Skitzocow Paul Richard Atkinson A.K.A The Alien Whisperer

[Phil Ken Sebben]

Another thing, if faster-than-light travel and communication are impossible (which is likely), why would aliens travel many light years just to talk to a few (probably mentally ill) people on Earth?

It's for this reason that while I've said many times I believe in aliens, I also don't believe we've ever been visited and I don't believe we ever will be visited. It would take somewhere between 50,000 - 120,000 years to just reach the closest star to our sun based on our level of technology. And since nothing can travel faster than light, the only way possible would be if we somehow find a wormhole which is mathematically possible to exist. We just don't know if they exist, if they're stable or what the conditions are inside of one.

So no alien visitations although I'd be totally for it if the aliens looked like this:

Spoiler

*(scientists speculate that a bipedal form is most compatible with sentience though)

Yeah, I've heard that too but I've always felt it came from a form of humanoid prejudice. You know, we use ourselves as the guide and then base everything on ourselves and how we fit into the universe. So we're sentient, it means that being humanoid denotes a greater chance of sentience as well.

 

[Kršćanin Čendlervic]

What if the aliens are from the Wrong Planet?

 

[ToroidalBoat]

It would take somewhere between 50,000 - 120,000 years to just reach the closest star to our sun based on our level of technology.

Spoiler: Infodump

With current technology. But if one could take advantage of time dilation and relativistic spaceflight (say through a ramscoop [1]), one could travel places a lot quicker. But to people on a planet one leaves behind, one only goes at very near light speed at most. This is due to the speed of light being constant in all reference frames.[2]

Traveling faster than light is probably impossible [3] (unless one could somehow warp space itself) - which is how I doubt that someone could telepathically talk with aliens light years away in realtime.

And due to the Fermi paradox, I think that spacefaring races out there, if any, are very sparse (I think one estimate based on the Drake Equation found more or less only one per galaxy at any given moment).

As for the humanoid thing, I think it comes from functionality, not necessarily prejudice, although it seems unlikely that aliens look like humans with makeup.

TL;DR: I also don't think aliens are visiting Earth, and I highly doubt people on Earth are telepathically talking with aliens in a star cluster hundreds of light years away.[4] Also, I wonder if the subject of this thread knows about the difficulties with space travel and the Fermi paradox.

Spoiler: sauces

[1] http://en.wikipedia.org/wiki/Bussard_ramjet
[2] http://www.convertalot.com/relativistic_star_ship_calculator.html
[3] http://www.theculture.org/rich/sharpblue/archives/000089.html
[4] http://en.wikipedia.org/wiki/Pleiades

 

[Phil Ken Sebben]

Spoiler: Infodump

With current technology. But if one could take advantage of time dilation and relativistic spaceflight (say through a ramscoop [1]), one could travel places a lot quicker. But to people on a planet one leaves behind, one only goes at very near light speed at most. This is due to the speed of light being constant in all reference frames.[2]

Traveling faster than light is probably impossible [3] (unless one could somehow warp space itself) - which is how I doubt that someone could telepathically talk with aliens light years away in realtime.

And due to the Fermi paradox, I think that spacefaring races out there, if any, are very sparse (I think one estimate based on the Drake Equation found more or less only one per galaxy at any given moment).

As for the humanoid thing, I think it comes from functionality, not necessarily prejudice, although it seems unlikely that aliens look like humans with makeup.

TL;DR: I also don't think aliens are visiting Earth, and I highly doubt people on Earth are telepathically talking with aliens in a star cluster hundreds of light years away.[4] Also, I wonder if the subject of this thread knows about the difficulties with space travel and the Fermi paradox.

Spoiler: sauces

[1] http://en.wikipedia.org/wiki/Bussard_ramjet
[2] http://www.convertalot.com/relativistic_star_ship_calculator.html
[3] http://www.theculture.org/rich/sharpblue/archives/000089.html
[4] http://en.wikipedia.org/wiki/Pleiades

Yeah, familiar with the whole concept of the Bussard Ramjet, same with "Project Orion", "Project Longshot" and "Project Daedalus". None of which are any more than just ideas that have been tossed around since the 60's and we're no closer to achieving them now than we were then.

