Love the combination of enthusiasm, pragmatism, and can-do spirit Jeff Greason exudes. His approach of proposing and investigating multiple ways to solve a particular problem or advance a step is a smart way to proceed. Enjoyed watching the interview. Thanks
22:38 All these years and I was unaware of the solar wind being a sheet, instead of an expanding sphere. As far as I recall not once I heard about it in educational YT channels... it turns out it's the "Heliospheric current sheet". It's just 10.000 km thick in the span of the solar is absolutely focused, it is even smaller than the earth diameter (if it wouldn't be distorted by the magnetic field of Earth). This interview keeps on giving :) I love it.
fund what? each area is a multi billion dollar endevore with no promised results, just more data, 3 x multi billion R&D, then if any of the tech works, multi billion R&D to fit them together, then production costs for the triple by pass, we need more energy and less polution here on earth, lets solve that first, leave rockets to Mars to Elon and co. ( it keeps them out of truble).
So, the ideal setup is a Blue Sky Research Space Agency, a Space Exploration Agency, and a Space Development Agency? That seems like an extremely productive tripartite arrangement. One specializes on its own thing, the Blue Sky Research Agency are NIAC on steroids and field lots of experimental systems, the Space Exploration Agency fields production-grade probes and builds the extraterrestrial equivalent of McMurdo Station in various places, and the Space Development Agency works on things like cyclers, off-world industrial base and non-rocket space launch.
This was such an interesting interview! You pick the coolest guests. Side note: please let your guest know that their website has an SSL certificate issue and is being marked as not safe by some browsers. "The certificate is not trusted because it is self-signed."
The thing that sticked the most with me is the conflict on interest that was created, when Nasa, the "Technology-Pushing Agency" also became the "Mission Connducting Agency". And we see it all the time, the mission conducting eats the funding of the technology-pushing. That should really get their own untouchable funding (back).
Maybe you don't see much of the picture. For one: things tend to get bigger and more complex, but the over all budget tends in the opposite. NASA has its Artemis program, which pushes much developement, and takes much of the budget. But they are the "Air & Space Administration". Thats more than rocket science. Laserbeam communication is one new developement they are funding. Eliminating the Sonic Boom, for supersonic travel over land areas, is another project. NASA is working on the infrastructure for autonomous drones in big cities and elsewhere. This is a big thing, not only for that Amazon then can deliver directly. Or to move freakin' taxi's in the air. Then there are the next generation Mars drones, and a drone for Titan. Submarine drones for Europa, Enceladus, and Earth. And don't forget JWST, Hubble, and many others. They still cost money to operate only. You see? Accusations without research mostly l👀k silly. The very first research step is best via their web page. From there, you can go on to other agencies, or universities. Also to involved companies, for further research. Believe me, Bro;•) this can be quite interresting! 🚀🏴☠️🎸
@@MichaelWinter-ss6lx it blows my mind that people actually believe that NASA is inefficient with their budget. I’m confident they do more per dollar than any other government/government adjacent agency. Objectively SLS is a fiscal anchor, but legally imposed upon them. Also let’s not forget that NASA quite literally saves thousands of lives every day since the late 70’s as they came up with and have normalized Crew Recourse Management (CRM) training for all commercial airline flight crew. Prior to that no 1st Officer or engineer would ever dare disturb the pecking order within the cockpit and question the captain…
Thanks to the both of you for this fascinating interview! Also thanks to Fraser for interrupting his vacation to get these out. Have fun in your forest, Fraser!!
Please stop believing that corporate lobbiests or any lobby in a crooked Bourgeoisie government is going to save us. Look at Peaceful revolution And a real people's government land reform.
4:54 "It is, in principle, possible to deflect a large enough cross sectional area of the solar wind..." My brain immediately thought, "Could a solar flare be deflected in the same way?" If we know one is coming and is going to hit Earth, could we at least deflect enough of it to weaken the effects on Earth, if not deflect the whole thing?
I think a more feasible idea for solar flare mitigation would be a very powerful electromagnet orbiting a Lagrange Point between the Earth and Sun, which generates a very large magnetic field to redirect or capture the energetic particles / radiation from the flare. But then you have the problem of frying your electromagnet. But I've seen this idea proposed as a way to augment the very weak Martian magnetic field for decreasing surface radiation on Mars for human colonies and terraforming.
Awesome guest, I really enjoyed the interview. To me it has always been obvious that an interstellar mission is a multistage mission, since no single propulsion system seems to be enough on its own (besides antimatter). The logical extention to that is the creation of "interstellar highways" consisting of previously accelerated beaming/refueling pods in between, daisy-chaining energy and/or momentum from the start to the traveling ship. You deploy the infrastructure for braking, if needed, the same way. By stacking terminal speed over terminal speed you create an acceleration channel within a "springy" shell of accelerating beaming stations and any final speed can be reached. The channel could be constantly sweeped of foreign dust by those same stations (GWs of laser/maser/mass accelerator beam is one hell of a sweeping broom). ....I thing I'm gonna watch the relevant Isaac Arthur video now ..... Fascinating topic!
you don't need a line of beaming stations, the space craft being pro-pulsed can be repeatedly injected with energy at each orbit of the sun of the accelerated craft, the beaming station acts as a battery and intermittently injecting accelerating energy ( with lasers or electron beams, or the mentioned thermionic converter)
@@wanfuseThat only works as long as the target orbits the sun. Once it reaches 617.5km/s you only have half an orbit before you will never see it up close again. 0.002c isn't really good enough for meaningful interstellar travel.
@@antonf.9278 wont take the time to relay the whole thing use solar wind and electrostatic field on 100 loops of wire out to about 1000 km for longest one, propell a million ton ship , you don't have to worry about the orbit change this way it will work ok up to 1/4 astronomical units( at least thats the back of envelop calculations)
a reason why i think manned interstellar missions are possible is simply due to what history has shown us. centuries ago the absolute fastest way to get around reliably was with a horse, and anyone back then would have laughed in your face if you suggested a way that anyone could travel around the world in a couple hours. it was a giant leap from traveling by animal to using machines, and maybe we will see another leap that would make near light or faster than light travel possible. personally i would love to see the Halo slip drives become a reality.
