Isaac Arthur Videos Discussion(Sleeping Giants)

[DAL59]

 

Edited February 15, 2018 by DAL59

[ChrisSpace]

Another brilliant video, although I personally find the timescale of Jovian colonization in the late 22nd century to be a little optomistic.

[NSEP]

I like his videos, but i get easily distracted from them.

I will watch his videos later this day.

Edited November 26, 2017 by NSEP

[cratercracker]

YES YES YES

He is my favorite youtuber! I love to listen to his videos while drawing!

[DAL59]

"We will talk about colonizing the sun.  Not Mercury or a dyson swarm, but the actual sun itself."

Um... WHAT?

Did he watch this video?

 

Seriously though, what was he talking about? 

[HebaruSan]

1 minute ago, DAL59 said:

"We will talk about colonizing the sun.  Not Mercury or a dyson swarm, but the actual sun itself."

Seriously though, what was he talking about? 

You'll just have to tune in next week to find out!

[DAL59]

Actually, not until January

 

[DAL59]

NEW VIDEO

 

[DAL59]

Tomorrows video is on hive minds.

[Spaceception]

33 minutes ago, DAL59 said:

Tomorrows video is on hive minds.

And I can't wait.

[Spaceception]

Hive minds!

 

[Guest]

The footage and images they find for these videos is hilarious when tied with Arthur's silly examples, makes watching them actually worthwhile.

[magnemoe]

On 30.11.2017 at 8:46 PM, DAL59 said:

NEW VIDEO

 

I liked that one a lot, and yes you don't trust people either for very critical stuff like nuclear weapons. 
And that an paranoid who find his cell door unlocked might well suspect that the guards want to kill him escaping. 
 

[Guest]

17 minutes ago, magnemoe said:

I liked that one a lot, and yes you don't trust people either for very critical stuff like nuclear weapons. 
And that an paranoid who find his cell door unlocked might well suspect that the guards want to kill him escaping. 

I agree, that was a very good episode.

On a side note, as silly as Destination: Void was from a technical standpoint it is probably my favorite "rogue AI" scenario. I find it amusing that Arthur touches on the scenario in part as much more viable than "genocidal AI".

Edited December 7, 2017 by regex

[YNM]

Interesting channel.

I'm not sure what depth does each of it goes. But apparently it does try to take care of all aspects.

Edited December 9, 2017 by YNM

[PB666]

On 12/7/2017 at 2:06 PM, regex said:

I agree, that was a very good episode.

On a side note, as silly as Destination: Void was from a technical standpoint it is probably my favorite "rogue AI" scenario. I find it amusing that Arthur touches on the scenario in part as much more viable than "genocidal AI".

The guy does a fairly good job of burying the logical flaws in his arguments but over time they begin to pop out, I watched many of his videos.

1. The strength of a metal makes no assumption that an object can built of that length and size.
For example if you are building a ring structure, that length limit may assume all of the the structure is made of the construction material, not just some.

2. There is no such thing as a reactionless system. This argument creeps into many of his arguments. The surface of the Earth has momentum and a direction vector, due to friction between the surface and the gases the gases that surround the earth also have momentum. This is why 1000 dV or so is wasted getting into orbit. Without getting rid of the gas (which turns out to be bad for the ecosystem) you cannot get rid of the friction.
a. launching a ship in a tube filled with plasma to create a vacuum is a really bad idea.
b. launching any ship in a tube from any mountain top in the world at near - orbital velocity is a very bad idea.
The only way a tube launch system will work is via strait up and lasers to repel the atmosphere around the tubes exit long enough for the rocket to acquire the momentum and altitude needed to completely avoid the lower atmosphere, which by the way can almost completely avoided by launching from a launch pad on a tall mountain (much cheaper just build a tractor way that goes up the side of a mountain).
 

3. This is actually 2b. but its so big. There is the basic opinion, for example raising an object from the Surface of the Earth to GSO or LEO cost much  less than a rocket. NO!!!!!, it costs in energy nearly as much, the only difference is that a rocket launches  loses about 10% of its energy due to gravity effects and drag. It takes 85% of the energy used to get a rocket into GSO as a magic hand-waving space elevator, but you also have to move the counter mass to keep it up. OK its not that bad, it could be worse!!!!

Here your object is traveling over an Earth with a non-uniform field, its mass is horrendous, the station keeping cost are horrendous. What you save is the mass of some rocket fuel that amounts to 1500 dV over 10000 dV total. how does that equal a cost to orbit in cents per kilogram?????????? (we forget here on Earth capital equipment has a cost, what that money spent on equipment could have earned say in interest, if it was not sitting in space). Trillions of dollars in infrastructure, the cost would not be zero maintenance.

