# negative mass is it possible?

Discussion in 'Physics & Math' started by ethernos, Sep 10, 2017.

1. ### ethernosRegistered Member

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two cone shaped sitting at point of each other like X. MASS COMES IN FROM TOP AND AT CENTRE REDUCED TO ZERO.WHEN MASS COMES OUT OF THE POINT TOWARDS THE BOTOM MASS TURNS NEGATIVE. HOW WOULD IT BE POSSIBLE?

3. ### Michael 345New year. PRESENT is 69 years oldValued Senior Member

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Like when you walk through a door which completely disintegrates you but a less than nothing you comes out the other side?

Like that???

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5. ### ethernosRegistered Member

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yeah....but that door has to be a wormhole or something

7. ### Michael 345New year. PRESENT is 69 years oldValued Senior Member

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Doesn't matter what it is - not going to happen

Are you confusing matter and Anti-Matter

Negative mass totally different

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8. ### exchemistValued Senior Member

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I suppose that, if you had negative mass, F=ma would imply that a force applied from left to right would cause the body in question to accelerate from right to left. Loopy.

9. ### Michael 345New year. PRESENT is 69 years oldValued Senior Member

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Ya right. And the more of a hole you dug in negative mass the more real mass you would produce

10. ### DinosaurRational SkepticValued Senior Member

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The two cones configuration does not make a nonsense idea more reasonable.

11. ### DinosaurRational SkepticValued Senior Member

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The concept of negative mass is related to the Powers of Pixie dust.

Antimatter has positive mass & there is not any other type of mass.

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12. ### ethernosRegistered Member

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thank you for the insight....

13. ### sideshowbobSorry, wrong number.Valued Senior Member

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I think the word "massive" should be banned. I've heard the news media talk about a "massive hole". If anything is the opposite of mass, it's a hole.

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14. ### Michael 345New year. PRESENT is 69 years oldValued Senior Member

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Do you think it might have started as a mis pronouncement of "a massless hole"???

That's one massless sink hole in the roadway

15. ### someguy1Registered Senior Member

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Does this gravitational field make me look fat?

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16. ### BaldeeeValued Senior Member

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I read an article on BBC website a while ago about some physicists observing what appeared to be properties that negative mass would exhibit.
If I recall, they reduced some rubidium atoms to a Bose Einstein condensate, and after some other stuff they did it seemed that some of it exhibited this odd behaviour where if you pushed it then it accelerated toward you.
Very bizarre.

Probably not true negative mass, but it may mean we can't rule it out entirely?

Also, which mass is being referred to?
Inertial or gravitational?
Antimatter has inertial positive mass but may well have negative gravitational mass?
Or has this been disproven?

17. ### originIn a democracy you deserve the leaders you elect.Valued Senior Member

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Antimatter has the same gravitational attraction as normal matter.

18. ### Michael 345New year. PRESENT is 69 years oldValued Senior Member

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Checked out a few articles about the above. Found this in a abstract

ABSTRACT
A negative effective mass can be realized in quantum systems by engineering the dispersion relation. A powerful method is provided by spin-orbit coupling, which is currently at the center of intense research efforts. Here we measure an expanding spin-orbit coupled Bose-Einstein condensate whose dispersion features a region of negative effective mass

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.155301

The last 3 words for me hold the clue

negative effective mass

So it sounds like mass present just not effective

I'm sure the whole kit and kaboodle is well outside my understanding but if someone from the experiment was explaining it to me the first question would be "Is this negative mass as in mass which exist as less than nothing"?

I would be very supprised if the answer was yes

19. ### BaldeeeValued Senior Member

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I wasn't aware that it had been proven experimentally, and that the issue is still up for debate, even if there is a broad consensus that it does as you suggest?

20. ### BaldeeeValued Senior Member

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The experiments have to start with something with positive mass, though, as that is all we currently have it would seem (other than massless stuff).
So achieving areas of negative effective mass among something that would otherwise have mass might be as good as we get.
If among a cloud of positive we end up with a localised pocket of negative, is that not still negative mass, albeit when you average the whole you still have positive?

But if we do manage to create something akin to Flubber, though...

21. ### originIn a democracy you deserve the leaders you elect.Valued Senior Member

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No it is clear that antiparticles have mass.

From wiki Antiparticle page.

The electric charge-to-mass ratio of a particle can be measured by observing the radius of curling of its cloud-chamber track in a magnetic field. Positrons, because of the direction that their paths curled, were at first mistaken for electrons travelling in the opposite direction. Positron paths in a cloud-chamber trace the same helical path as an electron but rotate in the opposite direction with respect to the magnetic field direction due to their having the same magnitude of charge-to-mass ratio but with opposite charge and, therefore, opposite signed charge-to-mass ratios

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Ta muchly.

23. ### hansdaValued Senior Member

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Your above description reminds me of the hourglass. https://en.wikipedia.org/wiki/Hourglass . Are you referring this. I am not sure.

As far as negative mass is concerned, it will cause a repulsive force(opposite of gravitational attractive force); like repulsive magnetic or repulsive electrical force. Repulsive gravitational force is not yet observed. So, perhaps negative mass is not yet observed.