# Naked Science Forum

## Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Professor Mega-Mind on 01/02/2019 09:02:16

Title: Does structural integrity vary proportionately with relativistic mass?
Post by: Professor Mega-Mind on 01/02/2019 09:02:16
...Relativistic Mass versus Structural Integrity .  What is the relationship ?  Specifically , as the rate of time passage varies , how goes structural integrity ?
P.M.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: esquire on 01/02/2019 21:17:49
relativistc mass, defined as momentum = energy x velocity
structure integrity defined as "an ability of an item—either a structural component or a structure consisting of many components—to hold together under a load, including its own weight, without breaking or deforming excessively"

a photon has no mass but it has relativistic mass. so a photon consisting of "three quarks and a gluon" has structural integrity under the auspcious of gravity. gravity in this case constraining the energetic relativistic mass to a speed of light, maximum limit. relativistic mass is relegated to anything that is already traveling at the speed of light. it is a reference to massless energy.  it is my understanding that the distinct between,  momentum = energy x velocity,  and e=hv is explained as physic semantics.

being massless, structural integrity has no or very little bearing in reference to relativistic mass.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: esquire on 01/02/2019 21:26:40
.Relativistic Mass versus Structural Integrity .  What is the relationship ?  Specifically , as the rate of time passage varies , how goes structural integrity ?

In relationship to science fiction terms. prior to scotty beaming up captain kirk, captain kirk's body has structural integrity, while being demolecularized, captain kirk's body is in a state of relativistic energy.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: evan_au on 01/02/2019 22:01:22
Let's assume that an object (or a person) has enough structural integrity to withstand Earth-normal gravity =1g.

Now accelerate them in a spacecraft at 1g for 10 years.
- After 1 year, they are travelling a significant fraction of the speed of light - and a big fraction after 10 years.
- Their relativistic mass has increased dramatically, but their rest mass (as measured in their frame of reference) has not changed.
- So their structural integrity is unchanged, in their frame of reference

However, if, after 10 years acceleration at 1g, you run into a speck of dust. It is like a bomb going off, and your structural integrity is shot to pieces.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Professor Mega-Mind on 01/02/2019 23:40:21
Mr. AU ,
After 10 years at 1g , you will mass as much as a blue whale , from the perspective of those on Earth .  My contention is that your structural integrity MUST increase lock-step , or you would disintegrate simply from walking into a wall .  On the other hand , such an impact would happen hundreds of times slower than on Earth , so far less strain on your structural integrity after all .
Balance in all things ?  A fast pea would definitely splash you then !
P.M.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Bored chemist on 02/02/2019 00:43:46
relativistc mass, defined as momentum = energy x velocity
No, it isn't.
After 10 years at 1g , you will mass as much as a blue whale
When in the name of all that's holy did "mass" become a verb?
Anyway, I'm sat here, rather more than 10 years old and perpetually subject to about 1g and my mass remains about 75Kg
So, you seem to be wrong by a factor of about 1900.
You haven't got close to defining "Structural Integrity" so you don't seem to understand what it takes for anyone to answer your question.

Did you consider actually learning science?
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Professor Mega-Mind on 02/02/2019 01:32:58
...RELATIVISTIC Mass .
Same as particles at relativistic velocities . They just THINK they're  normal , but we know better !
P.M.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Bill S on 02/02/2019 11:14:20
Quote from: BC
When in the name of all that's holy did "mass" become a verb?

Same time that "dead" became a verb, I imagine. :)

https://www.thenakedscientists.com/forum/index.php?topic=75738.msg563914
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Bored chemist on 02/02/2019 12:16:45
Same time that "dead" became a verb, I imagine.
OK, so you know from a previous thread that it's not a verb, and you used it as one anyway.Why be deliberately unclear?

