92 posts • joined Wednesday 27th August 2008 13:49 GMT
Re: education issue.
There is a related problem with the disposal of radioactive waste. Ie what warning message do you put on the site?
After all putting a great big warning message on a highly secure box/storage facility will just make some people think "I wonder what is really in there that they are so keen to hide?"
Shortly followed by "Ooh thats a pretty light"
Re: Radio Silence in Cars ?
I did in fact mean 200kbps and 64kbps, 64 bps would be really really dire
Re: Radio Silence in Cars ?
That will be because the sound quality of FM IS better than DAB. Most of the DAB stations transmit as cr**py sub 200bps digital, radio 5 live is sometime 64bps and it sure sounds like it too.
I have a DAB radio alarm clock and it is forever losing the signal, I wish it had an FM option...
Re: Great expectations...
TBH At the moment with my class I am getting them to use a PICAXE to monitor light gates and record the data etc. The next project is to control the flight computer for a water rocket.
I like the PICAXE the is a lot if "8bitness" to it.
10 Pin 1 Low
20 wait 1
30 pin 1 High
40 wait 1
50 goto 10
Oooh look the LED in Pin 1 flashes.
Besides they really are cheap the 08's are only £1.50 plus a battery and a bit of bread board to start.
Re: @ James Micallef
I don't think that is quite right. If the video/images is taken by and of persons in a relationship and is not shared with others I think it is legal. What happens when the relationship ends I am not sure. A bleeding stupid law IMHO the age of consent and the age limit for child pron should be the same IMHO.
Re: Mixed signals regarding privacy
Assume all you like it is not the case in the uk.
The age of consent here is 16, yet child pron is images of those who are or under 18. Go figure.
Half a minute will do little ot nothing, far too short a time.
With Hale Bopp if you were in a dark place and got dark adjusted ie at least an HOUR without any extraneous light (no lighting up, no looking at your phone etc) then you could really see it, and the tail extended across almost half the sky.....
(I was out taking photos of Hale Bopp one night and my eyes became so dark adjusted that I could see the lights from planes at cruising altitude on the ground, your eyes really are amazing)
Re: The media always hype this stuff
"Same goes for all the other ones since Hailey"
Hmmm, if I remember correctly Halley's comet was a bit of a damp squib.
However Hale Bopp in 1995/96 was a different story. As Wikipedia says Hale Bopp "was visible to the naked eye for a record 18 months, twice as long as the previous record holder, the Great Comet of 1811." I remember spending many a long night taking pictures of that one, get your eyes dark adjusted and it nearly spanned the entire sky. Pretty and pretty damned impressive.
Re: Is that thing SAFE?
Whilst in many ways I agree with your I cannot help but point out that the ISS was proposed long after the SS was designed and built.
"it is better to kill 100 innocent people than let one guilty person live" Vladimir Lenin
Re: Moons gravity to slow down?
Nope still does not make sense to me.
If you are getting closer you are essentialy failling (even if only slightly tangentially) and so will be increasing your speed.
Now I can quite understand how you can speed up or slow down by not going into orbit as you pass by an celestial body (ie the slingshot) but not how you can approach a body and slow down whilst at the same time going into orbit.
Moons gravity to slow down?
"The spacecraft will use the Moon's gravity to slow down, orbit the satellite, and then soft-land using rocket propulsion."
How does that work then? I was under the impression that you would speed up when approaching a gravity "well".
Re: For those complaining about things not working on Linux..
I am pretty sure that Lovefilm or Netflix is not available in the Popcornhour.
Would you need to get rid of the Humax can you not just leave it plugged into the Internet for CatchUp TV (iPlayer etc) for which I believe you do not need a license.
One problem with interlaced is when a moving image is displayed on a large screen the difference between the images becomes visible as a herringbone pattern around the edges of the moving object.
At university we had a version that played on a dot matrix printer. A page of print out per screen/frame. Timing your shots was really quite difficult
(Yes it was incredibly wasteful of paper.)
Re: Parking lots are full of things!
"can of real ale"
"Because it is, at least as far as false or unproven allegations are concerned."
Where does that leave the police announcing the name of someone being arrested/charged (and the nature of the alleged offence of course) or papers reporting on the same?
After all they are allegations and are by definition unproven.
Re: Your science is rubbish
Apart from anything in low Earth orbit the weight of something is near as dammit the same as here on the surface of the Earth.
