Dr. Kaku talks about spaceship with concept of interstellar travel that is simple enough that we could build it now and yet we don't. He explains why. Do you think the reasons are right?
Dr. Taylor not only designed the largest-yield fission bomb, but he also designed the smallest physical package, and the smallest-yield devices. He started in the business at Los Alamos during the War, and told George Dyson that at some point during the cold war, he went from coming up with a design feature and having it built into one of the production bombs being turned out, and sent to the range and he'd get data back in a few weeks to go on with. All this is why he was later in life outspokenly anti nuclear-weapons. He said that it's pointless to try to hold the technology back, and there are so many things it can help us with. Even he would have said that he knew only some of the ways to detect and enforce any non-proliferation of weapons while allowing peaceful uses. You can't stop people from making them -he knows very well how many easy ways there are, and burying the issue isn't doing us any favors. It's guaranteeing that when we do have to face the issue, it'll be a surprise -probably of a nasty sort. It's fair to say that Orion and associated fears of weapons proliferation make it similar to Breeder reactors. Breeders combined with Orion can close the fuel life-time cycle of spent fuel -the large portion of what we call radioactive waste from power reactors Lots of bombs needed for fleets of huge liner vessels crossing the Solar-system. All we need to do is get over war. Getting into space will help. Only the very long trips, to Saturn's moons or beyond, will simulate gravity. 21 days humans to Mars, including acceleration and deceleration and 80+ one way km/sec. A few months to Jupiter moon system or Trojans/Greeks or the Main Belt.
You're right. To go so fast requires a lot of energy (energy that can be weaponized). That is of course unless we manipulate space and make a "warp drive" But even then scientists say that such a device would release a lot of energy with its use. Energy that can be weaponized.
Hmm, you're in fact complaining that a spacecraft that uses thousands of nuclear weapons for a propulsion system by the very fact of the speeds it could attain be a weapon in itself... Kind of a redundant conclusion don't you think.
@@johnwang9914 No, no. I think you misunderstood. He meant that *any* method of propulsion that is fast enough for interstellar use is going to use a lot of energy. Be it nuclear pulse-propelled, antimatter, solar-sail via a Dyson swarm...yeah...anything that goes very fast would be a weapon. On another note...wow...this comment was made 2 years ago...good times
@@j-twd930 And hence the statement is a bit redundant as I said, any such interstellar travel requires the energy of devastating weapons. This redundancy is only mentioned due to the common ignorance that vehicles are indeed weapons, even an ordinary car is a deadly weapon.
@@j-twd930 each of these fuel sources by itsself is inherently an even more dangerous weapon than the ship that is driven by them though. Besides, traveling at near lightspeed is pointless anyway, the amount of fuel required starts rapidly approaching infinity for barely any gain at such speeds.
Note that very quickly in that world time-line, somebody would have started looking into mining asteroids, and with that, they'd end the rule of the scarcity economic theory regarding precious and monetary metals. Flying mountains of the stuff and as of now, no mining regulations. No need to fight wars over oil or minerals either. That upsets a lot of stockholders. The military capabilities in such a world based on guided impactors, scares everybody starting with the Generals and politicians with "Nuclear Club" membership.
It's expensive (for now) because of the Space Shuttle. The most complex and expensive vehicle ever (~$700 billion each. SLS is to be about $1.3 billion), the only human carrier with zero provision for crew escape during the first, worst part of the flight. Designed partly to USAF requirements for a winged manned bomber/satellite capture/interceptor. Recalculate co$t, using a fleet of '60s Convair Nexus or Boeing AMLLV, or Sea Dragon (or BFR). .5C is smoking hot for an Orion. Maybe a very hypothetically extrapolated micro-fusion future bomb. "Old Bang-Bang" might get .15C, very faintly possible one day to hope for .2C with something that probably doesn't use an A-bomb trigger (according to Freeman Dyson)
Imagine if we had to abandon earth and the thing that was threatening to destroy us would end up saving us. The idea is not dead. 4th gen mini nukes have not been achieved yet for technical reasons, so only a full-blown ship with megaton charges would could be built at the moment, which is just overkill for our budget. But this will certainly propel the first interstellar missions unless we're insanely lucky and figure out negative gravity for an Alcubierre-drive. For more efficency, as with an outside explosion most energy goes out the side rather than the back, you could encase the reaction in a massive lined concrete chamber with a nozzle and supply high-pressure plutonium, deuterium and tritium into the structure, make a nuclear rocket that runs like a chemical rocket but on fusion and fission. The problem: would have to be absolutely massive carrying a substantial fraction of humanity and and render the planet uninhabitable if launched. I just realized this is basically the plot of interstellar minus the nukes.
