Cosmic Journeys : Voyage to Alpha Centauri

[Abramelin 2,502]

At 4.37 light years away, it's part of the closest star system to our sun. Alpha Centauri is actually two stars, A and B, one slightly larger and more luminous than our own sun, the other slightly smaller.

The two stars orbit one other, swinging in as close as Saturn is to our Sun... then back out to the distance of Pluto. This means that any outer planets in this system... anything beyond, say, the orbit of Mars... would likely have been pulled away by the companion and flung out into space.

For this reason, Alpha Centauri was not high on planet hunters' lists... until they began studying a star 45 light years away called "Gamma Cephei." It has a small companion star that goes around it every 76 years. Now, it seems... it also has at least one planet.

That world is about the size of Jupiter, and it has planet hunters excited. Perhaps two-thirds of all the stars in our galaxy are in so-called binary relationships. That means there could be many more planets in our galaxy that astronomers once assumed.

At least three teams are now conducting long-term studies of Alpha Centauri... searching for slight wobbles in the light of each companion star that could indicate the presence of planets. If they find a planet that passes in front of one of the stars, astronomers will begin intensive studies to find out what it's like.

One of their most promising tools will be the James Webb Space Telescope, scheduled for launch in 2014 or 2015. From a position a million miles away from Earth, it will deploy a sun shield the size of a tennis court, and a mirror over 21 feet wide. The largest space telescope ever built, it will offer an extraordinary new window into potential solar systems like Alpha Centauri.

If it was headed in the right direction, it would need another 73,000 years to travel the 273,000 astronomical units to Alpha Centauri. When it comes to space travel, we've yet to realize the dream forged by rocketeers a century ago.

[Ashotep 13,713]

The Robinson's already did that aboard the Jupiter II.

[Abramelin 2,502]

The Robinson's already did that aboard the Jupiter II.

This woman did too......

[synchronomy 749]

That's an interesting video.

Travelling at high speed like that would require incredile navigation. There's a lot of "stuff" in the vast emptiness of interstellar space. Like the video said, one grain of sand could spoil your trip.

I think travelling at those speeds requires a lot more than just developing a huge power plant. The relative time shift for instance alone is a challenge.

If you spend say, one year near light speed, it's only a year to the people on the spacecraft...but back on Earth time would be centuries in the future.

There's a few bugs to be ironed out.

Even at far less velocities relative times come into play. GPS satellites even have to be time adjusted and they are only in Earth orbit.

[DONTEATUS 3,516]

What a story ! WHeres Speilburg ?

[Grandpa Greenman 9,177]

Wow, thank you, good find.

[joc 7,525]

That's an interesting video.

Travelling at high speed like that would require incredile navigation. There's a lot of "stuff" in the vast emptiness of interstellar space. Like the video said, one grain of sand could spoil your trip.

I think travelling at those speeds requires a lot more than just developing a huge power plant. The relative time shift for instance alone is a challenge.

If you spend say, one year near light speed, it's only a year to the people on the spacecraft...but back on Earth time would be centuries in the future.

There's a few bugs to be ironed out.

Even at far less velocities relative times come into play. GPS satellites even have to be time adjusted and they are only in Earth orbit.

Starships would have shields to protect against debris hitting the ship...and time isn't relative...so one year traveling at the speed of light is the same as one year standing still.

[synchronomy 749]

Starships would have shields to protect against debris hitting the ship...and time isn't relative...so one year traveling at the speed of light is the same as one year standing still.

Time isn't relative?

Ya better call Einstein and explain your theory to him!

All satellites have to account for the relative distortion of time.

Reference: http://en.wikipedia.org/wiki/Special_relativity#Time_dilation

Since one can not travel faster than light, one might conclude that a human can never travel further from Earth than 40 light years if the traveler is active between the age of 20 and 60. One would easily think that a traveler would never be able to reach more than the very few solar systems which exist within the limit of 20-40 light years from the earth. But that would be a mistaken conclusion. Because of time dilation, a hypothetical spaceship can travel thousands of light years during the pilot's 40 active years. If a spaceship could be built that accelerates at a constant 1g, it will after a little less than a year be traveling at almost the speed of light as seen from Earth. Time dilation will increase his life span as seen from the reference system of the Earth, but his lifespan measured by a clock traveling with him will not thereby change. During his journey, people on Earth will experience more time than he does. A 5 year round trip for him will take 6½ Earth years and cover a distance of over 6 light-years. A 20 year round trip for him (5 years accelerating, 5 decelerating, twice each) will land him back on Earth having traveled for 335 Earth years and a distance of 331 light years. A full 40 year trip at 1 g will appear on Earth to last 58,000 years and cover a distance of 55,000 light years. A 40 year trip at 1.1 g will take 148,000 Earth years and cover about 140,000 light years. This same time dilation is why a muon traveling close to c is observed to travel much further than c times its half-life (when at rest).

