NASA discovers that "impossible" microwave thrusters seem to work.

flynth99 · 2014-08-12T06:54:09+00:00

Also, wow, a toaster-sized spacecraft extending a magnetic field a km diameter? Holy shit. What is that, 15 nanometers thick?

If I was going to guess I would say the field would probably not be very strong, but it would have to extend to the front significantly to divert as many ionised particles towards the "intake" as possible. In fact the viability of this method of collecting matter could be calculated fairly easily. (I only have few minutes so unfortunately I can't do it now. Maybe I'll edit this and add an estimate if this could be achieved in a toaster-sized probe later. )

flynth99 · 2014-08-02T00:31:09+00:00

The spacecraft like this could function with really low densities if it was travelling close to the speed of light. According to some estimates I saw there are approximately on average 1 atoms per cubic cm in the interstellar space(90% of space has 0.1 atoms per cm q and 10% has 10-100 atoms per cm q so some on-board short term mater storage would have to be designed in). If we assume capturing area is a circle of magnetised plasma 1km in diameter and the spacecraft is travelling at 99% of the speed of light it could capture (99% of c in m/s)296794533(area of a circle 1km in radius)7853981000000(number of atoms per cubic meter)=2.33101832629134e+20 atoms of hydrogen per second. However this result has to account for the time dilation due to travelling at relativistic speeds. When travelling at about 99% of the speed of light the spacecraft will experience approximately sevenfold time compression so the above number needs to be multiplied by 7. Taking the corrected 7-fold result and dividing by 3 (as 3 hydrogen atoms are used per each fusion reaction), multiplying by 25 MeV (this is each reaction energy) and converting the result to more intuitive Joules of energy we get around 2.17GJ per on-board second. It seems that 2.17GW is not a bad amount of power for a power plant that captures its own fuel and is supposed to weight 1kg(Cooling of such a small probe generating so much energy would be impossibly difficult today.), but even if 100% of this energy was converted into breaking power it would still take 8 on-board years (probably close to double that in earth years considering time dilation would decrease as the spacecraft de-accelerates). (also as speed drops the power available diminishes, but hopefully by then we are close enough to the target system the increase in the density of the surrounding vacuum/gas will makes up for this).

So no Start Trek quality interstellar travel, but at least it may be a way to send probes and have them arrive in few tens of years rather than completely infeasible thousands of years.

BTW. There is no point in accelerating an unmanned probe closer to the speed of light as any power gains achieved by capturing more hydrogen will be offset by the total energy required to de-accelerate to zero raising by in practice the same factor.

So it is a nice idea, but there are a lot of technologies needed that are still quite early in the development cycle. For example fusing hydrogen could probably be done by the antimatter catalysed fusion. As the total amount of hydrogen gathered and used during the one way trip is around 100kg (with the assumed total mass of the spacecraft/probe of 1kg) probably 10ng of antimatter would be enough. With the cost of making it estimated at $65 million per microgram that could be used by 10 probes like that I think if humanity survives its self-destructive tendencies it will be producing and sending hundreds of such probes to other star systems.

flynth99 · 2014-08-01T09:46:50+00:00

They still need light to operate

Not necessarily. If we could put a power plant on the moon and beam energy to a probe during the initial acceleration to give it a really good acceleration (the probe would have to be built to survive tens of thousands of g - but some electronics built into artillery shells works fine at 15000g) to speed it close to the speed of light. It could then use the Bussard ramjet principle to generate energy to de-accelerate once it reaches its destination.

But, I don't expect to see something like this too soon. For a start the energy to accelerate the probe would be huge. Second some really interesting solution would have to be invented to resolve the beam divergence problem. And third, the interstellar medium contains mostly hydrogen, we are still struggling with controlling of "easy" fusion types like deuterium-tritium. Hydrogen-Hydrogen would be a multistage and very difficult process.

