Alien Life

[paul1598419]

Youch! Mike, what were you doing with such a high power flashlamp exposed to your face? Or, did it blow through your cavity?

 

[Alaskan]

OK, wear safety googles when working with these lamps, you might not know what someone really sold you. I was attracted to this rod due to the Brewster angled cuts, I would use this to shoot into a very large LBO crystal which came out of a big high power ND YAG, so they are perfect for it due to not needing an AR coating or a polarisation window.

 

[paul1598419]

Man, I would love to see that, Chris. What wavelength are you expecting to get? Depending on the efficiency, it could be a whole lot of power, too.

BTW, you need to change your avatar to 1 million. I'm just sayin'......

 

[Radim]

Those angled cuts are Brewster's windows. That is good for a polarized beam and narrow linewidth. You will need external mirrors for it, but it could make one hell of a build.

^^^This.

BTW: I'm glad this thread topic is about lasers right now. I'm always affraid to open threads like this or religion thread popping out recently. Too much things to say and discuss. And you know how it turns out often - hours a day spent on LPF - not a bad thing, but still so many stuff to do and these kind of threads are potentially large time consumers.

 

[Alaskan]

We can talk about aliens, but all we are doing to giving our opinions which don't really matter. That is, much like religion, a subject where it can be a waste of time to talk about. I doubt anyone here has actually seen an alien (or a God figure), UFO's sure, I have, but so what, that doesn't prove anything.

Finding the Brewster angle cut ends of this rod were a nice boon for the possibility of using one of the other lines, not sure yet which one, but I'm thinking of the possibilities. 12 mm diameter and 175 mm long is like finding a 10 kilowatt ham radio tube, like, wow. Likely to remain a conversation piece though, but the possibility of making some real power is there, even respectable power at the inefficient lines. Optics the killer for that, if you find a rod like this, now finding the right optics for a rare line just as much a challenge unless you spend $$$.

 

[paul1598419]

Yeah, I was taught from an early age that you NEVER discuss religion or politics. You can't change minds that are set and it often turns into an exercise in futility. That is a waste of time that is in short supply for me these days.

 

[Alaskan]

What about Trump? We can spend time on that I bet

 

[Hemlock_Mike]

Paul -- The flash lamp was about 9" long and was misrepresented as a basic xenon unit.
It was some type of high pressure tube. I had it laid out on the bench with only about 5 J connected and when triggered, it went POW I was wearing glasses.
HM

 

[paul1598419]

What about Trump? We can spend time on that I bet

I've already done that. It was a never ending debate that went nowhere. I'll pass, thank you Chris.

Paul -- The flash lamp was about 9" long and was misrepresented as a basic xenon unit.
It was some type of high pressure tube. I had it laid out on the bench with only about 5 J connected and when triggered, it went POW I was wearing glasses.
HM

At least you had glasses on to protect your eyes. That is something I would have tried only enclosed. But, I am the cautious type. :beer:

 

[CynicalBrad]

I voted yes. Seems like an awful waste of space if us semi-intelligent beings are the only "intelligent" life out there. I just don't expect SETI to find any proof. How many of our communications would actually be detectable on a cosmic scale if you didn't know exactly where to look and what to look for? I imagine at those distance, background radiation would completely drown it out.

Back on topic guys.

As for those last for variables of the drake equation, they would require a known sample set to fill in and I can't even begin to guess as to their values.

 

[BobMc]

It all depends on what you call alien life? Anything not born of women? Would Angels be considered alien life?

 

[Ears and Eggs]

I voted yes. Seems like an awful waste of space if us semi-intelligent beings are the only "intelligent" life out there. I just don't expect SETI to find any proof. How many of our communications would actually be detectable on a cosmic scale if you didn't know exactly where to look and what to look for? I imagine at those distance, background radiation would completely drown it out.

Agreed, I believe there are other civilizations out there, but it might be only a handful per galaxy. Most likely the bottleneck in the drake equation it the Fi value, ie percentage of life that becomes intelligent. (I won't be very surprised if we find the galaxy is teeming with simple life) If the average is only a handful per galaxy then it wouldn't even be that big a statistical anomaly for us to be the only one in the Milky Way.
Even if there were several in the Andromeda Galaxy the chance we would be able to detect them is extremely minute. My understanding is that unless they are intentionally directing a beam right at earth, our current technology is unable to detect radio wave leakage from another civilization beyond a few light years, basically nothing in the scheme of the galaxy.