Anyway, since plenty of things with practically no relativistic mass lack structural integrity, yet other things with plenty of it  do not, we know that the answer to your question is " Obviously not".
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: jeffreyH on 02/02/2019 12:34:17
The nearer an object's velocity gets to the speed of light, the effects will start to resemble the tidal forces on an object approaching a black hole. Since the forces holding the object together themselves travel at light speed this has to be the case. Otherwise relativity breaks down. If you plot relativistic gamma you will see that the tidal forces will only have such an effect VERY close to the speed of light. The amount of energy required to reach this point is well out of our technological reach so shouldn't be a concern.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Colin2B on 02/02/2019 13:53:37
Same as particles at relativistic velocities . They just THINK they're  normal , but we know better !
P.M.
No, they are normal, and you don’t know better.

You are confusing the measurement of mass with the quantity or density of matter.
In our own frame a mass at rest would weigh more if it contained a greater amount of denser matter. The moving mass has extra energy and this distorts spacetime hence increasing gravitational attraction which we measure as increased mass. However, there is no extra matter in the relativistic object, nor any greater bonding between parts, hence no change in structural integrity.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Halc on 02/02/2019 15:37:49
OK, so you know from a previous thread that it's not a verb, and you used it as one anyway.Why be deliberately unclear?
Mass has been a verb for a long time.  Look it up.  He even used it correctly in his sentence.

I am actually disappointed in the quality of answers I've seen to this question so far, Colin2B excepted.
One need not accelerate for years to have significant relativistic mass.  One only needs to consider said structure in a frame where it has that mass.

So I have a Popsicle stick that breaks when 12 Newtons of force is placed upon it.  Now I consider that same stick in a frame where it masses (verb!) 10 times its proper mass.  Would force applied to it in one frame be equal to force in another frame?  If so, the structural integrity of the stick is unaffected by its relativistic mass.
Perhaps the force in the strange frame depends on the direction of the force (in the direction of motion, or orthogonal to it for instance).  A perfectly circular orbit is squashed into an ellipse with the central mass at the middle, not one of the focus points.  That suggests that forces are not equal in the direction of motion vs the orthogonal direction, and that means that structural integrity is indeed a function of speed, and thus relativistic mass.

In our own frame a mass at rest would weigh more if it contained a greater amount of denser matter.
What do you mean by this?  It would seem to weigh more if it contained a greater amount of matter, but I don't see how density plays into that at all.
Quote
However, there is no extra matter in the relativistic object, nor any greater bonding between parts, hence no change in structural integrity.
This is a great point.  Suppose we had a structure that was so fragile that it barely held itself together.  Now we give it relativistic mass by considering it in another frame.  The forces acting upon it may or may not be the same depending on how you compute them (Earth is closer and has reduced radius in the direction I'm imagining, so force (as computed by Newton's non-relativistic special case) is greater, but equivalent acceleration is not proportional with it), and yet the structure is still just barely able to support itself.  So said integrity is not a function of relativistic mass at all.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: jeffreyH on 02/02/2019 21:23:58
The structural integrity of ice is disrupted by increasing its temperature. This disrupts the molecular bonding. The kinetic energy introduced to the system overcomes the bonding. The structural integrity of the molecules remains intact. Forces, that introduce stresses and strains, disrupt structural integrity. This obviously includes acceleration. However, relativistic mass does not require acceleration. It is a function of relative velocity. So the structural integrity in this case is simply a function of velocity. We can relate this velocity directly to kinetic energy.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Bored chemist on 02/02/2019 21:36:43
A sand dune has little, if any, relativistic mass, and little structural integrity.
The voyager 1 spacecraft has some (admittedly small)  relativistic mass and quite a lot of structural integrity.

There does not any reason to think the two factors are related.

There's also a problem. If an ant (in a space suit) was wandering round on Voyager, he wouldn't expect it to behave differently from how it behaved when it was on Earth. From his point of view, it's stationary so there's no relativistic mass to account for any changes in stiffness or whatever.

Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: alancalverd on 02/02/2019 22:22:17
The nearer an object's velocity gets to the speed of light, the effects will start to resemble the tidal forces on an object approaching a black hole. Since the forces holding the object together themselves travel at light speed this has to be the case. Otherwise relativity breaks down.

