3 ms·

Not a physicist, but I never heard of this before and looks quite interesting at first glance. Google indicates that mainstream physics regards it sceptically

Not a physicist, but I never heard of this before and looks quite interesting at first glance. Google indicates that mainstream physics regards it sceptically ("pseudoscience"), but it was difficult for me to find out why. I found a single paper containing criticism from an actual physicist ("A sceptical analysis of quantized inertia" by Michele Renda: https://academic.oup.com/mnras/article/489/1/881/5545603 https://academic.oup.com/mnras/article/489/1/881/5545603), but that did not make the theory sound that bad, and it even mentions "absence of arbitrary tunable parameters", which sounds very promising to me... I'd be very curious on why this is so controversial from an actual physicist (e.g. compared to MoND). Hopefully Hossenfelder will cover this at some point on youtube, those videos are always quite merciless with overhyped results...

chc4 2y ago
The main reason, as far as I'm aware, is because McCulloch then went on to claim to invent several thrusters (EmDrive, most notably) derived from the effect that break normal conservation of momentum.
- cwillu 2y ago
  In what sense does McCulloch claim to have invented the EmDrive? The only citation about him on the EmDrive wikipedia article isn't even talking about anything relevant to the purported mechanism of action of the drive.
  - chc4 2y ago
    The theory behind EmDrive is based on his quantized inertia theory. I was under the impression he was the original proposer of the idea. It looks like it was instead proposed by someone else in 2006; however McCulloch submitted a paper in 2013 supporting it (https://arxiv.org/abs/1302.2775 https://arxiv.org/abs/1302.2775) and publically advertises about how his theory allows for "an electric rocket" on his twitter https://twitter.com/memcculloch https://twitter.com/memcculloch
btilly 2y ago
My first criticism is this. The scale on which quantization works is the https://en.wikipedia.org/wiki/Planck_constant https://en.wikipedia.org/wiki/Planck_constant. We should not expect quantization to be a visible effect at the scale of stars. And if quantization was a visible effect at the scale of stars, it should be very visible in our own solar system. But no, our solar system operates classically to a crazy number of decimal places, and the deviations follow general relativity - with no evidence of quantization.
pdonis 2y ago
See my response to georgeburdell upthread. Tl/dr: Unruh radiation, on which the proposed model relies, is zero for an object in a free-fall orbit.

chc4 2y ago

The main reason, as far as I'm aware, is because McCulloch then went on to claim to invent several thrusters (EmDrive, most notably) derived from the effect that break normal conservation of momentum.

cwillu 2y ago
In what sense does McCulloch claim to have invented the EmDrive? The only citation about him on the EmDrive wikipedia article isn't even talking about anything relevant to the purported mechanism of action of the drive.
- chc4 2y ago
  The theory behind EmDrive is based on his quantized inertia theory. I was under the impression he was the original proposer of the idea. It looks like it was instead proposed by someone else in 2006; however McCulloch submitted a paper in 2013 supporting it (https://arxiv.org/abs/1302.2775 https://arxiv.org/abs/1302.2775) and publically advertises about how his theory allows for "an electric rocket" on his twitter https://twitter.com/memcculloch https://twitter.com/memcculloch

btilly 2y ago

My first criticism is this. The scale on which quantization works is the https://en.wikipedia.org/wiki/Planck_constant https://en.wikipedia.org/wiki/Planck_constant. We should not expect quantization to be a visible effect at the scale of stars. And if quantization was a visible effect at the scale of stars, it should be very visible in our own solar system. But no, our solar system operates classically to a crazy number of decimal places, and the deviations follow general relativity - with no evidence of quantization.

pdonis 2y ago

See my response to georgeburdell upthread. Tl/dr: Unruh radiation, on which the proposed model relies, is zero for an object in a free-fall orbit.