"Magnetic fields don't collect things, they scatter things." I'm not saying that isn't true, but I am curious then about how an apparent exception works: Don't planetary magnetic fields 'collect,' or at least funnel, charged particles that create auroras around magnetic poles?
@@plucas1 So what magnetic fields actually do, at the scale of individual particles in large homogeneous fields, is convert the particles' transverse velocity to rotation around the field lines. The longitudinal velocity stays the same. For a field at big as Earth's that means they orbit the field lines in the plane perpendicular to the lines, while the remaining longitudinal velocity moves the orbit along the lines until it reaches Earth.
I haven't seen or communicated with Jeff in a long time, so it was a great pleasure watching this interview; I realize how much I miss his amazing intellect, and even more amazing presentation style. Thanks very much for doing such a wonderful interview.
Let's go big and build a stellaser. 😊 Speaking of, while I imagine he's a bit busy these days, would be cool if you had Isaac Arthur on one of these times.
@@AndrewBlucher You should reflect on that. It’s not normal to detest people you will never meet in your life. Like whatever it is about him that bothers you so much is something you actually loathe about yourself and you’re projecting. It’s not like he’s done anything to justify it. You’re fabricating something and whether you think he’s annoying or insufferable or you can’t stand his voice…. That’s you dude. Not him. You didn’t even say “he’s annoying” you said you detest him. That’s really weird man.
@@jademoon7938 Over analysing and projecting. Or maybe just trolling. In any case, I don't follow advice from people I encounter by chance on social media. Do you give people advice often?
I get that the Bussard Ramjet wouldnt be sufficient to power a journey by itself but keeping in mind that at some point you will want to slow down and the ramjet will create resistance while collecting fuel, slowing the craft, maybe it would still have some utility if it was light enough?
I wonder what this technology could mean for in solar system travel. Solar system travel would surely be a step that would make interstellar travel not such a far fetched idea. I walked 2 miles , maybe I can do 5, 10, 20 etc, also alow the technology to be built on layers of experience
My take away is the issue is money. People still expect that there is some profit to be made that you are supposed to earn something... We live in a world fueled by the sun cooked for millions of years so all you have to do is reach out and take whatever you grab put it in your mouth and it will sustain you. And yet profit, finance ect. What profit do you expect from infinite resources? 10x? Someone have to start spawning new universes so you find a reason to explore beyond our perfect little fish bowl of a planet? Ridiculous even thinking about it....let alone discuss it.
The ongoing NASA Psyche mission is demonstrating laser communication from distances across the inner solar system, with sensitivity of detectors able to pick up a single photon. By the time we are ready to launch an interstellar probe decades from now, laser link technology should be capable of sending data back. Calculations show that a 1-watt laser communication transmitter on the probe can send back megapixel resolution images from the spacecraft as it travels through the Alpha Centauri system (or any other nearby star). Please see Section 5 in Philip Lubin's NASA study "A Roadmap to Interstellar Flight" for the details of the calculations (google title to find it, as links cannot be shared in UA-cam comments).
The ongoing NASA Psyche mission is demonstrating laser communication from distances across the inner solar system, with sensitivity of detectors able to pick up a single photon. By the time we are ready to launch an interstellar probe decades from now, laser link technology should be capable of sending data back. Calculations show that a 1-watt laser communication transmitter can send back megapixel resolution images from the spacecraft as it travels through the Alpha Centauri system (or any other nearby star). Please see Section 5 in Philip Lubin's NASA study "A Roadmap to Interstellar Flight" for the details of the calculations (google title to find it, as links cannot be shared in UA-cam comments).
The ongoing NASA Psyche mission is demonstrating laser communication from distances across the inner solar system, with sensitivity of detectors able to pick up a single photon. By the time we are ready to launch an interstellar probe decades from now, laser link technology should be capable of sending data back. Calculations show that a 1-watt laser communication transmitter can send back megapixel resolution images from the spacecraft as it travels through the Alpha Centauri system (or any other nearby star). Please see Section 5 in Philip Lubin's NASA study "A Roadmap to Interstellar Flight" for the details of the calculations (google title to find it, as links cannot be shared in UA-cam comments).
I have a question: If the particle beam is 10 000 km wide, could you then send multiple spaceprobes at the same time? It sounds like you could get more redundancy out of it without having to double the whole system.
Funnily enough I'm playing around with a story idea of a mission to another star system, and multiple stages for the acceleration. I likened it to shifting gears on a bike or a car. Each one has an effective acceleration range. Definitely going to take everything I've heard here into consideration.
Nuclear bomb acceleration would work too . Planet gravity slingshots for awhile etc . Plus we send very very small probes ahead and we need a communication line back etc or the speeds are slowly insane
Well, Jeff has put his finger right on a whole suite of problems in applied research. I don't 'work' in science or engineering anymore, but even in my new field we have the same problem. And guess what, all my actual breakthrough work is 100% unfundable, whereas my paid work is low risk and purely derivative.
We think of space travel like someone paddling a canoe, using known human energy and power to move everything against and through the water rather than harness the energy in the water.
So, the spacecraft won't get destroyed by hitting the interstellar medium at 20% the speed of light, but what about the radiation load on the electronics? If Jupiter's magnetic field throwing particles at you causes problems with radiation on the space craft then what happens when the interstellar medium runs into you at 20% the speed of light?
random theortical thing about solar sails... here is a question...... take a one hectare concave mirrored dish that is focused to a single point,point the dish at the sun, the solar energy at that focal piont is equal to 10,000sm of sunlight, about 1 kw per sq meter, so 10,000kw or 10,000 kilo joules per second, alot of energy, now squirt 1 gram per second of water through it and calculate the theoretical thrust by calculation the temperature change and the volume change, use the rocket equation, probs check out a steam table or two, then calculate the dela v with a sail weight of two tonnes and a 1 ton of water as propellant. how far can a 5 tonne craft do and how fast?
