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Messages - syhprum
« on: 28/08/2015 15:18:31 »
I would like to make a copy of the Portland vase
There are several factors to consider, the overall thermal efficiency will generally in terms of MPG will be lower when driving in a lower gear but you must bear in mind how the lengths of the different routes compare.
How long is a piece of string ?
« on: 15/08/2015 15:35:34 »
All though there much glib talk about putting 100 watts into speakers I am sure that speakers which are only about 1% efficient would soon go up in smoke if the voice coils tried to dissipate 99 watts.
the actual power in sound waves is very low I recall reading that a symphony orchestra puts out about 1 watt
« on: 13/08/2015 21:27:46 »
I remember a car running at Brands Hatch in the early sixties with a pulse jet engine similar to those in the V1 flying bomb, one disadvantage (amongst many !) was that it would not operate at less than 100kph
« on: 30/07/2015 19:55:01 »
I think we are putting too much blame on programmers surely many crashes are due to transient hardware glitches otherwise things would not run after the reboot if you attempted the same operation again.
Physics, Astronomy & Cosmology / Re: How is the electrical circuit completed between the powerstation and my home?« on: 30/07/2015 10:29:10 »
When servicing TV,s many years ago I found in one house the line voltage had dropped to about 130 volts and varying wildly which I diagnosed as a disconnection between the neutral connection of the local distribution transformer and the neutral line.
connecting the neutral line to ground at the house made a temporary fix so that I could check the TV
Physics, Astronomy & Cosmology / Re: How is the electrical circuit completed between the powerstation and my home?« on: 29/07/2015 22:44:03 »
When I first encountered it I found the USA system rather confusing they use a delta three phase system with one output winding centre tapped and grounded to supply either 117 or 234 volts for domestic use.
the result is if you check the voltage of the delta lines relative to ground you find two of 117v and one of about 160v which rather puzzled me !
I too thought such efficient mirrors were available but could not find a supplier, it would be interesting to set up an experimental system in one of the long tubes used for gravity wave research a possible IG noble project
Even with a 1mm hole and a 1m beam width the loss of energy would be trivial compared with the losses incurred by real world mirrors, it seem that the best available have a 0.1% loss at each reflection so making the box long is the best solution.
I assume your long light storage box would have slightly curved mirrors so that the light beam would stay on centre and not spread out.
Rather like the Spectra Physics lasers with which I used to work, your 12882 Km long device should have a quite high "Q" factor with only 23.28 reflections per second.
Assuming otherwise perfect mirrors the loss at each reflection the would be in proportion of the area of the hole compared to the beam width area
Physics, Astronomy & Cosmology / Re: How much energy is required to create absolute vacuum in one cubic meter?« on: 19/07/2015 11:36:25 »
It would be interesting to know how much power is expended per cubic meter to maintain the near perfect vacuum in the LHC
As far as I can ascertain the refrigeration system of the LHC consumes 170 KW to maintain 9000 cubic meters of vacuum which equate to about 19w/m^3 of course the initial pump down from atmospheric pressure would have required a considerable amount of energy.
We are up to version 10240 which it no longer lists as experimental so that should be the "final" one.
It can be downloaded from file sharing sources free of viruses (checked with three different AV software) and loaded preserving all your programs even if you are not a member, it is activated but I do not know for how long or whether it can be legally used for commercial purposes.
Windows 10 is rather perverse as regards video card settings my GS8400 cards require version NVIDIA 310 for the video processing programs to run in accelerated mode but windows 10 does not like this and as soon as an internet connection is available alters in back to 341 !
Physics, Astronomy & Cosmology / Re: Is it possible to monitor the outside of an aircraft, and detect if it will break beforehand?« on: 17/07/2015 17:35:44 »
I don't know to what extent it applies to aircraft but there is an old adage "if it ain't broke don't fix it"
Physics, Astronomy & Cosmology / Re: How much energy is required to create absolute vacuum in one cubic meter?« on: 16/07/2015 22:00:45 »
To condense every last particle of gas in a one cubic meter chamber a cold sink would have to be maintained for an indefinite time and or a getter fired as in CRT,s despite thermal leakage.
To remove EVERY particle would take an infinite time and energy.
If we take light as a general term for electromagnetic radiation we have the example of the resonant cavity used at radio frequencies, these are defined by there Q factors this being the ratio of stored energy verses that which dissipates.
Presumably one with a Q factor of 1000 would have the stored energy reduced to 1/e in one millisecond and pro rata.
Cavities where it is desired to store a great deal of energy such as in LHC are constructed of super conductive materiel.
I find the edge browser superior to IE11 but have difficulty starting it up, what I have to do is open some URL that naturally reverts to Edge (the default browser) and then with the favourites imported from IE11 get the URL I want.
I would be nice if I could open it from the taskbar as I di IE11.
The answer it is not high tech there is a built in facility called disk clean accessed from C drive/properties that does the job, all that is required is that the unwanted folder is correctly labelled and directly on the C drive
Both systems work well for getting rid of single files but seem to little use for getting rid of large blocks of unwanted data, after another system update I now have 30Gb of unwanted stuff !
As there is a fair amount of spare capacity the only problem it causes is if I run an anti virus program it wastes time checking thru these 30Gb of files but the only way out that I can visualise is to copy off everything but these 30Gb, format and copy back a rather long winded process.
« on: 09/07/2015 20:43:12 »
The best estimate I have seen is that the surface of the earth will cool to about 30°K much the same as the Kuiper belt objects maintained by radio active decay of the core.
The SETI people say that with Arecibo size antennas communication should be possible to 1000 LY,s
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