first contact

[MRlogic]

a nukes shockwave uses air pressure

[Moontanman]

Not necessarily. Surely many space faring civilizations would have the technology to have a constant acceleration near that of the gravitational acceleration their species evolved with. Especially since even at 1g, relativistic speeds are reached well under a year.

 

You could be correct but that would mean no need for slow boats and it would indicate a technology beyond what we can conceive of as well. The idea so far is that aliens wouldn't have technology beyond our understanding.

 

If said civilizations evolved in a gravity well, it's likely that they've become dependent upon gravity biologically. For example, our species has several issues with sustained zero g.

 

For such a species to ween itself off of gravity, it would need actual evolution.

 

I have to agree with this, living in zero gee would have consequences we do not know of for sure, i think there would have to be a minimum to keep us healthy as well as human. Of course some genetic engineering might make this a moot point...

 

 

Who said the target planet would be Earth size? What if the species evolved on a smaller planet like Mars or a moon like Luna and prefers lower gravity.

 

I think we can assume a planet has to be big enough to hold an atmosphere to be any more useful than asteriods which Luna cannot do and which Mars does very poorly. There is unlikely to be organisms that evolve in a vacuum

 

And an elevator couldn't be rigged from orbit? Lower down habitats etc and have a shipyard anchoring the elevator in orbit. That also lessens your issue with the fuel requirements of a planetary launch.

 

But this ignores the low probability that a planet would be useful for anything but resources, resources that can be obtained easier from asteriods...

 

Also, you're ignoring the fact that the civilization may want to stay a while.

 

That is the idea behind artificial habitats, everyone lives inside large structures, they travel from start to star in these structures, generations pass they loose any interest in planets. And it would take many thousands of years to use all the resources around one star. They use the debris around stars as sources of materials to build the artificial self contained colonies..

 

And they'd require loads of course adjustments. Not to mention the near constant course correcting during the actual mining process.

 

I'm not sure what you mean by this... Using gravity assist could take you all over the solar system with very little fuel....

 

They're no more iffy than using up all your fuel pulling up to asteroids that may or may not have fuel components.

 

What fuel components would a planet have that other smaller objects orbiting the stars would not have? You could easily target the asteroids that have everything from hydrocarbons to iron to water...

 

Why assume a target of a life-bearing world? Also, modular design of the space craft combined with the elevator idea above is an easy fix to your contaminant idea.

 

again, why would you want to land on any planet much less a lifeless one, asteroids in Trojan orbits around Jupiter would have everything Mars would have. Kuiper belt objects would be ideal, no need to even get close to the star...

 

a nukes shockwave uses air pressure

 

 

Nuclear weapons do far more than just use a shock wave, in space there would still be a blast of hard radiation, particles and EM radiation, i wouldn't want to be close to a nuclear weapon when it went off just because it was in a vacuum... A nuclear bomb for use in space might be designed slightly different but it would at the very least vaporize and irradiate anything close by... a neutron bomb (enhanced radiation bomb) might be better than a bomb designed for maximum blast effects on a planet...

Edited September 28, 2010 by Moontanman

[Ophiolite]

a nukes shockwave uses air pressure

So the aliens and their technology are impervious to radiation. I didn't know that.

[zapatos]

What if they didn't use the signals. What if their form of life was so different, that they wouldn't even recognize us as life at all?

 

 

Why assume they would even use EM signals? Why assume they would have similar technology?

 

Well, as I tried to explain in an earlier post, I think we would use similar technology because both the aliens and us would have grown up in the same universe. We both are exposed to the same properties of the universe, and while we may not understand all of the universe in the same way or utilize its properties in the same way, I would be surprised if we had no overlap at all. And while I might not recognize an alien as life, if it was altering its surroundings for some purpose, I'd probably give it a closer look.

[MRlogic]

So the aliens and their technology are impervious to radiation. I didn't know that.

 

 

there ships would be radiationless, thats how the could survive in space but an emp might work

[Ophiolite]

there ships would be radiationless, thats how the could survive in space but an emp might work

You have a knack for avoiding answering questions. I'll make it explicit. do you now understand that your claim that a nuclear bomb would not work in space was flawed? If not what will it take to convince you?

[MRlogic]

You have a knack for avoiding answering questions. I'll make it explicit. do you now understand that your claim that a nuclear bomb would not work in space was flawed? If not what will it take to convince you?

