A handful here have engaged in my crazy thought experiments. I couldn’t help but share this video as it is fun. https://youtu.be/M3GQM7tuq2w
After watching the video, I realized I was arguing for the aether as well and that we see it in gravitational waves. Gunnar Nordstrom, a Swedish physicist and colleague of Einstein, wrote a paper that said the gravitational field and electromagnetic field can be expressed as the same if we live in 4 dimensions inside a five dimension universe.
The video talks about using an interferometer to detect the aether. So could someone talk me down from the crazy since I’m not a scientist: how is LIGO different from the interferometer that was used to try to find the aether? Is it actually different or can we just measure more precisely? How do we know it detects gravitational waves and not the aether?
The main principle of the LIGO apparatus is the same as the Michelson-Morley experiment which was meant to detect aether. The differences are mainly in the scale and precision that the physicists care about. (Here is a link to LIGO’s webpage explaining this in more detail.) The LIGO apparatus has much longer arms (4 km) compared to MM’s (only 1.3 m). LIGO also has much more laser power bouncing back and forth in the cavity formed by the arms and mirrors, and their mirrors are stabilized to be immune to the effects seismic vibrations and other disturbances which may change the length of the arms. All of this is needed to get to their extreme level of precision. LIGO wants to make sure that any changes to the length of the arms of the interferometer are due to gravitational waves and not unintended terrestrial effects.
However, LIGO isn’t superior on all fronts. One thing the MM experiment could do better is that it could be freely rotated to alter the orientation of the arms relative to the direction of the aether flow. In contrast, the position of LIGO is fixed (and it would be very hard to artificially rotate an giant interferometer with 4 km arms). That being said, in principle LIGO could repeat the MM experiment by simply seeing how its signal changes as the earth rotates over 24 hours. But this would be a very slow and ineffective experiment.
In contrast, since MM performed their experiment in 1887, multiple experiments have replicated their setup and updated it with modern technology to keep increasing their precision. (You can see a selection in this Wikipedia article.) These experiments use similar principles as MM and LIGO, but they usually have both greater precision and a means to easily rotate the experiment (while keeping it stable). In fact, I worked on one such experiment in college. The search for aether has never stopped, it’s only that we’ve put more and more stringent upper bounds for the strength of its effects (assuming if it actually exists).
To be clear here though, the MM experiment and the LIGO were both interferometers, but they are looking for totally different signals.
LIGO is looking for chirps that take place over seconds or minutes. These chirps couldn’t be caused by an aether wind.
MM was looking for seasonal variation when we were on different sides of the sun.
Perhaps LIGO data could be mined to look for aether, but it’s a category error to think that looking for black hole mergers is the search for aether. It isn’t.
On a technical note, it would be interesting to see, knowing what we know to cosmology now, if MM had the sensitivity to detect aether if it was motionless relative to either our galaxy arm, our galaxy center, or the CMB. Would LIGO have enough power if MM did not?
Thanks for the explanation @dga471 . It’s all so very interesting.
I wonder if the two different LIGO stations are oriented the same way. I’m assuming they have to make some adjustments based on their position. I noticed that their waves are not exactly the same for the same event.
Can you explain what this means - “upper bounds for the strength of its effects”?
My crazy hypothesis is that if the electromagnetic field is 3-dimensional or consists of 2 planes, and in the 5-dimensional universe the gravitational field lies on top of the 2nd electromagnetic field, the aether that flows in all directions at once; then what’s actually being measured is when these two fields diverge at these barely measurable lengths. I’m sure that doesn’t make any scientific sense. It doesn’t quite make sense in my head and I’m barely able to explain it. I think it makes sense to the fact that we wouldn’t see any EM counterpart to any of these events and the few that do are misidentified.
I was just watching videos today on the aether wind, and wondering why it has to flow in one direction and not all directions at once. It’s a fun thought experiment if nothing else.
Earlier this week I also listened to the Science(ish) podcast Sabine Hossenfelder had linked in her blog we discussed earlier with gravitational waves. It did make LIGO seem very fishy, even more than her blog did. She was very even-handed. If they haven’t released old data to the public yet after all of the criticism, that’s problematic.
