This *IS* science. He's forming a hypothesis based on observed evidence.
No this is not science. Science is coming up with a testable hypothesis which explains an observation making the fewest possible additional assumptions (Occam's razor). This is a wild guess which explains nothing, is untestable and requires the existence of a vast chain of increasingly complex universes filled with intelligences each of which have created a simulation of a universe. If this is science then so is every religion we know of since they only assume the existence of one (or more) intelligences with the ability to create universes not a semi-infinite chain of them.
That is simply wrong. Fusion products as we will have them in fusion reactors are usually very stable.
A very common product of fusion reactions are neutrons which are themselves radioactive and can also be absorbed by nuclei to create an unstable nucleus.
That the tendency of having longer half lives the bigger the core is is wrong to, otherwise Iron would not be the most stable element....But you are right if you say _statistically_
Since I was using the term "in general" I was clearly talking statistically and, as shown above, you clearly contradict yourself since a "tendency" implies some sort of statistical average. Statistically speaking the larger the nucleus the longer the half life because of the difference in binding energy. If you look at the binding energy per nucleon its gradient is a lot steeper in the region below iron so unstable nuclei there are more likely to have a large difference in binding energy which will make the decay occur more rapidly. Conversely above iron where fission reactions happen the gradient is far shallower which is why unstable elements there tend (on average i.e. statistically) to have longer half lives.
Yes so they change in colour incredibly slowly over time due to an entirely different effect that has nothing to do with different travel velocities and which has a completely different signature since travel speed would affect the observation of changes not the long duration observation. What's your point?
Actually, we would have removed a host of variables, and introduced virtually no new ones
Really? Have you considered the host of charged particles and other radiation out in space? You will need to measure these to an incredibly high precision in order to exclude their effects and if you happen to think of some new effect after launch good luck trying to measure that to the precision required.
Why? We use gravity all the time with no understanding of how it works.
Not true, we know to a very high degree of precision how it works thanks to general relativity which is a theory which has been repeatedly tested and shown to always agree with observation. We don't know why there is gravity but we do have an extremely good mathematical model for it which we can use to predict its behaviour with such astounding precision that we can use it to accurately describe the gravitational waves given off by a merged of Black Holes over a billion light years away.
As for this engine we have no clue how or why this thing generates its thrust and a possible explanation without inventing new physics is that it emits charged particles which is something likely to lead to a reduction in thrust over time. That in itself a s good reason to be very cautious. Would you volunteer for a trip to Mars using a drive which nobody understands and which might well cut out and stop operating half way there? Sure you might be lucky but should we really be spending billions of dollars on something like that - especially since if we did studies here on Earth first to figure out what is going on it might lead to ideas to develop a far more powerful variant.
There may be a lot to gain but that's not a reason to throw caution to the winds and blow a huge amount of research money on something which should be studied first. I know that's the boring approach and we all want to be zipping around the solar system with amazing rocket drives but if you spend that much research money on something which turns out not to work in the end how many other amazing inventions and discoveries will you have delayed or will never even be found?
Well, yes but there are many other confounding factors too.
I get that it is hard but there is no rule in science that says things have to be easy. Just because it is hard to rule out existing physical effects does not mean you can just skip this step and jump straight to fairies and pixie dust explanations. At least not if you want any scientist to take you seriously. As Sherlock Holmes says "when you have eliminated the possible, whatever remains, however improbable, must be the truth" but the first step - eliminating the possible explanations - is a REALLY important one.
just build a small one, send it to space, turn the power on and see if it moves.
...and what would we really learn from that? There are a myriad of reasons why that might work or not work because you have suddenly introduced a whole host of new variables. If this is ever going to be a serious drive we have to understand how it works. Trying to do precision tests of tiny thrusts in space is far harder than doing them in a lab and you also need to be able to change things to test hypotheses. As for potential explanations proposing new, fundamental physics explanations without looking for simple explanations like going to a stage production of Peter Pan and when the actor playing Peter takes off and flies trying explaining it by trying to rewrite the laws of gravity rather than looking for strings. There is aways a chance that you could be right but lets not pretend that this is a sensible approach let alone science.
We do in vacuum otherwise things like distant supernovae would change colour over time due to the different arrival speeds of the different colours of light.
Short version: photons seem to have inertial mass after all.
...which raises some very serious questions such as why do we always observe photons as having the same speed regardless of frequency? In addition the proposed mechanism means that the quantization of inertia depends on the size of the universe. If this effect is observable today then shortly after the Big Bang the effect would have been incredibly huge due to the far, far smaller size of the universe. This raises serious questions bout the effect on nucleosynthesis etc. which Big Bang models without this physics appear to get right.
