[evan_au (OP)]

Looking back at the 20th Century, we deployed several near-universal networks (at least in suburban areas of Western Countries):

• Electricity to every home
  
• Running water to every home
  
• Telephone to every home
  
• Tarred roads to every home
  
• Mobile phone coverage to every home

These were all massive infrastructure projects. What do you think will be the new networks that get deployed in the 21st Century?

Some suggestions:

• Optical fiber to every home
  
• The DNA network mapped out between every individual and every family
  
• Interplanetary Internet?
• Any Suggestions?

[CliffordK]

• Interplanetary Internet?

Doesn't that imply that we will first have interplanetary communities?

Fiber to every house sounds like a reasonable goal.  However, it is quite possible that it would become obsolete as soon as it is rolled out.  I think the big thing that will happen over the next decade or two will be the merging of cell phones and data networks, so high performance wireless networking may be the future (it is already coming).  Then, of course, filling in dead spots. 

Depending on the cell network, the last time I was traveling, I hit some "dead spots" including half of Kansas, and most of Arizona and New Mexico.  Also a big chunk of Nebraska and most of Wyoming.

The bandwidth on your cable TV system is extraordinary, essentially giving one full bandwidth HDTV downloads of 100+ TV shows simultaneously.  However, what is only beginning to come out is adequate upstream bandwidth to allow each individual to download whatever show they want in full HDTV whenever they want it (part of this is already coming with better caching and delay systems, but that all means prior planning for the end users).

CRT's are rapidly being replaced, at least in the TV world for HDTVs.  3DTV is already being rolled out, and I have no doubt that 1080p will be surpassed in mainstream TV by the end of this decade.

As far as anything totally revolutionary?
I have no doubt there will be a big push for solar hot water, and distributed solar electric systems.  Electric cars?
Half of the houses in the USA have Natural Gas (in many cases, it replaced previous coal systems).  Will the next step be a hydrogen distribution system?

Will the Concorde be back?  Suborbital space hops?  No doubt, though, the typical subsonic jets will continue to be mainstream travel.

Why does the Pan American Highway stop in Columbia?
When will the Gibraltar Bridge (or tunnel) be built?

[syhprum]

When will the Gibraltar bridge be built ? when there is enough potential traffic to justify it I guess we don't even have a bridge yet from the UK to the mainland we have to put our cars on a train thru a tunnel, we are put to shame by the Swedes.
I was in Indianapolis last month and was surprised to find my host had a 50mb internet link.
As for Concorde I don't think we will see its like again a supersonic bomber made obsolete by ICBM,s disguised as a passenger plane.     

[CliffordK]

The last time I was in the UK, we took a hovercraft across the channel.  At least in theory, the tunnel is a step up from that...

There is a Spaceport being built in New Mexico in the USA, and perhaps another in planning in Sweden.  The idea of space tourism sounds pretty outrageous, but a suborbital space flight might be the quickest way to hop between continents, and could potentially replace the Concorde, at least for those individuals willing to spend outrageous sums of money to travel.

[evan_au (OP)]

Two other networks that appeared in the 20th Century:
- Airline network (the first succesful powered flight was 1903)
- TV networks: Broadcast/Cable/Satellite (first scheduled TV broadcasts around 1929?)

For the 21st Century:
- Getting large numbers of different computers to cooperate on a common task (first seen in SETI @ home?)
- Getting the human brain wired into the computer network?
- Self-driving cars/taxis/buses/trucks/aeroplanes? (There were a few self-driving trains in the 20th century, but a train line is a much more controlled environment than these more flexible pathways.)

[alancalverd]

I think we are going to have to revive and extend an old network. The decline of fossil-fuelled power stations and the slow return on capital investment of nuclear electricity generation means that for the UK at least we will see an increase in wind power. Problem is that you can't store electricity economically, so we will have to find some other means of storing energy until it is needed, and distributing it.

My money is (or would be, if I had any) on extending the gas grid and fuelling it with "Brown's gas" - 2H₂  + O₂ obtained by AC electrolysis of water. Since the original "town gas" grid coped with a substantial proportion of hydrogen, I don't foresee any particular problems of storage (remember the inflatable gasholders? quintessential part of the townscape!) and distribution, and unlike coal gas or methane, it has no noxious combustion products and doesn't vitiate the air if burned in a confined space. I remember the UK gas conversion program of the 1960's as one of the success stories of a nationalised industry: all the burners in the country were re-jetted in a very smooth operation as each district switched from town gas to natural gas. Conversion to Brown's gas should be simpler and will give us an indefnitely sustainable supply of instantaneous energy.   

[evan_au (OP)]

It is probably very practical to distribute H₂ via pipes, provided you sealed them quite well (H₂ diffuses quite quickly through small holes).

However, I think it very unwise to distribute a mixture of "2H₂  + O₂", as this is a highly explosive mixture (or would be, if it mixed well). A flame anywhere in the system would blow up every house attached to the network, and every road that it passed under!

It would also mean that in the morning, the house at the top of the hill would get almost pure H₂, while the house at the bottom of the hill would get almost pure O₂. Neither would cook very well if the burners were optimised for 2H₂  + O₂.

I think it's much safer to pipe the H₂ around town, and release the O₂ into the atmosphere (or use it for industrial processes like steel refining). Each home can then mix in O₂ from the atmosphere.

[CliffordK]

Perhaps there will be greater effort to recycle carbon dioxide.

Assuming we continue using fossil fuel burning generators, the carbon dioxide could be captured, and shipped to greenhouses.  Will we ever make algae or similar based fuel?  There have also been ideas about sequestering automotive CO₂, although I find it unlikely.

Where does the soda industry get its CO₂?

[evan_au (OP)]

In the 20th Century, a network of petrol/gasoline stations grew up to fuel the increasing fleet of motor vehicles, plus a network of repair shops and spare parts distribution.

Perhaps in the 21st Centrury we will need a network of electric car recharging stations, able to match the MegaWatts that can be delivered through the hose at our local petrol/gas station?

[syhprum]

I think the energy value of fuel should be more properly measured in Mega Joules rather than Mega Watts.

[syhprum]

I think there is a market for buying and selling CO2 but of course problems can arise as to its purity and how easily it is captured and even in Jewish and Moslem communities whether it is kosher.

[imatfaal]

I think the energy value of fuel should be more properly measured in Mega Joules rather than Mega Watts.

Agree - but the delivery of energy (which was Evan's comment) must surely be measured in joules per second aka Watts

[evan_au (OP)]

I think the delivery of energy to a vehicle could also be measured in "coffee cups" or "bathroom stops".

Filling a car's Petrol/Gasoline tank = 1 bathroom stop, or slightly less than 1 coffee cup.

With today's electric car charging points, recharging takes many cups of coffee and several bathroom stops, even though the total number of MegaJoules may be the same.

The difference is that the petrol pump can deliver these MegaJoules very quickly through the hose, while an electric recharger delivers these MegaJoules relatively slowly (too slowly?).

MegaJoules per second = MegaWatts (and this is better aligned with the metric system than coffee cups & bathroom stops).

[syhprum]

I guess you could talk about gas flowing out of the pump at a rate of so many litres per second as a flow of energy measured in Watts but when it gets into the fuel tank and stops flowing presumably Joules is the correct designation.
I have always thought that when you stop on the highway the last thing you want is a diuretic such as coffee refreshing as it may be.