# The Naked Scientists Forum

### Author Topic: What happens to mass at the cusp to the speed of light?  (Read 1913 times)

#### Expectant_Philosopher

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##### What happens to mass at the cusp to the speed of light?
« on: 16/12/2014 21:47:24 »
We know from Einstein that at the speed of light mass stretches to infinity.  What happens to mass before it reaches the speed of light?  Is the process gradual or does it happen all at once?  Can we harness the effects as mass approaches the speed of light to manipulate mass?  If we accelerate an entangled mass towards the speed of light do the effects of approaching the speed of light also impact the other entangled mass? Can we contain a mass that has a tendency to stretch to infinity, by opposing with another mass also tending towards infinity?

#### PmbPhy

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##### Re: What happens to mass at the cusp to the speed of light?
« Reply #1 on: 16/12/2014 23:54:38 »
Quote from: Expectant_Philosopher
We know from Einstein that at the speed of light mass stretches to infinity.
I wouldn't say that it's "stretched." That's a bad way to think of it. Just think of it as increasing, plain and simple.

Quote from: Expectant_Philosopher
What happens to mass before it reaches the speed of light?
Nothing "happens" other than the fact that the relativistic mass (i.e. inertial mass) increases in a continuous manner but never achieves the speed of light.

Quote from: Expectant_Philosopher
Is the process gradual or does it happen all at once?
[/quote[
Gradual. See the graph in the following page
http://www.emc2-explained.info/Emc2/Derive.htm

Quote from: Expectant_Philosopher
Can we harness the effects as mass approaches the speed of light to manipulate mass?
That doesn't make any sense to me. What exactly is it that you hope to harness? What does it even mean to harness it?

Quote from: Expectant_Philosopher
If we accelerate an entangled mass...
What is an entangled mass?

Quote from: Expectant_Philosopher
Can we contain a mass that has a tendency to stretch to infinity, by opposing with another mass also tending towards infinity?
Not that this makes any sense but I think that no matter how you described it to me the answer will be no.

#### domkarr

• Jr. Member
• Posts: 18
##### Re: What happens to mass at the cusp to the speed of light?
« Reply #2 on: 17/12/2014 07:51:32 »
This might be a silly question but has any one ever stretched or increased anything to infinity by taking it to the speed of light?
What I mean to say is, that do we have definitive proof that mass does actually stretch or increase?
Or are we simply relying on the maths to tell us that is what happens?

I only ask because I have heard on a number of occasions that quite often molecular science has a tendency to defy the physics. And if an object is in fact increased does that mean that there are more molecules and particles in that object or do they become larger? or are we talking about something that isn't fully understood here?

I would have thought, if I were to take a stab at it, that the mass wouldn't change at all but were more sort of in more than one place at one time having sort of outrun time itself. but I have to admit that I am not as learned as I want to be in physics.

#### PmbPhy

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##### Re: What happens to mass at the cusp to the speed of light?
« Reply #3 on: 17/12/2014 16:47:36 »
Quote from: domkarr
This might be a silly question but has any one ever stretched or increased anything to infinity by taking it to the speed of light?
No, since "stretching" has no meaning in that sense.

Quote from: domkarr
What I mean to say is, that do we have definitive proof that mass does actually stretch or increase?
Stretch? No. Increase? Yes. It's confirmed all day long in particle accelerators across the world and has to be taken into account in the design of the accelerators.

Quote from: domkarr
Or are we simply relying on the maths to tell us that is what happens?
That's not a meaningful statement.

Quote from: domkarr
I only ask because I have heard on a number of occasions that quite often molecular science has a tendency to defy the physics.
You've heard wrong. You have to pay close attention to the source of where you hear these things.

Quote from: domkarr
And if an object is in fact increased does that mean that there are more molecules and particles in that object or do they become larger?
Neither. Their resistance to acceleration is large and that's a result of the properties of spacetime.

#### Expectant_Philosopher

• Sr. Member
• Posts: 229
##### Re: What happens to mass at the cusp to the speed of light?
« Reply #4 on: 17/12/2014 18:01:55 »
To PmbPhy, I think  I understand now.  The original mass is unchanged, but the speed of the mass changes the mass of the system. That is mass original plus velocity equals the increased mass.  Why doesn't it ever achieve the speed of light?  Einstein said the mass of the system increases to infinity at the speed of light.  As far as entanglement of particles, replace particle for mass and accelerate to the speed of light.  Then my question.  As for the opposing masses, I had thought what would be the effect of a mass that is at the speed of light in the presence of another mass at the speed of light, could one affect the other.  Would there be special effects at work or would it merely be Newtonian interaction between the masses?  As far as an ability to manipulate a mass that is at the speed of light, similar to my previous, is there special effects at work when a mass is at the speed of light.

#### PmbPhy

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##### Re: What happens to mass at the cusp to the speed of light?
« Reply #5 on: 18/12/2014 18:11:32 »
Quote from: Expectant_Philosopher
Why doesn't it ever achieve the speed of light?
First off no particle can be created going the speed of light since it would violate the principle of the conservation of energy. To get a particle moving one must do work on it. To get a particle to move "at" the speed of light it would take an infinite amount of work and therefore an infinite amount of energy to do so. Therefore no particle with non-zero proper mass can move at the speed of light.