 

 

the only thing a nuke would causein space is radiation and heat

[ydoaPs]

Well, as I tried to explain in an earlier post, I think we would use similar technology because both the aliens and us would have grown up in the same universe. We both are exposed to the same properties of the universe, and while we may not understand all of the universe in the same way or utilize its properties in the same way, I would be surprised if we had no overlap at all. And while I might not recognize an alien as life, if it was altering its surroundings for some purpose, I'd probably give it a closer look.

There's no reason that they would use EM radiation for communication. What if they evolved on a planet whose only continent is a small island? You don't seem to understand the ALIEN part.

 

the only thing a nuke would causein space is radiation and heat

Radiation, activation, contamination, heat, shrapnel, etc. Not to mention the EMP effect of a nuclear detonation. Imagine if we simply took an existing design and added an outer casing filled with ball bearings? That would vastly increase the impact of a nuclear weapon in space(especially if the balls were made of something like cobalt-59).

 

What if the nuke had relativistic velocity relative to the target and actually makes impact? There's really no reason to say that nukes aren't effective in space.

[zapatos]

There's no reason that they would use EM radiation for communication. What if they evolved on a planet whose only continent is a small island? You don't seem to understand the ALIEN part.

This thread started with the proposition of humans making contact with an advanced alien race. Unless this race originated in some other universe with different physical properties, then they have been exposed to the same properties of the universe that we have. These properties are the only ones we have to work with to develop communications, a means of travel, a means to do any of the things our technology allows us to do.

 

All I am saying is that if we have the same raw materials to work with (EM, gravity, hydrogen, space, planets, etc.), then we may very well recognize when someone else has manipulated those raw materials for some purpose (such as using EM for communications). I recognize that we might not utilize all of the same properties of the universe, but I would think there would be some overlap. For example, if the aliens traveled here, they may very well have created some type of ship to travel in which doesn't look like an asteroid or travel the same path as an asteroid (for example, it may make a soft landing on a planet).

 

I never said they would use EM radiation for communication, but there is a reason they could use EM radiation for communication. It works. Do you believe that an advanced alien race is unlikely to be aware of the EM that is bombarding them constantly from all directions?

 

And I admit I don't understand how you are using the concept of ALIEN. You seem to be implying that if they are ALIEN, then everything about them MUST be different than everything about us. Why would that be? Why couldn't many of our technologies share the same underlying properties of the universe?

 

I admit that it is possible that we would not recognize other life, but you seem to imply that it is nearly a certainty.

[Mr Skeptic]

Kind of like convergent evolution. The same solution can be arrived at independently, more so for particularly good solutions.

[MRlogic]

now an EMP would be devastating. its the number 2 weapon of mass destruction just below nuclear weapons but it might work on the aliens cause i dont think any thing stops an EMP. is there?

[Mr Skeptic]

A tin-foil hat will stop the EMP. You'll need a thicker tin-foil hat for a more powerful EMP. It won't completely stop the EMP though, but it just has to reduce it to a harmless strength. If you have extra money to spend, upgrade to a Faraday cage.

[Moontanman]

now an EMP would be devastating. its the number 2 weapon of mass destruction just below nuclear weapons but it might work on the aliens cause i dont think any thing stops an EMP. is there?

 

 

Yes, a grounded wire mesh will stop EMP, as will enclosing stuff in a meal box. The flash of gamma rays would be the worst long range effect of a nuke...

[MRlogic]

an emp only effects mechanical items like cars and electricity. it has no effect on humans that i no of. maybe we could use this against the aliens if there hostile

[Mr Skeptic]

A strong enough EMP will kill humans just fine. But we're not very conductive, so it would have to be quite strong to do some damage to us.

[Moontanman]

If the Nuke isn't actually touching the object you want to "kill" I think the gamma ray flash would be the worst part of it for any living beings nearby. In the atmosphere the gamma ray flash is absorbed quickly by air, in space it would not be diminished by anything other than distance...

[Airbrush]

gamma ray flash would be the worst part of it for any living beings nearby. In the atmosphere the gamma ray flash is absorbed quickly by air, in space it would not be diminished by anything other than distance...

 

Interesting. Could there be a way to focus the gamma ray burst in the manner a giant star collapses? How much gamma ray power would such a beam need to destroy material objects?

 

Any ETI with the capability of coming here would be so far beyond us that they could evade detection by disguizing themselves as human aircraft, such as helicopters, airplanes, and jets. They could occupy the deep ocean, anywhere underground, or even in office buildings. Then they infiltrate our cities and set off bio-bombs that destroy their human competitor, and take Earth as their's. This proves to me they have not found us, or are here but only as probes gathering info for transmission to the home planet 100 ly away.

