How fast can we humanly possibly go in space?

reply to post by DevolutionEvolvd


"The key to the experiment was that the pulse reformed before it could have gotten there by simply travelling through empty space. This means that, when the waves of the light distorted, the pulse traveled forward in time. "

If that could be done with matter, then we could conceivably travel great distances in space but would actually go back in time.
Only old folks could go on long trips.
Can't have toddlers piloting starships.
Wouldn't be prudent.

Currently, humanitys capabilities for travelling through space are relativly small. We can currently hit a few tens of thousands of mph. But given further advances in technology, we will be able to hit any velocity we desire. At the moment, we can't hit the speed of light, but thats not to say we never will. As our technology gets more and more advanced, we will may well be able to travel as fast as we want, aslong as we remember that its acceleration that causes us damage, not velocity.

No one can say that we will never travel faster than light. No one. Not Einstein, not Newton or Galileo, no one. Everything that they spoke about in relation to space is their best guess taken from their point of view at their point in history, they knew, just as we know only what is on our door step because thats as far as we have gone.

In years to come, as our technology advances and allows us to venture further into interstella space, further from our door step, the THEORIES of the great minds of our time will be shown as true, or shattered to nothing. I can tell you everything about the details of my door step. But ask me about the door step of a house on the otherside of the world? Not a chance. Because I havn't gone there and seen it for myself, or any point in between.

The same metaphor applies to life on other planets. We search for it. Search for radio signals or communications, anything, because we assume they'll evolve along similar paths as we did. But we're only going on the variety of life we know, on earth, on our door step. Whats to say they even use radiowaves? Or even a type of communication we even understand, or even have the equipment to detect?

"We know only what is on our doorstep, for we have ventured no futher"

Theres a little philosophy from Martin Smith. Hope that has manifested in all your minds and urging you into another discussion

you can move as fast as you want, if only ! there is no Friction after the first burst of Movement

every object has a Magnetic field, the larger the object with mass the more it pulls others towards it and away from it. if you disable Magnetic fields and the Friction, you can go as fast as you want, speed of light no problem. nothing holding you back.

Originally posted by UofCinLA
It isn't the speed it's the acceleration. Humans can handle 3g ok (normal shuttle launch) and upwards of 6 to 9 for very short periods. Launch and accelerate at 3G for long enough and you would approach light speed but the fuel is the problem....

We are actually traveling thru the galaxy at close to light speed BTW - nifty....

Does that mean that light travelling the same direction only travels ata speed that is the difference between our velocity and that of light? I always wodnered about that.

It's not the speed or even the acceleration you have to worry about.

It's the direction, slowing down and getting back that'll mess you up.

It always amuses me that people only consider "speed-of-light" travel in one direction.

It's all very well hurtling off into the void but Why and Where?

I guess the answer to your question is: As fast as possible within physical boundries of the human body and craft in a predictable and safe direction with there being a good enough reason I suppose.

I'll just watch it on TV. Star Trek has a lot to answer for.

Light speed? That is all fine, but traveling at the speed of thought is faster than the speed of light. If one can construct a vessel that can run off brainwaves. The speed is limitless.

to the above poster.
at what speed do you think electrical energy is transmitted between neurons in your brain?

einstein tells us at or slower than the speed of light, probably the latter.
to be honest i don't know the exact speed but anyway.

Ok Real true Rocketscientist here

i could write alot of thoery i could quote einstien we could dream together the possiblities

but instead im gonna explain it so a 5 year old could understand


we are currently to busy diverting funds to wars that have no real meanings

as well the only speed we are currently at is the space shuttle and then behind that all the technology is in the missles your tax dollars buy day in and day out to drop on schools and united nations refuge shelters


if we could divert that money to rocketry and ballistics as well as pay some damn good engineers to build some stuff maybe include a few quantum / particle physics geniusus

then we would well be on our way to reaching hyper speeds within 40 years

( the lhc project is well on its way tho to proving our true meaning and place in the universe as well as give us a better understanding of how we can use particles to make these superfast safe machines )

hint star trek antimatter does exsist we just got some more figuring out to do but dont count on warps 1 thru 9 we stand a better chance learning how to go down super mario drain pipes

also look for engines that use particles in the vac of space for propulsion oh wait ion thrusters we got those already ok so look for more agressive particle thrusters

google ion thrusters we have used a few of em on satellite projects



but for now hot and cold running war and religion enjoy !