Project Orion Would have been a huge Space ship, there were a couple of designs one for space exploration And the other was a space battleship. These vehicles would have been quite heavy, the rear end of the ship had pushed plates , attached to hydrolic pumps in the center of the plates was a gun tube, that was attached to a cylinder if I recall that held small designer Atomic Bombs, this was the engine, the bomb would be propelled down the barrel and the fuse was set to detonate the bomb at a given distance from the pusher plates and space craft of coarse , and the Orion would ride the shock waves. Before you laugh, though, alot of money and science and engineering went into the Orion project. Flyable models using conventional Explosives were built , and the flew! They estimated the real Orion could have reached three quarters light speed. Thus a Manned Mars mission would take a few weeks as opposed to months to get to Mars.
With nukes as we know them and some sort of giant mechanism for physical interaction with the plasma jet, he would be nervous about promising even 15%. His two favorite thought-experiment designs used either momentum or temperature, to limit the stresses you could exert, and the scale of what's possible. Theodore Taylor was a Los Alamos bomb designer and top physicist and bomb maker. Worked at GA in the late '50s and brought Dyson in on the Orion program. Taylor said that what you're looking for is ways to stretch the momentum out as long as possible to impart as much KE without exceeding structural strength, while delivering the total impulse of the plasma jet fast enough that heat doesn't have time to affect the materials. He said there were any number of worked-out ways of tinkering with bombs and delivery to do it.
They never said 3/4 the speed of light. The Freeman Dyson back of the napkin calculations of a flyby mission to Alpha Centauri required 300,000 twenty megaton bombs used over a 30 day period to reach 3.5% the speed of light. Keep in mind that at the peak of the cold war, there were about 18,000 nuclear bombs at an average of 7 megatons each. I appreciate your enthusiasm but stop inflating Project Orion's capabilities.
So it's okay using in wars but not okay in terror events. What's the difference? The time has changed. Now we are face to big scale wars where not only the soldiers end up dead but civilians too. So, to me, these are all the same.
He did mention the miniaturization dilemma too. This isn't why the project ended, but it is important. The atmospheric test ban killed the project. Military control killed the project. Essentially politics killed the project, but pollution was a big factor.
Orion is like NERVA in that there were no real obstacles but will. Even the political obstacles could be overcome if there was will. It died because it represented an embarrassing excess of capability to an agency & government apparatus that had no interest in anything but a show of propaganda for the Cold War.
yeah the math checks out our current chemical rocket can get us to 58,000 km/h that an acceleration of 4-5 g for about only 10 minutes in space any force act upon the craft will accelerate it in the vacuum of space so if you can get a nuclear pulse drive with explosion of around 5-10g of constant acceleration in space for enough duration that yeah you can hit 50 percent light speed that will cut our space travel from our solar system to Alpha Centauri A which is around 4.2 light years away that mean we will reach the nearest orbit in around 8.4 years but you see like what he said to achieve such speed a propellant must have extraordinary amount of power for the given weight to make it work but that properties is also a blessing in disguise you would have to develop countless mini nuclear pebbles with the explosion power to level a town imagine a terrorist group with a fist full of nuclear pebbles they could level a hole country any form of energy can focus on both productive and non productive means for example an rtg nuclear generator on vovager 1 is still producing enough power after 41 years of constant power generation to operates its scientific equipment and transponder or the mars rover that is still working after 5 years with a many high energy equipment on board a modernize improve rtg unit can easily power a family car for at least 20 years without a single charge a us aircraft carrier is powered by a fist size lump of uranium and that with fission technology a very wasteful way of actually extracting useful power a fusion nuclear technology the limits of such power source is almost mathematically limitless but so is its destruction power the only limiting factor to the development of such technology is the human factor or the lack of maturity of the human race to handle such power this was mention in the Fermi paradox theory the reason we dont see any life form except for us is that before they could reach type 1 technology they self destruct with technology similar to nuclear fusion the thing about life that we know it is that its predominantly selfish for example all cells that we know of act to self preservation in any form from reptiles to mammals even plants and any sacrifice it chose to do is only an act of preserving or furthering species survival like how we human would go to war for resources or how a fox will eat a rabbit and not care at all about what might happen to the baby rabbits that just lost its provider and protector as long as we survive even virus that can barley be called alive attach it self to the host and replicate and mutate as best as it could to survive regardless of the damage it may or may not do to its host that why 99.9999 percent of all living species have gone extinct in fact we are the most capable and smartest species to ever roam the earth we have gotten through great filters that have devastated million of other species and condemns them to extinction but the filter that lies ahead of us is still yet to come the Fermi paradox predict that we will not pass the next great filter that will turn us into a type 1 civilization i hope the guy who came up with this theory is wrong i pray that we shall overcome the limits of our maturity to explore this oyster of the universe a great philosophy once said ''society grows great when old men plant tree whose shad they know they shall never sit in''
Freeman Dyson never wrote about that with any confidence. We can hope for "bombs" that are non-fission, non-radioactive. possibly smaller and more nearly continuous like the fusion-rocket "torch-ship". His interstellar thought-experiment designs used thousands of bombs, tens of megatons each, and each one is packaged and thrown aft with ~1300 tons of some sort of propellant to be shot at the ship. A couple ways he figured it could work very plausibly, but the best you could hope for was maybe .15C. Cross your fingers and hope for .2C, with some unknown non-nuke primary.