From what Jeff Greason is saying about "you'd want a slower beam" about the "direct mag-sail/e-sail method" of using the charged particle beam, I can think of an easy tool to reach for to enable that. Proton beams instead of electron beams. The mass of the beams individual particles is that of a proton rather than an electron, so you have a much higher mass, but if you focus the same amount of power into that beam, each proton gets accelerated to a much lower velocity. There's your slower beam, and even better yet, the increase in mass of each particle means you carry much more momentum than energy. However, that's probably only useful for lower velocities and/or higher accelerations, and (complete speculation on my part) probably has a much shorter "runway length" due to plasma interaction effects with solar wind electrons and protons being.... different for protons than electrons. ...or maybe it's better? Anyways, the point is that if you hold the power and particle flux (by count of particles) constant and vary the mass of the particles used (by swapping from electrons to protons), the velocity of the created charged particle beam changes in an inversely proportional fashion (protons go slower if you use the same number of them and the same accelerating power)
If you want more mass in your beam us muons. But every which way you work it the energy expended by tthe time you get a given mass to a given destination is the same. As he points out the trick is where you get that energy from and the biggest energy source we have available is the sun. Untill somebody figures out some sort of 'Star Trek' drive
What about using technology we already posses like a microreactor? A continuous nuclear reactor which can propel the aircraft non-stop for a minimum of 10 years. That would get us there, granted then the problem is stopping.
"Blessed is he who plants trees under whose shade he will never sit." My personal opinion is that to reach a nearby star with a satellite we need to send a probe that will outlive those who launched it. The project may take over 100 years to reach alpha century - but it *will* reach it.
Incredible interesting talk! Thank you Fraser! I am SOOO STUNNED by skyrising intellect of your speaker @jeffgreason. It was really mind bending and highly thrilling to follow your well choosen and very precise words, Jeff. Actually, I had to listen to this interview twice, just to get all the bits of information.
Agreed. There is more than enough for humans to do within the solar system. But now I sound like one of those weird deceleration people who oppose humans leaving Earth to colonize the Moon and Mars, and spaceflight in general, "because we have enough problems here on Earth that money should be spent on". I say if someone wants to fund it and fly the mission, let them!
I'm glad this went into the lack of funding. Nasa's budget isn't even .5% percent of the US budget most years if ever to my knowledge. Some praise capitalism for "innovation" but it inherently limits innovation by requiring people to focus on basic needs instead of innovation. That isn't to say nothing innovative has come from capitalism. Companies also have no interest in projects that don't make them money as mentioned here so it fails in that regard too. Lack of funding and the general shortsightedness of humans will limit and slow what is accomplished in many fields unfortunately imho.
The “shortsightedness of humans”. But not you right; it’s far sightedness by you to move money from all the domestic problems to escapism. Good grief, do you listen to yourself ahole?
"Capitalism inherently limits innovation" Did you think before you wrote that? Literally ALL innovation comes from the free enterprise of individuals in the free market. You are speaking the opposite of the truth.
@@dirtypure2023 You can pretend to know what you are talking about, but here are somethings invented outside capitalism like oh i don't know, the internet (government funded), NASA and space exploration, polio vaccine, open-source software, human genome project... there are many more. If anyone should think before writing it looks like well... in this case it isn't me.
@@Behgork Your statement was that "capitalism limits innovation". Now you're arguing that government itself invented the idea of the internet. Do you believe the internet sprang out of a government money printer, or was it an innovative group of individuals with an idea that DARPA decided to throw money at? The fact that government puts taxpayer dollars into funding private universities and companies to do R&D does not prove your original conceit that "capitalism actually limits innovation". That was your claim.
For the Question Show: Would it be possible to use one of these particle beams like a interplanetary terraforming conveyor belt? Could we either push atmosphere off of Venus towards Mars, skipping Earth? or pull atmosphere from Venus and transfer it to Mars within an interplanetary beam?
So, we seem to be talking about a straight shot from Earth to Alpha Centauri without doing orbits around the sun, like we have always done (with all of the probes we sent out). Is that even feasible? I mean, the reason we send them around the sun a few times is because it requires way less energy than any attempt to go straight out. Plus, the Earth is already moving that way, so we use some of its momentum. With any kind of particle beam or energy beam technology like he is describing, would we still be able to launch in an orbital trajectory around the sun, or would we have to do a straight shot away from it, requiring hundreds of times more energy?
This is so cool! Once humanity recognizes that something is possible, somebody will eventually find a way to make it happen. Sailing vessels 500 years ago to the new world, railroad across the continent 150 years ago, interstate highway system 70 to 60 years ago, the Apollo program to the Moon similar time frame, currently we have Elon Musk spearheading the Starship program that will make Mars possible within hopefully 30 to 40 years....this? Maybe in a hundred years...I don't know
Based on this conversation, it is safe to say that best case scenario we are decades away from a mission of this sort, and that's if this is even possible which he admitted he doesn't know how to make it work. Neat, but more science fiction than realistic.
It sounds like an interesting concept but this guys estimates are total nonsense. He thinks it’ll take “10 years from when we get serious” and cost “on the order of Apollo”. Absolutely not, I think those terrible estimates ruin the credibility of what he’s saying. He admits he doesn’t even know key details like how to capture energy from the e-beam, the necessary materials to handle such insane energy levels, electronics/communications. If you asked this guy, he’d say that stone age humans could land on the moon “in a decade or two if they tried”
@@eyeborg3148 ""If you asked this guy, he’d say that stone age humans could land on the moon “in a decade or two if they tried”" No, he didn't he said “10 years from when we get serious” so for the stone age people which were present for the period which lasted for roughly 3.4 million years and ended between 4000 BC and 2000 BC, with the advent of metalworking. So after about another 4000 years, on September 12, 1962 we got serious and put a human in less than 7 years on the Moon. So he was saying "when we get serious", that could be another 10, 100 or even a 1000 years or more....., just saying.
So the problem of a constant energy beam directly hitting the target is overheating, at what point does that become an advantage because you want to use it for asteroids deflection?