I am entirely clueless about all these time differences.
Forget about space expansion. If a photon travels at the speed of light, and it travels the distance of 4 light years, it would take 4 years to get there. Right? Now, you said you have a clock on board the photon, and only 3.5 years elapsed on board. That's a physical defect of your clock, not actually less time has passed. Right? We established that earlier, it takes 4 years for the photon to travel 4 light years distance. Then you said 5.6 years elapsed on earth. It's another physical defect of the time keeping. Right? I assume everything in the universe is going on its own business, and the universal clock (UC), not our humanly designed clock keeps on ticking, and the UC stays constant. Maybe you feel 1 minute like 1 year when your tooth aches, but as far as UC is concerned, it's stll 1 minute. Right?


"You would need to decelerate half the time in order to stop at your destination. For example I did the calculation for a distance of 4 light years: 3.5 years elapsed on board, 5.6 years elapsed on Earth, max. speed = 0.90 c."

2 mach or Transonic or 2000kmph is ok ,, 5 mack is too much but can be survived ,but slow increase and let body settle down and again increase in speed can be alright.
i don't think that human will ever reach any where near other star system with given technology in days or technologies which advocate propulsion system .it need to be done by anything else. it looks like a bull chariot rider trying to use his technology to fly.

originally posted by: deltaboy
I was just reading the news about the launch of the probe to space heading to Pluto about 36,000 mph. Can we go faster if we can push the momentum to let say 100,000 or 1,000,000 mph? Can the humans withstand that type of speed in space? After all I see astronauts in earth's orbit doing spacewalk going about what 8,000 miles per hour? I forgot so anybody can help correct me.

humans can withstand any speed. it's not speed that kills. it's acceleration forces. you accelerate too fast and you become a spray of pink mist composed of broken cell bits and cytoplasm. but that does not mean anything about top speed because you can accelerate at a leisurely pace and obtain the top physically possible speed in about 6 months.

a reply to: butbeliever

Mach and transonic are different totally. Transonic is sub mach. And neither matters, as humans can survive either quite easily.

originally posted by: wu1821
I am entirely clueless about all these time differences.
Forget about space expansion. If a photon travels at the speed of light, and it travels the distance of 4 light years, it would take 4 years to get there. Right? Now, you said you have a clock on board the photon, and only 3.5 years elapsed on board. That's a physical defect of your clock, not actually less time has passed. Right? We established that earlier, it takes 4 years for the photon to travel 4 light years distance. Then you said 5.6 years elapsed on earth. It's another physical defect of the time keeping. Right? I assume everything in the universe is going on its own business, and the universal clock (UC), not our humanly designed clock keeps on ticking, and the UC stays constant. Maybe you feel 1 minute like 1 year when your tooth aches, but as far as UC is concerned, it's stll 1 minute. Right?


"You would need to decelerate half the time in order to stop at your destination. For example I did the calculation for a distance of 4 light years: 3.5 years elapsed on board, 5.6 years elapsed on Earth, max. speed = 0.90 c."

no. If you were on a ship travelling at 99.99 percent light speed the gamma factor (time dilation) would result in an onboard elapsed time of only a few days. and it's not a defective clock at all because biologically you would only age a few days as well. if you returned home the same way everyone greeting you on arrival would have aged over 8 years.

this assumes zero acceleration and deacceleration time for simplicity's sake. but it also clearly illustrates that the onboard clock isn't defective. it is properly recording time within it's reference frame. this just happens to be different from the rest frame at home or looking at the ship from off in the distance to one side.

originally posted by: butbeliever
2 mach or Transonic or 2000kmph is ok ,, 5 mack is too much but can be survived ,but slow increase and let body settle down and again increase in speed can be alright.
i don't think that human will ever reach any where near other star system with given technology in days or technologies which advocate propulsion system .it need to be done by anything else. it looks like a bull chariot rider trying to use his technology to fly.

the reason mach 5 is risky for humans is because that is done in earths atmosphere.

take away that atmosphere and velocity would be limited predominantly by fuel and fuel consumption.

It's acceleration that can be dangerous or even fatal for humans, not speed. From the traveller's frame of reference, being under uniform motion is the same as being stationary (with no forces acting on the spaceship and its inhabitants), even if you're going at 0.99 of the speed of light. Conversely, being under constant acceleration equates to standing on a planet or moon and feeling the effect of gravity.

en.wikipedia.org...
en.wikipedia.org...

