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No, negative masses have not revolutionized cosmology

backreaction.blogspot.com

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Re: No, negative masses have not revolutionized cosmology

#31

Post by eutropia »

ajkjk wrote: post #25
eutropia wrote: post #15

Tone of this blog post is extremely pedantic and comes across as if the author were personally insulted by the paper. But her argument is basically "You didn't understand the math, and you misunderstood the work that you cited". I feel like the burden is a little higher -- i.e. put in some effort to at least show the readers the math she's talking about and the counterfactual conclusions they arrive it if worked out.…

The argument presupposes that a person either believes (if they're not a physicist) or knows (if they are) that a spin-2 field must obey those rules, and that gravity is a spin-2 field, which makes the conclusion follow naturally. The math for this would not make any sense to a layperson, but is widely accepted. Proposing a new theory of negative mass means proposing much more significant alterations to the underlyin…

True. I'm not a physicist, so help me understand -- we've only ever observed fermions with spin 1/2 and bosons with spin 1 (and recently, Higgs at 0). We've postulated that gravitons would have to be spin-2 because of how the math works out (I don't understand the math but wikipedia suggests that its because gravity is defined by the use of 2nd order tensors) but we've not confirmed the existence of gravitons. Hopefully I'm not talking past you by speaking of particles, correct me if I'm wrong but particles/fields are interchangeable as a matter of quantization, right?

I definitely trust the general relativity math -- gravitational lensing /GPS atomic clock corrections are perhaps the easiest bits to wrap my head around as evidence.

Anyways, all that is to ask the question -- Is this negative mass model in conflict with observations or is it in conflict with other models of those observations?

Re: No, negative masses have not revolutionized cosmology

#32

Post by jcranberry »

benwr wrote: post #2

This is a critical response to https://news.ycombinator.com/item?id=18609375 ; in the comments is a response by Jamie Farnes, the author of the paper, and a rebuttal by the blog's author.

I have absolutely no idea who is right, but I don't see why Dr. Hossenfelder is being so patronizing? In her rebuttal in the comments she says

>Trust me, I do not enjoy doing this, but I do not want false claims to spread in the popular science literature.

The only way to stop popular science lit from misinterpreting/aggrandizing scientific findings and publishing what eventually amounts to false claims would be to just never publish anything provocative at all...and then they'd still probably find some BS to publish. I don't really see why such reasoning would prompt this response for the paper.

Re: No, negative masses have not revolutionized cosmology

#33

Post by eutropia »

vanderZwan wrote: post #30
eutropia wrote: post #15

Tone of this blog post is extremely pedantic and comes across as if the author were personally insulted by the paper. But her argument is basically "You didn't understand the math, and you misunderstood the work that you cited". I feel like the burden is a little higher -- i.e. put in some effort to at least show the readers the math she's talking about and the counterfactual conclusions they arrive it if worked out.…

> Tone of this blog post is extremely pedantic and comes across as if the author were personally insulted by the paper. I suspect she is insulted, but more so by the press release surrounding a new paper unconfirmed by experimentation. That is now how science works. One could say it's like calling a buggy alpha version of a software project a stable finished product, if we pretended people actually did give a damn ab…

Yeah the press release and subsequent science journalism is all annoying and breathless and overblown -- totally agreed.

But to say that its unconfirmed by experimentation and "not how science works" is a bit silly, don't you think? The paper proposes a model, shows outputs of the model, and demonstrates how it predicts things we have already observed. It's a good starting point for other experiments and observations, don't you think? Plenty of papers do purely theoretical work and science is better for them, too.

Re: No, negative masses have not revolutionized cosmology

#34

Post by jetrink »

khawkins wrote: post #12

Occam's razor is a heuristic used in the investigative process, not a principle. While it's fair to point out that a theory makes everything more complicated and thus might make it less likely to be sound, it's not fair to push back on the first bit of research into a theory because they haven't had the time to fully develop it. Indeed, a scientific revolution generally starts by treating as false an assumption previ…

As I read that paragraph, I thought to myself that the author should read Sabine Hossenfelder's recent book Lost in Math: How Beauty Leads Physics Astray. In that book, Sabine argues quite convincingly that our aesthetic judgements of new theories can mislead us. She says of simplicity,

> This dream still drives research today. But we do not know whether more fundamental theories necessarily have to be simpler. The assumption that a more fundamental theory should also be simpler—at least perceptually simpler—is a hope and not something that we actually have reason to expect.

Re: No, negative masses have not revolutionized cosmology

#35

Post by throwawaymath »

jetrink wrote: post #34
khawkins wrote: post #12

Occam's razor is a heuristic used in the investigative process, not a principle. While it's fair to point out that a theory makes everything more complicated and thus might make it less likely to be sound, it's not fair to push back on the first bit of research into a theory because they haven't had the time to fully develop it. Indeed, a scientific revolution generally starts by treating as false an assumption previ…

As I read that paragraph, I thought to myself that the author should read Sabine Hossenfelder's recent book Lost in Math: How Beauty Leads Physics Astray . In that book, Sabine argues quite convincingly that our aesthetic judgements of new theories can mislead us. She says of simplicity, > This dream still drives research today. But we do not know whether more fundamental theories necessarily have to be simpler. The…

> As I read that paragraph, I thought to myself that the author should read Sabine Hossenfelder's recent book Lost in Math: How Beauty Leads Physics Astray.