Do the electrons being sent out in the beam run out? Do they come from the metal through the thermionic thing but get replaced by the sun or something?
Didn't watch the entire video but I didn't find discussion of how to stop at the other end. If that was discussed, please add the timestamp to the chapter list.
A trick I've never heard anyone propose: build the craft on the way, by absorbing an incoming matter beam. So you get a minimum-possible system up close to the final velocity you want, but the matter beam just keeps arriving and is captured and added to the mass of the craft - e.g. giving it the mass needed for a big solar sail for deceleration at the other end, and probably instruments scientists back in the solar system want available to inspect the new star system.
I does not matter how you get the mass to the place you want at the velocity you waant, all in one piece or a molecul at a time, the energy required will be the same.
@@mikeegan In Physics 101, perhaps. In real engineering, pretty much never. There's always energy losses, system costs, design costs, etc - all of which vary greatly depending on overall system design, all of which have to be considered for trade-offs. Is an "add to it as if flies" approach better? Worse? I don't know, it just sounds worthy of consideration. It's main advantage would be that the same matter beaming system used to impart energy/momentum to the craft can be used for the secondary purpose of enlarging the craft, rather than needing a much larger beaming system to drive a craft of the same size to the same velocity. The downside is added complexity of the original craft to collect the added mass and convert it into useful systems, which is essentially at Tech Level 0 today - i.e. not much more than a half-baked idea.
@@mikeegan Unless the matter is found on the way there. Send a blue print, a means to shift direction, then use Kuiper Belt & Oort cloud objects to gradually enlarge and create.
@@tomcraver9659 Engineering does not get to play hooky from physics. There is no cheat code. The gentleman you're replying to was 100% correct. Adding mass incrementally along the voyage *simultaneously* increases the amount of energy required to continue accelerating the vehicle up to the desired speed. No one gets to hand wave physics away.
@@dirtypure2023 My comment regarding physics 101 not being enough doesn't deny that physics is supreme - just that simple physics is not enough physics to understand the engineering requirements in real world situations. If one instead tried to launch a greater mass from the start, the matter beaming would need to be proportionally scaled - which brings in issues of engineering practicality. Note that my original post specified that the craft was assumed to already have achieved the desired final velocity when it starts accumulating more mass - any matter 'catching up' to it (to be accumulated) has obviously already had all the energy (and then some) needed for it to hit that same velocity, so mikeegan's comment was either misguided, or I guess he could simply have been agreeing with me in a fashion that made it sound like he was disagreeing.
How fast could you make a probe go if they could use gravity assist and laser? If it was to do a Voyager style trip around the solar system then when it was on the proper trajectory blast it with a laser. With the gravity assist past the sun and several planets you could (maybe) create several opportunities to target it.
Ooh, on the first topic of solar statites and balancing mass vs solar output, I'd be really interested in learning how much of an impact dynamic solar weather will have.
Can the solar wind currents/magnetic/electric fields passing the static satellite (statite) provide the energy needed to drive the shield needed to divert the solar wind? Somewhat the “wind mill” concept you mentioned?
“Then don’t do it that way” is such a useful phrase in so many areas of life. 😂 Jeff Greason has always been great. Thanks for having him as a guest.
Love the combination of enthusiasm, pragmatism, and can-do spirit Jeff Greason exudes. His approach of proposing and investigating multiple ways to solve a particular problem or advance a step is a smart way to proceed. Enjoyed watching the interview. Thanks
22:38 All these years and I was unaware of the solar wind being a sheet, instead of an expanding sphere. As far as I recall not once I heard about it in educational YT channels... it turns out it's the "Heliospheric current sheet". It's just 10.000 km thick in the span of the solar is absolutely focused, it is even smaller than the earth diameter (if it wouldn't be distorted by the magnetic field of Earth). This interview keeps on giving :) I love it.
Thanks!
The long awaited interview with Jeff Greason. Thanks!
Simply fascinating. Nuts and bolts discussion of interstellar travel. Love it!
Takes the lead over political discussions any fucking day
The idea of using a magnetic solar sailor is so epic!
and how that work? where u get that amount of power from?
@@jetli740the sun
@@jetli740maybe watch the interview
@@zelrex4657 and with this soundtrack
ua-cam.com/video/MiqJjxQiNbY/v-deo.htmlsi=s1h1IyjoAUHt-UOK
It will be legendary
The only thing İ could say is, give this guy funding!
In this area of research funding is "earned" by reasons delineated by the interviewee (e.g. by a goal, by a need, etc.)
fund what? each area is a multi billion dollar endevore with no promised results, just more data, 3 x multi billion R&D, then if any of the tech works, multi billion R&D to fit them together, then production costs for the triple by pass, we need more energy and less polution here on earth, lets solve that first, leave rockets to Mars to Elon and co. ( it keeps them out of truble).
So, the ideal setup is a Blue Sky Research Space Agency, a Space Exploration Agency, and a Space Development Agency? That seems like an extremely productive tripartite arrangement. One specializes on its own thing, the Blue Sky Research Agency are NIAC on steroids and field lots of experimental systems, the Space Exploration Agency fields production-grade probes and builds the extraterrestrial equivalent of McMurdo Station in various places, and the Space Development Agency works on things like cyclers, off-world industrial base and non-rocket space launch.
"... After we get serious. Which is sometimes between next week or never." That's very well put...
This was such an interesting interview! You pick the coolest guests.
Side note: please let your guest know that their website has an SSL certificate issue and is being marked as not safe by some browsers.
"The certificate is not trusted because it is self-signed."
The thing that sticked the most with me is the conflict on interest that was created, when Nasa, the "Technology-Pushing Agency" also became the "Mission Connducting Agency". And we see it all the time, the mission conducting eats the funding of the technology-pushing. That should really get their own untouchable funding (back).
Maybe you don't see much of the picture. For one: things tend to get bigger and more complex, but the over all budget tends in the opposite.
NASA has its Artemis program, which pushes much developement, and takes much of the budget. But they are the "Air & Space Administration". Thats more than rocket science.