4. Energy. OK so lets talk about energy. Suppose you want to put 1kg into space 1000km up, the energy require to place an object into orbit is this -(u/r₁ - u/r₂) + 1/2(7824-460)^2 = ~9,800,000 + 27,113,200 = 36914000 J/ kg lets assume that the process is 60% electrical efficient (very optimistic given the distances that need to be covered) and you pay 0.05$ per kilowatt hour. A kilowatt hour is 3,600,000 J. Thats 10 Kwh per kg, we are not talking about cents per kilogram, we are talking dollar per kilogram (this is ideal). The capitalization cost for solar panels on a ring floating in space or other energy producing devices would likely have a cost 5 times that high. RIght now SpaceX charges 60,000,000 for 20,000 to LEO, but that cost is expected to fall. But there is another thing, while you are lifting something into space, there is a gravity cost and friction cost to be paid, for example an elevator does not conserve all or even most of its energy. The other disclamer that is buried in there is that it cannot be used to life humans . . .whats the point then. Before you would ever have enough free capital to invest in a space ring, space X will have the cost down so far it would never be competitive.

4b. This generally applies to any handwaving means of getting an EP PL into space except the rotating space bar (I will not deal with a completely insane proposal) Even if fusion power does not become a thing, these projects are still doable! Even if you have fusion power its not going to be a thing, If you cannot take humans into space via elevator, neither are you going to be able to lift a fusion reactor. The other problem see above, the cost of the infrastructure outweighs the benefit of infrastructure once complete. To transmit power from point A to point B requires either increasingly larger conductor (and field losses, leakage losses) or increasingly higher voltage. The PL that is being moved around is not where the power source is, either it power is on the ground or in space and you have to transmit power 100s of km (two wires) which means you are carrying conductor with payload or more likely the PL has to provide its own power. If you are going solar and you want to carry a kilogram of material into space OK so lets say you want to move the payload at 10 m/s. This would take 100,000 sec to go a million meters. So lets consider this: A solar powered PL would not be able to reach its destination in a day, it would stop, wait for sunrise, continue, stop, etc. So that 10 m/s averages out at 5 m/s. If the infrastructure is at its load limit then the transfer times are 2 days in length 180 PL/year. 10m/s is 980 watt per kg, solar panels at 1 kg/sq.meter produces optimally 400 watt per kg. So you are not going to travel 10 m/s on a tether. So lets put the ascent rate at 2 m/s we could have 190 watt per kg 19 watt for PL-carriage, 190 watt for solar panel. This gives us a transfer time to say 1000 km of 15 days.
The power required increased from $1,00 per kilogram to what . . a meter of solar panel cost $500? OK so we reuse the solar panel it needs to be removed and reinstalled in space, lets say we generously give the PL buyer 450$ credit on the cost of the panel he is still at ~55$ per PL not considering the cost of depreciation of the infrastructure. He said the PL cost is a few cents, he's only off by a factor of 1000.

He's very good at tucking very difficult problems under the rug, but they are still under the rug.

5. The very basic problem in some of these is that they were proposed by an author 50 years ago or some handwaving physicist. If the proposal does not have a credible source, its probably not credible. There are lots of people who designed space rockets for movies or books, none of them where the Saturn V.  Its the folks at JPL and NASA that made the moon landing thing, not the folks in Hollywood. None of these guys are experts in cost analysis.
 

 

 

[Guest]

55 minutes ago, PB666 said:

The guy does a fairly good job of burying the logical flaws in his arguments but over time they begin to pop out, I watched many of his videos.

Why the hell are you quoting me in particular?

55 minutes ago, PB666 said:

None of these guys are experts in cost analysis.

Of course not, they're futurists, they talk about things that could be if everything fell into place. That never happens IRL but if something is plausible then it is open to discussion.

[adsii1970]

7 minutes ago, regex said:

Why the hell are you quoting me in particular?

Because you are the all-knowing and great regex... Everyone on the forum knows this; I'm surprised you didn't!

7 minutes ago, regex said:

Of course not, they're futurists, they talk about things that could be if everything fell into place. That never happens IRL but if something is plausible then it is open to discussion.

Not only are they "futurists," but they are not there to provide the technology nor means to actually create what they use for movies. They are creating to entertain. Kinda like the movie, Galaxy Quest, where the aliens actually believed they were watching Earth history documentaries and created the ship they saw on the television show. Funny as all get out, but a great illustration and reminder that Hollywood creates dreams, visions, and desires for entertainment purposes without the thought about what is truly plausible or practical.

Unless Hollywood is creating a movie based on a famous event in history for the sake of making a movie, there is no market for a 100% accurate spaceflight movie. It would have about as much action as synchronized swimming, as much excitement as watching golf on television, with all the special effects of an international air flight.

Edited December 10, 2017 by adsii1970

[DAL59]

2 hours ago, PB666 said:

The very basic problem in some of these is that they were proposed by an author 50 years ago or some handwaving physicist. If the proposal does not have a credible source, its probably not credible.

That doesn't mean they should be ruled out.  Most of these haven't been extensively studied because of the expense.  

2 hours ago, PB666 said:

To transmit power from point A to point B requires either increasingly larger conductor (and field losses, leakage losses) or increasingly higher voltage.

