That we would receive a signal with the radio telescope discussed here would pretty much demand either that they make tremendous use of a very specific form of propulsion, or that they are putting a substantial fraction of their available energy into contacting civilizations of precisely our technological level. There's no thought that we'd pick up their radio chatter between themselves- we couldn't pick up Earth's radio noise from that distance, and we're only getting quieter as our technology becomes more effective.

Aliens in the business of contacting emerging civilizations must find themselves with an interesting tradeoff between transmitter power usage and contactee technology level- at a guess, it would be exponentially more expensive to contact species earlier on in their development. We may still just not be far along enough that the cost-benefit ratio makes sense to talk to us.

First time I started reading about quantum computers and the idea of entangled particles I immediately thought it would be a neat way to solve long distance space Comms. Anyone with a better brain than me care to explain if it could be a possibility?

In short, "it doesn't work the way you think it does"

People keep digging in this area because it's hard to measure accurately so we're not 100% yet, but the current consensus is that the interaction between entangled particles, isn't faster than light and should not be faster than light.

Do the effects of gravity move faster than light?

Simple reason - because every object or structure in the known universe can emit waves.

So we'll never abandon radio technology because everything can do it? That's not a very convincing reason.

We'll likely never abandon radio technology because it is an absurdly cheap and universal means of communication that propagates throughout the universe at the speed of light, a hard practical limit for how fast anything can send information. We certainly don't know everything, not by a long shot, and there are theoretical frameworks for FTL communication, but we don't have any hard observational or experimental evidence that this universal speed limit can be broken after a century of research that was more productive than the previous ten thousand years.

It's great to be hopeful and work towards such technology but you can't discard the very, very real possibility that the speed of light can't be exceeded or that doing so to communicate might require a Type II or III civilization, which might also be practically impossible to achieve due to the speed limit for travel.

For those equality puzzled about what akiselev meant by Type II / III civilizations, it comes from the Kardashev scale:

"The Kardashev scale is a method of measuring a civilization's level of technological advancement, based on the amount of energy a civilization is able to utilize.[1] The scale has three designated categories called Type I, II, and III. A Type I civilization uses only resources available on its home planet, Type II harnesses all needed energy from its local star, and Type III of its galaxy."

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

It's almost as if you've never read historical journals of scientists saying silly things like "This obviously if the height of human achievement, we'll never possibly find anything better", over and over and over throughout history.

That's a great cop out when you don't want to think critically about the history or current state of science. Besides, I didn't say that we are at the "height of human achievement" but that there are physical laws that remain practically unchallenged by centuries of observational or experimental evidence. the speed of light as a cosmic speed limit happens to be one of those.

No, it isn't.

"Heavier than air flying machines are impossible." -- Lord Kelvin

The physics didn't change, just our understanding of how to manipulate them.

Yes, it is. That argument is nonsense because it can never be falsified. No matter how much we learn, even if it's trillions of years into the future and we're short seconds away from the heat death of the universe, anyone who is too lazy to look at the state of science can just claim "We don't know everything! That magic anti-entropy perpetual motion machine is just around the corner!" and be done with it. It's the scientific equivalent of "God did it."

One cherry picked quote demonstrating a famous scientist's lack of imagination does not represent the scientific consensus, especially since da Vinci's lift and thurst research (based on heavier than air flying birds) from centuries earlier was well known.

No it's not. Two words, Em drive. Seriously, we are infants in our scientific understanding of the universe and physics. You speak as if we have a clue. If we had proven unified theory of everything, then your argument wouldn't be nearly as ignorant. But we don't. We don't even know what accounts for the majority of the universe. To assume we already have the answers is literally stupid.

Back to the original question and your EM Drive. Using waves and radars, EM Drives will easily be detected by radars and technology we have today - as the magnetic forces are ultimately form of energy..

This is a point that we do not yet have all the answers. Besides, we could easily stealth that shit out of that.

For starters we can easily talk/communicate to your grandmother and any human in history.

So I assume that you think they fear being found and are not trying to communicate (I find it unlikely they just don't care, as humans we are very interested in working out communications in the most simplest animals and plants)

Yet we have found them with our 'primitive' technology.

No, these structures would have started being built before we knew knew how to calculate volume. Our radio waves will not reach them for 1300 years. With the degradation of signal, and amplification of noise, we're not sure if what they detect will even be decipherable from noise. They may have discovered a way to communicate that is more efficient, so they may not even be listening on those frequencies.

We found them because they built massive space structures. 1300 years ago, we were invisible.