[alancalverd]

Not a good idea to go to Hawaii since that will involve either a plane or a boat, designed by an engineer who hadn't seen it before and therefore had no idea what maths to use.

[alright1234 (OP)]

The 10^-18 m mirror displacement is three order less than the diameter of an electron!

[Kryptid]

The 10^-18 m mirror displacement is three order less than the diameter of an electron!

No it isn't. The upper limit of the electron radius as determined from a Penning trap is around 10^-22 meters: https://iopscience.iop.org/article/10.1088/0031-8949/1988/T22/016/meta

[Bored chemist]

The 10^-18 m mirror displacement is three order less than the diameter of an electron!

No it isn't.
But even if it was, why would it matter?
We aren't trying to measure the electron.

[Bored chemist]

since the mirror displacement of ΔL = 10-18 m is less than the diameter of an electrons which is to small of a displacement to experimentally measure.

Do you remember now?
It was not true when you said it the first time.
Saying it again makes you look silly

[alright1234 (OP)]

The 10^-18 m mirror displacement is three order less than the diameter of an electron!

No it isn't. The upper limit of the electron radius as determined from a Penning trap is around 10^-22 meters: https://iopscience.iop.org/article/10.1088/0031-8949/1988/T22/016/meta

The Penning trap is based on a cyclotron that uses a proton beam. How do you produce a proton beam and protons exist.

[Kryptid]

How do you produce a proton beam and protons exist.

This explains how: https://protons.com/proton-advantage/how-does-proton-therapy-work

[Bored chemist]

The Penning trap is based on a cyclotron that uses a proton beam

The traps used for looking at electrons use electron beams...

[particlephysics]

The LIGO states that a 10^18 m displacement is measured but how can this displacement be measured?  Also, Geiger counters only detect gamma rays---- right, since alpha particles cannot propagate through glass that has the mass close to a helium atom.

[Bored chemist]

The LIGO states that a 10^18 m displacement is measured but how can this displacement be measured?

By interferometry.
You can find out more by looking at the sort of web page that tells you that the displacement is 10^-18m
(I'm assuming the missing  minus sign in your post is a typo)

Geiger counters only detect gamma rays---- right, since alpha particles cannot propagate through glass that has the mass close to a helium atom.

No
Geiger counters aren't very good at spotting gammas- gammas tend to go straight through them without stopping.
You can make alpha sensing Geigers- you just need a very thin wall or window.
Thin sheets of mica are one option.