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So there's this puzzle that people enjoy thinking about regarding space travel. Say that it finally becomes possible to reach a planet of a nearby star. It's

So there's this puzzle that people enjoy thinking about regarding space travel. Say that it finally becomes possible to reach a planet of a nearby star. It's a new technology that enables it, and we can build a spaceship that will support several generations of people during the trip. Maybe it takes 500 years to get there. Well, 500 years is a long time. It's not as if our technological development will stop in the meantime. In fact, given 100 years of development, we might be able to construct a new ship that will only take 300 years to get to that planet. Which would mean it would overtake the first, and beat it by a hundred years. In which case, why build the first ship at all? That's the objection I've heard most recently against building high-speed rail in the united states. For instance, in the context of self-driving cars that might be able to organize themselves into "trains" on the road, or fit conditions where they would qualify for a higher speed limit, etc. While it may be true that we need high-speed rail now, is it going to be as true by the time they would actually get built?

lutusp 14y ago
But the argument for high-speed rail isn't that it will serve as a stopgap measure until we have self-driving cars, it is that a railroad train is vastly more efficient than any imaginable car technology. Railroad trains are very energy-efficient, compared to cars driving along a road, or even trucks driving along a road. And if we suddenly had self-driving cars, packed close together and safer than the existing system, trains would still be more efficient. The link below shows a table of transportation methods and efficiencies -- it shows railroad trains beating even motorcycles for efficiency. http://en.wikipedia.org/wiki/Energy_efficiency_in_transportation#US_Passenger_transportation http://en.wikipedia.org/wiki/Energy_efficiency_in_transporta...
- stock_toaster 14y ago
  In addition to your point, high speed rail can also carry cargo as well as passengers.
- ams6110 14y ago
  The reality is not quite that simple, you need to consider the energy required by and environmental impact of building out and maintaining a high speed rail infrastructure. Rail efficiency is also highly sensitive to occupancy, a train carrying a small number of passengers could well be less efficient than transporting that number of people by auto. And cars are getting more fuel efficient as well And if the government is involved, forget about it. It will be a massive mess of cost overruns and other financial shenanigans. And Amtrak proves that the government can't even run a railroad, let alone build one.
  - dyno12345 14y ago
    All these criticisms seem to apply equally to roads and bridges
    - snogglethorpe 14y ago
      Yup, and rail is much more durable, much less resource-intensive, and has much less of a negative effect on the environment than roads (in typical usage, a single dual-track rail line carries the same number of people as 10-20 lanes of highway)...
- newbie12 14y ago
  The table is missing railroad unions-- the anti-efficiency factor that's ruined American passenger rail.
  - krschultz 14y ago
    Amtrak makes good money where there are customers, even with the same unions. It's almost 100% the fault of politicians that won't let Amtrak shut down low passenger volume lines. If we shut down the losers and actually invested the profits from the Northeast Corridor back into that line, you would see great growth. You know, the way a company would do it.
    - uvdiv 14y ago
      If we shut down the losers and actually invested the profits from the Northeast Corridor back into that line, Yglesias wrote up this exact argument this week [1]. The Northeast Corridor profit he dug up [2] amounts to all of $136 million/year for the Northeast Corridor; a proposed upgrade is estimated at $151 billion [3]. (And the profit figure only includes operating costs -- the actually relevant figures aren't available). [1] http://www.slate.com/blogs/moneybox/2013/03/01/amtrak_profits_in_the_northeast_where_people_use_it_they_make_money.html http://www.slate.com/blogs/moneybox/2013/03/01/amtrak_profit... [2] http://www.brookings.edu/~/media/Research/Files/Reports/2013/03/01%20passenger%20rail%20puentes%20tomer/passenger%20rail%20puentes%20tomer.pdf http://www.brookings.edu/~/media/Research/Files/Reports/2013... [3] https://en.wikipedia.org/wiki/Northeast_Corridor https://en.wikipedia.org/wiki/Northeast_Corridor
- trevorstrohman 14y ago
  The Wikipedia article shows that passenger trains use about 35% less energy per passenger/mile than the average car. If fuel efficiency for cars rose to 40 mpg (less than a Prius), they'd be equivalent.
  - mark-r 14y ago
    Self-driving cars wouldn't need the jack-rabbit acceleration and deceleration characteristics that drive sales of US cars, and so would probably be more efficient even without the heroic technology of hybrids. If we ever got to the point of self-driving taxis rather than owning your own car, right-sizing would drive the efficiencies even further - if you're just commuting by yourself, call for a single-occupant tiny car rather than driving an oversized hunk of metal down the road.
rayiner 14y ago
Infrastructure technology progresses extremely slowly, in a way I think is hard for people used to the progress in computer technology to understand. Most electricity in the U.S. is still produced by coal power, in plants that usually aren't dramatically more efficient than they were a century ago. 2050 is 37 years from now. 37 years ago was 1976. Most of the transit infrastructure we use today was already built by 1976, down to the physical rail cars used on Amtrak today. On the train line I take to work every morning, they're just now replacing 1970's train cars with ones built in the 2000's. Holding infrastructure development hostage to starry-eyed visions of what we might have in the future is just foolish. The fundamental building blocks of society--power, water, transit, etc, have been pretty much unchanged since the 1960's. It's unlikely that they will do so in a dramatic way by the time HSR gets built.
