10 ms·

Feel free to correct my math =================================== Voyager 2 (man's fastest space craft) is traveling 35,000 miles per hour / 60 = 583 miles per

Feel free to correct my math =================================== Voyager 2 (man's fastest space craft) is traveling 35,000 miles per hour / 60 = 583 miles per second. 187,000 miles per second equals the speed of light. Light can travel 57,395,520,000,000 miles in one year (roughly 5.7 trillion miles). So, in 21 years that would equal 57,395,520,000,000 miles x 21 years, or roughly 120 trillion miles. Thus, if Voyager 2 was our space craft we'd have 583 miles per second x 60 seconds x 60 minutes x 24 hours x 365 days x 21 years to get 386,095,248,000 billion miles towards our new planet. There is a huge gap between 386 billion and 120 trillion miles, like 311 times. That means it would take us roughly 310 x 21 years = 6528 years to get there using current technology. I just don't see us going there as being very practical.

sliverstorm 16y ago
I think the point is that it exists. We can work on getting there once we figure out whether it exists or not; no point in working on the travel part if we aren't sure the destination exists.
inerte 16y ago
If you were born 200 years ago, you would say us being there was impossible. In a couple centuries, (hopefully) it'll be a non-issue. Who knows? The important thing is that we actually found something only theory foresee. Assuming this particular news really did it, because I'm certain I've read similar headlines in the past.
param 16y ago
Let me correct your math - there are 3600 seconds in an hour, so the Voyager is actually going <10 miles/sec
- jws 16y ago
  It is also more direct to calculate Voyager's speed as a fraction of the speed of light and then divide that into the 21 light years. Voyager goes 35,000 miles per hour (given) ... 10 miles per second Light goes 187,000 miles per second (given) Voyager goes 1/2000 the speed of light Light takes 21 years to get there (given) Voyager takes 42,000 years to get there. Hopefully I didn't drop too many zeros or use the wrong reciprocal too many (non-canceling) times. But Voyager was not intended to go fast by interstellar speeds. It just needed to get to all of its planets before its electronics died. Any speed beyond that was a waste and could have been traded off against more data gathering equipment. When it comes time to send the nanobots with the directions to fabricate exploration gear and giant space arrays to transmit back the results to us, I'm sure we can make them go faster.
  - Rhapso 16y ago
    Why not just have them assemble the people too?
    - jws 16y ago
      The google is strong with me today. http://www.kuro5hin.org/story/2002/12/21/17846/757 http://www.kuro5hin.org/story/2002/12/21/17846/757 One of my favorite sci-fi short story trilogies.
julian37 16y ago
Your math must be off if Google's calculator is to be trusted: http://www.google.com/#q=21+light+years+%2F+35%2C000+miles+per+hour http://www.google.com/#q=21+light+years+%2F+35%2C000+miles+p... (21 light years) / (35 000 miles per hour) = 402 369.978 years
- dbrannan 16y ago
  Ah, I should have just Googled it. That being said, 402,370 years makes it sound even more far fetched.
deleted 16y ago
[deleted]
wlievens 16y ago
With current technology it's probably possible to build a 99%C speed [unmanned] spacecraft but it would cost hundreds of billions and we'd have to get over some politically difficult issues such as shipping tons of weapons-grade plutonium into NEO. That ship would get there in 25 years or so, so most of us would live to see the reply on its telemetry around the time our grandchildren are our age.
- narag 16y ago
  I don't know much about relativistic effects, but people that does told me that that's not practically possible, even with tons of money. But c/2 is not unthinkable if things like http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magne... keep developing.
- arethuza 16y ago
  What current technology? The energies involved in getting something to 99% of C are insanely high (the kinetic energy of each kilogram at that speed is about the same as the output of a 132Mt bomb). Then there are the problems of traveling at that speed - which are significant. "Realistic" designs for interstellar probes generally rely on not carrying the fuel with the probe and having ultralight masses (e.g. Bob Forwards "Starwisp" http://en.wikipedia.org/wiki/Starwisp http://en.wikipedia.org/wiki/Starwisp) - this still requires impressive engineering (a 560km diameter transmitter producing 56GW) for a total probe mass of 1kg and payload of 80g. And that would "only" manage 20% of C. http://en.wikipedia.org/wiki/Starwisp http://en.wikipedia.org/wiki/Starwisp Do I believe something like Starwisp will be built - absolutely. In my lifetime? No chance. I'd be happy if we get people to Mars in my lifetime - something I don't expect to see.
  - retube 16y ago
    Yeah - it requires a city-sized power station to accelerate mere protons at the LHC to ~c.
  - wlievens 16y ago
    In retrospect I think I exaggerated it. But if we would somehow put our effort to it and invest a couple trillion in it, it may be achievable in this century.
varjag 16y ago
Voyager's goal was to use a number of gravitational maneuvers to sling itself to as many study objects as possible. It was not launched for interstellar travel, otherwise it could be possible to shoot it out a notch faster with the exact same technology.
- hugh3 16y ago
  True. Given a goal of shooting a probe out of the Solar System at the highest possible speed with conventional rockets, we could do a little better. Nothing to bring travel time down below the hundred thousand year mark, though.
retube 16y ago
At 35,000mph would take 402,000 years. Inter-stellar travel is not for the feint-hearted. It's probably possible to accelerate a space-craft to around 10x this speed using current motor technology. Even so, that's still 40,000 years - and 21 light years is like a nano-meter away on a galactic or cosmological scale. Really, if you want to cross inter-stellar space in any kind of reasonable time - O(human lifetime) - you need to go faster. Possible solutions are: solar sail or new kinds of ion thruster. Both of these impart a very small force (and hence acceleration) for an exceedingly long time, resulting in very high velocities. Your target speed is about 10% of c. In the case of the solar sail it receives momentum from sun for ~ 50% of distance (assuming similar-sized star to our sun), and then is braked by the momentum from the target star for the rest of the journey. Problem with solar sail is it needs to be GIGANTIC, and composed of materials stronger and lighter than those available today. Additionally force from sunlight is proportional to 1/r^2 so your acceleration decreases with distance. So, nuclear powered ion thruster is probably the answer. But, obviously, this kind of project is expensive. And either way, you need living quarters for an entire society to live and reproduce.
- khafra 16y ago
  Or you can just keep dropping nuclear bombs out the back of your spaceship and blowing them up.
  - Rhapso 16y ago
    I want to see some math on how fast we could go if we disarmed our militaries and used our nukes as rocket fuel.
    - retube 16y ago
      back in the 50s there was Project Orion, studying how conventional, explosive nuclear bombs could be used to power inter-stellar spacecraft: http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29 http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propul...
- avar 16y ago
torial 16y ago
FWIW, your math is off you state: "35,000 miles per hour / 60 = 583 miles per second." Really, this would be: 35,000 mph / (60 minutes per hour) / (60 seconds per minute) = 9.72 miles per second. Then just decrease the distance traveled by a factor of 60, so instead of 386 billion miles traveled by V2, it would be about 6.4 billion miles.

