UFO sighting in Texas...

[Exoduso]

They probably saw a plane... all the people they talked to in that video seemed to be either high or stupid.

[Woozie]

9,460,730,472,580.8 km * 4.2 = Too lazy to load calc.exe

Length dilation. If there is a star that is seen as 9,460,730,472,580,000 meters away, a person traveling at 90% of the speed of light will only measure 4,123,836,806,205,200 meters away, making the distance traveled only 43% as long.

?L'=?L*sqrt(1-v^2/c^2)

To travel 4,123,836,806,205,200 meters at 90% of the speed of light (2.7x10^8), then time = distance/Velocity = .48 years = nearly 6 months.

However, since the people on Earth measured 9,460,730,472,580,000 meters being traveled at 2.7x10^8 m/s, they will measure 1 year. So when the person gets back to Earth, he will have aged 6 months, whereas the Earthlings will have aged 1 year.

[Jer]

So, we have a ship that can reach 90% of the speed of light, and we travel to the closest star, that is not the Sun (Proxima Centauri)

9,460,730,472,580.8 km * 4.2 = Too lazy to load calc.exe

We can't make the distance any less, and the ship can't reach the speed of light, are you telling me a passenger of that ship will not be 4.2~ years older? No cryogenic stuff.

I don't get it :/

To put it simply, or maybe not so simply, the closer that you travel to the speed of light, the shorter your trip would seem, while time passed normally on the outside. If we could travel at the speed of light, discounting acceleration and decceleration time, trips would be instantaneous to the occupants of the spaceship while the outside world would actually see how long the trip was. However you don't have to travel *at* the speed of light to see this effect, though you do have to travel at relativistic speeds.

[archibaldcrane]

And we all know that life exists where the conditions to support it arise.

Well, we only have one example of that (earth) and we can't even recreate those conditions to success in a lab, so...

Um.. yes we can.

What the fuck are you talking about.

If you dont fucking understand science, please stop posting. So many god damned debates on this forum started from people that just dont know what the hell they are talking about.

When have we created life from non-living matter in a lab? That's what I mean by saying "recreate those conditions to success in a lab". Give me a link, an article, something - non-living matter into living matter, where life wasn't present beforehand.

[Tajin]

wait what? how the hell you make less distance?


From: http://hyperphysics.phy-astr.gsu.edu/hb ... /tdil.html

The length of any object in a moving frame will appear foreshortened in the direction of motion, or contracted. The amount of contraction can be calculated from the Lorentz transformation. The length is maximum in the frame in which the object is at rest.

Are you sure?

I get the part about how it seems / looks from outside / inside the ship. Still does not tell me how I end up NOT 4.2 years older at the end of the trip.

[Anakron]

And we all know that life exists where the conditions to support it arise.

Well, we only have one example of that (earth) and we can't even recreate those conditions to success in a lab, so...

Um.. yes we can.

What the fuck are you talking about.

If you dont fucking understand science, please stop posting. So many god damned debates on this forum started from people that just dont know what the hell they are talking about.

Are you referring to the Miller-Urey experiment? Because in that experiment, they just created organic compounds, which is nothing close to "life." Care to elaborate a little beyond just stating it, or cite a few examples?

I mean, f? in the Drake equation is something that scientists debate about and some believe that it's high, but to say that it's 1.00, and that it's common knowledge ("...we all know...") is going a bit far, no?

[Woozie]

Tachyons have never been observed and aren't believed to really exist. Their mass will always be equal to an imaginary number instead of a real number. I don't know exactly what you mean when you ask "how" they move faster than light. Any particle with imaginary mass travels faster than light at all times. Any particle with real mass travels slower than light at all times. Any particle with no mass travels at exactly the speed of light at all times. These are required by relativistic energy formulas.

How many people actually believed in Black Holes when they were only mathematical?

The difference is that theories with tachyons usually present logical paradoxes or are unstable. Whereas black holes can exist without paradoxes or without being unstable (or making the theory it is predicted from unstable). Not to say that tachyons can't exist, I'm just saying that physicist who think tachyons don't exist have better reasoning than people who didn't believe black holes. Of course, it's very possible that physicist who don't believe in tachyons could be completely wrong, but as of right now, there's no experimental evidence to support tachyons.

[Neosutra]

Ok then, I will bite into this argument that will obviously lead to no where but a headache:

What do you consider life?

For me, proteins = life.

[Remyo]

They probably saw a plane... all the people they talked to in that video seemed to be either high or stupid.

what I was thinking as well maybe an experimental plane or something. When the B2 bomber was developed tons of ufo sightings were reported.

[Woozie]

wait what? how the hell you make less distance?


From: http://hyperphysics.phy-astr.gsu.edu/hb ... /tdil.html

The length of any object in a moving frame will appear foreshortened in the direction of motion, or contracted. The amount of contraction can be calculated from the Lorentz transformation. The length is maximum in the frame in which the object is at rest.