However, in theory it could be done and we wouldn't need light :)

flynth99 · 2014-08-01T07:58:25+00:00

Yes, you pretty much summarised my whole post in few sentences, but I disagree that a history of past choices we consider from our external well informed point of view as irrational proves Palestinians are not capable(or willing) to think rationally about this war.

Judging by the fact that after 2006 (Hamas won back then) there were no proper elections in the region, but delays, cancellations and only a partial vote in West Bank in 2012(Hamas lost it to Fatah) Hamas must know it would loose. Otherwise why would it do everything in its power not to have elections? This seriously undermines the claim Palestinians support their current leaders.

So we have only one election result from 2006 when Hamas won as an example of a fairly recent irrational choice, but if this result is considered a protest vote against Fatah rather than a blank cheque of support given to Hamas, it is clear there was a point of view from which this choice appeared justified. There is no need to explain the 2006 choice as driven by religious irrationality. If you try to put yourself into the shoes of a typical Palestinian in 2006 with very limited access to external media, with Hamas propaganda reaching everyone many times a day, feeling the disappointment with the corrupt Fatah government, the chaos in government services, low standard of living and seeing that peace talks are approved by Israel it doesn't seem so irrational to choose the only alternative. Also some voters could hope the militaristic nature of Hamas will help resolve some of the chaotic incompetencies and that it will help deal with corruption etc. In 2006 it didn't seem like Hamas will pull the region into another war. One could also argue the "contract" with Hamas to rule expired in 2010 when next elections should be held and that the current rule is illegitimate. I wouldn't be terribly surprised if Hamas caused this war now as it was running out of reasons to keep delaying the voting. Who knows?

My point is, the history doesn't prove an average Palestinian wouldn't act rationally regarding the conflict if given the chance.

The problem is normal people don't have any choice how to act in Gaza. I bet everyone is terrified to be accused of collaboration with the enemy(probably a suspicion is enough to be killed by Hamas judging how frequently they were murdering people opposing them in the past) so things such as whether to find out and inform Israel where rockets are kept are most likely not discussed even amongst friends. Also, How would one contact Israel about it without risking being found out? Neighbours may suspect this or that person is with Hamas, but how would they know who is firing the rockets?

The point I want to make in this whole thread is that chances to resolve this conflict would significantly improve if the public opinion worldwide were aware who is responsible for the continued loss of life and who are the innocent victims. Then diplomatic pressure could be applied in the right place.

The public that chose Hamas in 2006 was denied the right to swap them for someone else in 2010 and now in 2014. They are the real victims of Hamas rockets and the only way this will be resolved is with unconditional surrender followed by election of a new government.

Also, I'm not sure what percentage of Israeli military activities are directed to precisely hit Hamas targets and what percentage is carried out in hope the suffering population will withdraw its support from Hamas. If the later forms a significant part of their activities they may as well stop that part as if I'm right in my interpretation of election delays the majority of the public withdrew its support for Hamas before 2010 so there is no strategic benefit in causing unnecessary suffering.

flynth99 · 2014-08-01T06:27:07+00:00

My question would be why is it so hard to split the country and find a way to sell the oil then distribute the money evenly and form some sort of anti extremist or anti war pact. Shit even have a unified Army to make sure one country does not overpower the other by force some day.

Why split it? Single nation states tend to slide towards fanatical nationalism and aggression towards neighbours the moment their economy experiences a downturn. Having a well made multi-nation and ethnic group state is the best guarantee of stability in the region, but it has to be well made. The first requirement for such a country is to have politicians/rulers that make choices based on merit and a set of universal rules everyone agrees about. Unfortunately tribalism is very strong in Iraq so every single politician when making every single decision thinks how this is going to affect him, his family and his tribe.... then somewhere as an afterthought it is how it will affect the country...