Re: I must admit
If only they were large steel tubes, more a series of steel rings connected together by dodgy joints into what resembles a steel tube.
There was a video of the british Blue Streak rocket (liquid fueled) on TV (British Space Race?) and it showed that the skin on the blue streak was literally paper thin, unless pressurised it could not support its own weight...
Re: I've often wondered why this wasn't tried before. It seems such an obvious thing to do.
No not 2x bigger not even close. Much much much bigger.
The cost of fuel, as you point out, is not the problem it is the cost of a vastly bigger rocket that would be required that is the problem.
IIRC the Apollo capsule had a mass of about 5.5 tonnes and the Saturn 5 had a mass of about 3500 tonnes. Doubling the mass of the capsule would NOT mean adding a few tonnes of fuel but making the whole rocket vastly bigger.
More fuel means you need a bigger rocket which has a bigger mass so you need more fuel which mean you need a bigger rocket which means you need more thrust and more fuel so you need a bigger rocket and bigger engines, repeat etc etc. Carrying enough fuel/rocket up so that you can use it to come back down seems a non starter to me.
Re: Imagine being able to see one whole side of the Earth without having to change orbit!
The Wiki article says it can see the whole of the sunlit side of the Earth all the time,
So if you want to beat the USAF early warning system that you describe then it might be an idea to launch your attack at night.......
Why is this a USAF project?
Re: As a post op...
I think that he is making a valid point.
If you went into a computer suite with 30 already wired in computers it would take ages to get the pupis to unplug the keyboards mice etc, (even if they could as most keyboards/mice etc are locked to the cases to prevent theft) find a plug socket for the PSU etc. Ecen then a fairly high proportion of the class would have forgotten their SD card etc etc.
The idea of getting thirty pupils to put the PC,s back together at the then of the lesson in a state where the PCs will just boot in anything less that 10 - 15 minutes is a laugh. If my school is anything to go by you the teacher have to check each pc individually and sign that they are working OK before leaving the classroom.
Overall this would take half the lesson or more.
If you are thinking that the school would dedicate a room with 30x RPi all set up ready to go then I think this would be a very rare school indeed, they just do not have the room for something that will be used once in a while.
Re: Doing it Old school
"the benefits of the hi tech trend is there are undeniable trails left behind. Use them!"
There is a danger there that if those doing the tracing are credulous then miscarriages can occur.
See Operation Ore
It is not just in space
I remember doing some work on the then state of the art Seawolf missile system (about 1986)
Although our experimental kit used the wonders of, IIRC, a Z80 cpu the ships Seawolf computers were some huge Ferranti(?) size of a room computers fore and aft. They used core memory and the programme was loaded from paper tape which did not seem to work very well as it took hours to get it working.
The final bit of tape to be loaded was taped to the side of a filing cabinet and I was told it was this that informed the launcher were the various bits of superstructure were on this particular ship, without this bit the launcher could launch into masts etc....
I was gobsmacked.
"You never know when you might need that 20m CAT5 ethernet cable. Or that 3m SCART."
Of course you do it will be within a week of throwing them away.
Re: Makes me sad
Be fair and give credit where credit is due. The HTP technology that we used to launch our only satellite was a development of the technology we picked up from the Germans after WWII. So it wasnt entirely our own efforts.
Re: "rapists - now there's a deserving test group."
"Except by the time you are a rapist you're already a fully functioning male, and loss of your testicles will only prevent you reproducing."
Removing the testicles and hence the majority of testosterone production will in most cases also make you unable to perform or for that matter want to perform. This is the reason why chemical castration was/is used on sex offenders by the use of anti androgens to reduce testosterone production and in some cases female hormones. See amongst others Alan Turing.
Of course this is the same cocktail as used by male to female transexuals so maybe a study of the life expectancy of that relatively large group would be informative.
Re: Not surprising
You are wrong about one thing it is not nearly £800 it is in fact nearly £900. Who pays this? My car cost less than that ;-)
The Apollo Command Module had just over 6m^3 for 3 people for sometimes over a week.
I think it might have got a touch smelly in there.
Re: Virgin on the silly
According to Newton F=(GM1M2)/r2.
r is the distance between centres of mass of the two objects in this case SS2 and the centre of the Earth so about 6000km or 6 million metres when the SS2 is on the ground.
So on the ground r2=36000000000000 at 200km ie r= 6200km then r2=38440000000000 so the effect of gravity 200km up would be a about 5% per cent less 200km up than it is here.