Laserbeam communication is one new developement they are funding.
Eliminating the Sonic Boom, for supersonic travel over land areas, is another project.
NASA is working on the infrastructure for autonomous drones in big cities and elsewhere. This is a big thing, not only for that Amazon then can deliver directly. Or to move freakin' taxi's in the air.
Then there are the next generation Mars drones, and a drone for Titan. Submarine drones for Europa, Enceladus, and Earth. And don't forget JWST, Hubble, and many others. They still cost money to operate only.
You see? Accusations without research mostly l👀k silly. The very first research step is best via their web page. From there, you can go on to other agencies, or universities. Also to involved companies, for further research.
Believe me, Bro;•) this can be quite interresting!
🚀🏴☠️🎸
NASA is pushing new technologies all the time. Congress just doesn't give them the money to get those concepts off the ground.
@@MichaelWinter-ss6lx it blows my mind that people actually believe that NASA is inefficient with their budget. I’m confident they do more per dollar than any other government/government adjacent agency. Objectively SLS is a fiscal anchor, but legally imposed upon them.
Also let’s not forget that NASA quite literally saves thousands of lives every day since the late 70’s as they came up with and have normalized Crew Recourse Management (CRM) training for all commercial airline flight crew. Prior to that no 1st Officer or engineer would ever dare disturb the pecking order within the cockpit and question the captain…
you don't remember Ingenuity?
Thank you for having Jeff Greason.
Loving Jeff's optimism and grounding that says it's realism.
Fascinating. Let's keep the ball rolling or beams running. The rewards could be stellar. Needs more funding, research, and testing. Time is ticking.
Thanks to the both of you for this fascinating interview! Also thanks to Fraser for interrupting his vacation to get these out. Have fun in your forest, Fraser!!
Who do we lobby to get this done? And how do we work with those planning those missions?
Please stop believing that corporate lobbiests or any lobby in a crooked Bourgeoisie government is going to save us.
Look at
Peaceful revolution And a real people's government land reform.
4:54 "It is, in principle, possible to deflect a large enough cross sectional area of the solar wind..."
My brain immediately thought, "Could a solar flare be deflected in the same way?"
If we know one is coming and is going to hit Earth, could we at least deflect enough of it to weaken the effects on Earth, if not deflect the whole thing?
You would need a solar sail many times the size of earth to block an entire solar flair.
Solar flares are huge man. Think a of a blade of plasma the size comparable to the distance between the earth and moon. That's a rough estimate btw
I think a more feasible idea for solar flare mitigation would be a very powerful electromagnet orbiting a Lagrange Point between the Earth and Sun, which generates a very large magnetic field to redirect or capture the energetic particles / radiation from the flare. But then you have the problem of frying your electromagnet. But I've seen this idea proposed as a way to augment the very weak Martian magnetic field for decreasing surface radiation on Mars for human colonies and terraforming.
Thank you both, that was a fantastic discussion.
"There's a whole literature on interstellar dust impacts."
Science is so goofy and it's great. ❤🔭
Mind boggling video. Keep it up!
Awesome guest, I really enjoyed the interview. To me it has always been obvious that an interstellar mission is a multistage mission, since no single propulsion system seems to be enough on its own (besides antimatter). The logical extention to that is the creation of "interstellar highways" consisting of previously accelerated beaming/refueling pods in between, daisy-chaining energy and/or momentum from the start to the traveling ship. You deploy the infrastructure for braking, if needed, the same way. By stacking terminal speed over terminal speed you create an acceleration channel within a "springy" shell of accelerating beaming stations and any final speed can be reached. The channel could be constantly sweeped of foreign dust by those same stations (GWs of laser/maser/mass accelerator beam is one hell of a sweeping broom).
....I thing I'm gonna watch the relevant Isaac Arthur video now ..... Fascinating topic!
That’s just crazy enough to work.
you don't need a line of beaming stations, the space craft being pro-pulsed can be repeatedly injected with energy at each orbit of the sun of the accelerated craft, the beaming station acts as a battery and intermittently injecting accelerating energy ( with lasers or electron beams, or the mentioned thermionic converter)
@@wanfuseThat only works as long as the target orbits the sun. Once it reaches 617.5km/s you only have half an orbit before you will never see it up close again.
0.002c isn't really good enough for meaningful interstellar travel.
@@antonf.9278 its ok my full reply was removed and replaced with about 1/4th my solution
@@antonf.9278 wont take the time to relay the whole thing use solar wind and electrostatic field on 100 loops of wire out to about 1000 km for longest one, propell a million ton ship , you don't have to worry about the orbit change this way it will work ok up to 1/4 astronomical units( at least thats the back of envelop calculations)
a reason why i think manned interstellar missions are possible is simply due to what history has shown us. centuries ago the absolute fastest way to get around reliably was with a horse, and anyone back then would have laughed in your face if you suggested a way that anyone could travel around the world in a couple hours. it was a giant leap from traveling by animal to using machines, and maybe we will see another leap that would make near light or faster than light travel possible.
personally i would love to see the Halo slip drives become a reality.
Absolutely fascinating guest. Thanks for this!
One of the best episodes!
This was a gem of an interview. Optimism and brutalism rolled into a fascinating technical discourse. 👍👍
This was fantastic! Some of the particle physics went over my head so I'm gonna listen to it again tomorrow.
Please keep these videos coming 🙏🎉
The man clearly knows his stuff. Great guest
"Magnetic fields don't collect things, they scatter things."
I'm not saying that isn't true, but I am curious then about how an apparent exception works: Don't planetary magnetic fields 'collect,' or at least funnel, charged particles that create auroras around magnetic poles?
Your question involves very complicated areas of physics of which can be counterintuitive.
@@plucas1 So what magnetic fields actually do, at the scale of individual particles in large homogeneous fields, is convert the particles' transverse velocity to rotation around the field lines. The longitudinal velocity stays the same. For a field at big as Earth's that means they orbit the field lines in the plane perpendicular to the lines, while the remaining longitudinal velocity moves the orbit along the lines until it reaches Earth.