But even if it's somehow possible to travel almost at the speed of light and I'm talking 99.999999999999999999995% if would still take roughly 2 1/2 years @ 2G's accelleration to reach the star based solely on the time effects on the ship. On Earth however it would taken them a little more than 5 years to get there. A bit of a difference and this problem is compounded the further you go.

At 2G's accelleration to get to the Pleiades cluster again at 99.99999999...% the speed of light would only take 6 1/2 years of ship time. Over 400 years would pass on Earth.

To reach the Andromeda Galaxy, it would take some 15 years of ship time compared to 2 million years on Earth. This is why relativistic flight to reach other star systems simply doesn't work. The time dilation the astronauts experience grows exponentially the further and faster they go. Within a couple generations people would have forgotten about them, after a couple hundred years the language spoken on Earth would have changed. In a sense these astronauts would be seen as relics of an earlier time and possibly no longer interested in.

This is why in every story of ships travelling faster than light, there's some bullshit physics involved using ideas that don't necessarily stand up to reality. I'm not saying that one day we might not find a way to do this, but right now it's still within the realm of science fiction no matter what these freaks say.

 

[Kršćanin Čendlervic]

We've had the capability for interstellar flight with nuclear propulsion systems like project Orion for years now. I think the main reason we haven't utilized it yet is lack of will rather than technological limitations. Plus not many people would want a giant rocket detonating atomic bombs in our atmosphere.

 

[ToroidalBoat]

still within the realm of science fiction no matter what these freaks say.

I'm well aware of the problems involved with time dilation - which is why it seems even more ridiculous that aliens would travel for 400ish years (Pleiades time, if FTL isn't real) just to whisper about lizardmen and whatnot to some obscure person on Earth.

 

[Phil Ken Sebben]

I'm well aware of the problems involved with time dilation - which is why it seems even more ridiculous that aliens would travel for 400ish years (Pleiades time, if FTL isn't real) just to whisper about lizardmen and whatnot to some obscure person on Earth.

Personally I still don't see why any alien would want to do this to us. We're a primitive species on a backwater world in the unfashionable end of the Western Spiral Arm of the galaxy.

It just smacks of hubris when people like this say that aliens want to talk to us like we're somehow special.

We've had the capability for interstellar flight with nuclear propulsion systems like project Orion for years now. I think the main reason we haven't utilized it yet is lack of will rather than technological limitations. Plus not many people would want a giant rocket detonating atomic bombs in our atmosphere.

Which is why it would have to be launched in space which contravenes the treaty on nuclear arms and blah blah blah.

My main issue with the Orion project is namely how it is they intend to detonate a nuclear weapon in space and how do they intend for it to work? I'll admit I'm not a physicist and physics was actually my worst class. But I do understand certain things about bombs in general and that's they produce pressure in the form of a blast wave and heat from the explosion. Both of which are carried through the atmosphere. In space, there is no atmosphere so really the blast wave is nullified and the heat just kinda sits there before dissipating almost immediately. You're left with radiation and that's pretty much it. So how's that going to push the pusher plate? Unless they have a pressurized chamber that they detonate the bomb in that somehow pushes the pusher plate I really don't get how it works for interstellar travel.

 

[Kršćanin Čendlervic]

It would work the same way a rocket does. It's just Newton's third law

 

[Phil Ken Sebben]

It would work the same way a rocket does. It's just Newton's third law

I understand the 3rd law, for every action there's an equal and opposite reaction and I'm not questioning that. What I'm questioning is the effect of a nuclear charge in space.

An explosion needs a medium to travel through. Unless you can explain to me how, in the absence of a medium like air, this can work?

 

[XYZpdq]

I understand the 3rd law, for every action there's an equal and opposite reaction and I'm not questioning that. What I'm questioning is the effect of a nuclear charge in space.

