The Official Cricketweb Science Thread!

[R_Powell_fan]

No I don't think they do.... Does anyone know at least how they detect the ball only....

[Gotchya]

They use signals(light beams) to detect balls, speed guns the yare called. A measured distance (crease to creas is used and the time taken for the ball to reach it is calculated through these guns. (How much time did it take for the ball to interruppt the beams) and the speed is calculated.

Bazza you are confusing me Planck's constant ? ?

[aussie_beater]

A speed gun is based on the "Doppler Shift" principle.The device sends out an RF signal of around 10.5 Ghz and detects the beam as it comes back after getting reflected by the moving object(in this case the cricket ball).There is a shift in the frequency of the reflected signal and is called the Doppler shift which is proportional to the speed of the moving object that caused the shift.

Plain old Doppler effect....and all the police car radars etc. are all built on the same principle more or less with varying degrees of accuracy.

[Deja moo]

A raisin dropped in a glass of champagne would keep bobbing up to the surface, then sink, then bob up again, sink again and so on.

Anyone willing to explain why?

[silentstriker]

A raisin dropped in a glass of champagne would keep bobbing up to the surface, then sink, then bob up again, sink again and so on.

Anyone willing to explain why?

Yea, I know its six years old, but I couldn't resist and this thread is awesome!

They bob up and down because raisins have the type of surface which allows bubbles to form. As the bubbles form on the surface, the raisin's weight (which isn't much) is countered, causing the raisin to float up to the surface. When it reaches the surface, the bubbles dissipate, and the raisin goes back down again.

[Top_Cat]

Holy good God, I'm such a geek.

[Matteh]

Put a lightbulb in a half filled glass of milk, shove it in the microwave and it lights up.

Why?

(It's a cool trick, give it a go)

[Son Of Coco]

1) Why do so many lights on telegraph poles seem to go out when I'm near them?

2) Why do I see so many shooting stars?

3) Am I Jesus?

4) I like this thread!

[silentstriker]

Put a lightbulb in a half filled glass of milk, shove it in the microwave and it lights up.

I don't think the milk has anything to do with it, except perhaps to keep the lightbulb from exploding (I believe so it can absorb excess microwave). My guess is that its due to the simple electromagnetic emissions. If the lightbulb is has a W filament (Tungsten), it has the same frequency as the microwave, which excites the photons causing it to jump to a new orbital, and as they go down the orbital, it emits a photon.

More information for those interested.

[Top_Cat]

Why post an article on MO theory when you're talking about atomic absorption?

Bloody med students. Wouldn't know your ligands (chemical) from your ligands (biological).

The MO article was good, though.

EDIT: you're right, the milk is essentially irrelevant, just acts to mop up excess microwaves otherwise they'll bounce around inside the oven. Could be any liquid, really.

[cover drive man]

I remember my science teacher saying that nuclear energy doesn't cause any pollution but the waste it produces is very dangerous. I know that but he then went on to say that they've found some sort of bacteria which can (Apparently) deteriorate this waste. Can anyone clarify this for me?

[silentstriker]

Why post an article on MO theory when you're talking about atomic absorption?

Bloody med students. Wouldn't know your ligands (chemical) from your ligands (biological).

Oops, wrong article. And I'm not a med student, I would never demean myself by admitting so. Math > Physics > Biology any day.

[silentstriker]

I remember my science teacher saying that nuclear energy doesn't cause any pollution but the waste it produces is very dangerous. I know that but he then went on to say that they've found some sort of bacteria which can (Apparently) deteriorate this waste. Can anyone clarify this for me?

This is a very hot field right now. Some of the research I am planning to work on is similar. And yes, it might be possible in the future. I think she might be talking about this article.

[cover drive man]

This is a very hot field right now. Some of the research I am planning to work on is similar. And yes, it might be possible in the future. I think she might be talking about this article.

Interesting 230000 tons in 30 years is quite a figure though, can this bacteria accumulate this type of waste?


And by the way my science teachers a man.

[silentstriker]

Interesting 230000 tons in 30 years is quite a figure though, can this bacteria accumulate this type of waste?

Well, they've simply found the bacteria that can live there. You might be able to genetically engineer the bacteria to produce something else from the waste, or render it unharmful. But that article is talking about figuring out how the bacteria can live and store this radioactive material, and how they can make artificial technologies that can do the same (to remove the metals from the soil).

You'd still have the problem of what to do with the metals though, and for that, there is (unfortunately), very little to do at the moment except lock it up and make sure it doesn't leak. On the whole, nuclear power is still very clean and safe compared to coal and other options (not as clean as wind or hydro though obviously).