Ok, stupid questions: What is your opinion about the Fermi Paradox?

>>8318545

either life can't into intelligence of we're being kept in a cage like a zoo

>>8318545
If we can't see them it's either because they are not there, or because they are hiding.

The real question is :
What they are hiding from?

Ok, guys, I just noticed something that's bothering me a lot.

Suppose you have a spaceship with mass 15 tons that starts at 0 m/s and accelerates 1m/s^2 to 100 m/s. By simple calculation, the spaceship had 0 kinetic energy but now has 75 mj.

Now, presume it changes from 100 to 200. The difference between the two is 225 Mj.

Now, I know that this change in speed an the first one will require the same amount of force to carry out, and because an engine burns in relationship to how much force it produces, both will consume the same amount of fuel for the same increase. Yet, in one the object is clearly gaining far more kinetic energy than the other.

Like, what am I missing? Why is this the case?

>>8318651
Relativistic impactors?

>>8318769
work = force*distance.
It's pretty much as simple as that.

>>8318777
OOh shit, you are right. Now I feel like a complete retard. Work would greatly increase because it's being applied on longer distances as it moves along.

Fuck, how did I forget about that...

>>8318545
Our radio waves would only travel about 0.3 light years before being drowned out by cosmic background radiation. This is not how far they have traveled, its the maximum distance they are readable using the radio transmitters commonly used today. The fermi paradox is inherently flawed because it assumes that signs of these alien civilizations would ever reach us in a manor that is distinguishable from all the background noise. Aleins on proxima b, with roughly our level of scientific advancement could be looking right at earth with radio telescopes right now and still not be able to conclusively say whether humans are producing radio waves on that planet. Any signal we get from space is going to be from a MASSIVE radio transmitter with a retarded amount of energy powering it. It would come from a level of technology we cant even come close to building now, and probably wont have the ability to for many years. To simplify this further, the fermi paradox is the earthly equivalent of going to wisconsin (usa) and saying "i know there is people in michigan, swimming in lake michigan, but i see no wave patterns consistent with people doing cannon balls off of docks here in wisconsin".

>>8318983
I meant recievers in that first useage of the word transmitter. You get the idea though.

>>8318545
Signal attenuation is a mother fucking bitch.

Unless you turn a star into a light house and blast out 1s and 0s, you will never get your signal to reach anything intelligent where it can be recognized as a signal let alone still contain any information.

>>8319010
> Unless you turn a star into a light house and blast out 1s and 0s

This is actually not as far-fetched as it sounds. It's totally conceivable that a reasonably-advanced civilization could do this, to an extent. Here's how:

Let's pick a reasonably common metal. Say aluminum. In terms of opacity, it has an absorption coefficient of 1.45e6 cm^-1 for yellow light. So that means that we only need a sheet of aluminum 5 nm thick in order to block roughly 50% of the sun's light (give or take). Let's round up to 10 nm just to be on the safe side.

If you could place a large array of 10 nm-thick sheets of aluminum in orbit around the sun, and if each sheet had tiny manouevering thrusters, then you could use them as shutters to periodically block and unblock the sun's light in a certain direction.

Now, we already have the technology to easily detect when Earth-sized planets occlude distant stars. We can even do this with modestly-sized telescopes. So, what if we made a fleet of aluminum sheets that had a total combined cross-sectional area equivalent to Earth's cross sectional area?

How much aluminum would this require? Well, the cross-sectional area of the Earth is 1.2e14 m^2. If you multiply this by the thickness of 10 nm, you get 1.2e6 m^3. This works out to 2.4 million tons of aluminum.

If you check out this plot: https://en.wikipedia.org/w/index.php?title=File:Aluminium_-_world_production_trend.svg&lang=en you can see that the yearly world production of aluminum is about 40 million tons in 2016. So, in principle, you'd only need about 6% of a single year's supply of aluminum in order to build such a fleet of reflectors.

Obviously it would be impractical to launch all of that mass into space using conventional rockets. But there's more than enough metals available in the asteroid belt. It's not inconceivable that an advanced civilization could mine a few million tons of material from their system's asteroids and construct a fleet of orbital sun-shades.

>>8318651
>>8318769
That could be also one of the hypotheses of why hide? So does that mean you can have civilizations trying to annihilate the other?

>>8318983
How about you go read a wiki article about the Fermi Paradox before you comment on it? It has nothing to do with "why can't we detect their radio trasmissions" and everything to do with sub-FTL being fast enough compared to geological time scales.

>>8320760
You could possibly have civilizations trying to annihilate each other.

Wouldn't it be better for advance civilizations that make contact work together though?

File: scary.png (36KB, 740x570px) Image search: [Google]

36KB, 740x570px

>>8320839
Would it?

>>8320839
no that would be gay

I don't see how it's a paradox

>>8320828
I honestly don't see how it's likely that
A: life occurred on another planet
B: said life became so intelligent it could conduct space travel
C: it had reason to conduct such travel within an area we could detect
D: all of this happened within the time we would be able to detect it

>>8319881
I think the big problem would be fuel for maneuvering. You might be better off using a reaction wheel system to rotate the panels such that they work like shutters.

>>8321137
high probability of earth like planets vs total lack of evidence of any life in the observable universe = paradox

>>8321139
>within an area we could detect
That's kind of the point. With the time scales available the "area" should be the entire galaxy.