Quote
Reported in November 1994 in Monthly Notices of the Royal Astronomical Society is a galaxy with a measured red shift of z=4.25 , a new record. This value for the z parameter corresponds to a recession speed of .93c
. but I haven't noticed any change in my structural integrity.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Professor Mega-Mind on 02/02/2019 23:45:13
...The essence of the question .
Looking at the crew compartment of a spaceship travelling at relativistic speed , from Earth (somehow) .  You observe that objectively (to you) , the individuals inside it weigh many tons .  You also observe that objectively , time is greatly dilated (slowed) for them .  The question is whether the four fundamental forces (within the ship) are normal-strength , from your objective viewpoint , or have they changed (less or more) ?
D.H.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: alancalverd on 03/02/2019 08:40:03
Is there any reason why they should have?
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Bored chemist on 03/02/2019 09:28:01
...The essence of the question .
Looking at the crew compartment of a spaceship travelling at relativistic speed , from Earth (somehow) .  You observe that objectively (to you) , the individuals inside it weigh many tons .  You also observe that objectively , time is greatly dilated (slowed) for them .  The question is whether the four fundamental forces (within the ship) are normal-strength , from your objective viewpoint , or have they changed (less or more) ?
D.H.
If the "integrity" of their ship is adversely affected, it falls apart.
That's a thing that would be noticed by the crew and the people back on Earth.
It can't be different depending on your point of view.

And, as Alann points out, from the perspective of an observer in that galaxy, we are doing 93% of the speed of light, but our planet isn't falling apart.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Professor Mega-Mind on 03/02/2019 11:30:24
Is their a consensus , then , amongst the big heads , that the 4-forces would measure normal-strength on-board , as measured from Earth , when the ship passed by ?
P.M.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Bored chemist on 03/02/2019 13:18:14
Is their a consensus , then , amongst the big heads , that the 4-forces would measure normal-strength on-board , as measured from Earth , when the ship passed by ?
P.M.
The "ship" is always passing by.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: jeffreyH on 03/02/2019 16:03:16
The nearer an object's velocity gets to the speed of light, the effects will start to resemble the tidal forces on an object approaching a black hole. Since the forces holding the object together themselves travel at light speed this has to be the case. Otherwise relativity breaks down.

Quote
Reported in November 1994 in Monthly Notices of the Royal Astronomical Society is a galaxy with a measured red shift of z=4.25 , a new record. This value for the z parameter corresponds to a recession speed of .93c
. but I haven't noticed any change in my structural integrity.

It all depends upon whether or not you consider the space between the galaxies to be expanding without affecting other processes. For instance, at that recessional velocity time dilation would start to have dramatic effects upon our ability to accurately determine velocities. What we would measure would be .93c but is it accurate?
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: PmbPhy on 03/02/2019 17:04:58
relativistc mass, defined as momentum = energy x velocity
That is incorrect. Rel-mass  "m" is defined as p = mv. Also the energy in E = mc^2 is not always (total/all) energy of a body.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: yor_on on 04/02/2019 14:42:17
The structural integrity of something will be the same in any uniform motion, ignoring blue shifts now. Doesn't matter how fast you consider yourself to move. A acceleration on the other tentacle can play havoc with any 'structural integrity', and there it doesn't matter from what relative uniform motion you started that acceleration.
=

This is presuming space.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Professor Mega-Mind on 05/02/2019 17:58:31
...Interpretation .
It SOUNDS like , objectively , the forces affecting the crew are the same .  That is ; a psychic using their gifts , would percieve those forces as being normal-strength .  They would percieve the crew's mass as blue-whale level . Lastly , they would percieve the crew's rate of time-passage (change) , as absolutely glacial .
So , the answer is apparent .  It   is a teeter-totter (a balance) , between mass , and strength/ speed of the forces affecting the "crew" .
This answers questions such as "why don't electrons in relativist-ically travelling objects escape their orbital-shells , as they increase in mass ?" .
Balance in all things , even
Qu.-azy things , yah ?

P.M.
Title: Re: Does structural integrity vary proportionately with relativistic mass?
Post by: Bored chemist on 06/02/2019 19:25:53
...Interpretation .
Misinterpretation.