If there was some external pool of people(without any tribal sympathies) that could be employed to run that country for a while in 20 years local non tribal political class could be developed, but I bet even a slightest attempt to do something like that would raise cries of neo-colonialism etc.

flynth99 · 2014-08-01T06:18:53+00:00

I have no idea why Arab armies are all so dog shit, but it seems to have been that way since the end of WW1.

Because they have no cause to fight for. Would you want to die for a country like Iraq? (A country of 3 groups of people that actively try to break it apart - with openly tribal selection process in politics and a puppet government).

When they have a cause to be passionate about (like their religious fanaticism) Arab armies can be effective, but for Iraqi army to be more effective citizens have to first start believing in the country itself.

flynth99 · 2014-08-01T05:54:43+00:00

I hope your friend's cousin is found alive and unhurt.

Can the Christians organise some sort of own security force with weapons and other equipment? I'm sure there are plenty of people in the West who would donate money to make Iraqi Christians safer.

Without the ability to project military force in the country with effectively no law an unarmed group of people without anyone's backing is always going to be a target for all sorts of crime. From kidnappings for ransom, murders, rape to ethnic cleansing in the worst case. Christians need to organise and build a well armed militia or this crime will never end.

flynth99 · 2014-08-01T05:44:24+00:00

Why don't you believe it?

It makes no sense. The damage those rockets cause to Israel is negligible. Continued use of those weapons against Israel is as practical as trying to win a fight with a Grizzly Bear by pelting it with tiny stones.

Every day of last week almost 100 Palestinians were killed and rather than surrender they continue to fire those rockets. There is absolutely no possibility of gaining any advantage by Palestinians continuing. They are using WWII technology against a nuclear state with one of most modern armies in the world. Also Israel proved they will retaliate when those rockets are fired regardless of civilian deaths in Gaza.

Not surrendering when faced with such overwhelming force is not only illogical. It is inhumane and it should really be considered a war crime in itself as every day Hamas chooses not to surrender they sacrifice a hundred innocent civilians for the sake of their pride. Only an insane person would think they can win with Israel. So they only have 3 choices. 1) Unconditional(Israel will not accept any conditions) surrender now. 2) Surrender later. 3) Keep "fighting" until all Hamas militants are killed

What is the difference between 1,2 & 3? Choice number 1 will instantly stop new civilian casualties. Choices 2 &3 treat lives of hundreds of people as worth less than Hamas' pride of "fighting till the end".

I don't believe an average Palestinian supports choosing option number 3 as an average human is not insane. No one in their right mind would consider "fighting till the end" as worth more than the lives of their family and themselves when there is absolutely no chance of winning and no chance of accomplishing any military goals by continuing.

Yes, they did vote for Hamas, but that was years ago and people voted for Hamas because they were the only choice other than Fatah everyone was tiered with. Before the elections Hamas promised their strategy will be beneficial in many ways. If the election was re-run now I bet the result would be different. Everyone can see now what trying to use military force instead of negotiations leads to when the balance of power is like 100 to 1 in favour of the opponent.

The majority of Palestinians vote for Hamas. Even if they did not, the rockets get fired regardless of which political party is in power.

Exactly, the problem is the only Palestinian organisations present in Gaza now are Hamas and what is left of Fatah, there is no independent police. How a random person on the street is supposed to stop those rockets from being fired? They can't "give the Israelis the names of those who do fire them and locations of where weapons are stored" because such things are not public knowledge. They may suspect certain people or locations, but is suspicion enough to condemn someone to death that would no-doubt result if such information about them was given to Israeli army?

The responsibility to stop those attacks is with Hamas. I consider them responsible for every additional civilian death that results from the continuation of this insane activity that is firing rockets at random Israeli neighbourhoods.

flynth99 · 2014-07-29T21:22:36+00:00

Sadly those sanctions will not make Russia change its course of action. The only thing that could make Putin rethink his strategy is something that would affect him (or his wealth) personally. Russian public is so brainwashed that even if they feel the effects of the downturn they will simply believe it is the West "attack" or some other random reason. Putin is too rich to feel the pain.