Quote from: Expectant_Philosopher
Einstein said the mass of the system increases to infinity at the speed of light.
No. Not a system. Either a body or a particle.

Quote from: Expectant_Philosopher
As far as entanglement of particles, replace particle for mass and accelerate to the speed of light.
Entanglement has nothing to do with this and as I explained, you cannot accelerate to the speed of light.

Please keep in mind that any time you ask a question about what happens when something moves with the speed of light that the response is "It's impossible to do so. Therefore your question is meaningless. Okay? :)

#### Expectant_Philosopher

• Sr. Member
• Posts: 229
##### Re: What happens to mass at the cusp to the speed of light?
« Reply #6 on: 19/12/2014 18:45:22 »
Don't take this in a negative light, but you depress me.  I am depressed for wont of your understanding of science.  In my imagination there are no limits, I try to synthesize new ideas based on varied disciplines.  Up against the stark reality of science I feel at a loss that I don't have the knowledge I need to make my dreams, my ideas real.  Would that I had the opportunity to learn each area of science my imagination touches upon, so that I could improve the world.  Lacking that I attempt to float these ideas with an expectation that some of them may hit the mark, and others may bring to fruition.  I admire your wisdom.

#### domkarr

• Jr. Member
• Posts: 18
##### Re: What happens to mass at the cusp to the speed of light?
« Reply #7 on: 20/12/2014 01:43:18 »
Don't be depressed expectant philosopher. at least you didn't spend years working on something that was impossible only to find that out in front of a large group of you're peers, right?
although I noticed Pmb said nothing of converting mass to particles of zero mass before attempting to accelerate them toward the speed of light.
Still as i understand there is still no technology capable of such grand feats. I think that was one of the goals of the particle accelerator.

and besides I believe the scientific community has moved their attention towards folding space rather than accelerating mass as a means of transport.
seeing as we're on the topic, has there been any word on what exactly has been discovered by the particle accelerator? the last I heard was that they had discovered a new particle just not the one that they wanted.

Also I'm going to take a wild guess that what you were thinking of was harnessing the energy created by mass traveling at light speed as perhaps some sort of new energy source?

I don't know if I am right in that deduction but I can understand that way of thinking. the problem there is that it would take a large amount of energy to force anything even a particle, as the particle accelerator proves, to the speed of light and then I assume the only way to get the particle to release that energy would be to force it to stop abruptly. the energy would be either to great to harness or impossible to create as Pmb mentioned.

besides we already have devices that release such massive amounts of energy, nuclear bombs for one and the problem there of course is containing the energy and harnessing it. and although I am sure that I am going to receive a number pointers from Pmb as to the correctness of my statements I am very thankful for them because it take guts to tell someone that they are wrong and hardly ever are people grateful for being told so.

#### PmbPhy

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##### Re: What happens to mass at the cusp to the speed of light?
« Reply #8 on: 20/12/2014 09:26:19 »
Don't take this in a negative light, but you depress me.  I am depressed for wont of your understanding of science.  In my imagination there are no limits, I try to synthesize new ideas based on varied disciplines.  Up against the stark reality of science I feel at a loss that I don't have the knowledge I need to make my dreams, my ideas real.  Would that I had the opportunity to learn each area of science my imagination touches upon, so that I could improve the world.  Lacking that I attempt to float these ideas with an expectation that some of them may hit the mark, and others may bring to fruition.  I admire your wisdom.
Thank you EP. That's very kind of you. With that attitude you'll be able to learn a lot and achieve your goal. You just need to keep an open mind and you'll go far. I'll help you in anyway that I can.

#### PmbPhy

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##### Re: What happens to mass at the cusp to the speed of light?
« Reply #9 on: 20/12/2014 09:33:51 »
Quote from: domkarr
although I noticed Pmb said nothing of converting mass to particles of zero mass before attempting to accelerate them toward the speed of light.
I didn't mention it because its irrelevant to the problem at hand. For example; you cannot change a single particle having non-zero rest mass to a single particle having zero rest mass. The reason being that there would be a violation of the conservation of momentum and that would violate a law of physics, i.e. the law of conservation of momentum. Here's why: Suppose we have a particle at rest in the inertial frame S. The momentum of the particle is the mass times the velocity. Since the velocity is zero then so too is the mass. Now suppose the particle changes to a particle having zero mass. Then it must be moving at the speed of light. Now it has momentum. Therefore the momentum changed from zero to something.

Now let's suppose that we have two particles such as an electron and a positron. Analyze what happens in the frame of reference in which the total momentum is zero. The electron/positron pair can annihilate each other resulting in two photons traveling in opposite directions. The total momentum is still zero. However there was never a particle moving at the speed of light in this example. So why mention it?

#### The Naked Scientists Forum

##### Re: What happens to mass at the cusp to the speed of light?
« Reply #9 on: 20/12/2014 09:33:51 »