Negative Mass Matter

[Ags]

Apparently I can build a faster than light starship powered by the Alcubierre Drive, all I will need to make it work is a lump of negative mass matter. This exotic substance is apparently not forbidden by our current physical theories, but I am wondering if there is any observational evidence of this stuff.

For example, as negative mass matter (NMM) would produce negative gravity, is dark energy potentially produced by a hazy intergalactic cloud of NMM.

[saac]

Amazon are out of the stuff  

I'll get my hat and coat 😋

[andrew s]

32 minutes ago, Ags said:

For example, as negative mass matter (NMM) would produce negative gravity, is dark energy potentially produced by a hazy intergalactic cloud of NMM.

As it makes up some 68% of the mass/energy of the Universe we would not see the gravitationally formed structures we see today if it were your proposed negative mass.

Regards Andrew 

[Ags]

3 hours ago, saac said:

Amazon are out of the stuff  

 

If you can't get it on Amazon, it almost certainly doesn't exist! I'll have a look on the 'bay though, you never know!

[Ags]

I might have to rethink my Christmas holiday to Antares...

[Ags]

19 hours ago, andrew s said:

As it makes up some 68% of the mass/energy of the Universe we would not see the gravitationally formed structures we see today if it were your proposed negative mass.

Regards Andrew 

Aaaaah, but maybe the negative mass matter only started popping into existence a billion years after the big bang? The galaxies would have already clumped together, and my fuzzy negative cloud would increasingly provide the negative gravity to explain dark energy. All we have to do is get out into intergalactic space and harvest the exotic matter, and then we can build the hyperdrive to get to intergalactic space.  It's a bit chicken and egg, it sounds like the first requirement for achieving interstellar travel is a time machine 😀

[andrew s]

35 minutes ago, Ags said:

Aaaaah, but maybe the negative mass matter only started popping into existence a billion years after the big bang? 

Along with the flying pigs. 😊

[Ags]

Not flying pigs - dark pigs that don't interact with light or even truffles.

 

2 hours ago, andrew s said:

Along with the flying pigs. 😊

[Macavity]

Quite fun to imagine... 😉
https://youtu.be/uAJlg8MDAlU?si=K5T-ZzTJcJqjKVPr

 

[Ags]

While we are talking about different kinds of numbers to put before the kg symbol, are other number lines possible, like imaginary mass? Which way would imaginary gravity pull you?

[andrew s]

10 hours ago, Ags said:

While we are talking about different kinds of numbers to put before the kg symbol, are other number lines possible, like imaginary mass? Which way would imaginary gravity pull you?

Of course you can. We have "on shell" real mass and "off shell" virtual mass. As far as I know both are normal with respect to gravity.

Here is an introduction. 

Regards Andrew 

[Ags]

Ok, so if I held a bowling ball made of imaginary mass, what would it feel like? Would a few imaginary kilos feel the same as a few real kilos?

[andrew s]

34 minutes ago, Ags said:

Ok, so if I held a bowling ball made of imaginary mass, what would it feel like? Would a few imaginary kilos feel the same as a few real kilos?

It's imaginary it's up to you what you imagine. It's not that complex. 😊

Regards Andrew 

[billhinge]

4 hours ago, Ags said:

Ok, so if I held a bowling ball made of imaginary mass, what would it feel like? Would a few imaginary kilos feel the same as a few real kilos?

The energy squared (which is proportional to mass squared) of the neutrino is often measured to be negative in radioactive decay but within certain error and is taken as positive, it gets measured to be a negative number but there is just enough error in measurement  that mass could be slightly positive by convention since imaginary mass doesn't exist. 

 

[Gfamily]

On 13/09/2023 at 22:33, Ags said:

While we are talking about different kinds of numbers to put before the kg symbol, are other number lines possible, like imaginary mass? Which way would imaginary gravity pull you?

Trying to imagine the gravitational attraction between -

- some imaginary mass and some ordinary mass

- two pieces of imaginary mass

- three pieces of imaginary mass! 

[DarkAntimatter]

7 hours ago, billhinge said:

The energy squared (which is proportional to mass squared) of the neutrino is often measured to be negative in radioactive decay but within certain error and is taken as positive, it gets measured to be a negative number but there is just enough error in measurement  that mass could be slightly positive by convention since imaginary mass doesn't exist. 

 

So a confidence interval around the measurement would lie mostly in the negative energy squared region (and therefore imaginary mass)?  Or what am I misunderstanding?

[billhinge]

3 hours ago, DarkAntimatter said:

So a confidence interval around the measurement would lie mostly in the negative energy squared region (and therefore imaginary mass)?  Or what am I misunderstanding?

Whats to misunderstand? 