I haven't seen or communicated with Jeff in a long time, so it was a great pleasure watching this interview; I realize how much I miss his amazing intellect, and even more amazing presentation style. Thanks very much for doing such a wonderful interview.
Get Jeffback soon! Fascinating stuff. He's so down to earth when discussing such advanced propulsion concepts.
Let's go big and build a stellaser. 😊
Speaking of, while I imagine he's a bit busy these days, would be cool if you had Isaac Arthur on one of these times.
I would totally MISS that one
@@AndrewBlucher why?
@@aykut3158 Mr Arthur is one UA-camr I detest. That's fine, other people like him.
@@AndrewBlucher You should reflect on that. It’s not normal to detest people you will never meet in your life. Like whatever it is about him that bothers you so much is something you actually loathe about yourself and you’re projecting.
It’s not like he’s done anything to justify it. You’re fabricating something and whether you think he’s annoying or insufferable or you can’t stand his voice…. That’s you dude. Not him.
You didn’t even say “he’s annoying” you said you detest him. That’s really weird man.
@@jademoon7938 Over analysing and projecting. Or maybe just trolling. In any case, I don't follow advice from people I encounter by chance on social media. Do you give people advice often?
Great interview! Keep up the good work. 👍🏻
Great interview, thanks for taking the time to put this together!
Awesome interview!
Excellent discussion
Another great interview, thank you!
i like this guy! give him moneyyyyy pls!
Really interesting guest and show. Thank you very much!
I get that the Bussard Ramjet wouldnt be sufficient to power a journey by itself but keeping in mind that at some point you will want to slow down and the ramjet will create resistance while collecting fuel, slowing the craft, maybe it would still have some utility if it was light enough?
I wonder what this technology could mean for in solar system travel. Solar system travel would surely be a step that would make interstellar travel not such a far fetched idea. I walked 2 miles , maybe I can do 5, 10, 20 etc, also alow the technology to be built on layers of experience
Oh, love the call out at the hour mark (or so) good call Fraser
We don't get over immersed in this thinking do wo?
Completely forgetting time and space presently in?
😂
Great guest and the way you both explain these concepts in layman's term. Thank you!
Damn good interview. 👍
Biggest problem for interstellar probe will be coms... It will be super hard to detect the signal of the probe while it's next to the star.
My take away is the issue is money. People still expect that there is some profit to be made that you are supposed to earn something... We live in a world fueled by the sun cooked for millions of years so all you have to do is reach out and take whatever you grab put it in your mouth and it will sustain you. And yet profit, finance ect.
What profit do you expect from infinite resources? 10x? Someone have to start spawning new universes so you find a reason to explore beyond our perfect little fish bowl of a planet?
Ridiculous even thinking about it....let alone discuss it.
The ongoing NASA Psyche mission is demonstrating laser communication from distances across the inner solar system, with sensitivity of detectors able to pick up a single photon. By the time we are ready to launch an interstellar probe decades from now, laser link technology should be capable of sending data back.
Calculations show that a 1-watt laser communication transmitter on the probe can send back megapixel resolution images from the spacecraft as it travels through the Alpha Centauri system (or any other nearby star). Please see Section 5 in Philip Lubin's NASA study "A Roadmap to Interstellar Flight" for the details of the calculations (google title to find it, as links cannot be shared in UA-cam comments).
The ongoing NASA Psyche mission is demonstrating laser communication from distances across the inner solar system, with sensitivity of detectors able to pick up a single photon. By the time we are ready to launch an interstellar probe decades from now, laser link technology should be capable of sending data back.
Calculations show that a 1-watt laser communication transmitter can send back megapixel resolution images from the spacecraft as it travels through the Alpha Centauri system (or any other nearby star). Please see Section 5 in Philip Lubin's NASA study "A Roadmap to Interstellar Flight" for the details of the calculations (google title to find it, as links cannot be shared in UA-cam comments).
I guess you saw the interview from a few months back: Swarming Proxima Centauri and Getting Data Back [NIAC 2024]
The ongoing NASA Psyche mission is demonstrating laser communication from distances across the inner solar system, with sensitivity of detectors able to pick up a single photon. By the time we are ready to launch an interstellar probe decades from now, laser link technology should be capable of sending data back.
Calculations show that a 1-watt laser communication transmitter can send back megapixel resolution images from the spacecraft as it travels through the Alpha Centauri system (or any other nearby star). Please see Section 5 in Philip Lubin's NASA study "A Roadmap to Interstellar Flight" for the details of the calculations (google title to find it, as links cannot be shared in UA-cam comments).
I like Jeff! He seems feisty!
That was awesome 👍👍👍👍
I have a question:
If the particle beam is 10 000 km wide, could you then send multiple spaceprobes at the same time?
It sounds like you could get more redundancy out of it without having to double the whole system.
I've questioned this for years. Couldn't be happier this came across my feed.
Funnily enough I'm playing around with a story idea of a mission to another star system, and multiple stages for the acceleration. I likened it to shifting gears on a bike or a car. Each one has an effective acceleration range. Definitely going to take everything I've heard here into consideration.
Nuclear bomb acceleration would work too . Planet gravity slingshots for awhile etc . Plus we send very very small probes ahead and we need a communication line back etc or the speeds are slowly insane
let me know where i can chip in!!! does he have a patreon??? pleaseeee give this man money!
Well, Jeff has put his finger right on a whole suite of problems in applied research.
I don't 'work' in science or engineering anymore, but even in my new field we have the same problem. And guess what, all my actual breakthrough work is 100% unfundable, whereas my paid work is low risk and purely derivative.
Very thought provoking
First time here, this is one of the more in depth convos I've ever seen on UA-cam. Thank you.
We think of space travel like someone paddling a canoe, using known human energy and power to move everything against and through the water rather than harness the energy in the water.
great vid. both you and he know exactly how to share your interest well :)
Really enjoyed this interview
A really interesting video, thank you
Sooo great to learn this is so close to feasibility, at least on paper for now. I had no idea that theory got so far in this field. Thank you!