- oijaf888 14y ago
  I think coal plants are vastly more efficient than they were in 1913 from improvements in materials technology, higher pressures and more efficient combustion.
  - jacquesm 14y ago
    What we can do (http://en.wikipedia.org/wiki/Aved%C3%B8re_Power_Station http://en.wikipedia.org/wiki/Aved%C3%B8re_Power_Station) vs what we do most of the time are two different things. Avedøre shows we can do 91% thermal and 49% electrical efficiency if we set our minds to it. But the fact is that most plants don't do better than 33% at both (because they're not that efficient and because they throw out all the heat).
  - rayiner 14y ago
    "Vastly" is a relative term. See: http://www.netl.doe.gov/technologies/coalpower/refshelf/role_of_coal.pdf http://www.netl.doe.gov/technologies/coalpower/refshelf/role... page 10. Focus on the chart showing tons of greenhouse gas emissions per megawatt-hour. 1913 was still in a period of rapid technological development, but the curve necks around 1930. From 1930 to 2000, GHG emissions per megawatt hour dropped from around 1.5 tons/MWh to 1.0 tons/MWh. This is what technological progress looks like. You have periods of rapid improvement followed by a plateau with extremely gradual improvements.
pm90 14y ago
There is always some amount of risk that a new technology will make all your investment worthless. The most extant example of this is the US telephone system: billions invested to have a copper wire in every home which is pretty much useless now (and appears to be a reason why US operators charge such high rates). Countries like India and many African states are bypassing this investment in infrastructure by going directly with mobile phones. Does that mean that the US should not have invested all that money? No! The system was very useful while it lasted; there was a demand which it satisfied. It made its owner ATT immensely profitable, and gave it enough legroom to start a research lab where eccentric geniuses could hack away on projects that would be so much more useful than what anyone could have ever imagined
- luser001 14y ago
  High speed Internet access whether DSL, cable, or ethernet requires "a copper wire in every home" [ok, fiber requires a glass wire, but it's still the same concept]. Why do you say copper wire is useles?
  - mark-r 14y ago
    The wires that were run for telephones aren't always appropriate for high-speed usage. When you have to design for lowest common denominator this becomes a real burden.
natermer 14y ago
High speed rail: It's like combining a buss and a plane. Except that it's going to be either slower (then a plane), more expensive (then a bus), and doesn't actually want to go were you want to go (compared to either). It's a huge step backwards. There is a reason why people stopped traveling by rail in the USA years ago. And (hint) it wasn't because of lack of government subsidies. Automobiles and busses get you were you actually want to go, were as with rail, more then likely, you have to travel a few hours to get on the train and then you have then travel a few more hours to get were you want to actually go. And beyond intermediate distances a plane is just obviously faster then either. So that leaves passenger trains purely as a nitch product. They have to fill the gap between "farther then I'd like to drive or ride a bus" and "closer then flying makes economic sense" and it still needs to be combined with: "enough people want to do this very specific route every day to fill the trains". There are only very few areas of the country were that makes sense and they are already serviced by trains perfectly fine. High speed rail is a boondoggle. It's a waste of money and resources that is much better spent on something that people actually will use. The only way high speed rail will be a success is if the Federal government managed to make travelling by plane so unpleasant that people will be willing to take sleeper cars across the country. This is extremely unlikely because the Feds are going to make train travel as unpleasant and stressful as they made the airliners.
deleted 14y ago
[deleted]
pyre 14y ago
Are these self-driving cars expected to organize themselves into 'trains' that go 220mph or am I missing something? Also, w.r.t. the spaceship, what happens if the time between the tech for spaceship #1 and the tech for spaceship #2 includes an extinction-level event? Why build spaceship #2 when we can just wait another couple hundred years and assume that obviously we will improve it even more? Why buy a new computer when it will be obsolete within a couple of months? I should just never buy a new computer and then I will never have to worry about it being obsolete!
luser001 14y ago
The fuel efficiency of a vehicle rolling on rigid steel wheels on a rigid steel track is FAR higher than that of a vehicle rolling on pneumatic tires on asphalt. The number I have seen quoted is that a train can move 1 ton 400 miles using 1 gallon of diesel.
- mark-r 14y ago
  That is an incredible number - I'd love to see a citation.
  - luser001 14y ago
    Yep. https://www.google.com/search?q=train+fuel+efficiency+400+miles+1+ton+gallon https://www.google.com/search?q=train+fuel+efficiency+400+mi... One of them: http://www.ctls.uconn.edu/do-csx-trains-really-move-1-ton-of-cargo-500-miles-on-1-gallon-of-fuel.html http://www.ctls.uconn.edu/do-csx-trains-really-move-1-ton-of...