[MRlogic]

well we have tech thats cloaks us you no stealth fighters and now were even producing stealth ships. im sure the aliens might have the same devices.

[Equilibrium]

well we have tech thats cloaks us you no stealth fighters and now were even producing stealth ships. im sure the aliens might have the same devices.

 

In fact, i'm pretty sure if they survived the brutal process called "civilization" (with all the wars and riots included) they probably have far better weapons of mass destruction compared to our petty nuclear bombs. Besides, what would the aliens want from us? we are like apes/cavemen compared to them. They might even be sympathetique towards us like feeling bad for a stray puppy as far as I'm concerned.

[Moontanman]

Interesting. Could there be a way to focus the gamma ray burst in the manner a giant star collapses? How much gamma ray power would such a beam need to destroy material objects?

 

Yes, it's called a nuclear pumped gamma ray laser, it's pumped by a nuclear explosion...

 

http://www.projectrho.com/rocket/rocket3x1.html

 

Bomb-pumped x-ray and gamma-ray lasers

A special type of laser is the bomb-pumped laser. This is generally found as a missile warhead. A "submunition" is a warhead that is a single-shot bomb-pumped gamma-ray laser. The original concept was developed by Edward Teller under the name "Excalibur." Teller and Excalibur were later discredited, but the basic idea wasn't.

 

Here's the problem: the lasing medium in a laser has to be "pumped" or flooded with the same frequency that the laser emits. This isn't a problem with infrared or visible light, but sadly there are not many good sources of x-rays and gamma-rays. About the only good source is a detonating nuclear device, which has the distressing side-effect of vaporizing the laser. So the idea is to make a laser that can frantically manufacture one good x-ray zap in the few microseconds before it is destroyed by the bomb blast. This is the reason it is "one-shot."

 

 

 

Any ETI with the capability of coming here would be so far beyond us that they could evade detection by disguizing themselves as human aircraft, such as helicopters, airplanes, and jets. They could occupy the deep ocean, anywhere underground, or even in office buildings. Then they infiltrate our cities and set off bio-bombs that destroy their human competitor, and take Earth as their's. This proves to me they have not found us, or are here but only as probes gathering info for transmission to the home planet 100 ly away.

 

 

Unless of course the Earth was useless to the aliens due to trace elements or atmosphere not having enough oxygen or too much methane or ammonia or any one of thousands of different reasons it would be worthless to any being who hadn't evolved here...

[MRlogic]

i dout the earth would be worthless since water is such an important liquid for life, they might even be looking for a place to settle there population.

[ydoaPs]

i dout the earth would be worthless since water is such an important liquid for life, they might even be looking for a place to settle there population.

Unless they use a different solvent.

[Moontanman]

i dout the earth would be worthless since water is such an important liquid for life, they might even be looking for a place to settle there population.

 

 

Water does not necessarily make a planet inhabitable, just one trace element out of place could make the earth useless to any aliens, they might use arsenic instead of phosphorus, some life forms on the earth do, they might need extra mercury or be very sensitive to it and the Earths mercury levels could make it unusable to them. If the mercury levels on a planet were just a few times higher than they are now we wouldn't be able to use it. Another planet might contain stuff like ammonia or methane and thus they would not be able to breath ours. Far too many variables to say a planet with water is usable by aliens or us for that matter...

[Marat]

The essential problem in interacting with aliens is that they may well conceive the universe in ways radically incommensurable with our own way of understanding things, so that all communication might be impossible. An example cited by the philosopher Willard Quine highlights the difficulties of communication even on Earth. It was noted that an exotic tribe said 'gavagai' whenever they say rabbits, so western anthropologists and linguistics assumed that 'gavagai' meant 'rabbit' in the tribe's language. However, on further study much later it was discovered that 'gavagai' actually referred to the feeling of happiness the tribe members experienced on seeing anything as active as a rabbit. The point of this anecdote is that the way an alien intelligence factors experience into significant units and important distinctions may be radically unexpected, so communication may be difficult or impossible across the gulf of vastly different approaches to meaning.

 

If such gulfs in meaning exist even among different human tribes, the potential gults in meaning between alien beings and humans would be unimaginable. Perhaps their idea of 'communication' is pretending to have an epileptic seizure every time they see a goldfish at the same time as they smell tobacco.

[MRlogic]

as far as we know life cannot survive without water. even in enviroments such as sulfur, there are still traces of water to support life