I’m waiting for the John questions 🤣 been watching to much event horizon 😂 great show Fraser as always 😊
So, the spacecraft won't get destroyed by hitting the interstellar medium at 20% the speed of light, but what about the radiation load on the electronics? If Jupiter's magnetic field throwing particles at you causes problems with radiation on the space craft then what happens when the interstellar medium runs into you at 20% the speed of light?
1:01:43 - When satite? Not a well posed question. "Your asking: How long does it take to run when we don't know when we start the race."
I survive on talks like this.
What about in conjunction using both a fast high gamma electon beam for energy supply and a slower heavy ion beam to resupply the reaction mass?
It's true. I was the whole day at work and not one person talked about multistage interstellar spacecraft. No idea why not.
random theortical thing about solar sails... here is a question...... take a one hectare concave mirrored dish that is focused to a single point,point the dish at the sun, the solar energy at that focal piont is equal to 10,000sm of sunlight, about 1 kw per sq meter, so 10,000kw or 10,000 kilo joules per second, alot of energy, now squirt 1 gram per second of water through it and calculate the theoretical thrust by calculation the temperature change and the volume change, use the rocket equation, probs check out a steam table or two, then calculate the dela v with a sail weight of two tonnes and a 1 ton of water as propellant. how far can a 5 tonne craft do and how fast?
From what Jeff Greason is saying about "you'd want a slower beam" about the "direct mag-sail/e-sail method" of using the charged particle beam, I can think of an easy tool to reach for to enable that.
Proton beams instead of electron beams. The mass of the beams individual particles is that of a proton rather than an electron, so you have a much higher mass, but if you focus the same amount of power into that beam, each proton gets accelerated to a much lower velocity.
There's your slower beam, and even better yet, the increase in mass of each particle means you carry much more momentum than energy.
However, that's probably only useful for lower velocities and/or higher accelerations, and (complete speculation on my part) probably has a much shorter "runway length" due to plasma interaction effects with solar wind electrons and protons being.... different for protons than electrons.
...or maybe it's better?
Anyways, the point is that if you hold the power and particle flux (by count of particles) constant and vary the mass of the particles used (by swapping from electrons to protons), the velocity of the created charged particle beam changes in an inversely proportional fashion (protons go slower if you use the same number of them and the same accelerating power)
If you want more mass in your beam us muons. But every which way you work it the energy expended by tthe time you get a given mass to a given destination is the same. As he points out the trick is where you get that energy from and the biggest energy source we have available is the sun. Untill somebody figures out some sort of 'Star Trek' drive
@50:00 what kind of time dilation would the spacecraft experience for this type of misson?
wow, his day job is amazing!!! XD this man is more important than Elon Flask!
33:10 Could the receiver be a comet with a probe attached , that is heading in the desired direction ?
What about using technology we already posses like a microreactor? A continuous nuclear reactor which can propel the aircraft non-stop for a minimum of 10 years. That would get us there, granted then the problem is stopping.
"Blessed is he who plants trees under whose shade he will never sit."
My personal opinion is that to reach a nearby star with a satellite we need to send a probe that will outlive those who launched it. The project may take over 100 years to reach alpha century - but it *will* reach it.
Incredible interesting talk! Thank you Fraser! I am SOOO STUNNED by skyrising intellect of your speaker @jeffgreason. It was really mind bending and highly thrilling to follow your well choosen and very precise words, Jeff. Actually, I had to listen to this interview twice, just to get all the bits of information.
We could learn to surf the magnetosphere of the Sun or Jupiter.
Excellent interview
we won't be getting outside of our solar system until we start space mining
there are 2 known sats in interstellar medium
If you mean human beings, well yeah.
IBEX is on the way, and IMAP is in development now.
Exactly, mining, producing, the whole space economy. It will enable totally different tools and completely redefine what's affordable.
Agreed. There is more than enough for humans to do within the solar system. But now I sound like one of those weird deceleration people who oppose humans leaving Earth to colonize the Moon and Mars, and spaceflight in general, "because we have enough problems here on Earth that money should be spent on".
I say if someone wants to fund it and fly the mission, let them!
good one thanks😀
I want to go have a look at the stars.
Loved this interview, loved his attitude.
I'm glad this went into the lack of funding. Nasa's budget isn't even .5% percent of the US budget most years if ever to my knowledge. Some praise capitalism for "innovation" but it inherently limits innovation by requiring people to focus on basic needs instead of innovation. That isn't to say nothing innovative has come from capitalism. Companies also have no interest in projects that don't make them money as mentioned here so it fails in that regard too. Lack of funding and the general shortsightedness of humans will limit and slow what is accomplished in many fields unfortunately imho.
Space Force is a sneaky way to get more funding for space research.
The “shortsightedness of humans”. But not you right; it’s far sightedness by you to move money from all the domestic problems to escapism. Good grief, do you listen to yourself ahole?
"Capitalism inherently limits innovation"
Did you think before you wrote that? Literally ALL innovation comes from the free enterprise of individuals in the free market. You are speaking the opposite of the truth.
@@dirtypure2023 You can pretend to know what you are talking about, but here are somethings invented outside capitalism like oh i don't know, the internet (government funded), NASA and space exploration, polio vaccine, open-source software, human genome project... there are many more. If anyone should think before writing it looks like well... in this case it isn't me.
@@Behgork Your statement was that "capitalism limits innovation". Now you're arguing that government itself invented the idea of the internet. Do you believe the internet sprang out of a government money printer, or was it an innovative group of individuals with an idea that DARPA decided to throw money at?
The fact that government puts taxpayer dollars into funding private universities and companies to do R&D does not prove your original conceit that "capitalism actually limits innovation". That was your claim.
Very very good video. Got me thinking on a lot of things.
For the Question Show:
Would it be possible to use one of these particle beams like a interplanetary terraforming conveyor belt? Could we either push atmosphere off of Venus towards Mars, skipping Earth? or pull atmosphere from Venus and transfer it to Mars within an interplanetary beam?