You cannot just rewrite fundamental physics to fix one issue without also looking at the implications of your theory for other predictions which is it likely to change. Worse it seems that nobody has tested these drives for the emission of charged particles. A far, far simpler explanation is that this drive works by electron emission. There are a variety of way this can work which all work in a vacuum but whic would unfortunately not work in space where you are electrically isolated and would eventually build up a counter charge and cause the thrust to reduce to zero over time. This all uses established fundamental physics so it would be nice to see this ruled out BEFORE coming up with crazy new physics. It might be less exciting but it is better science.
I've done a lot of counseling sessions with people whose relationships and lives were ruined by the persons addiction to porn. I have yet to do a single one where sugary drinks, for example, caused it.
That's because these ruin lives and relationships by causing premature sickness and death. Sick people tend to go to doctors for medical treatment and dead people don't have much use for counselling.
On some level we all understand that you have given permission for Slashdot to display your comments to people who view this page.
This is a logical consequence which is directly tied to the point of typing in the comment in the first place. It is not a logical consequence of purchasing a piece of hardware that I want to hand over all my rights to content I create with it beyond the absolute minimum required for the normal operation of the device.
Fusion "products" don't have a shorter half live than fission "products".
No fusion product has a nucleus larger than iron-56 which is the most stable nucleus because any larger nucleus will take energy to create rather than release energy in its production. Fission products typically have mass numbers 2-3 times larger because they come from the decay of elements with mass numbers just below ~300.
As a general rule the half lives of heavier nuclei tend to be far longer than those of smaller nuclei. In addition because the stable value of the ratio of neutrons to protons depends on the mass number of the nucleus both fission and fusion products tend to be unstable because you are taking nuclei with one ratio and combining or splitting them to form a larger or smaller nucleus.
So yes while technically you can have both fusion and fission reactions which lead to stable products that is not common (although perhaps more common with fusion) radioactive products are common and those of fission typically have far longer half-lives than those from fusion because the nuclei are larger. This is a general _statistical_ rule though and you can certainly find specific exceptions.
fission reactors.... fusion reactor - the two are entirely different concepts. In this case the fuels are (relatively) inert when not involved in an experiment, the only radioactivity being produced is during collisions.
Actually that is not really correct. Before use uranium fuel is only very mildly radioactive (the half life is in the billion year range) but is toxic whilst hydrogen is explosive if it mixes with air so both have their own hazards neither of which is really radioactivity before use. Both fission and fusion reactions produce radioactive products such as tritium from fusion depending on what you are reacting. The key difference is that fusion reactions produce light nuclei which, if they are radioactive, decay with short half-lives unlike the products of fission which have half-lives in the thousands or years or more.
Both types of reactor also produce lots of neutrons which activate the material around the reaction when they are absorbed. So really the two types of reactor are very similar the difference being the far short half-lives from fusion which make it far easier to deal with (just store the waste for a few years and it becomes safe) and the fact that the fuel in a fusion reactor is enough to last of order a second while a fission reactor's fuel can last for of order a year. This makes a fusion reactor far safer because all you have to do if anything breaks is wait a second (or less) for the reaction to stop plus you don't have a reactor which contains many months of radioactive decay products that need active cooling.
It might be standard but I thought in most countries to be enforceable the agreement had to be made before purchase of the item. You can't sell the item to someone and then try to add a whole load of terms and conditions which were not readily visible on the outside of the box after you already agreed to the sale.
A guy who once left [grapevine.is] in the middle of a parliamentary session while answering questions because he had a craving for chocolate cake?
Leaving seems to be a thing with him: he apparently walked out of an interview when they asked him about his off shore accounts. Perhaps there was some more cake on offer.
David Cameron and George Osbourne are removing welfare that WORKING people need in order to work and be independent
What is wrong with this is not that they are removing it but that working people need welfare in order to work and be independent in the first place. Paying welfare to people who are in work just allows companies to pay lower wages increasing the profits for the fat cats at the top.
I am guessing that you are not aware that many universities use GMail for business under agreements where Google will actually manage the email for the university domain i.e. my university email address is essentially a GMail account that I can access through GMail on the web or via IMAP. We have an agreement with Google which means that they agree not to mine our email for advertizing and we don't get ads displayed on the Google pages. They also gave us unlimited Google Drive space as well although I suspect if I tried dumping petabytes of ATLAS LHC data there it might turn out to have a limit at some point.
