1

Physics, Astronomy & Cosmology / Why is a hot shiny surface such a poor emitter of infra red

« on: 06/11/2009 18:19:26 »

The cup will never be warmer than the kettle at best they'll equalise and the kettle is being warmed by electricity so it's entirely losing heat and no perpetual motion to worry about.

The shiny surface also has a lower surface area than a scratched surface so it loses less heat.

2

Technology / Re: Could we make better fuels for Formula 1?

« on: 28/09/2009 23:46:04 »

Liquid Oxygen would be the best fuel and it's clean by product being water.

Producing the Liquid Oxygen and super cooling it in the first place likely takes a lot of energy ruining the green part.

3

Physics, Astronomy & Cosmology / Why does a gas get colder when it expands?

« on: 28/09/2009 23:43:15 »

Because the Heat Energy which was contained in the gas is spread over a larger area so less heat energy at any point.

Also with can's of compressed gas ( deodorant say ) when you compress the gas into the can,  the can heats up and then losses that heat,  so the gas comes out at room temperature and then expands as above.

4

Physics, Astronomy & Cosmology / Why wouldn't this perpetual motion machine work?

« on: 28/09/2009 23:37:16 »

It will slow down and stop eventually likely on it's side.


It's simply not possible to do.

5

Physics, Astronomy & Cosmology / Re: Does Space go on forever with no end?

« on: 28/09/2009 23:33:33 »

Thats an example of curved space which is just a theory,  I'd personally think it goes on forever,  but the human race will likely never know for sure!!

6

Physics, Astronomy & Cosmology / What would happen if earth was knocked off its orbital path?

« on: 28/09/2009 23:28:53 »

Speed up the earth then it'll orbit in a ever increasing circle before going out to deep space.

Slow it down and it'll orbit in a ever increasing circle before plunging into the sun,  or as near as you can get.

It's also possible we'd just move into a different orbit,  odds on a collision are ofcourse low with other planets the solar system is huge and after all,  but it could put us into the path of some large asteriods.


Option 1 means we'd all freeze to death!!

7

New Theories / 2012 meteor to destroy the earth?

« on: 18/09/2009 01:07:34 »

So if it hits a 1tonne MAX Sattelite this 200Bil Tonne object is going to have it's orbit altered enough to make it hit earth on it's next pass,  hmmmmmmmmmmmmm  nope I don't think it'll care in the slightest.

And 320metres wide and 200Bil Tonnes yeah okay.

I think we can consider the news article to be hugely bogus!!

8

New Theories / 2012 meteor to destroy the earth?

« on: 18/09/2009 01:01:17 »

No it's all true,  the world will end on Dec 12th 2012 and this is the real reason why!!

1.   I'm 41, 2days later thats just sad.
2.   I can't take another xmas.

So I'm going to hack into Norad ( not hard Bush's password is in effect still  "1234" shhhhhh ) and launch all of the nukes!!

Anything is better than suffering another Xmas so here is hoping


* yes it's totally ridiculous *

9

Geek Speak / XP Install Problem With Hard Disk Space

« on: 15/09/2009 01:22:19 »

Right click My Computer  then Go Manage,  then find the Hard Disk setups right click on D and Format it or resize it or what ever.

10

Chemistry / Can we "run out" of radioative materials?

« on: 15/09/2009 01:13:38 »

From my understanding there rare and getting rarer,  new reactors use them a lot more efficently though as there is no need to enrich the material for weapons these days.


There is a abundancy of Helium 3 they think on the moon though,  thats why the new interest in it,  bringing that back to earth would power everyone for 100,000years I heard,  this could be mainly speculation though.

11

Physics, Astronomy & Cosmology / Why do bicycles have such big wheels?

