I just re-watched a show called 'megstructures' where they featured a rollercoster called kingda ka that reached over 200kph in 3.5 seconds and is also the tallest in the world. 

If we put cost aside, and only focus on a) human ability to withstand ride and b) the ability of the physical structure to withstand.  could we potentially see roller costers the height of buildings going at yet unseen speeds and heights?

i understand how some trained people can withstand g forces like fighter pilots.  But keep in mind rides need to be for general public.

We vote on online polls everyday.  For just about anything.  Sometimes people vote online or do surveys out of pure boredom.

Why don't we vote online using PC's and phones etc for issues such as war or laws?

Before you say it is unfair that not everyone can vote, not everyone votes in the first place. 

I ask this because it took thousands of years to develop the most simple tools, machines once lasted hundreds of years then decades, and now it seems like my phone is out of date every month.

will we have everything, or will it be things are out of date every day, or will the growth reach a peak and stop at some point?

I'm researching this for my company, in the name of 'green IT'.  Is there a tipping point?  A number of copies at which it becomes better to use one of the methods? 

Why is it that meteo radars don't detect low clouds like fog. Are they just looking up to avoid distractions or is there something in the fog that makes it invisible?

I had a thought that it would make for a spectacular image at a festival where you have thousands of phones transmitting and receiving thousands of texts and calls.

I remember there was a lot of debate about the information about the Earth and the human race carried by the Pioneer/Voyager spacecraft becoming an invitation to invade by hostile aliens.

We consider ourselves an advanced/space-faring civilization but if a similar spacecraft from another civilization was to pass say between the Earth and the Sun (a) would it be detected? and (b) Could we capture it? I imagine that stopping a Kombi van sized object travelling at + 10 km/s without damaging it would be difficult. Also, the time between detection and being able to mount a capture mission would probably be impossibly short.

I remember reading a SF book in the 1960s which included a means of weather control. The theory given was that in an arid region, a length of tough flexible plastic tube was prepared. One end of the tube was anchored down, allowing a flow of air to enter the base, and then air was pumped into the end anchored. The tube was inflated and gradually stood up with the column of air extending the vertical tube. At a critical height the warmer air at the base of the column would begin to be sucked in to replace the cooler air rising to the top. The pump could be switched off and when fully extended at a predetermined height column of cooler air at the top would condense into clouds and result in rain. This would be self sustaining with the cool air being drawn in at the base and escaping at the top. The technology and materials were obviously not available when the book was published,  but is this still true today?

Time has not been around forever. Most scientists believe it was created along with the rest of the universe in the Big Bang, 13.7 billion years ago.

Some physicists like Michael Berry, Thomas Gold, and Steven Hawking have also proposed that time may reverse when the universe begins to contract. Using this as our base grounds, could we go into future or fast forward the time if we could somehow increase the expansion rate of the universe?