lutusp 14y ago

But the argument for high-speed rail isn't that it will serve as a stopgap measure until we have self-driving cars, it is that a railroad train is vastly more efficient than any imaginable car technology. Railroad trains are very energy-efficient, compared to cars driving along a road, or even trucks driving along a road. And if we suddenly had self-driving cars, packed close together and safer than the existing system, trains would still be more efficient. The link below shows a table of transportation methods and efficiencies -- it shows railroad trains beating even motorcycles for efficiency. http://en.wikipedia.org/wiki/Energy_efficiency_in_transportation#US_Passenger_transportation http://en.wikipedia.org/wiki/Energy_efficiency_in_transporta...

stock_toaster 14y ago
In addition to your point, high speed rail can also carry cargo as well as passengers.
ams6110 14y ago
The reality is not quite that simple, you need to consider the energy required by and environmental impact of building out and maintaining a high speed rail infrastructure. Rail efficiency is also highly sensitive to occupancy, a train carrying a small number of passengers could well be less efficient than transporting that number of people by auto. And cars are getting more fuel efficient as well And if the government is involved, forget about it. It will be a massive mess of cost overruns and other financial shenanigans. And Amtrak proves that the government can't even run a railroad, let alone build one.
- dyno12345 14y ago
  All these criticisms seem to apply equally to roads and bridges
  - snogglethorpe 14y ago
    Yup, and rail is much more durable, much less resource-intensive, and has much less of a negative effect on the environment than roads (in typical usage, a single dual-track rail line carries the same number of people as 10-20 lanes of highway)...
newbie12 14y ago
The table is missing railroad unions-- the anti-efficiency factor that's ruined American passenger rail.
- krschultz 14y ago
  Amtrak makes good money where there are customers, even with the same unions. It's almost 100% the fault of politicians that won't let Amtrak shut down low passenger volume lines. If we shut down the losers and actually invested the profits from the Northeast Corridor back into that line, you would see great growth. You know, the way a company would do it.
  - uvdiv 14y ago
    If we shut down the losers and actually invested the profits from the Northeast Corridor back into that line, Yglesias wrote up this exact argument this week [1]. The Northeast Corridor profit he dug up [2] amounts to all of $136 million/year for the Northeast Corridor; a proposed upgrade is estimated at $151 billion [3]. (And the profit figure only includes operating costs -- the actually relevant figures aren't available). [1] http://www.slate.com/blogs/moneybox/2013/03/01/amtrak_profits_in_the_northeast_where_people_use_it_they_make_money.html http://www.slate.com/blogs/moneybox/2013/03/01/amtrak_profit... [2] http://www.brookings.edu/~/media/Research/Files/Reports/2013/03/01%20passenger%20rail%20puentes%20tomer/passenger%20rail%20puentes%20tomer.pdf http://www.brookings.edu/~/media/Research/Files/Reports/2013... [3] https://en.wikipedia.org/wiki/Northeast_Corridor https://en.wikipedia.org/wiki/Northeast_Corridor
trevorstrohman 14y ago
The Wikipedia article shows that passenger trains use about 35% less energy per passenger/mile than the average car. If fuel efficiency for cars rose to 40 mpg (less than a Prius), they'd be equivalent.
- mark-r 14y ago
  Self-driving cars wouldn't need the jack-rabbit acceleration and deceleration characteristics that drive sales of US cars, and so would probably be more efficient even without the heroic technology of hybrids. If we ever got to the point of self-driving taxis rather than owning your own car, right-sizing would drive the efficiencies even further - if you're just commuting by yourself, call for a single-occupant tiny car rather than driving an oversized hunk of metal down the road.

rayiner 14y ago

Infrastructure technology progresses extremely slowly, in a way I think is hard for people used to the progress in computer technology to understand. Most electricity in the U.S. is still produced by coal power, in plants that usually aren't dramatically more efficient than they were a century ago. 2050 is 37 years from now. 37 years ago was 1976. Most of the transit infrastructure we use today was already built by 1976, down to the physical rail cars used on Amtrak today. On the train line I take to work every morning, they're just now replacing 1970's train cars with ones built in the 2000's. Holding infrastructure development hostage to starry-eyed visions of what we might have in the future is just foolish. The fundamental building blocks of society--power, water, transit, etc, have been pretty much unchanged since the 1960's. It's unlikely that they will do so in a dramatic way by the time HSR gets built.