An explosion needs a medium to travel through. Unless you can explain to me how, in the absence of a medium like air, this can work?

Over in a robot cartoon forum I hang out on this comes up since in suchandsuch show the bad guys launch a nuke at a space fleet.
According to some guy online apparently there's been some research done in detonating nukes without an atmosphere, they still blow up, make a big sphere of explosion, just without as much size to it since there's no atmosphere to work with. There's still little particles of crap and stuff floating around to react with, just not the wall-to-wall air that we're used to on Earth.

 

[Phil Ken Sebben]

Over in a robot cartoon forum I hang out on this comes up since in suchandsuch show the bad guys launch a nuke at a space fleet.
According to some guy online apparently there's been some research done in detonating nukes without an atmosphere, they still blow up, make a big sphere of explosion, just without as much size to it since there's no atmosphere to work with. There's still little particles of crap and stuff floating around to react with, just not the wall-to-wall air that we're used to on Earth.

I know the radiation would be there and obviously the particulate matter from the bomb itself but it just seems so... wasteful. Granted again this was imagined by people much smarter than I am so there's got to be a way that explains it.

Wikipedia is no real help and the papers I've seen on the NASA website don't really explain it much.

 

[XYZpdq]

I know the radiation would be there and obviously the particulate matter from the bomb itself but it just seems so... wasteful. Granted again this was imagined by people much smarter than I am so there's got to be a way that explains it.

Wikipedia is no real help and the papers I've seen on the NASA website don't really explain it much.

I'll see if I can scrounge up what I've seen. I vaguely remember something either NASA or DOD cited.

 

[Sanshain]

As far as I'm aware, the energy released via a nuclear explosion pushes away any matter in its path - the energy has to go somewhere, and energy can be transmitted in any number of ways. A nuclear engine would harness the kinetic or motive energy of the explosion to launch itself away from the epicenter of the blast.

 

[Phil Ken Sebben]

As far as I'm aware, the energy released via a nuclear explosion pushes away any matter in its path - the energy has to go somewhere, and energy can be transmitted in any number of ways. A nuclear engine would harness the kinetic or motive energy of the explosion to launch itself away from the epicenter of the blast.

But it's not a nuclear engine. It's a bunch of nuclear bombs, (well technically a series of shaped nuclear charges) that go off and push against a "pusher" plate which pushes the spaceship forward. And again, you're talking about an explosion where the blast wave travels through a medium such as air. There is no air in space. "Energy" has no mass therefore it can't propel the spaceship forward.

 

[Sanshain]

Energy has motive force. All matter is made up of energy, and all energy is made up of matter. Lasers are just accelerated energized photons, and they can exert a tangible force on solid objects. Absolutely any interaction between energy and matter exerts force, even if it is an infinitesimally minuscule amount. When a nuclear bomb detonates, it transforms a portion of the energy it contains in the form of matter into regular old released energy, which expands outwards with incredible force. The energy to mass ratio is beyond obscene - if all the matter in a single human body were instantly transformed into energy, the resulting blast would flatten an entire city and resemble an atomic explosion.

Basically, there doesn't have to be any atmosphere for a nuclear blast to travel through in order to create motive force. Plus, particles released by a nuclear blast do have mass - the vast majority of particles in the universe do. Alpha, beta and gamma radiation particles all have a great deal of mass compared to other particles - that's why they're so deadly.

Even photons have mass, as a matter of fact. Lightwave propulsion is all about deploying a sail that catches the speeding photons emitted by stars and using the combined impact of many trillions of them to generate motive force to propel a spacecraft. The sail would need be to be kilometers large, but in theory one could reach velocities far beyond anything ever reached by humanity before with one - albeit at the acceleration rate of a geriatric snail.

 

[ToroidalBoat]

Here's an interesting video:
Generation Ship

Also, anything new from the subject of this thread?

 

[Saney]

As fascinating as this is, truly, weren't we talking about a lolcow? Maybe you guys should shift this to Off-Topic or somewhere.