If email is so important to you that you can lose your job if it does the wrong thing, then you should be using an email service with an SLA
I work at a university where we have an SLA agreement with Google (mainly to cover privacy issues) and are supposed, though not required, to use GMail for all official email. However it's also not the type of environment where you would ever get fired for something like this...although it might raise a few eyebrows!
You use the wind/solar instead of hydro when they're available. This preserves the Hydro as on-demand for peak times and/or when wind/solar are unavailable.
Modern hydro power stations use far smaller dams in order to reduce environmental impact and so cannot easily store large volumes of water for later use. Even for stations which do have large dams you cannot rapidly vary the water flow nor cut off the river entirely due to environmental impact: you cannot have some hiker downstream getting washed away simply because everyone turned their kettle on and you opened the flood gates to generate power.
And for every Megawatt of Hydro-electric capacity you have you can match it with a megawatt of wind/solar and it doesn't matter how intermittent the wind / solar is because you have the hydro as back-up.
It's not really hydro power you need but pumped storage schemes to act as a backup for wind/solar. This is not the same as hydro because you need a lake at the bottom to pump the water out of when you are running the system in reverse to store energy. On the plus side you do not need to worry about water replenishment for the upper lake which means that you can have a larger height difference that with ordinary hydro. There is no point in backing wind/solar with ordinary hydro because you might as well just use the ordinary hydro and forget the wind/solar.
However this is still not enough. There was a study done a few years ago in the UK which showed that you would need to convert every body of water over a square mile in size in the UK into a pumped storage scheme to provide enough backup for the wind and solar stations that you would need to power the country....and even then you need to find sufficient area to build all the wind and solar stations you need and since there is not much solar in the UK that was a huge area (IIRC equal to Wales).
Wind and solar can certainly be improved and should be an important part of energy generation but if we really want to go carbon neutral then the only current technology which will let us do that is nuclear which comes with its own, but different risks.
It is if you want to install one which can charge your car rapidly. This is not just your standard wall socket and if you only plug it into a standard wall socket it you get 46km range per hour from Tesla's own figures (so that might be on the optimistic side) so if you ever forget to plug it in you will be 1-2 hours late for work. Even then the 240V socket only doubles the recharge rate.
The comparison of petrol stations to charging spots is also highly disingenuous. For a start a single petrol station has multiple pumps, typically 8-12, so you would need an order of magnitude more charging stations than petrol stations assuming the charging stations are for one car at a time. Then there is the time requirement. A typical tank of petrol will let a vehicle drive ~7-800km. So since most public stations only support the slow recharge rate (again a claim from Tesla's own website) what takes me ~5 minutes at a petrol station will take me 15 hours (=700/46) at a public charging station. Hence if each petrol station has 10 pumps then you need approximately 1,000 charging stations to be able to provide the same number of kilometres of range in the same amount of time.
Electric cars are the way of the future but there are still significant hurdles to overcome before they are ready for mainstream use. The most likely use-case at the moment is for a run-about-town vehicle but for that to happen the cost needs to drop to the ~$20-25k range. I doubt the next generation of "affordable" vehicles will be that cheap...but if they are I may be getting one!
Slashdot Mirror
This *IS* science. He's forming a hypothesis based on observed evidence.
No this is not science. Science is coming up with a testable hypothesis which explains an observation making the fewest possible additional assumptions (Occam's razor). This is a wild guess which explains nothing, is untestable and requires the existence of a vast chain of increasingly complex universes filled with intelligences each of which have created a simulation of a universe. If this is science then so is every religion we know of since they only assume the existence of one (or more) intelligences with the ability to create universes not a semi-infinite chain of them.
That is simply wrong. Fusion products as we will have them in fusion reactors are usually very stable.
A very common product of fusion reactions are neutrons which are themselves radioactive and can also be absorbed by nuclei to create an unstable nucleus.
That the tendency of having longer half lives the bigger the core is is wrong to, otherwise Iron would not be the most stable element....But you are right if you say _statistically_
Since I was using the term "in general" I was clearly talking statistically and, as shown above, you clearly contradict yourself since a "tendency" implies some sort of statistical average. Statistically speaking the larger the nucleus the longer the half life because of the difference in binding energy. If you look at the binding energy per nucleon its gradient is a lot steeper in the region below iron so unstable nuclei there are more likely to have a large difference in binding energy which will make the decay occur more rapidly. Conversely above iron where fission reactions happen the gradient is far shallower which is why unstable elements there tend (on average i.e. statistically) to have longer half lives.