oijaf888 14y ago
I think coal plants are vastly more efficient than they were in 1913 from improvements in materials technology, higher pressures and more efficient combustion.
- jacquesm 14y ago
  What we can do (http://en.wikipedia.org/wiki/Aved%C3%B8re_Power_Station http://en.wikipedia.org/wiki/Aved%C3%B8re_Power_Station) vs what we do most of the time are two different things. Avedøre shows we can do 91% thermal and 49% electrical efficiency if we set our minds to it. But the fact is that most plants don't do better than 33% at both (because they're not that efficient and because they throw out all the heat).
- rayiner 14y ago
  "Vastly" is a relative term. See: http://www.netl.doe.gov/technologies/coalpower/refshelf/role_of_coal.pdf http://www.netl.doe.gov/technologies/coalpower/refshelf/role... page 10. Focus on the chart showing tons of greenhouse gas emissions per megawatt-hour. 1913 was still in a period of rapid technological development, but the curve necks around 1930. From 1930 to 2000, GHG emissions per megawatt hour dropped from around 1.5 tons/MWh to 1.0 tons/MWh. This is what technological progress looks like. You have periods of rapid improvement followed by a plateau with extremely gradual improvements.

pm90 14y ago

There is always some amount of risk that a new technology will make all your investment worthless. The most extant example of this is the US telephone system: billions invested to have a copper wire in every home which is pretty much useless now (and appears to be a reason why US operators charge such high rates). Countries like India and many African states are bypassing this investment in infrastructure by going directly with mobile phones. Does that mean that the US should not have invested all that money? No! The system was very useful while it lasted; there was a demand which it satisfied. It made its owner ATT immensely profitable, and gave it enough legroom to start a research lab where eccentric geniuses could hack away on projects that would be so much more useful than what anyone could have ever imagined

luser001 14y ago
High speed Internet access whether DSL, cable, or ethernet requires "a copper wire in every home" [ok, fiber requires a glass wire, but it's still the same concept]. Why do you say copper wire is useles?
- mark-r 14y ago
  The wires that were run for telephones aren't always appropriate for high-speed usage. When you have to design for lowest common denominator this becomes a real burden.

natermer 14y ago

High speed rail: It's like combining a buss and a plane. Except that it's going to be either slower (then a plane), more expensive (then a bus), and doesn't actually want to go were you want to go (compared to either). It's a huge step backwards. There is a reason why people stopped traveling by rail in the USA years ago. And (hint) it wasn't because of lack of government subsidies. Automobiles and busses get you were you actually want to go, were as with rail, more then likely, you have to travel a few hours to get on the train and then you have then travel a few more hours to get were you want to actually go. And beyond intermediate distances a plane is just obviously faster then either. So that leaves passenger trains purely as a nitch product. They have to fill the gap between "farther then I'd like to drive or ride a bus" and "closer then flying makes economic sense" and it still needs to be combined with: "enough people want to do this very specific route every day to fill the trains". There are only very few areas of the country were that makes sense and they are already serviced by trains perfectly fine. High speed rail is a boondoggle. It's a waste of money and resources that is much better spent on something that people actually will use. The only way high speed rail will be a success is if the Federal government managed to make travelling by plane so unpleasant that people will be willing to take sleeper cars across the country. This is extremely unlikely because the Feds are going to make train travel as unpleasant and stressful as they made the airliners.

deleted 14y ago

[deleted]

pyre 14y ago

Are these self-driving cars expected to organize themselves into 'trains' that go 220mph or am I missing something? Also, w.r.t. the spaceship, what happens if the time between the tech for spaceship #1 and the tech for spaceship #2 includes an extinction-level event? Why build spaceship #2 when we can just wait another couple hundred years and assume that obviously we will improve it even more? Why buy a new computer when it will be obsolete within a couple of months? I should just never buy a new computer and then I will never have to worry about it being obsolete!

luser001 14y ago

The fuel efficiency of a vehicle rolling on rigid steel wheels on a rigid steel track is FAR higher than that of a vehicle rolling on pneumatic tires on asphalt. The number I have seen quoted is that a train can move 1 ton 400 miles using 1 gallon of diesel.

mark-r 14y ago
That is an incredible number - I'd love to see a citation.
- luser001 14y ago
  Yep. https://www.google.com/search?q=train+fuel+efficiency+400+miles+1+ton+gallon https://www.google.com/search?q=train+fuel+efficiency+400+mi... One of them: http://www.ctls.uconn.edu/do-csx-trains-really-move-1-ton-of-cargo-500-miles-on-1-gallon-of-fuel.html http://www.ctls.uconn.edu/do-csx-trains-really-move-1-ton-of...