As an example, if a spaceship accelerates at 1g (thus creating a comfortable earth-like gravity for the astronauts), it will get to 0.76 c within 1 year, 0.97 c in 2 years, and 0,999999996 c in 9,5 years. It will never reach the speed of light because of the ship's ever-increasing mass, but from the astronauts' point of view they will reach their destination within a reasonable amount of time due to time dilation and length contraction.

originally posted by: wu1821
It's another physical defect of the time keeping. Right? I assume everything in the universe is going on its own business, and the universal clock (UC), not our humanly designed clock keeps on ticking, and the UC stays constant. Maybe you feel 1 minute like 1 year when your tooth aches, but as far as UC is concerned, it's stll 1 minute. Right?

Actually there is no universal clock. Everything in the universe that is moving (which is everything) has time that moves differently. If Earth and a distant galaxy were moving away from each other at a good fraction of the speed of light, the rate at which time elapses for us compared to them would be noticeably different.

That in a nutshell is why the Theory of Relativity is called the Theory of Relativity. Things in the universe moving different relative to each other will experience the universe differently.

I sometimes wonder that if there is a universal reference point for the rate that time elapses, that universal reference point would be for things that move at the speed of light such as photons), and that universal rate of time passing would be "zero", because things moving at the speed of light do not experience the passage of time. I wonder if that would be the universes "default" rate of time, and then anything that is not moving at the speed of light (anything with mass can never do so) would have time passing at faster (non-default) rates.

originally posted by: wildespace

As an example, if a spaceship accelerates at 1g (thus creating a comfortable earth-like gravity for the astronauts), it will get to 0.76 c within 1 year, 0.97 c in 2 years, and 0,999999996 c in 9,5 years. It will never reach the speed of light because of the ship's ever-increasing mass, but from the astronauts' point of view they will reach their destination within a reasonable amount of time due to time dilation and length contraction.

Ya know...I see all of y'all thinking this, about mass increasing and all...but

Would it be possible for any of you to actually SHOW the math for this?

originally posted by: tanka418

originally posted by: wildespace

As an example, if a spaceship accelerates at 1g (thus creating a comfortable earth-like gravity for the astronauts), it will get to 0.76 c within 1 year, 0.97 c in 2 years, and 0,999999996 c in 9,5 years. It will never reach the speed of light because of the ship's ever-increasing mass, but from the astronauts' point of view they will reach their destination within a reasonable amount of time due to time dilation and length contraction.

Ya know...I see all of y'all thinking this, about mass increasing and all...but

Would it be possible for any of you to actually SHOW the math for this?

you do not want to see the math. it is easily searcheable. if you did wanna know about the math you could easily find it.

start with: en.wikipedia.org...

then you know that mass is considered a measure of the energy as well. for example kinetic energy which is what we are dealing with in motion velocity and acceleration.

The familiar equation E=MC^2. contains all relevant terms. you just have to restate the equation to put what ever term you are interested in on one side of the equals sign. normally energy is set to the left. but you can also state Einstein's equation so that mass or the speed of light is by itself on the left or right.

so M (total mass) =Total Energy (including KE) / C^2

This is true if total mass and total energy are being considered. components of the energy and mass that are different being compared uses an extended form of the equation which i am not going to take the trouble to enter here.you can find the extended equation on the link i posted above.

but since mass and energy are equivalent it makes sense that since it takes energy to push an object or accelerate an object adding that energy to an object increases the mass of the system/moving object. otherwise you are getting something for nothing.



Choose your units of measure.

m=m0/sqrt(1-v*v/c*c)

on line Relativistic mass calculator:

www.ultimate-theory.com...

or much more delicious spaceship calculator:

www.orionsarm.com...

a reply to: stormbringer1701

I'm sorry y'all...But, I'm afraid that I don't view the speed of light quite the same way. For those equations to even begin to work, "C" must be some sort of hard limit in things, and logically, it can only be a cognitive limit...kind of like "speed of observation".

Anyway, I don't really want to argue that...

Although, many of the responses I've seen here reflect archaic thinking. One of the primary reasons that Terrestrial space vehicles can't accelerate to any reasonable speeds is because of the gas propelling it...the "nozzle velocity" of the rocket is the limiting factor. You can have all the fuel you want and it can't help.

Ion drives are better for attaining high velocities, but will take a very long time due t lack of thrust, even IF the "nozzle velocity" is higher.

There is some science for a sort of "field drive":
www.hpcc-space.de...

I've pointed this tech out before, most try to dismiss it based on really poor data. I bring it up here because, a field drive does not need fuel, nor does it's "drive" capabilities decrease as the mass of the vehicle it is driving does. It's kind of like it scales all on its own, never requires additional energy, fuel, etc.