« on: 06/09/2009 23:40:33 »

As a Mountain Biker who's messed with wheel sizes and has been running a 29" wheel on the front of a standard normal 26" wheel for 2years,  I can safely say the main advantage is it takes longer from contact to highest spot therefore the peak bump force is lower,  therefore they ride smoother over rough ground which makes them more efficent as they stall less,  which leads to going over the bars and pain and maybe even a broken kneck!!

There is a slight drop in rolling resistance,  the foot print becomes slightly longer but narrorow and the narrower part helps in short,  for the same air pressure though the overall size is unchanged.

12

Physics, Astronomy & Cosmology / Is cold fusion possible?

« on: 31/08/2009 23:45:38 »

I say not possible in our life times.

13

Physics, Astronomy & Cosmology / Is cold fusion possible?

« on: 31/08/2009 23:44:02 »

I know someones who's working on the fusion reactor ITER near Oxford,  just a engineer tech guy,  but the problems are huge,  they've got the plasma stable kinda for milliseconds then they need to do major work on it repair wise any more than that and they've still got no way to get power out of it other than the use the heat it generated to create steam so best hitech stuff we've got connected to a 100+ year old steam engine,  laughable really.

They reckon 40 years before they achieve it but they've been saying 40 years for quite some years already.

I think the yanks have a bigger 1 being tested.

14

Physics, Astronomy & Cosmology / The Big Bang and the "Horizon Problem"

« on: 31/08/2009 20:32:31 »

Well the answers are :-

1.  We are smack bang in the middle of the universe.
2.  There is something we dont' understand about photon's and billions of years.

I suspect 2,  I also expect in time the Big Bang theory won't hold any water at all and we'll never understand this.

I also expect the universe is much much much bigger than we thing.


Big Bang is based on way to many what if's for my liking,  we don't understand things on the earth so even thinking we understand the universe is well madness to me.

15

Physics, Astronomy & Cosmology / Why does a gas cool as it expands?

« on: 31/08/2009 20:29:54 »

It cools when you compress it,  as there is the same heat in a smaller area if you felt a can / oxygen cylinder when it's being compressed it's warm / hot,  so when it leaves it's lost the temperature already.

If you put your can in the oven and heat it to 100c most likely all through then the gas should come out near room temperatue.


Don't try this the can will explode

16

Physics, Astronomy & Cosmology / Why does a gas cool as it expands?

« on: 31/08/2009 00:15:04 »

Nice,  when you compress the gas,  the heat energy compresses which creates heat,  which is then lost as this will resume to room temperature,  so when you release the gas your releasing gas with less heat nice.

Never considered that before.

I like science.

17

Technology / What is holding back electric car technology?

« on: 27/08/2009 12:25:18 »

Teleportation would be great,  off to visit a mate 5000 miles away,  back in 10mins,  Zap!!!

On holiday,  get a call out zap to the client fix the issue and zap back to 5000miles away / the moon

18

Technology / What is holding back electric car technology?

« on: 27/08/2009 12:22:33 »

New battery Tech out in a few years,  promising 10x's the energy density and fast recharge times,  like 5mins to a 80% charge,  making refueling at a petrol station actually possible.

The Volt claims 10p electricity to do 40miles,  better than £4 so thinking all in taking into account petrol transport costs,  making it, bla bla bla bla bla your still using less energy over all with a electric car.

The chemicals required to make these batterys are expensive and wasteful though.

Might be better off,  driving a electric motor at home to pressurise a air canister,  which would also open up petrol stations being able to re pressurise your tank in a reasonible period of time.

19

Physics, Astronomy & Cosmology / Are generators and electric motors the same?

« on: 27/08/2009 12:16:13 »

I think you'd have to spin in reverse or it might just be a input that makes it work,  but yes basically.

Why Hybrid cars can re generate using there electric motor as a brake.

20

Geek Speak / How do touch-screen computers work?

« on: 27/08/2009 12:14:20 »

I thought the I-Phone has CCD's like in your camera underneath the screen,  but working on a thermal wave length so when you touch the glass they see the heat from your finger,  why you can't use stylus's.