything we know relative or is there something absolute in this universe?
ZapperZ said:This is rather vague. Let's start with something clearer.
Do you know about Special Relativity? Yes? Then what have you concluded from that?
No? Then maybe we can start you with that.
Secondly, what do you mean by "everything"? There are covariant/invariant values and expressions in physics that are NOT relative.
Zz.
Hertz said:The speed of light is absolute. So is mass. The charge of an electron is absolute. Etc
Hertz said:The speed of light is absolute. So is mass. The charge of an electron is absolute. Etc
quawa99 said:Isn't mass relative?
Enigman said:Mass is NOT absolute.
##M=\frac{M_0}{\sqrt{1- \frac{v^2}{c^2}}}##
Mass?But I heard that mass increases with Speed(Kinetic Energy)Hertz said:The speed of light is absolute. So is mass. The charge of an electron is absolute. Etc
adjacent said:Mass?But I heard that mass increases with Speed(Kinetic Energy)
quawa99 said:So bottom line velocity of light and charge are the two physical quantities which aren't relative ?
quawa99 said:Isn't charge relative because electric and magnetic fields are relative?
Hertz said:Why is this necessary?
Enigman said:Mass is NOT absolute.
##M=\frac{M_0}{\sqrt{1- \frac{v^2}{c^2}}}##
Yes, I was talking about relative or 'observed mass' as I thought it would be obvious from the context and not rest mass which is by definition frame-invariant.Nugatory said:The quantity ##M## in that equation is not frame-invariant, but ##M_0## is. It's something of a matter of taste which one you consider to be "mass", and that taste has changed over the years.
Hertz said:I learned relativistic kinetic energy as:
[itex]T=(\gamma_u - 1)mc^2[/itex] where mass is absolute. This is from the book "Modern Physics" second edition by Randy Harris
Also, total relativistic energy:
[itex]E=\gamma_u mc^2[/itex]. Where mass is absolute.
ZapperZ said:Y'know, the more things change, the more they remain the same. This thing keeps coming back like an unwanted guest.
https://www.physicsforums.com/showthread.php?t=642188
Please note this FACT: when you read the mass values of the various particles in the Particle Data Book, you'll notice that they never cite the corresponding speed. If mass is "relative", then there will not be a unique, unambiguous value.
Zz.
Hertz said:Thanks for this link. This person has some very interesting points :)
ZapperZ said:If by "this person" you meant Lev Okun, he is on this forum:
https://www.physicsforums.com/showthread.php?t=696144
Zz.
Hertz said:Why would I be referring to Lev Okun? He doesn't even make an appearance in the link I quoted...
Zz.
This view seems pretty interesting too...ZapperZ said:We may need a FAQ entry on this topic since this keeps popping up.
The theory of relativity is a scientific theory proposed by Albert Einstein in the early 20th century. It describes how the laws of physics apply to objects that are moving at a constant speed in a straight line, and how they differ from objects that are accelerating or in a gravitational field.
According to the theory of relativity, there is no such thing as absolute space or time. Instead, space and time are relative and depend on the observer's frame of reference. This means that the laws of physics are the same for all observers, regardless of their relative motion, but their measurements of space and time may differ.
The theory of relativity has had a major impact on our understanding of the universe. It has helped us to understand the behavior of objects at high speeds, such as the effects of time dilation and length contraction. It also plays a crucial role in our understanding of gravity and the structure of the universe.
Special relativity deals with the laws of physics in non-accelerating frames of reference, while general relativity extends these laws to include accelerating frames and the effects of gravity. Special relativity is also limited to flat, uncurved space, while general relativity can explain the curvature of space caused by massive objects.
Yes, there are several practical applications of relativity, including the development of GPS technology, which relies on the precise synchronization of clocks in orbit and on the ground. Relativity also plays a crucial role in nuclear energy and particle accelerators, allowing us to study the behavior of particles at high speeds.