Plenty of articles of varying technicality in google , question is why. I always remember this one because I did a third year project involving this and I also measured a negative value

https://www.google.com/search?q=negative+energy+squared+of+neutrino&oq=negative+energy+squared+of+neutrino&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIGCAEQRRg80gEMNjI0NTQwNzBqMGo0qAIAsAIA&sourceid=chrome&ie=UTF-8

[andrew s]

An indirect way to approach the mass of a neutrino is to measure its speed. This gives a speed difference from that of light of 2x 10^-9 from the supernova 1987A. Whatever the mass it's very small.

When trying to measure a value you not only have to worry about statistical variations but also systematic errors. The latter are very hard to eliminate. 

As an example this is the history of the speed of light measurements

There looks to be a systematic difference between the early and late results.

Regards Andrew 

Edited September 17, 2023 by andrew s

[billhinge]

42 minutes ago, andrew s said:

An indirect way to approach the mass of a neutrino is to measure its speed. This gives a speed difference from that of light of 2x 10^-9 from the supernova 1987A. Whatever the mass it's very small.

When trying to measure a value you not only have to worry about statistical variations but also systematic errors. The latter are very hard to eliminate. 

As an example this is the history of the speed of light measurements

There looks to be a systematic difference between the early and late results.

Regards Andrew 

In radioactive decay the negative mass square is a consequence of conservation of momentum and energy of the resultant positron and neutrino (since thats its 'job') not a speed measurement.  It isn't even an unusual result, there are some people who take this literally but most state that it is systematic error 'somewhere' since its 'obvious' that it cant be negative and there it must be positive. I make no claim for either viewpoint, my beef is that if there is systematic error then someone should identify where. The most successful standard model says neutrino mass = 0 and therefore must travel at c (but they can't since they oscillate). 

 

[andrew s]

4 minutes ago, billhinge said:

In radioactive decay the negative mass square is a consequence of conservation of momentum and energy of the resultant positron and neutrino (since thats its 'job') not a speed measurement.  It isn't even an unusual result, there are some people who take this literally but most state that it is systematic error 'somewhere' since its 'obvious' that it cant be negative and there it must be positive. I make no claim for either viewpoint, my beef is that if there is systematic error then someone should identify where. The most successful standard model says neutrino mass = 0 and therefore must travel at c (but they can't since they oscillate). 

 

I know that. I was pointing out an alternative approach based on speed measurement. One way to avoid systematic error, which are very difficult to identify,  is to use very different techniques. 

As you say they oscillate so they should have some mass. There are a  number of unexplained anomalies within the standard model of particle physics,  as there are within the LCDM and come to that any theory you care to mention.

They are still currently the best we have. It's not for lack of effort by theoretical physicist but  no one seems to have made any significant advances in a long time.

Regards Andrew 

[billhinge]

5 minutes ago, andrew s said:

I know that. I was pointing out an alternative approach based on speed measurement. One way to avoid systematic error, which are very difficult to identify,  is to use very different techniques. 

As you say they oscillate so they should have some mass. There are a  number of unexplained anomalies within the standard model of particle physics,  as there are within the LCDM and come to that any theory you care to mention.

They are still currently the best we have. It's not for lack of effort by theoretical physicist but  no one seems to have made any significant advances in a long time.

Regards Andrew 

Yes I appreciate that, point is that there are still many mysteries to solve, we don't know everything and we may even have got some assumptions wrong? (not picking on anything specific)

 

[andrew s]

1 minute ago, billhinge said:

Yes I appreciate that, point is that there are still many mysteries to solve, we don't know everything and we may even have got some assumptions wrong? (not picking on anything specific)

 

Indeed, but I am always amazed by what we do know 😊

Regards Andrew 

[saac]

2 hours ago, andrew s said:

Indeed, but I am always amazed by what we do know 😊

Regards Andrew 

A point often missed by the armchair physics fans beloved of U Tube/Tiky Toc who freely criticize with what must surely be little understanding. 

Jim 

[billhinge]

1 hour ago, saac said:

A point often missed by the armchair physics fans beloved of U Tube/Tiky Toc who freely criticize with what must surely be little understanding. 

Jim 

I taught myself the maths and physics of GR to tensor level from the standard grad level books ( beyond what I did at  3rd year BSc specialisation) I don't claim to be an expert but I know my Riemann tensor from my Ricci\Weyl tensor from my Ricci scalar, my covariant from my contravariant  and now that I'm about to be semi retired I'm going back to study for a physics masters to enjoy it with a 'desire' to to do further study afterward if possible (I can afford to self fund  if required) . No need to find a job at the end or get involved in the typical student social activities 😉 

I think criticism (I don't mean flat earth and other mystic woo woo)  is an important part of science because it forces physicists to defend what they preach - they often disagree after all

Do real physicists really have their feelings hurt if they are criticised on youtube?

[Ags]

52 minutes ago, billhinge said:

Do real physicists really have their feelings hurt if they are criticised on youtube?

Not sure, but imaginary physicists have their feelings hurt by a negative amount. 

Edited September 17, 2023 by Ags