So, we seem to be talking about a straight shot from Earth to Alpha Centauri without doing orbits around the sun, like we have always done (with all of the probes we sent out). Is that even feasible? I mean, the reason we send them around the sun a few times is because it requires way less energy than any attempt to go straight out. Plus, the Earth is already moving that way, so we use some of its momentum. With any kind of particle beam or energy beam technology like he is describing, would we still be able to launch in an orbital trajectory around the sun, or would we have to do a straight shot away from it, requiring hundreds of times more energy?
This is so cool!
Once humanity recognizes that something is possible, somebody will eventually find a way to make it happen. Sailing vessels 500 years ago to the new world, railroad across the continent 150 years ago, interstate highway system 70 to 60 years ago, the Apollo program to the Moon similar time frame, currently we have Elon Musk spearheading the Starship program that will make Mars possible within hopefully 30 to 40 years....this? Maybe in a hundred years...I don't know
There will be boots on Mars in less than 20 years. It will happen in the early-mid 2030's.
Based on this conversation, it is safe to say that best case scenario we are decades away from a mission of this sort, and that's if this is even possible which he admitted he doesn't know how to make it work. Neat, but more science fiction than realistic.
Yeah..I think the move is to seriously establish a permanent base on the moon. You could expand the caves and tunnels and fill it with atmosphere.
A lot and I mean A LOT of Science Fiction is reality, today.
It sounds like an interesting concept but this guys estimates are total nonsense. He thinks it’ll take “10 years from when we get serious” and cost “on the order of Apollo”.
Absolutely not, I think those terrible estimates ruin the credibility of what he’s saying. He admits he doesn’t even know key details like how to capture energy from the e-beam, the necessary materials to handle such insane energy levels, electronics/communications.
If you asked this guy, he’d say that stone age humans could land on the moon “in a decade or two if they tried”
@@eyeborg3148 ""If you asked this guy, he’d say that stone age humans could land on the moon “in a decade or two if they tried”"
No, he didn't he said “10 years from when we get serious” so for the stone age people which were present for the period which lasted for roughly 3.4 million years and ended between 4000 BC and 2000 BC, with the advent of metalworking. So after about another 4000 years, on September 12, 1962 we got serious and put a human in less than 7 years on the Moon. So he was saying "when we get serious", that could be another 10, 100 or even a 1000 years or more....., just saying.
Multi-Stages can also be Relay-Stations, for automated communications, and emergency-shelters, or repair-stations for future travelers.
Why did I just find this channel. I’ve been watching space UA-cam for nearly a decade
So the problem of a constant energy beam directly hitting the target is overheating, at what point does that become an advantage because you want to use it for asteroids deflection?
Do the electrons being sent out in the beam run out? Do they come from the metal through the thermionic thing but get replaced by the sun or something?
Frase, you’re awesome dude. 🔥⚡️🤜
Excellent, thank you both
Didn't watch the entire video but I didn't find discussion of how to stop at the other end. If that was discussed, please add the timestamp to the chapter list.
Multi-stage -- Chewy, cut in the sub-light engines! Cap. Archer: "Polarize the hull plating." "Space 1999": take the Moon with you?
A trick I've never heard anyone propose: build the craft on the way, by absorbing an incoming matter beam.
So you get a minimum-possible system up close to the final velocity you want, but the matter beam just keeps arriving and is captured and added to the mass of the craft - e.g. giving it the mass needed for a big solar sail for deceleration at the other end, and probably instruments scientists back in the solar system want available to inspect the new star system.
I does not matter how you get the mass to the place you want at the velocity you waant, all in one piece or a molecul at a time, the energy required will be the same.
@@mikeegan In Physics 101, perhaps. In real engineering, pretty much never. There's always energy losses, system costs, design costs, etc - all of which vary greatly depending on overall system design, all of which have to be considered for trade-offs.
Is an "add to it as if flies" approach better? Worse? I don't know, it just sounds worthy of consideration.
It's main advantage would be that the same matter beaming system used to impart energy/momentum to the craft can be used for the secondary purpose of enlarging the craft, rather than needing a much larger beaming system to drive a craft of the same size to the same velocity. The downside is added complexity of the original craft to collect the added mass and convert it into useful systems, which is essentially at Tech Level 0 today - i.e. not much more than a half-baked idea.
@@mikeegan Unless the matter is found on the way there. Send a blue print, a means to shift direction, then use Kuiper Belt & Oort cloud objects to gradually enlarge and create.
@@tomcraver9659 Engineering does not get to play hooky from physics. There is no cheat code. The gentleman you're replying to was 100% correct. Adding mass incrementally along the voyage *simultaneously* increases the amount of energy required to continue accelerating the vehicle up to the desired speed. No one gets to hand wave physics away.
@@dirtypure2023 My comment regarding physics 101 not being enough doesn't deny that physics is supreme - just that simple physics is not enough physics to understand the engineering requirements in real world situations. If one instead tried to launch a greater mass from the start, the matter beaming would need to be proportionally scaled - which brings in issues of engineering practicality.
Note that my original post specified that the craft was assumed to already have achieved the desired final velocity when it starts accumulating more mass - any matter 'catching up' to it (to be accumulated) has obviously already had all the energy (and then some) needed for it to hit that same velocity, so mikeegan's comment was either misguided, or I guess he could simply have been agreeing with me in a fashion that made it sound like he was disagreeing.
The long term employment of science teams over a decades long interstellar mission reminds me somewhat of the famous pitch drop experiment.
Most fascinating. Would be interested in learning more about Solar statites and fermionics
How fast could you make a probe go if they could use gravity assist and laser? If it was to do a Voyager style trip around the solar system then when it was on the proper trajectory blast it with a laser. With the gravity assist past the sun and several planets you could (maybe) create several opportunities to target it.
Ooh, on the first topic of solar statites and balancing mass vs solar output, I'd be really interested in learning how much of an impact dynamic solar weather will have.
Can the solar wind currents/magnetic/electric fields passing the static satellite (statite) provide the energy needed to drive the shield needed to divert the solar wind? Somewhat the “wind mill” concept you mentioned?