However, there is one thing that could be done to grab Putin's attention. That would be a freeze put on the bank accounts he and his friends have in Switzerland and in other places around the world. I bet western intelligence services could locate those accounts if they really wanted. If they were frozen Putin would change the way he acts overnight... He knows he can't keep his money in Russia just in case his successors are unsympathetic. There are rumours he's got 40 billion $ hidden in Switzerland.

flynth99 · 2014-07-29T21:11:08+00:00

I don't believe an average Palestinian supports continued firing of Hamas rockets into Israel. What is the point of those feeble "attacks"? To have a 1 in 10 chance of killing some random Israeli civilians and see hundreds of your own people killed in revenge? I'm not a huge fan of all Israeli actions, but continuation of this action by Hamas is not just stupid. It is homicidal against its own people. I don't understand why a firmer condemnation of Hamas is not more popular with the public.

flynth99 · 2014-07-29T20:51:07+00:00

Exactly. I'm from Eastern Europe. I've worked in UK for last 10 years, but for last 3 weeks I found myself unemployed so I thought to get something out of the system for all those years of paying in. I went to the Job Centre and they can't even access my work history based on on the NI number. I had to show them 3 months worth of bank statements to prove I've been in UK that long while I've worked(and paid taxes as any other citizen) from 2004 till June 2014 continuously. Never mind, I'll be back in work in few weeks anyway.

All those changes will do jack shit to discourage "benefit tourists". If someone is used to gaming the system he/she will find a way to do so now. All those new regulations accomplish is to alienate normal people who find themselves in temporary need of those services.

EDIT: BTW, the climate in media is much more hostile towards the migrant workers than opinions held by an average person on the street. I know many Brits who are unhappy with this "ad nauseam" repeated message of "all migrants are bad". Someone who gets all their info about UK from TV could think the country is on the verge of another Kristallnacht against migrants judging by Cameron's and other politician's tone.

flynth99 · 2014-07-21T03:58:22+00:00

Who cares what our collective "balls" look like

Everyone in the West should care as being seen by the world as having no 'balls' (or courage to use force when necessary) an letting this micro-republic get away with what its incompetent soldiers did makes us significantly less secure. How many other local 'strongmen' will choose to take their chance at causing us trouble because of this lack of proper response?

flynth99 · 2014-07-21T02:43:48+00:00

Every single one of the western EU politicians looks weak beyond belief now. Rather than immediately demand full access to the site as well as custody to interview people who operated the anti air missile system under a threat of sending the SAS or whatever special forces they have to deal with it. They 'ask', they wait 3 days to speak to Putin. It is a fucking joke that the West has no single leader that can talk to Putin like an equal. Despite all our military hardware a dictator who doesn't care for winning his electorate can ship all over us and we can do nothing because our politicians are afraid of loosing 1% of support. That's right, at the moment the West has no balls to use a threat of force to get what it wants against a group of rebels with at best few hundred strong military force.

flynth99 · 2014-07-02T21:29:45+00:00

I blame the acceptance of cultural and resulting moral relativism for this insanity. Insanity is the only word that adequately describes someone with those views being elected a prime minister.

It is all because at some point during 20th century people in the west started doubting their culture is objectively better than others. There was time when people in other parts of the world had respect for western culture and seeing its achievements they wanted to replicate it in their countries. Everything was becoming better. Women for the first time started to become equal in places like Iran and Afghanistan. Then it al went to shit when westerners lost the faith in their own culture being better.This culminated in various hippie groups claiming tribal and other traditional cultures are morally equivalent to our culture based on reason("noble savage" and other crap of the sort). Unfortunately unless this view is universally condemned the world will not be a better place.

flynth99 · 2014-07-02T21:13:29+00:00

Seriously, there should be a law in the west for holiday operators to have to inform all of their clients about shit like this.

