Being the heaviest living organism on the planet (that doesn't photosynthesise or isn't a ridiculously big fungi) , baring in mind that it lives in water, what's the fastest a Blue whale has been recorded swimming? being a huge lump of a mammal, it has probably never felt the need to out run anything or take on random spurts of speed to leap on krill, nor is it built to race...much at all...except krill..and maybe other blue whales for a mate. but theoretically how fast could a Blue Whale be if it let it's metaphorical hair down? Thomas Frost, Suffolk, UK

If you sink an object and then let go then it accelerates upwards. What if I sank something a very long way (say a mile or so)?

I've read in New Scientist about the potential of using supercavitation to travel very fast through water.

So what’s to stop me attaching a lightweight projectile onto a big rock with a piece of string which will detach at a certain depth, dropping it off a boat and firing something into space?

I garden under the flight path to Bristol airport and listen to the radio. I,ve tried to use a wind up radio but every time a plane flies over the battery drains instantly and i need to wind it up again. Considering a plane comes over every 5 minutes it's impossible to use one. Why does this happen?

Tsunamis move fast, and tow-in surfers use various vehicles to catch large waves. A friend has a son who wants to ride a 100-foot wave. Is this possible? How big of a wave could an unassisted surfer catch?

Some engines can operate at higher temperatures/pressures than the human body. On the other hand, vehicles have extra weight, possibly have different drag characteristics, etc. For "normal" speeds and loads, what would be the properties of a vehicle at a crossover point equal to the efficiency of an average human?

Theoretically, if Santa Claus delivered one parcel to every household globally, using current conventional methods of transportation, how long would it take him?

On a long haul flight I wondered with the amount of people who now fly, and the amount of money airlines make, surely one that was as big as an Airbus yet as fast as a concorde would certainly dominate the market in which people want to use.

I am not only concerned with cost as I am sure they would make the money back, but is it possible to make such a big plane fly so fast? 

In the early days of motor vehicles they took more time to put in gear and get moving, and even longer to stop, so an intermediate light warning you that one or other action would soon be needed made sense, but not nowadays.

Having two-light signals, with a longer interval where both directions show red, would surely be a lot cheaper to build, programme and maintain.

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?

As a passenger in a car the other day, I noticed the extreme frustration that our slow acceleration after takeoff from traffic lights caused other drivers.  In a ten minute journey, I counted no less than 6 instances where cars overtook us, using extreme acceleration and braking to do so.  The driver's defence for the slow acceleration was that it is 'economical'.  My question is: is it, when the fuel consumption of all drivers concerned is considered?  For those who know their physics and maths, how many irritated drivers accelerating around a slow driver, or flooring it to get through traffic lights because the car in front of them took forever to get going, would it take to counteract the fuel conservation effect of driving economically?