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Proxima Centauri in 25 years

I don’t know if I’ve posted this musing before…but to get radio telescopes out past the heliopause if not the Oort might be revealing…get out of our big solar radar’s ground clutter, as it were.
 
publiusr said:
I don’t know if I’ve posted this musing before…but to get radio telescopes out past the heliopause if not the Oort might be revealing…get out of our big solar radar’s ground clutter, as it were.
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Specifically, how are the solar wind plasma, cosmic ray interaction with the interplanetary magnetic field, the termination shock, the heliopause, the heliosheath, and Oort cloud objects interfering with radio astronomy done from the vicinity of Earth? What radio bands are affected, why, and to what extent? Do you have any technical references for your proposal?

Your suggestion is an extremely expensive pipe dream and there's no justification for it if there isn't any evidence that any interference with radio observations exists.
 
Perhaps very weak ET signals can’t make it in…just the buzz of the cosmos at large. It would be nice to start hearing signals.
 
publiusr said:
Perhaps very weak ET signals can’t make it in…just the buzz of the cosmos at large. It would be nice to start hearing signals.
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The solar wind plasma has an effect on radio signals - much like the ionosphere does - but then so does the ionised interstellar medium. It's an interesting question. It was the examination of fluctuations of the radio signals from quasars due to the solar wind plasma that led to the discovery of pulsars.
[...] interplanetary scintillation can be used as a probe of the density of the solar wind. Interplanetary scintillation measurements may also be used to infer the velocity of the solar wind.

[...] it was an investigation of interplanetary scintillation that led to the discovery of pulsars, even though the discovery was a by-product rather than the purpose of the investigation.
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Interplanetary scintillation - Wikipedia

There's also the inverse-square law to contend with, of course.
 
publiusr said:
That’s a more satisfying answer to Fermi than us being alone.
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Yeah, our TV and radio broadcast signals likely get lost in the noise beyond a couple of light years. Radar pulses from Arecibo (when it was operating) and from military radars probably get somewhat farther. Aliens might use lasers, masers, gravitational waves, or even neutrinos to communicate over light years. Unfortunately, it appears that quantum entanglement doesn't offer any way of transmitting and receiving information even at light speed. If the aliens want to be found, either they or we need to try harder. I suspect many alien civilisations would find it easier to simulate universes to explore rather than actually do it. It's less expensive and also far less risky. When their (presumably roughly solar mass or less massive) suns eventually leave the main sequence, things get tricky during the red giant phase but the eventual white dwarfs emit exploitable energy for a long time - perhaps a hundred billion years.
 
Imaus said:
Our local neighborhood is REALLY big. Even just the Local Bubble alone. I don't doubt there's alien civilizations out there. But if radio signals decay at 2 ly, and even directed signals have a low chance of being recieved, we have to rely on telescopes and sub-relativistic laser-communication probes, and those might not get back results until the higher end of this century, if we even launch any this century: this might be a very Mars and Venus and Titan and Callisto focused century, which is fine - but it does mean we're not looking far out, and most of our scopes and missions might go to Centauri, Bernard's, maybe Wolf or something of that nature.
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What do you consider "our local bubble", would that be just our galaxy?

What if there is life just outside of our solar system? I don't know where but what if there was something outside of our little system that we just can't detect now?
 
I'd like to see it tested in space. It doesn't sound very expensive to construct and it might fit on a small cubesat. How much power is required to generate the claimed 200 μN of thrust and how efficient is the device? I assume waste heat needs to be radiated away. Assuming it is shown to work, how well would it scale up into something much larger? Nuclear fission would be required for power beyond a few AU presumably.
 
Roko's Basilisk said:
I'd like to see it tested in space. It doesn't sound very expensive to construct and it might fit on a small cubesat. How much power is required to generate the claimed 200 μN of thrust and how efficient is the device? I assume waste heat needs to be radiated away. Assuming it is shown to work, how well would it scale up into something much larger? Nuclear fission would be required for power beyond a few AU presumably.
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I brought this up elsewhere when my suggested crowd-funded vomit-comet flight with one on Zero-G didn't go anywhere (and in retrospect, seeing how many problems Fran Blanche from FranLab had on her recent Zero-G flight trying to get her cameras ready in between arcs, i have to agree. it has to be a satellite. )

I think a 2 unit cubesat might be enough. Maybe two units. The cheapest that a one unit cubesat launches right now is probably through Nanoracks, and they launch directly off of ISS. It might be cheaper as a piggy back payload if someone was willing, but not counting the cost of the sat itself, probably looking at $50 to $60k US for the satellite.

They've been stating 60mN from 1kw input, at least that was the last I heard. (that's not what Tajmar's test at Dresden used though, I do not believe, but that test did not have positive results).

https://www.cubesatshop.com/product/single-cubesat-solar-panels/ offers 2.3 watt PV's for a 1u cubesat. Scaling down, seems like that would work scaled down for this 200 μN thuster, with the second unit for the computer, radio, startracker, etc.
 
Assuming the thrust scales linearly with power, it'd require 3.3W of power so perhaps it's doable although it sounds tiny. Extensible solar panels would help or maybe some sort of SNAP generator would be permitted? I don't know what would be available off the shelf, if anything.
 
for an initial orbital test i imagine 3u cubesat might be the most anyone could get with university, SSI, or public funding. the third unit could be a deployable solar panel, maybe.

I know Woodward and Fearn got some money from the NIAC grant but that probably all went into research. they've been trying to find a piezo material that doesn't fall part as quickly as what they are using now.
 
XCV666 said:
I know Woodward and Fearn got some money from the NIAC grant but that probably all went into research. they've been trying to find a piezo material that doesn't fall part as quickly as what they are using now.
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Have they tried piezoelectric polymers? The piezo-response is not as great as for ceramics but they might be more durable.
 
I think some materials research is needed to get this effect---if real--to really take hold.

it seems you can levitate particles in a vacuum:
https://phys.org/news/2021-10-levitating-particles-vacuum.html

Now, let's say I am ET. I use sleeper ships to surround a subject system---and maybe use standing waves to pantograph probes back and forth where I need them...no light delay--the waves already bathe the system...I just need to surf them....even as we may use nano probes in the human body---just on a larger scale.

The probe doesn't need to provide its own power---it is just a physical cursor as it were. Combine that with the structure Woodward wants...and you might get an effect that we can't get loading a craft with its own heavy systems.

Side effects might be some feedback that could short out cars maybe? Radars might down it? Sound familiar?

get some airships with some rectennas to draw some power off--you can down one I bet.
 
Asbo Zaprudder said:
Have they tried piezoelectric polymers? The piezo-response is not as great as for ceramics but they might be more durable.
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sorry for the late reply. I don't know how I missed it. I recall reading from a presentation by Fearn to the Space Studies Institute that long term they did want to find a better replacement for the current pzt material. A lot of it was funding related as the more exotic stuff is apparently expensive and doesn't have a lot of baseline information. One of the problems is not getting positive results but getting consistency since timing is critical on each pulse. It reminds me a bit of how long it took the initial rocket scientists to figure out those critical first few seconds of ignition.

Work goes on but not a lot of information on it.

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here's a test of one of the more recent thrusters, however, from November.
 
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