Are you sure?

I get the part about how it seems / looks from outside / inside the ship. Still does not tell me how I end up NOT 4.2 years older at the end of the trip.

In your own reference frame, the overall trip is shorter, and therefore, it doesn't take you as long to travel. In the example you stated, 57% of your trip is cut out, so you're traveling less than half the distance than you thought you were going to travel when you were on Earth measuring interstellar distances.

[Jer]

wait what? how the hell you make less distance?


From: http://hyperphysics.phy-astr.gsu.edu/hb ... /tdil.html

The length of any object in a moving frame will appear foreshortened in the direction of motion, or contracted. The amount of contraction can be calculated from the Lorentz transformation. The length is maximum in the frame in which the object is at rest.

Are you sure?

I get the part about how it seems / looks from outside / inside the ship. Still does not tell me how I end up NOT 4.2 years older at the end of the trip.

In your own reference frame, the overall trip is shorter, and therefore, it doesn't take you as long to travel. In the example you stated, 57% of your trip is cut out, so you're traveling less than half the distance than you thought you were going to travel when you were on Earth measuring interstellar distances.

What he said. If you had a spaceship that could accelerate at 9.8 m/s^s until it reached .99999% the speed of light, you could travel anywhere in the universe in 2 years, 1 year to accelerate and 1 year to decelerate. However, time would have passed normally for the rest of the universe, so if you traveled to Andromeda (2.5 million light years away) that much time, roughly, would have passed.

[Kaylia]

Now, there could be technical way to reduce sonic boom, but does it worth the effort if anyone could see your ship?

It wouldn't be worth it when they spend most of their time in space anyways, would it?

I can't rationalize why they would come here with tiny spaceship to fly around Earth, so trying to rationalize details like this is pointless.

The whole thing is bogus in the first place. They come here using space ship made of normal matter, you can see them fine, but they won't emit any burst of energy that would be required to accomplish anything of the sort

[Woozie]

Good point.

[Tajin]

Again, does not compute, a light year is: 9,460,730,472,580.8 km (specifically the distance that light travels in a vacuum in one year) give or take since space is not completely vacuum.

Proxima Centauri is 4.2 lightyears away, so again, how can you make those 4.2 x 9~zeroes kms. any less?

[Tajin]

If you had a spaceship that could accelerate at 9.8 m/s^s until it reached .99999% the speed of light, you could travel anywhere in the universe in 2 years, 1 year to accelerate and 1 year to decelerate.

Good sir, this is pure bullshit.

[Woozie]

Again, does not compute, a light year is: 9,460,730,472,580.8 km (specifically the distance that light travels in a vacuum in one year) give or take since space is not completely vacuum.

Proxima Centauri is 4.2 lightyears away, so again, how can you make those 4.2 x 9~zeroes kms. any less?

Length is relative. A distance measured at one speed is different than that at another.

The distance is 4.2 light years, as measured from Earth. However, if you were in a spaceship traveling 90% of the speed of light, the distance would only be 1.8 light years, not 4.2 light years. If you were traveling 99.99% of the speed of light, the distance to the star would only be 0.013 light years away. If you were going at light speed, the distance would be zero.

[archibaldcrane]

Ok then, I will bite into this argument that will obviously lead to no where but a headache:

What do you consider life?

For me, proteins = life.

For myself, something that could be argued decently as "counting" as an organism is life. Animo acids alone don't cut it for me.

I believe that abiogenesis is possible - probable even, but the only actual evidence of it is that life exists - it hasn't been reproduced as of yet. I hope it will be in my lifetime.

I really hope this doesn't give you a headache.

[Jer]

If you had a spaceship that could accelerate at 9.8 m/s^s until it reached .99999% the speed of light, you could travel anywhere in the universe in 2 years, 1 year to accelerate and 1 year to decelerate.

Good sir, this is pure bullshit.

Okie dokie.

[Jotaru]

Not really. Its frame of reference.

It'd be two years for anyone on board. Time would pass regularly for anyone outside that frame of reference; it would take forever long for them to get anywhere, for us... But to someone moving at the speed of light time doesn't pass at all, so just below it, almost any distance travelled would be instantaneous, meaning only acceleration / deceleration would take 'time'.

[Woozie]

If you had a spaceship that could accelerate at 9.8 m/s^s until it reached .99999% the speed of light, you could travel anywhere in the universe in 2 years, 1 year to accelerate and 1 year to decelerate.

Good sir, this is pure bullshit.

From Wiki's time dilation page

For example, one year of travel might correspond to ten years at home. Indeed, a constant 1 g acceleration would permit humans to travel as far as light has been able to since the big bang (some 13.7 billion light years) in one human lifetime.

(1g = 9.8m/s^2. The importance of accelerating at this speed is that in addition to allowing you to travel pretty much anywhere, it creates an artificial gravity indistinguishable from that of Earth).