# Turning mass to zero

• Kalrag

#### Kalrag

I have been wondering about this while I was studying photons. Is it possible to turn the mass of a body to or close to zero? Just wondering.

No. The mass of a body is an intrinsic property that cannot be changed except by adding or removing something to it.

That's not true. Rest mass of an object approaching event horizon of a black hole goes to zero. If you could lower an object down onto event horizon from above without letting it drop, you could reduce the object's mass as much as you want. I'm not sure why you'd need that, though.

Now how and why does the mass go to zero on an event horizon?

Given the specific use of "turn the mass of a body to or close to zero" I'd say the OP is asking if we are able to use a device to reduce mass.

In which case, it's a no.

I suspect the OP would eventually evolve to "if we could 'turn the mass down', we could get to near light speeds easily" or "we could travel at c".

Of course, I could be way off here but I felt it was worth noting. As a sci-fi fan I have noted a few examples of such devices in the genre (http://andromeda.wikia.com/wiki/Gravity_Field_Generator" [Broken]*) and can see which way this conversation could potentially head.

* The example is from a sci-fi show, it is not a link to a 'proposed device'.

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Jared has the right idea. This thread was meant to find a way (not machine) to reduce mass to zero.

In classical physics, mass is concerved- it is not possible to change the mass of and object.

In relativity physics, mass-energy is concerved. It is possible to convert mass to energy as is done, for example, in a nuclear reactor or bomb.

It's a pity I'm right.

What you are talking about is taking an object of mass 100kg and, for example, making it's mass appear to be 1kg.

In the sci-fi link above, they take the ship which is X thousand kilograms and reduce it to 1kg, so when they fire the engines the resultant acceleration is phenomenal (instead of it being a=f/X it's a=f/1), allowing for incredible speeds to be attained.

This is all still well within the realms of sci-fi and just not possible.

In the form I've given above (sci-fi) and to which you are apparently referring, aside from explaining why it isn't possible I don't see it as a valid topic of discussion here.

But do you have any theories how the sci-fi mass reductin might work?

In superconductors photons can behave as if they had mass. Now there is an analogy between superconductivity and the Higgs mechanism, so that particles get a non-zero rest mass. Hence if you could create the equivalent of a non-superconducting 'bubble' in the Higgs field, then you should be able to remove the mass of particles, so they should all travel at the speed of light. I wrote about this idea in my entry for last year's fqxi essay contest. http://www.fqxi.org/community/forum/topic/567

In superconductors photons can behave as if they had mass.
Quasi-particles can have all sorts of non-physical properties, because they are not physical particles. They simply help describe complex systems.

Kalrag said:
But do you have any theories how the sci-fi mass reductin might work?
The only way to do that is to reduce potential energy by mc². The only potential you have a chance to do this with is gravitational potential, and then we are talking a black hole and event horizon. There is no other way to do that which would be consistent with physics we know.

But do you have any theories how the sci-fi mass reductin might work?

No, and there aren't any. That is what makes it sci-fi. If it really worked it would be sci-fact.

I don't try to explain sci-fi because quite simply, it can't and was never meant to be explained.

And before you give the "it must be based on something" spool, don't.

They took a real life problem and invented a solution to overcome it for the purpose of the story (warp engines, quantum slipstream, jump drive - are all examples of FTL devices - fictional solutions to a real problem that cannot be overcome). These fictional devices are designed purely for entertainment and to try and bring them into the realms of reality is just plain ridiculous.

This 'what if' style discussion and attempting to explain science fiction concepts isn't a topic worth discussing, much less here.

A focus on "is it possible" should suffice. As per K^2 answers, I think that answers it nicely.

But do you have any theories how the sci-fi mass reductin might work?
By writing fiction!