 

[RedCowboy]

Yea, we have to find a way to get there faster than the speed of light, once we can convert matter to energy in a controlled manner we will have a start at a start of what's needed to start really thinking about how we could warp the fabric of space time, then a lot of learning.

Also there's a lot of radiation out there, heck we could all be wiped out by a Gama ray burster here, to traverse light years of space would be dangerous in many ways even if we could do it. Plus we lack the ambition as a nation, maybe when the Chinese start going places we will get interested again, so much wasted time, the greed of our elected reps has put us in debt and slowed a lot of what could have been.

I'm afraid I wont live long enough to see us really go anywhere, maybe Mars.

BTW

Anyone see the movie : The Fifth Wave ?

Visitors could already be among us.

 

[Hemlock_Mike]

HEY -- Losta fun stuff here but I want to get back to my YAG gun. I hope this is a good forum for this.

As I said above in post 63, I built a 3.1 X expander using Surplus Shed "coated" lenses. I can get specific coated lenses from Edmonds
with specific AR coatings but with my current lenses, I can adjust the focus but small adjustments result in narrow 1 foot focal points.
At present, I can pop a balloon at 9 feet but the depth of field is small.
I was hoping a 3X expander would give me a 3' range to pop a balloon. RIGHT -- POP A BALOON !! I have no other way to
observe the beam from a pulse YAG but I would like a 3 to 4 foot depth of field -- ie a tight beam over that distance.
Do I need to change the magnification of the BE?

The SSY-1 is lasing but I need some help on the expander lenses. Also, As I stated above, I'm dumping about 25 J into the flash tube at near 1,000 VDC. This is high ESR photo flash caps and the excitation is likely providing multi passes through the rod but can I add a few more J's to the unit considering the bad ESR.

WOW -- A lot of questions for an old dumb ass!!!!

HM

Cowboy -- You are right on !!

AND if this bunch of BS is in the wrong place -- Please move it.

 

[Benm]

How many of our communications would actually be detectable on a cosmic scale if you didn't know exactly where to look and what to look for? I imagine at those distance, background radiation would completely drown it out.

Interestingly, fewer and fewer every year.

At the time those equations for detecting alien life were developed, broadcast analog TV and radio were still very widely used.

By now broadcast analog TV has been shut down in many countries, and broadcast analog radio is likely to follow in a decade or two.

We still have broadcast digital radio and tv, but those are much harder to detect, and if someone ever does, much harder to interpret. The latter is especially true if the signals are encrypted. Those digital, wide spectrum, modes already look more like some random background radiation if you don't know what to look for, but if they are intentionally encrypted it would be difficult to make out their content for any alien civilization since they do not have the decryption key.

An interesting question to ask is: at what distance could we detect ourselves? As in another copy of earth broadcasting the same signals etc.

We used to have blaring loud and simple radio signals like analog TV stations outputting up to megawatts of power in a narrow band, but those are all disappearing. With on-demand content replacing broadcast earth is becoming radiosilent to a degree.

Surely we cannot presume this works the same way on every other planet, but looking at ourselves we've gone from moderately transmitting, through blaringly loud, back to almost silent again in a period of about a century.

If other populated worlds follow a similar pattern however, our chances of detecting their signals are slim. Also there is the option that another planet would not need any high power transmissions like we used to because the population is confined to a smaller area or such: we had (and sometimes still have) shortwave radio stations that need to be received on the other side of the planet. There is no reason to assume this would be true for other planets in general though.

 

[Ears and Eggs]

An interesting question to ask is: at what distance could we detect ourselves? As in another copy of earth broadcasting the same signals etc.

I think that's exactly why we're not finding anything. Even with out best radio telescopes, like the Very Large Array, we would be unable to detect a civilization equal to us any farther than 5-10 light years at best if we are just listening for incidental radio leakage.

Only way we'd detect them is if we got REALLY lucky and one of our radio telescopes was aimed at them just at the right time to pick up a signal they deliberately aimed at us. If we happen to find anyone with today's technology, it either means we got VERY lucky or they are significantly more advanced than us.



Probably our best bet in terms of near term technologies is to invest in increasingly bigger and better orbiting optical telescopes. It may then be possible to detect at great distances if a extra-solar planet has life or not just through spectral analysis of it's atmospheric composition. Wouldn't tell us if the life is intelligent or just some algae, but would certainly narrow the search by orders of magnitude and give a target for our radio telescopes.