Forgot your password?
typodupeerror

Comment: Few links on current efforts (Score 1) 151

This is a youtube video with history of discoveries https://www.youtube.com/watch?v=xJsUDcSc6hE , http://neo.jpl.nasa.gov/stats/ - has more up to date info. There are two projects to find almost all asteroids in comining decades http://en.wikipedia.org/wiki/Large_Synoptic_Survey_Telescope https://en.wikipedia.org/wiki/Pan-STARRS Pan STARRS already works to some degree see http://neo.jpl.nasa.gov/stats/ again, Those projects, which work now, are in process of upgrade http://www.dailymail.co.uk/sciencetech/article-2117062/Nasa-boosts-funds-telescope-team-hunting-dangerous-asteroids.html and then there will be http://en.wikipedia.org/wiki/Asteroid_Terrestrial-impact_Last_Alert_System Europeans too have project to deploy some telescopes http://belissima.aob.rs/Conf2012/Milani_2012.pdf and Russians think of this too. There are also satellites which look for asteroids like http://en.wikipedia.org/wiki/Near_Earth_Object_Surveillance_Satellite there are pending projects in Europe http://www.dlr.de/fa/Portaldata/17/Resources/dokumente/abt_17/projekte/Handout_Asteroid_Finder.pdf ( I think it can be resumed later ) and in Russia. There are consents http://b612foundation.org/sentinelmission/ and http://en.wikipedia.org/wiki/Near_Earth_Object_Camera of satellites with infrared telescopes. combined we have: we know almost all big asteroids > 1 km ( 95% now ) , so probability the Earth is hit hard is less, than, say 30 years ago - because we know 95% of big asteroids are already do not hit us in near future ( btw asteroid which caused dino extintion was several km wide, we know maybe 99.9% of all such asteroids now). Currently we have quite a high rate of discovery ( which will be much bigger in 2020s due to planned big asteroid hunting telescopes ) so in 30 years - we have only unknown asteroids few meters wide ( similar to than in Chelyabinsk ), we could be faster if mentioned satellites are launched and they work as expected. But even if we keep just today's rate of discovery the worst we could unexpectedly get - is a destruction of a city, in 30 years even with the current rate ( given planned improvements though ) of discovery we will have very low probability to have even this unexpected event.

Comment: there is a catch - more efficient coal (Score 1) 341

by SergeyKurdakov (#42081791) Attached to: The World Falls Back In Love With Coal
While most current coal power stations have 33% efficiency it is possible to make them 50%+ ( up to 57% efficient ) with the use of supercritical co2 turbines ( or 40-50% improvement of ratio energy/co2 ) see about this technology http://www.echogen.com/documents/TMISept_Oct12_000.pdf with few percents of efficiency going into 70% capture of co2 ( which are noticeable with 33% efficiency but much less with 50% efficiency ) co2 capture turns to be quite feasible even for china

Comment: Satellites and lasers (Score 1) 590

I see few of those who thinks a little broader - that the question is not about panels on aircraft, but solar powered aircraft The practical approach might be to use satellite solar power, beamed with lasers http://en.wikipedia.org/wiki/Space-based_solar_power to aircraft. In fact for aircraft in flight there could be less obstacles than for any place on earth, so beaming solar power to aircraft might be a closer aim, than beaming solar power to earth stations. Thus - 24 hours flight, the only catch - to have enough power to get out of clouds ( usually they do not obstruct much of sun light below 10 000 meters ) and then the whole flight might be powered by solar power

Comment: check asteroid size and probabilities to hit (Score 1) 352

from article Students asumed "A series of assumptions must be made due to limited information in the film. First, the asteroid is approximated as a spherical object 1000km in diameter " and the biggest asteroid has just 1000 km size https://en.wikipedia.org/wiki/Ceres_(dwarf_planet) and we know this asteroid does not pose threat. - all others are much less in size http://en.wikipedia.org/wiki/List_of_notable_asteroids#Largest_by_diameter and these too do not pose threat too. and no known big asteroid larger than 1000 meters threatens earth in near future http://www.newser.com/story/129849/nasa-weve-ided-most-killer-asteroids-out-there.html so there is not only a such a bomb exists - there is no such a threat. and for real asteroids the humanity might encounter - the existing bombs are more than enough to destroy them

Comment: solution for just $280 billion (Score 1) 462

by SergeyKurdakov (#40769361) Attached to: Is There Still a Ray of Hope On Climate Change?
solution to fix all things ( and maybe even improve climate variability ) http://www.sciencedaily.com/releases/2008/12/081222114546.htm to change 'local' climate - there is need for much less area. I think that mass produced aluminum foil on some substrate could be used as well ( will be easy to scale back reflection if needed )

Comment: greenhouses (Score 1) 592

by SergeyKurdakov (#39506103) Attached to: Ask Slashdot: How To Feed Africa?
greenhouses produce 6+ times compared to out of doors cultivation. Africa has suitable climate for greenhouses ( see Israel greenhouse projects ), then using hydroponics, there is no need in rich soils. of cause there is question of money - there is need in quite a bit of them to start. But this is another question. Africa can produce enough crops, and 'poor' soils do not prevent Israeli deserts to produce a lot of food.