[joc 7,525]

Time isn't relative?

Ya better call Einstein and explain your theory to him!

All satellites have to account for the relative distortion of time.

Reference: http://en.wikipedia....y#Time_dilation

Since one can not travel faster than light, one might conclude that a human can never travel further from Earth than 40 light years if the traveler is active between the age of 20 and 60. One would easily think that a traveler would never be able to reach more than the very few solar systems which exist within the limit of 20-40 light years from the earth. But that would be a mistaken conclusion. Because of time dilation, a hypothetical spaceship can travel thousands of light years during the pilot's 40 active years. If a spaceship could be built that accelerates at a constant 1g, it will after a little less than a year be traveling at almost the speed of light as seen from Earth. Time dilation will increase his life span as seen from the reference system of the Earth, but his lifespan measured by a clock traveling with him will not thereby change. During his journey, people on Earth will experience more time than he does. A 5 year round trip for him will take 6½ Earth years and cover a distance of over 6 light-years. A 20 year round trip for him (5 years accelerating, 5 decelerating, twice each) will land him back on Earth having traveled for 335 Earth years and a distance of 331 light years. A full 40 year trip at 1 g will appear on Earth to last 58,000 years and cover a distance of 55,000 light years. A 40 year trip at 1.1 g will take 148,000 Earth years and cover about 140,000 light years. This same time dilation is why a muon traveling close to c is observed to travel much further than c times its half-life (when at rest).

That's all voodoo and Einstein's theory was voodoo too. There is no time...therefore time is not relative. When the sun burns out...approximately 8 minutes later the Earth will freeze and break into a million pieces. Time is a measurement. A mile is measurement. A degree is a measurement. That is all.

[Zeta Reticulum 152]

Distance in space = GOD's quarantine

[Abramelin 2,502]

That's all voodoo and Einstein's theory was voodoo too. There is no time...therefore time is not relative. When the sun burns out...approximately 8 minutes later the Earth will freeze and break into a million pieces. Time is a measurement. A mile is measurement. A degree is a measurement. That is all.

Something like the next video Saru once posted:

Wubbo Ockels - Time and Gravity

Prof. dr. Wubbo J. Ockels is a Dutch physicist, and also the Netherlands original astronaut. He is a Professor of Aerospace Sustainable Engineering and Technology at the University of Delft, and tries to stimulate a mentality change among Dutch citizens.

In his mind-bending TEDxAmsterdam talk, Ockels explains how time is created by human beings, as a way our brains can make sense of gravity. The speed of light is constant, because it is made by us: its the clock by which we have calibrated our existence. Based on this premise, Ockels proposes a new way to explore life in our galaxy.

[bmk1245 3,038]

That's all voodoo and Einstein's theory was voodoo too. There is no time...therefore time is not relative. When the sun burns out...approximately 8 minutes later the Earth will freeze and break into a million pieces. Time is a measurement. A mile is measurement. A degree is a measurement. That is all.

Apparently, ignorance is a bliss...

Without accounting the effects of GR and SR, GPS would be worthless. So, tell us more about voodoo...

[StarMountainKid 7,731]

Wubbo Ockels - Time and Gravity

I've watched this video before, and he's stating his opinion. There are other physicists who consider time a real dimension. I think Einstein defined time as what we measure by a clock. I think what he was really saying was all clocks measure time differently in different reference frames. There is no universal time in the universe.

I think time is a dimension of the universe. I like what Kurt Godel said: space and time are a continuum, they cannot be separated, so if we consider all space to exist, all time must exist too.

To shield a space ship from debris and radiation while traveling at a considerable percentage of the speed of light, that shield will have to be very strong.

[Abramelin 2,502]

I've watched this video before, and he's stating his opinion. There are other physicists who consider time a real dimension. I think Einstein defined time as what we measure by a clock. I think what he was really saying was all clocks measure time differently in different reference frames. There is no universal time in the universe.

I think time is a dimension of the universe. I like what Kurt Godel said: space and time are a continuum, they cannot be separated, so if we consider all space to exist, all time must exist too.

To shield a space ship from debris and radiation while traveling at a considerable percentage of the speed of light, that shield will have to be very strong.

I know it was just Ockel's opinion, but an interesting one nevertheless.

And yes, shielding from debris. How about a detector for asteroids and comets?

[joc 7,525]

Apparently, ignorance is a bliss...

Without accounting the effects of GR and SR, GPS would be worthless. So, tell us more about voodoo...

Ignorance is indeed bliss. But I am not ignorant...yet I do experience an ongoing state of bliss. Perhaps that is because I Am. It is pure joy to be. Just...to be.