Or a superconductor.  

2 hours ago, PB666 said:

the only difference is that a rocket launches  loses about 10% of its energy due to gravity effects and drag. It takes 85% of the energy used to get a rocket into GSO as a magic hand-waving space elevator

There is still a great advantage.  With a rocket, you have to build a new one every time, and it can explode, is loud, depends on good weather, ect.   

[Spaceception]

Hey, @DAL59, could you edit the title of this from "Isaic" to "Isaac"? The misspelled name is kinda bugging me.

[DAL59]

@Spaceception Done

[Spaceception]

1 minute ago, DAL59 said:

@Spaceception Done

Thanks

 

Back on topic, I can't wait for the intergalactic travel episode in a couple weeks, sci-fi research  

[DAL59]

3 minutes ago, Spaceception said:

I can't wait for the intergalactic travel episode

There are, believe it or not, proposals for intergalactic travel.

http://crowlspace.com/?p=1488

[magnemoe]

1 hour ago, adsii1970 said:

Because you are the all-knowing and great regex... Everyone on the forum knows this; I'm surprised you didn't!

Not only are they "futurists," but they are not there to provide the technology nor means to actually create what they use for movies. They are creating to entertain. Kinda like the movie, Galaxy Quest, where the aliens actually believed they were watching Earth history documentaries and created the ship they saw on the television show. Funny as all get out, but a great illustration and reminder that Hollywood creates dreams, visions, and desires for entertainment purposes without the thought about what is truly plausible or practical.

Unless Hollywood is creating a movie based on a famous event in history for the sake of making a movie, there is no market for a 100% accurate spaceflight movie. It would have about as much action as synchronized swimming, as much excitement as watching golf on television, with all the special effects of an international air flight.

None takes Hollywood seriously, worse they tend to mess up for themselves trying to simplify stuff. Matrix humans as batteries rather than processors, no processors might not work out in practice but would not bee an head-bang moment for anybody with any knowledge of basic physic, including plumbers with some experience in heat pumps. 
Don't try to explain magic just make it coherent all over Star wars 4 is the main error. 
Made more fun in the high number of man-hours who has been used to balance magic. Yes this is important in an MMO who is an billion dollar industry. 

[PB666]

On 11/25/2017 at 7:52 PM, DAL59 said:

 

It is extremely difficult to watch these videos, really, Im not making fun of the guys accents but:

He is treating non-physical concepts as if they are real physics, I can give a couple of points. I can see how people in this group are getting confused, this is a grand discussion of science-fiction and fantasy.

1. Habitation.
You cannot place habitats anywhere without paying the 'anywhere costs'. I'm not trying to be nitpicky but I reach a limit when the habitation stuff is not plausible physics or just waves off the cost.

a. Example as before - a materials strength does not afford the highest plausible spin rate, that plausibe rate does not afford engineering tolerance of payload costs in determining the height of high.
b. Example colonizing rogue planets - yes its possible, but its not a generation ship because you cannot control its destination, most of the rogue planets we will encounter are those that are and will always be tied to the Sun and very close proximity to our system, which means they will take the age of human species to reach the proximity to another system. A rogue planet is a planet in which the gas on the planet is either in frozen or liquid form. Entering such a world and colonizing it requires the payment of a huge energy cost. Rogue planets have all but zero breaking atmosphere, and where your energy is almost certainly fusion, how do you drop a 1 kt reactor onto the surface of a rogue planet???? Yes rogue planets have a huge level of resources, they might as well be in  the Polaris system. The dV required to get to a Rogue planet and the time required is beyond even the capability of roboticized fusion driven ion drive systems. ION drives canot land, which means they need to carry a lander on board.
c. Example. Any number of the rings. Seriously high  walls to hold in the gas, your spinning at 9.8 g centripedal force and you intend to build a wall 300,000 meters in height?????
d. A central cyclinder with LED lights to similate a blue sky? PLants don't need blue light, they generally like red and a trace of blue an no green, your lights are purple. Human can have place the LED screens on the windows of their houses to simulate.

2. Everything evolves some type of matter that is eitehr hard to get in space or does not exist. Carbon fiber planet sized structures . . .there is not even that much carbon on Earth. Where in the solar system do we find planet sized loads of carbon, in the middle of the sun? Nuetronium fibers? OK lets say it does exist, who would want to live in a structure made of mesostable neutrons.

3. With all the really bad physics what is the obsession with night time, you can't spend on day-night cycle before it flys apart into space and there is no nighttime.

4. Gravity is not a space occupation killer, humans may do just fine at 0.5 g, there is no reason to spin a ship to SQRT(9.8/r)  before one even things about spinning a ship at that angular velocity they should first consider the added weight for doubling gravity and the added thickness of materials.  if you are thinking about Nuetronium structures, artificial gravity should not be your major health concern. 
 

If I watch more of the videos I will only find more problems, its the reason I don't watch Star-Wars movies, all I see is bad physics modelling.