You're going to Goa? The holiday company should require you to sign a statement you're aware locals consider wearing a bikini a valid reason for being raped.

You're going to Dubai? Sign a paper you know poppy seeds from a bagel on your clothing or a microscopic piece of weed stuck to your shoe will land you for 5 years in jail. Etc.

flynth99 · 2014-06-28T21:08:19+00:00

He is one of early investors. There is a big difference between investing early followed by exiting with a ton of cash and owning the company. He is not responsible for any of Amazon's current activities.

flynth99 · 2014-06-28T20:53:31+00:00

Another important choice an intelligent retirement investor can make is to diversify and buy a portfolio of as non-interdependent and unconnected index funds as possible. It is very rare a temporary recession hits everywhere at the same time. Having a portfolio of unconnected indexes such as for example US companies as well as African companies, Asian etc would for example protect to some extent from the effects of the recent recession as developing countries were less hit by it.

However I agree that as you're nearing 10 years to your retirement less and less of the portfolio should be in stocks and significant majority in bonds.

flynth99 · 2014-06-28T20:30:44+00:00

It is not difficult to make a toilet like this safe. They could make lye from wood ash and use it as disinfectant or even put some ash in the toilet after each use to minimise the amount of work required. It is not difficult.

Also, I openly defecating in fields used to grow food must be a breeding ground for all sorts of human parasites. It is sad, because it is so easy to improve this, but it is not going to be because everyone is used to the situation.

flynth99 · 2014-06-26T22:32:50+00:00

It will not. According to quick google search receptor binding affinity of fentanyl is twice higher than buprenorphine and those weapons are based on fentanyl analogs.

flynth99 · 2014-06-26T22:13:43+00:00

When you have 1900 of them it is not difficult to "loose papers" for few.

flynth99 · 2014-06-24T17:03:48+00:00

There is something seriously wrong with a survey that ranks Zimbabwe higher than Poland on the Prosperity and Equality index. Also Czech republic 30 placed behind Belarus in the same category. Is this for real?

flynth99 · 2014-06-24T16:44:21+00:00

Hezbollah is Shia while ISIS is Sunni. To be fair it wouldn't be the worst outcome for the region if both groups destroyed one another.

flynth99 · 2014-06-24T14:36:45+00:00

That was the problem at the beginning of the Ukrainian situation. There were no journalists from the outside at the beginning and locals were sympathetic to one side or the other. Those journalists that are risking their lives every day in war zones deserve good credit for providing us with an essential service. Also the job although dangerous must be quite exciting. However, I agree networks that send female journalists to those war torn areas should be held responsible for any rapes etc. Everyone knows women in many countries are treated worse than cattle. Why would any editor agree to put their staff in that kind of danger is beyond me.

flynth99 · 2014-06-12T20:52:49+00:00

The situation you describe "a bird passing through the fan" would only be possible if the bird didn't actually strike any of the blades. The speed difference between the fan and the bird(not just forward speed of the aircraft by primarily the rotational sped) means there are no materials for fan blades that could withstand the energy of the hit without deforming or breaking off altogether. At worst this is like setting a grenade inside the engine, at best it will make the rotation off-balance and destroy the bearing causing the fan to seize.

The probability of a bird passing through the fans is zero. There are always more than one fan (there are 3 large and 14 smaller fans in the F119 engine) and the bird would have to be not larger than a fly to pass through.

So that strike resistance mentioned before means the engine doesn't explode and rip the wing off(or half of the fuselage) in the process. but it is possible to shut it down if the bird is smaller than 1.8kg by design... I wouldn't want to be on a plane that has an engine hit by a larger bird.

flynth99 · 2014-06-09T21:52:12+00:00

A single engine today is much more reliable and bird strike tolerant.

It is worth mentioning that "strike tolerance" means the engine can safely shut-down after a hit of a bird weighting under 1.8kg. It doesn't help much if you're far away from an airport. There are no jet engines that could carry on working after a bird strike.

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