Comment: Re:looks like waste of lithium (Score 1) 128

by SergeyKurdakov (#38532336) Attached to: Russia Building World's Largest Li-Ion Battery Plant
no cells do not warm up, they are kept warm all the time using insulation ( consider that on the other temp range is a liquid hydrogen and it it stored for quite a while in cars ), the insulation adds cost, but less, than difference between lithium and molten salt cost. for that reason molten salt vehicles work ok at - 40 C while lithium cars just stop working. also molten salt does not explode, though can splash, but in buses it is situated such that it is last thing to be hit from outside. li ion batteries actually is a sort of relatively recent breakthrough, that is why so much hype around. but there are other alternatives, btw, such as aluminium air or zink air batteries (and even li air batteries). there are still problems with them - but at the cost/weight side - they are the only batteries which can compete with gasoline, so it is really strange that instead of attempts to improve in a way which can finally resolve gasoline dependance relatively scarce lithium is wasted.

Comment: looks like waste of lithium (Score 1) 128

by SergeyKurdakov (#38529394) Attached to: Russia Building World's Largest Li-Ion Battery Plant
from press release it is clear, that the plant is not for plug in hybrids market ( and the possible answer - is low quality,which in below the current plugin batteries ). For buses and for grid storage - molten salt batteries are preferred ( because materials are much more abundant and cheaper and for these applications the biggest problems of molten salt batteries ( high temperature ) could be of less significance than in cars ). There are examples of such uses http://asmoronurhadi.blogspot.com/2011/03/tindo-worlds-first-solar-electric-bus.html and http://engineering.blogs.lincoln.ac.uk/2011/03/11/so-what-battery-technology-powers-our-electric-bus/ etc, there are new developments http://nextbigfuture.com/2011/03/low-temperature-molten-salt-battery-ten.html http://www.greencarcongress.com/2011/11/sumitomo-2011111.html in this field, which could make molten salt batteries even more attractive. and if to consider, that lithium reserves are quite limited - mass production of low quality batteries seems a strange idea. I can't say for any good reasons for RUSNANO except they need to spend huge money on something ( they have a big budget and just few mostly idiotic projects )- it is moronic organization which is run by the man who put Russia into poverty in 90s due to badly designed reforms and any degree of idiotism could be expected, but what drives Chinese in this venture is an intresting question. It might turn out, that both sides are driven by bureaucratic logic and thus the project has no real value.

Comment: The earth is flat and ends just on border of US (Score 1) 62

by SergeyKurdakov (#37506300) Attached to: NASA Satellite Falls Back To Earth; Landfall in Canada
What is interesting that for authors of the article from CSM( quote: The 6-ton UARS satellite — the biggest piece of space debris to fall from the sky since Sky Lab in 1979 ) the deorbited Mir station http://en.wikipedia.org/wiki/Mir_space_station has never existed - because only Skylab and this satellite existed as space debris.

Comment: Re:There is more effective fuel - 8 times payload (Score 1) 229

by SergeyKurdakov (#35107950) Attached to: Neal Stephenson On Rockets and Innovation
and our entire atmosphere isn't much better. no, practically low earth transfer orbit starts at 150 km at this altitude a satellite will not decay into atmosphere for quite a while. and while at space station orbit there is also atmosphere - it does not change much - they just fix orbit every few days with quite a few amount of fuel. As for higher altitude start - it is actually already exploited in air launch. and building launch from mount will increase payload several times ( just check for existing projects ). the things I describe are not money wise - they really would require too much money to be spent relative to possible outcome - so currently it just make no sense. but not only rocket system are proposed - there are about a dozen of different future space launch proposals,

Comment: There is more effective fuel - 8 times payload (Score 1) 229

by SergeyKurdakov (#35093640) Attached to: Neal Stephenson On Rockets and Innovation
Rockets are no nearly perfect - given new fuel http://nextbigfuture.com/2010/12/swedish-researchers-have-discover.html shuttles could have 4-8 times more payload. And this is actually huge step. Next - launch could be performed from towers few kilometers hight or even mountains - it will take money - but still will make quite a change. There are other possibilities such as quad airship launch (walrus was designed for 500 -1000 tonnes - so the rocket could be 4000 tonnes of weight and could be launched, say from 15000 meters hight ), there are other, non rocket ways to launch things into space - but even rockets could be times more effective, than now.

Time sharing: The use of many people by the computer.

Working...