sliverstorm 16y ago

I think the point is that it exists. We can work on getting there once we figure out whether it exists or not; no point in working on the travel part if we aren't sure the destination exists.

inerte 16y ago

If you were born 200 years ago, you would say us being there was impossible. In a couple centuries, (hopefully) it'll be a non-issue. Who knows? The important thing is that we actually found something only theory foresee. Assuming this particular news really did it, because I'm certain I've read similar headlines in the past.

param 16y ago

Let me correct your math - there are 3600 seconds in an hour, so the Voyager is actually going <10 miles/sec

jws 16y ago
It is also more direct to calculate Voyager's speed as a fraction of the speed of light and then divide that into the 21 light years. Voyager goes 35,000 miles per hour (given) ... 10 miles per second Light goes 187,000 miles per second (given) Voyager goes 1/2000 the speed of light Light takes 21 years to get there (given) Voyager takes 42,000 years to get there. Hopefully I didn't drop too many zeros or use the wrong reciprocal too many (non-canceling) times. But Voyager was not intended to go fast by interstellar speeds. It just needed to get to all of its planets before its electronics died. Any speed beyond that was a waste and could have been traded off against more data gathering equipment. When it comes time to send the nanobots with the directions to fabricate exploration gear and giant space arrays to transmit back the results to us, I'm sure we can make them go faster.
- Rhapso 16y ago
  Why not just have them assemble the people too?
  - jws 16y ago
    The google is strong with me today. http://www.kuro5hin.org/story/2002/12/21/17846/757 http://www.kuro5hin.org/story/2002/12/21/17846/757 One of my favorite sci-fi short story trilogies.