The author is Sabine Hossenfelder :)

Re: No, negative masses have not revolutionized cosmology

#36

Post by apo »

Can't help but think of phlogiston:

Eventually, quantitative experiments revealed problems, including the fact that some metals gained mass when they burned, even though they were supposed to have lost phlogiston. Some[who?] phlogiston proponents explained this by concluding that phlogiston had negative weight;

https://en.wikipedia.org/wiki/Phlogiston_theory

Eventually, the mass paradox was resolved by the realization that combustion is really something else altogether: the combination with a then-unknown element, oxygen:

Phlogiston remained the dominant theory until the 1770s when Antoine-Laurent de Lavoisier showed that combustion requires a gas that has mass (specifically, oxygen) and could be measured by means of weighing closed vessels.

Re: No, negative masses have not revolutionized cosmology

#37

Post by narrator »

apo wrote: post #36

Can't help but think of phlogiston: Eventually, quantitative experiments revealed problems, including the fact that some metals gained mass when they burned, even though they were supposed to have lost phlogiston. Some[who?] phlogiston proponents explained this by concluding that phlogiston had negative weight; https://en.wikipedia.org/wiki/Phlogiston_theory Eventually, the mass paradox was resolved by the realizatio…

The Egyptians and Babylonians didn't really technologically advance much for 1000 years. They placed the most emphasis in their society on maintaining the social order above all else.

Progress can be stopped if you interfere properly with disruptive advances in science. Much of the world is still trying to roll back the development and widespread dissemination of small arms technology because it interferes too much with the maintenance of social order. The last major physics discovery gave us atomic weapons. Who knows what deadly forces future advances in physics would unleash? Heaven forbid they were easy to engineer! Perhaps it's in the interest of national security to direct fundamental physics research into "how many angels can fit on the head of a pin" type discussions via directing grant money such as we see with string theory. These endless manipulations of already existing knowledge and an aversion to more daring experimentalism should keep scientists from developing the successors to atomic weapons.

Re: No, negative masses have not revolutionized cosmology

#38

Post by danharaj »

garmaine wrote: post #20
mbell wrote: post #14

I'm not a physicist, just an interested bystander but some of these arguments don't seem to hold water to me: > There’s a more general point to be made here. The primary reason that we use dark matter and dark energy to explain cosmological observations is that they are simple. > A creation term is basically a magic fix by which you can explain everything and anything. Dark matter is an unknown 'substance' that inter…

Dark energy is the cosmological constant introduced by Einstein. So that criticism is rather ironic.

Actually, a cosmological constant is derivable from the Standard Model. But it's off by a very remarkable amount. Dark energy is the observation that that the Standard Model mispredicts the cosmological constant, so there must be something wrong with it.

Re: No, negative masses have not revolutionized cosmology

#39

Post by jetrink »

throwawaymath wrote: post #35
jetrink wrote: post #34

Earlier quoted context omitted.

As I read that paragraph, I thought to myself that the author should read Sabine Hossenfelder's recent book Lost in Math: How Beauty Leads Physics Astray . In that book, Sabine argues quite convincingly that our aesthetic judgements of new theories can mislead us. She says of simplicity, > This dream still drives research today. But we do not know whether more fundamental theories necessarily have to be simpler. The…

> As I read that paragraph, I thought to myself that the author should read Sabine Hossenfelder's recent book Lost in Math: How Beauty Leads Physics Astray. The author is Sabine Hossenfelder :)

I realized when I reached the bottom of the post. It is odd to me to see her saying that the new theory is disqualified for not being as simple as alternatives after reading her book.

Re: No, negative masses have not revolutionized cosmology

#40

Post by simonh »

narrator wrote: post #37
apo wrote: post #36

Can't help but think of phlogiston: Eventually, quantitative experiments revealed problems, including the fact that some metals gained mass when they burned, even though they were supposed to have lost phlogiston. Some[who?] phlogiston proponents explained this by concluding that phlogiston had negative weight; https://en.wikipedia.org/wiki/Phlogiston_theory Eventually, the mass paradox was resolved by the realizatio…

The Egyptians and Babylonians didn't really technologically advance much for 1000 years. They placed the most emphasis in their society on maintaining the social order above all else. Progress can be stopped if you interfere properly with disruptive advances in science. Much of the world is still trying to roll back the development and widespread dissemination of small arms technology because it interferes too much w…

It’ll keep scientists in the countries that do this from discovering such weapons. Meanwhile elsewhere in the world...
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