Christopher Merrell this will work one day we do need this technology because we are destroying our world maybe they can find a distant planet where man can spread out and have all the land he wants think about this....
Freeman Dyson did a back of a napkin calculation of a flyby Alpha Centauri mission which used 300,000 atomic bombs over a thirty day period to reach 3% the speed of light. Later in his tv show Cosmos, Carl Sagan mentioned the Orion project could reach 10% the speed of light but there's no evidence that he did any calculations to substantiate that. More recently, the National Geographic docudrama "Evacuate Earth" presented an O'Neill Cylinder powered by the Orion external nuclear fission drive and said it could reach 7% the speed of light, again no actual calculations mentioned though it was likely based on a similar spaceship proposed under DARPA's 100 year starship program which asked scientists to speculate how an interstellar spacecraft could be built within the next 100 years. Again, the paper with that design did not offer reasonable calculations so the 7% is likely merely splitting the difference between Sagan's 10% and Dyson's 3%. As to where this 50% the speed of light is coming from, I can only surmise that it's from Dr. Robert Forward's laser sail proposals which was recently revamped into the Starshot proposal. Forward's proposal required massive solar and or nuclear power plants in Mercury's orbit or in or it around our Moon feeding lasers to drive a laser sail ship carrying a small crew on a 40 year mission. Deceleration was by a segment of the sail detaching and the remaining spacecraft using the reflected laser light from the detached sail to slow down, this is possible because obviously the both Earth and the destination are moving so the path of the spaceship would not be in a direct line between it's destination and it's origin. Likewise the return to Earth would be by detaching another segment of the sail to reflect the light. The estimated speeds were 40% the speed of light. Forward also proposed the Starwisp project where the sail would be a mesh of wires or conductive carbon nanotubes and masers would be used instead of lasers so that it would be RF microwaves not light that drove spaceship so that the sail need not be continuous but simply a mesh of conductive material with no opening larger than the wavelength of the radio waves. The spaceship payload was to be 17 grams, enough for a small camera plus communications circuitry and the estimated speeds was 70% the speed of light. That's the problem with these theoretical physicists, they are often citing inaccurate information as if they were just talking at a bar over a pint of beer. Now I love a good talk over a pint of beer but I'm not paid for doing so, these idiots are and don't prepare their statements as well as a drunk engineer such as myself would. For the long term survival of mankind and our civilization, we should do this but it means making hundreds of times more nuclear bombs then existed through the cold war, would unlock resources in the asteroid belt thereby breaking all the scarcity business models our economy depends upon and create unknown quantities of independent human colonies in O'Neill Cylinders, Bernal Spheres, and Stanford Toruses which would eventually no longer answer to authorities on Earth and could devastate any earthbound nation simply by throwing rocks. No businesses or government's would tolerate such a scenario even if it ensured mankind's existence for billions of years.
$1,000 per pound is what it cost NASA to do it, Everybody know how much they waste money, If it cost NASA $1,000 per pound a private company should be able to do it for $200.00 and still make a good profit
The cost thing is bullshit. If the entire earth really want to get something done, they won't eve' price something. But hey... We leave in a world where even people are priced for no reason.