julian37 16y ago

Your math must be off if Google's calculator is to be trusted: http://www.google.com/#q=21+light+years+%2F+35%2C000+miles+per+hour http://www.google.com/#q=21+light+years+%2F+35%2C000+miles+p... (21 light years) / (35 000 miles per hour) = 402 369.978 years

dbrannan 16y ago
Ah, I should have just Googled it. That being said, 402,370 years makes it sound even more far fetched.

deleted 16y ago

[deleted]

wlievens 16y ago

With current technology it's probably possible to build a 99%C speed [unmanned] spacecraft but it would cost hundreds of billions and we'd have to get over some politically difficult issues such as shipping tons of weapons-grade plutonium into NEO. That ship would get there in 25 years or so, so most of us would live to see the reply on its telemetry around the time our grandchildren are our age.

narag 16y ago
I don't know much about relativistic effects, but people that does told me that that's not practically possible, even with tons of money. But c/2 is not unthinkable if things like http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magne... keep developing.
arethuza 16y ago
What current technology? The energies involved in getting something to 99% of C are insanely high (the kinetic energy of each kilogram at that speed is about the same as the output of a 132Mt bomb). Then there are the problems of traveling at that speed - which are significant. "Realistic" designs for interstellar probes generally rely on not carrying the fuel with the probe and having ultralight masses (e.g. Bob Forwards "Starwisp" http://en.wikipedia.org/wiki/Starwisp http://en.wikipedia.org/wiki/Starwisp) - this still requires impressive engineering (a 560km diameter transmitter producing 56GW) for a total probe mass of 1kg and payload of 80g. And that would "only" manage 20% of C. http://en.wikipedia.org/wiki/Starwisp http://en.wikipedia.org/wiki/Starwisp Do I believe something like Starwisp will be built - absolutely. In my lifetime? No chance. I'd be happy if we get people to Mars in my lifetime - something I don't expect to see.
- retube 16y ago
  Yeah - it requires a city-sized power station to accelerate mere protons at the LHC to ~c.
- wlievens 16y ago
  In retrospect I think I exaggerated it. But if we would somehow put our effort to it and invest a couple trillion in it, it may be achievable in this century.

varjag 16y ago

Voyager's goal was to use a number of gravitational maneuvers to sling itself to as many study objects as possible. It was not launched for interstellar travel, otherwise it could be possible to shoot it out a notch faster with the exact same technology.

hugh3 16y ago
True. Given a goal of shooting a probe out of the Solar System at the highest possible speed with conventional rockets, we could do a little better. Nothing to bring travel time down below the hundred thousand year mark, though.

retube 16y ago

At 35,000mph would take 402,000 years. Inter-stellar travel is not for the feint-hearted. It's probably possible to accelerate a space-craft to around 10x this speed using current motor technology. Even so, that's still 40,000 years - and 21 light years is like a nano-meter away on a galactic or cosmological scale. Really, if you want to cross inter-stellar space in any kind of reasonable time - O(human lifetime) - you need to go faster. Possible solutions are: solar sail or new kinds of ion thruster. Both of these impart a very small force (and hence acceleration) for an exceedingly long time, resulting in very high velocities. Your target speed is about 10% of c. In the case of the solar sail it receives momentum from sun for ~ 50% of distance (assuming similar-sized star to our sun), and then is braked by the momentum from the target star for the rest of the journey. Problem with solar sail is it needs to be GIGANTIC, and composed of materials stronger and lighter than those available today. Additionally force from sunlight is proportional to 1/r^2 so your acceleration decreases with distance. So, nuclear powered ion thruster is probably the answer. But, obviously, this kind of project is expensive. And either way, you need living quarters for an entire society to live and reproduce.

khafra 16y ago
Or you can just keep dropping nuclear bombs out the back of your spaceship and blowing them up.
- Rhapso 16y ago
  I want to see some math on how fast we could go if we disarmed our militaries and used our nukes as rocket fuel.
  - retube 16y ago
    back in the 50s there was Project Orion, studying how conventional, explosive nuclear bombs could be used to power inter-stellar spacecraft: http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29 http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propul...
avar 16y ago

torial 16y ago

FWIW, your math is off you state: "35,000 miles per hour / 60 = 583 miles per second." Really, this would be: 35,000 mph / (60 minutes per hour) / (60 seconds per minute) = 9.72 miles per second. Then just decrease the distance traveled by a factor of 60, so instead of 386 billion miles traveled by V2, it would be about 6.4 billion miles.