Not a lot of difference there, you would need to go a lot higher than a few hundred miles to have appreciably less effect of gravity.
"orbit is just a free fall toward the earth at an angle that keeps you form falling TO EARTH"
No it is a free fall towards earth at an ANGULAR velocity that ensure that you keep missing ;-)
As to escape velocity being mach 5 if you can do that I bet NASA would like to talk to you as they thought that they needed to make the Saturn V go at 27000mph or about mach 38 in order to reach escape velocity.
TBH I think it is harder than you think and I take my at off to the pioneers in the 50's and 60's for making it happen.
Re: Virgin on the silly
Errr not so sure about your tinking there.
Spaceship 2 is predicted to fly at a maximum of 2500mph and reach 68 miles altitude. To go into orbit, not just space, you need to be able to go about 18,000mph AROUND the Earth not straight up, even at that speed you would come straight back down if you went straight up. To go into orbit is much more difficult than what they are proposing with spaceship 2.
Sure a few of thousand miles an hour straight up will take you into space for a few minutes but you will come straight back down.
Oh and losing 1/2 a tonne of cargo ie the passengers will make not a lot of difference to the max altitude maybe 100 miles up and then straight back down.
I can see how blowing the top off a solid rocket booster would cut off the thrust but only by having equal amounts of thrust coming out of both ends, possibly not a good idea if you are sat on the top.
You cannot stop the burning, more of an explosion really, once started as the fuel and oxidiser are intimately mixed. The only way to stop it is to let it burn out or self destruct the booster.
The shuttle SRB uses as a propellant the same chemical composition that display fireworks use to explode mortar rounds in the sky and that provide that real thump you feel in your chest. But display fireworks only use a few grams the shuttle SRBs use 500 tonnes each, good luck with turning that off...
(The miracle is that they can sort of control it in the first place.)
I think you will find that this is pretty standard.
I certainly cannot think of one liquid fueled rocket system that isnt clamped down until all engines are running within specs. For one thing you really do not want to allow a launch to occur when one side is at a higher thrust level than the other. In the case of the shuttle it was held down, and the SRB not started, until the engines were running and the whole structure had swung back after the "twang" (shock) of the main engines starting.
It is of course one of the nice things about liquid fuel systems. Once a Solid Rocket is lit it cannot be turned off.
At Lohans operating altitude, when travelling at mach 6-8 there will be more than enough air passing into the engines for it to work. These engines are designed to work at these and higher altitudes.
Re: First laser?
Whenever light is refracted the light is split into its component parts to a greater or lesser degree, it is just that a prism refracts it two times and each time to an extreme degree.
All simple lenses split the light into its components and it is a PITA if you try to build an inexpensive telescope/camera as it leads to chromatic aberration, expensive compund lenses are used to try and remove the aberration.
Re: A plague on all of them
I cannot agree more. I have walked out on more than one evening when people are answering their phones all the time.
Last week I was in a lovely country pub and an attractive couple were there for the evening having a meal etc. I did not see them talk to each other more than once or twice very briefly. Almost all the time, including when eating the meal, they were on or staring at their phones. I cannot help but feel that at least one of them had their priorities wrong.
In a way I rather hope that they had just had a huge argument.
Re: Paedophiles and Terrorists are varieties of criminal
"However, a record should be available of the existence of a warrant, and the details of the warrant SHOULD be public after it has expired."
I really hope that you do not mean that.
I was falsely arrested and a search warrent used to search my house/business and after a thorough investigation and no evidence having been found (of course not I had not done anything) the case was dropped.
Should details of the warrant used be public knowledge then?
Re: Serves him up
I seem to remember that in America less than 10% of cases go to trial the rest are plea bargained.
Now either the prosecutions cases are almost always fantastic fantastic, or the threat of draconian sentences if you do not bargain and lose leads some innocent people to accept the bargain. (600Hrs Vs 10 years is a hell of an incentive to accept.)
Re: Re: Re: Local caching?
I was always under the impression that iplayer used a form of peer to peer. Am I wrong then?
"It doesn't operate like a Tivo, unfortunately."
I think that that is the problem. My 10 years old Series 1 Tivo still has a far better UI & functionality than anything else I have tried.
If it wasnt for the lack of HD and twin tuners I would still be using it all the time, as it is it is there to remind me what I am missing ;-)
Why is it so, I cannot believe that TIVO have the patents on everything that make it so good, or do they?
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