The Physics That Makes Interstellar Travel IMPOSSIBLE ...

[TomYoung]

His assumptions are based on current humans knowledge and tech.
There is allegedly a craft in Korea something like 40 feet in outside diameter but a size of a football field when you step inside, and time flows very differently inside the craft, 2 mins inside is over an hour outside the craft.
We may not understand or replicate that advanced tech yet but we may in the future.

It’s not okay to spout this nonsense about technology that simply does not exist in “Korea” or elsewhere. The current apex is heading back to the moon. This bigger on the inside idea showed up in Star Trek TNG. The idea of time flowing differently is a further embellishment.

 

[burbguy82]

Yeah, how was nobody else pointing out that this was not actually Feynman?

In some of the videos, it states that it is not him.

 

[Cheetah-kins]

we spend way to much money funding theoretical stuff that will benefit no one in their lifetime (like quantum mechanics) and way too little money funding stuff that might have practical use now - like curing disease or alternative energies or even travel within our solar system.

^ I didn't mention this in my original comment, but I think trying to get to Mars and so forth is a giant waste of money and resources. As are Musk's space tourism rockets that squander huge resources and greatly pollute the planet so a few 'celebrity' types can pretend they're astronauts. Same for when he launched one of his cars into orbit. Humans have already irrevocably polluted Earth itself and next is low Earth orbit and possibly a few of the closest planets. That money/resources imo could be much better used making our planet better, imo. Setting up a 'colony' on Mars one day is not gonna lead to massive space exploration no matter how Musk and others like him spin it.

 

[oilboy123]

So aliens aren't real because they can't go fast enough........ I think they are real. So they somehow can.

I have thought about how fast they can possibly travel. I have a very hard time comprehending how far things really are in time and space.
Yes the nuclear bomb thing scares me. Even if I'm taken out on earth, I hope the human species survives on another planet.

 

[CleanSump]

It’s not okay to spout this nonsense about technology that simply does not exist in “Korea” or elsewhere. The current apex is heading back to the moon. This bigger on the inside idea showed up in Star Trek TNG. The idea of time flowing differently is a twembellishment.

Bigger on the inside was in the first 1963 episode of Dr. Who the introduction of the Time and Relative Dimensions in Space (TARDIS) machine. I stepped in one once, but it was just an old phone booth inside.
It has to be real because it's against the law to lie on TV! A 6 year old told me that once.

 

[Snagglefoot]

Looks like we are closing in on an expedition to Mars. It will be so much cheaper not to bother bringing them back. I would imagine we’ll have no problem finding volunteers with that understanding.

 

[CleanSump]

Looks like we are closing in on an expedition to Mars. It will be so much cheaper not to bother bringing them back. I would imagine we’ll have no problem finding volunteers with that understanding.

Sunday Elon announced he's focusing on a permanent Moon base first now. Maybe he realized sometimes you need to take smaller bites.

 

[Snagglefoot]

Sunday Elon announced he's focusing on a permanent Moon base first now. Maybe he realized sometimes you need to take smaller bites.

I see. Also, that way he can sent his humanoid robots to Mars on that one way trip.

 

[MolaKule]

Were the AI creators of this video true to what Dr. Feynman said, except for the little Youtube bit? Or did they take other liberties? It makes me doubt the value of the whole vivideo.the message

The physics from the message is scientifically correct and is indicative of RF's style from his lectures.

I would call it an AI video of a scientific celebrity.

 

[BusyLittleShop]

They said the same thing about the sound barrier.

Our understanding of reaching Mach 1 was accomplished by Ernst Mach
an Austrian-Czech physicist and philosopher (born 1838 died 1916)
who made contributions to physics and the philosophy of science. Mach
was the first to study super-sonic motion. Einstein credited him as
the philosophical forerunner to the theory of relativity with his
critique of Newtonian physics.

"They" were the barrier believers... but not so for Ernst Mach or Larry Bell or Chuck Yeager... it was a just another step in managing sound...

The actual Bell X 1 Mach meter signed by pilot Chuck Yeager...

 

[PWMDMD]

Right. Light doesn’t travel. Somehow a photon is massless and does not experience time.
I saw the space/time budget video some time ago and it makes one scratch their head.

You can use the Lorenz factor to show as v approaches c, 1-(V^2/C^2) goes to zero, and 1 over this term goes to infinity. Technically, it means there is no valid rest frame for a photon, massless things MUST necessarily travel at c in a vacuum, and rest mass only exists for particles with mass. Time doesn't "stop" for a photon - it simply exists on a null worldline with zero proper time between emission and absorption.

 

[PWMDMD]

The physics from the message is scientifically correct and is indicative of RF's style from his lectures.

I would call it an AI video of a scientific celebrity.

RF had such a great way of speaking. "You have this thing and it acts on that thing, and something happens, that things that happens is governed by some math, you see." He was always so animated and he spoke in such simply terms.

 

[PWMDMD]

They said the same thing about the sound barrier. Truth be told we probably really don't know squat about the universe.

It's always interesting to me that people who don't understand something want to somehow make the leap that because they don't understand it, no one does. It's a patiently absurd conclusion, much like your conclusion that we don't know squat about the universe.

You may not know squat about the universe but humans can explain ALMOST every single thing going on around you with a precision that is mind blowing. There are only a handful of things we can't full explain - gravity, dark energy, dark matter, neutrino masses, matter-anti-matter asymmetry, why the constants of the universe are precisely what they are, inflation, and quantum spacetime.

