Uhm, no. Some things will be possible in the future, I just don't think ships that travel at light speeds the size of a truck is possible, EVER. The majority of videos of aliens show them flying in the aircraft, not teleporting, not going through wormholes, flying. If they're flying at supersonic/hypersonic speeds, that's too slow to reach the nearest star, let alone another galaxy. They need to travel at the speed of light, and maybe if they had infinite fuel, it'd be possible, but given the size that most ships in the videos are, unless they get 1,000,000 lightyears to the gallon, they're not coming to earth.Quote:
Originally Posted by juroara
I doubt they think of impossible things to make. As far as I know, no one ever said traveling at the speed of sound was impossible or anything. I'm pretty sure scientists have a fairly good idea of what's possible, and what isn't, by using physics and maths.Quote:
Originally Posted by juroara
So far, traveling at light/superluminal speeds IS impossible, so I don't see what's so naive about it. Sure, there might be life out there like us, but I highly doubt they're traveling to places lightyears away from them.Quote:
Originally Posted by juroara
Why say that when I've yet to be shown an aircraft the size of a one-passenger plane going at or faster than 186,000 miles per second?Quote:
Originally Posted by juroara
I haven't had a reason to accept aliens traveling at or faster than light is possible. I also haven't had a reason to accept that Abraxas from Fantastic Four is aiding them in their galactic travels.Quote:
Originally Posted by juroara
Also, if they do exist, why don't they come into contact with us? They're supposedly been coming for hundreds/thousands/millions of years, so why haven't they came into contact?
I edited my post earlier with quotes and links to the articles.Quote:
Originally Posted by drewmandan
EDIT: I'll just post them in here.
EDIT:
Here's some things I found:
http://en.wikipedia.org/wiki/Faster_than_light#Tachyons
http://www.wonderquest.com/ftl.htmQuote:
In special relativity, while it is impossible to accelerate an object to the speed of light, or for a massive object to move at the speed of light, it is not impossible for an object to exist which always moves faster than light. The hypothetical elementary particles that have this property are called tachyons. Their existence has neither been proven nor disproven, but even so attempts to quantise them show that they may not be used for faster-than-light communication.[15] Physicists sometimes regard the existence of mathematical structures similar to Tachyons arising from theoretical models and theories as signs of an inconsistency or that the theory needs further refining.[16]
http://www.projectrho.com/rocket/rocket3v.htmlQuote:
Q: Why is it impossible to go faster than light? (Manuel, Someplace, World)
A: It is impossible for any object to achieve the speed of light by a mechanical acceleration, which, indeed, makes going faster than light also impossible by such means. Suppose we try to accelerate an object of rest mass, m, that's traveling at a velocity, v, up to the speed of light, c — what happens? We can't do it because we would need an infinite amount of energy, as the relativistic energy equation (below) shows: When v = c, the energy, E, required is infinite.
http://www.wonderquest.com/2006-08-22-equation.jpg
That's not, however, the end of the story. There's nothing in this equation that proves it's impossible to go faster than light by some other means.
For example, particles that might have always been going faster than light. Thus, they need not reach the speed of light to get faster than light. We have never found such particles (called tachyons), but that doesn't mean they don't exist. Perhaps, the big bang created some tachyons, and some remain from that ancient event.
"Articles claiming to have found experimental evidence for tachyons spring up from time to time in the literature, but none have lasted long or held up to critical scrutiny," says physicist Rod Nave, professor at George State University.
Theory is not encouraging, even if it doesn't rule out the possibility of faster than light travel. Einstein's theory of special relativity says, if a particle goes faster than light, then time becomes an imaginary number (the square root of a negative number). And "we haven't a clue what that means," says Nave.
"Relativity is so counter-intuitive" it's good to have conceptual anchors to stop us from floating too far adrift. Nave throws these two out to keep his classes from taking their speculations too seriously:
* Light speed (c = 186,282 mi/s = 299 792 km/s, in a vacuum) is the speed limit of the universe.
* "When you talk about speeds faster than c, that is science fiction, not science." Because there is no experimental evidence.
http://www.physicsguy.com/ftl/html/F...l#chap:barrierQuote:
Originally Posted by The Light-Speed Barrier.
Quote:
Chapter 7: The First Problem: The Light Speed Barrier
In this section we discuss the first thing (and in some cases the only thing) that comes to mind for most people who consider the problem of faster than light travel. I call it the light speed barrier. As we will see by considering ideas discussed in Part I , Chapter 1 of this FAQ, light speed seems to be a giant, unreachable wall standing in our way. I note that various concepts for FTL travel may deal with this problem, but here we simply want to talk about the problem in general.
7.1 Effects as One Approaches the Speed of Light
To begin, consider two observers, A and B. Let A be here on Earth and be considered at rest for now. B will be speeding past A at a highly relativistic speed as he (B) heads towards some distant star. If B's speed is 80% that of light with respect to A, then tex2html_wrap_inline878 for him (as defined in Section 1.4 ) is 1.6666666... = 1/0.6. So from A's frame of reference, B's clock is running slow and B's lengths in the direction of motion are shorter by a factor of 0.6. If B were traveling at 0.9 c, then this factor becomes about 0.436; and at 0.99 c, it is about 0.14. As the speed gets closer and closer to the speed of light, A will see B's clock slow down infinitesimally slow, and A will see B's lengths in the direction of motion becoming infinitesimally small.
In addition, If B's speed is 0.8 c with respect to A, then A will see B's energy as a factor of tex2html_wrap_inline878 larger than his rest-mass energy (Note, I use an equation for energy here defined in Section 1.5, Equation 1:8 ):
(Eq 7:1)
http://www.physicsguy.com/ftl/equations/eofbina.gif
where m(B) is the mass of observer B. At 0.9 c and 0.99 c this factor is about 2.3 and 7.1 respectively. As the speed gets closer and closer to the speed of light, A will see B's Energy become infinitely large.
Obviously, from A's point of view, B will not be able to reach the speed of light without stopping his own time, shrinking to nothingness in the direction of motion, and taking on an infinite amount of energy.
Now let's look at the situation from B's point of view, so we will now consider him to be at rest. First, notice that the sun, the other planets, the nearby stars, etc. are not moving very relativistically with respect to the Earth; so we will consider all of these to be in the same frame of reference. Remember that to A, B is traveling past the earth and toward some nearby star. However, in B's frame of reference, the earth, the sun, the other star, etc. are the ones traveling at highly relativistic velocities with respect to him. So to him the clocks on Earth are running slow, the energy of all those objects becomes greater, and the distances between the objects in the direction of motion become smaller.
Let's consider the distance between the Earth and the star to which B is traveling. From B's point of view, as the speed gets closer and closer to that of light, this distance becomes infinitesimally small. So from his point of view, he can get to the star in practically no time. (This explains how A seems to think that B's clock is practically stopped during the whole trip when the velocity is almost c. B notices nothing odd about his own clock, but in his frame the distance he travels is quite small.) If (in B's frame) that distance shrinks to zero as his speed with respect to A goes to the speed of light, and he is thus able to get there instantaneously, then from B's point of view, c is the fastest possible speed.
From either point of view, it seems that the speed of light cannot be reached, much less exceeded. This, then, is the "light speed barrier", but most concepts people have in mind for producing FTL travel explicitly deal with this problem (as we will see). However, the next problem isn't generally as easy to get away with, and it probably isn't as well known among the average science fiction fan.
