Cant it be done by analysing the video of these players bowling?
Speed=distance the ball travelled from bowlers hand to the landing(or to the bat?) / time taken.
Sure it can be done by special softwares, modern equipment?
Atleast it will be possible in near future?

Do you know how the technology works today for monitoring speed?

As far as im aware the speed that is recorded is the speed of the ball when its released from the bowlers hand.

We would never know the speed of the ball when it has reached the batsmen.

Speed guns work by radar system just as the traffic use for speeding vehicles.
Simply, the gun throws the wave towards the moving ball, it has initial frequency, f.
But when the same wave is reflected back the f changes because if the ball is moving away(ie if measured from nonstriker end), the reflected f will take longer to arrive, ie f decreses and the change in f is used to calculate the v, ie velocity as in v=frequency*wavelength(ie fixed).
.
To simplify further, imagine a ambulance with siren.when it is coming toward you the siren increases and when it goes away from you the siren sound declines.
Such change in frequency is detected by the radar and it calculates the speed.
Have I made myself clear?

However with the advent of modern equipment like Hotspot, the velocity can be calculated simply by v=distance/time formula, but still think, the traditional radar system is more accurate since the variable in that system is change in frequency,whereas in Hotspot system its both distance as well as more importantly time of which a very slight miscalculation cause a great deviation in final velocity measure.

Did some digging and cricketinfo says this; Point to note is that it uses microwave technology.

How does it work?

The speed gun is mounted on a pole and positioned next to the sight-screen. The device relays a beam from a radar head, which detects movement across the entire length of the pitch. A small pipe is used to aim the beam accurately. The whole process runs on microwave technology.

Does wind speed have an impact on the calculations?

The wind speed has no bearing on the speed gun, since the microwaves are a very strong force that can penetrate all weather conditions.

The margin of error is less than 1kph, and if the device is set up correctly, there should be no variation in speeds between geographical regions.

Is the technology the same as that used in other sports?

Yes. Tennis was the first sport to adopt the speed gun. The parameters of the software used were changed to have it apply to cricket.

The software is the most important part of the speed gun. It interrogates the speeds coming through via the radar, processes the data, and then calculates the final speed.

There are only three manufactures of the hardware, and about five companies that own the proprietary software in the world today.

Thommo would have smashed them all for speed.

It's a wonder Thommo didn't seriously injure someone what with uncovered wickets and no helmets.

Just speculating without fact is one thing and being measured and tested is quite another.
You would say Ryan Harris is way quickerrr than Chris woakes the last ashes test(same test mind).
There's more to the Speed of a cricket ball than meets the eye.
There is lot of Optical illusion involved you know.
Who knows Jeff could be a mere 82 mph bowler,or may be not.
Of all the bowlers i've looked at without checking the meter,Shoib akhtar is the quickest, exagerrated by his marathon run up and his hair flying back as if he was riding a motorbike in a highway without helmet.

and to add to that, there is no way bowlers of 70s and 80s are quicker than bowlers of now. Just look at how much facilities they get. All bowlers have good physios, technologies, gym and so many body conditioning equipments around. It would be stupid to say bowlers back then were quicker then bowlers now.

Akhtar and Lee were probably the last of the super quicks that bowled spells above 95mph. Unfortunately both suffered injuries throughout there career due to them putting there body on the line. Bowling coaches now won't allow bowlers to bowl like this which is a shame because there is nothing more exciting in cricket than seeing a quick bowler steaming in.

Mitchell Johnson looked dam quick yesterday. One delivery nearly blew the keeper back to the boundary.

Kharse/Viru - Agree with both your comments. Personally i think Thommo was very quick looking at Video footage. Still think Aktar in his pomp was quick so was Waqar Younis and Lee.

Wasnt a long time ago Tino Best / Edwards were both bowling 90 - 95 mph at the England openers. Well that's if the speed guns are to be trusted.

Another thing i have never quite worked out is what makes a Fast, Fast Medium, Medium Fast, Medium bowler. Any guesses.

Bumble keeps banging on about speed saying that 80mph wasn't quick enough for international cricket then Broad/Anderson/Bresnan were all bowling around 80mph for England. Admittedly of late they have all gained a yard of pace so it may have have been a David Saker tactic.

Older people talk about Frank Tyson bowling faster in the 50's than any man in history before or since. The ability to bowl fast at say 90 MPH is something you are born with. I am not sure if training and diet would add an awful lot to your speed. It may mean you could sustain it for longer however.

You can estimate the speeds by watching video as we know the distance the ball has travelled and we can time it. We can calculate the average speed and then extrapolate to the point at which the ball leaves the bowler's hand.

Av. speed = distance / time
The distance will be the hypotenuse of the crease length and the bowler's arm height (assuming 8ft)
Av. speed = 17.84 metres from crease to crease ie the bolwer's hand to the batsman / time taken

I have done some rough estimates from Youtube and Sir Richard Hadlee bowled at an average of 85.51mph based on three balls to Ian Botham

Link: http://www.youtube.com/watch?v=3HR7EGbzV3Y

Michael Holding bowled at an average of 102.33mph based on two balls to Ian Botham

Link: http://www.youtube.com/watch?v=1aHSarzMLb4

Ian Botham bowled at an average of 95.02mph based on three balls to Australian batsmen

Link: http://www.youtube.com/watch?v=CNUIsMNxGpM

If the radar readings are taken from the ball leaving the hand, then we should increase the speed that I have given as the ball will decelerate due to friction

Therefore, assuming the video is played at the correct speed, from these figures, it would seem the bowlers of yesteryear did bowl at similar speeds. Whether they could keep up the speeds or if these few balls are typical of their bowling, that is the question but they look fast enough to me.

You can see in this video of Michael Holding to Geoff Boycott that Geoffrey barely has time to react and so it wouldn't surprise me if it was over 100mph.

http://www.telegraph.co.uk/sport/cricket/international/england/4864184/Action-replay-Michael-Holding-bowls-fastest-ever-over-to-Geoffrey-Boycott.html

Good work son - how are you recording the time it has taken for the ball to go crease to crease?

Just on optical them West Indies bowlers were quicker than a lot of what we see today. Had a quick browse for Patrick Pattterson. He was brutal. Apparently it was down to holding & patterson who was the quickest.

Botham was never a 95mph bowler. They called him beef for a reason