The 5% of the universe that is ordinary matter, which makes up 99.999999% of your reality, is completely explainable, testable, and it has been tested tens of thousands of times over the past 200 years to at least 10 decimal places. The standard model and quantum mechanics/chromodynamics/electrodynamics is the most successful and tested scientific theory in the history of humanity.

 

[Cheetah-kins]

It's always interesting to me that people who don't understand something want to somehow make the leap that because they don't understand it, no one does. It's a patiently absurd conclusion, much like your conclusion that we don't know squat about the universe.

You may not know squat about the universe but humans can explain ALMOST every single thing going on around you with a precision that is mind blowing. There are only a handful of things we can't full explain - gravity, dark energy, dark matter, neutrino masses, matter-anti-matter asymmetry, why the constants of the universe are precisely what they are, inflation, and quantum spacetime.

The 5% of the universe that is ordinary matter, which makes up 99.999999% of your reality, is completely explainable, testable, and it has been tested tens of thousands of times over the past 200 years to at least 10 decimal places. The standard model and quantum mechanics/chromodynamics/electrodynamics is the most successful and tested scientific theory in the history of humanity.

I have to disagree, it's not a 'patiently ridiculous conclusion' at all.

All jokes aside, it takes the hubris of someone truly full of themselves to believe that we understand the universe but for a handful of mysteries. Believe you what want but every discovery has led to more questions - usually lots of them. That is not likely to change in the foreseeable future, imo.

 

[PWMDMD]

I have to disagree, it's not a 'patiently ridiculous conclusion' at all.

All jokes aside, it takes the hubris of someone truly full of themselves to believe that we understand the universe but for a handful of mysteries. Believe you what want but every discovery has led to more questions - usually lots of them. That is not likely to change in the foreseeable future, imo.

Have you studied physics and if you haven't, why would you expect to have ANY perspective on something you know nothing about? Not busting your chops but it's a lot like asking me what I think about whatever when I know nothing about whatever. BTW...these are rhetorical questions, I already know the answers to these questions.

 

[burbguy82]

There are only a handful of things we can't full explain

Who is we? Does we include you? Or maybe me?

The 5% of the universe that is ordinary matter, which makes up 99.999999% of your reality, is completely explainable, testable, and it has been tested tens of thousands of times over the past 200 years to at least 10 decimal places. The standard model and quantum mechanics/chromodynamics/electrodynamics is the most successful and tested scientific theory in the history of humanity.

You seem to know quite a bit.

 

[MolaKule]

So aliens aren't real because they can't go fast enough........ I think they are real. So they somehow can.

According to known physics principles and laws, they can't go fast enough.

 

[Number_35]

With our current understanding of physics it makes interstellar travel DIFFICULT...not impossible. Current science fiction based faster than light travel using warp-drives or the like are based in (highly theoretical) relativistic physics but require an understanding and implementation that is way beyond us, if at all even possible.

Nuclear fission based (thermal/electric) propulsion is currently feasible, though still requires additional improvements and development. Project KIWI/NERVA from the 60's/70's proved that it works. This applies more to improved travel times within our own solar system, not really to traveling to our neighbors. Current systems are being designed to get us to Mars in weeks, not months.

Nuclear fusion travel will get us to our nearest stars, though not as fast as on a sci-fi TV. On a smaller scale (and slightly more practical), shows like "The Expanse" make good use of nuclear fusion propulsion to provide reasonable travel times within our own solar system.

Movies like "Avatar" and "The Passengers" also provide somewhat realistic interpretation of nuclear fusion travel on the interstellar scale though the scale and use of the technology involved is enormous in these movies, but is theoretically achievable with our current understanding and implementation of physics. Think 15+ years or decades to travel to our nearest neighbors, not minutes.

Achieving the speeds that allow for even slowest reasonable forms of human interstellar travel comes with a whole host of other problems. Directly hitting a microscopic dust particle at 25% or higher the speed of light can not be a possibility.

Some version of artificial gravity is required, be it artificial gravity like we see on TV or a centrifugal version. We will need some method of induced hibernation as well. Time dilation will also become an issue with further distances.

Communication back home will also be a significant problem. If we parked ourselves in orbit of our nearest neighbor, Alpha Centauri, and sent a message back home it would take ~4.5 years for the message to be received..... and another ~4.5 years to receive a response. You are essentially on your own with no help from home.

Robert Heinlein's SF novel "Time For The Stars" dealt with this issue by having pairs of telepaths - one on the ship, and the other remaining on Earth.

Of course he assumed telepathy was instantaneous, rather than limited to C.

 

[oilboy123]

According to known physics principles and laws, they can't go fast enough.

Me and the aliens don't recognize physics.......

I was kind of being tongue and cheek on the earlier post.

 

[Arc]

Why would you align a telescope to magnetic north? That's not even close to polar alignment. Or does the computer controller take over from there?
OTOH, Maybe it's just good enough for casual observing though.

It was software controlled and required me to set it up each time if I wanted it to automatically go to certain areas. I don't have it anymore. An employee use to stop by all the time with his kids so they could use it. They loved it and always got excited so I eventually just gave it to them. It wasn't anything fancy just a cheap ten inch Dobson, some random tripod with a motor that I hooked to a laptop with an electronic eye piece. It was worth it just to see the kids get so excited. I hope it helped them in some way now that they are adults with their own kids.