Yes so they change in colour incredibly slowly over time due to an entirely different effect that has nothing to do with different travel velocities and which has a completely different signature since travel speed would affect the observation of changes not the long duration observation. What's your point?
Actually, we would have removed a host of variables, and introduced virtually no new ones
Really? Have you considered the host of charged particles and other radiation out in space? You will need to measure these to an incredibly high precision in order to exclude their effects and if you happen to think of some new effect after launch good luck trying to measure that to the precision required.
Why? We use gravity all the time with no understanding of how it works.
Not true, we know to a very high degree of precision how it works thanks to general relativity which is a theory which has been repeatedly tested and shown to always agree with observation. We don't know why there is gravity but we do have an extremely good mathematical model for it which we can use to predict its behaviour with such astounding precision that we can use it to accurately describe the gravitational waves given off by a merged of Black Holes over a billion light years away.
As for this engine we have no clue how or why this thing generates its thrust and a possible explanation without inventing new physics is that it emits charged particles which is something likely to lead to a reduction in thrust over time. That in itself a s good reason to be very cautious. Would you volunteer for a trip to Mars using a drive which nobody understands and which might well cut out and stop operating half way there? Sure you might be lucky but should we really be spending billions of dollars on something like that - especially since if we did studies here on Earth first to figure out what is going on it might lead to ideas to develop a far more powerful variant.
There may be a lot to gain but that's not a reason to throw caution to the winds and blow a huge amount of research money on something which should be studied first. I know that's the boring approach and we all want to be zipping around the solar system with amazing rocket drives but if you spend that much research money on something which turns out not to work in the end how many other amazing inventions and discoveries will you have delayed or will never even be found?
Well, yes but there are many other confounding factors too.
I get that it is hard but there is no rule in science that says things have to be easy. Just because it is hard to rule out existing physical effects does not mean you can just skip this step and jump straight to fairies and pixie dust explanations. At least not if you want any scientist to take you seriously. As Sherlock Holmes says "when you have eliminated the possible, whatever remains, however improbable, must be the truth" but the first step - eliminating the possible explanations - is a REALLY important one.
just build a small one, send it to space, turn the power on and see if it moves.
We do in vacuum otherwise things like distant supernovae would change colour over time due to the different arrival speeds of the different colours of light.
Short version: photons seem to have inertial mass after all.
You cannot just rewrite fundamental physics to fix one issue without also looking at the implications of your theory for other predictions which is it likely to change. Worse it seems that nobody has tested these drives for the emission of charged particles. A far, far simpler explanation is that this drive works by electron emission. There are a variety of way this can work which all work in a vacuum but whic would unfortunately not work in space where you are electrically isolated and would eventually build up a counter charge and cause the thrust to reduce to zero over time. This all uses established fundamental physics so it would be nice to see this ruled out BEFORE coming up with crazy new physics. It might be less exciting but it is better science.
I've done a lot of counseling sessions with people whose relationships and lives were ruined by the persons addiction to porn. I have yet to do a single one where sugary drinks, for example, caused it.
That's because these ruin lives and relationships by causing premature sickness and death. Sick people tend to go to doctors for medical treatment and dead people don't have much use for counselling.
On some level we all understand that you have given permission for Slashdot to display your comments to people who view this page.
This is a logical consequence which is directly tied to the point of typing in the comment in the first place. It is not a logical consequence of purchasing a piece of hardware that I want to hand over all my rights to content I create with it beyond the absolute minimum required for the normal operation of the device.
Fusion "products" don't have a shorter half live than fission "products".
No fusion product has a nucleus larger than iron-56 which is the most stable nucleus because any larger nucleus will take energy to create rather than release energy in its production. Fission products typically have mass numbers 2-3 times larger because they come from the decay of elements with mass numbers just below ~300.
As a general rule the half lives of heavier nuclei tend to be far longer than those of smaller nuclei. In addition because the stable value of the ratio of neutrons to protons depends on the mass number of the nucleus both fission and fusion products tend to be unstable because you are taking nuclei with one ratio and combining or splitting them to form a larger or smaller nucleus.
So yes while technically you can have both fusion and fission reactions which lead to stable products that is not common (although perhaps more common with fusion) radioactive products are common and those of fission typically have far longer half-lives than those from fusion because the nuclei are larger. This is a general _statistical_ rule though and you can certainly find specific exceptions.
fission reactors .... fusion reactor - the two are entirely different concepts. In this case the fuels are (relatively) inert when not involved in an experiment, the only radioactivity being produced is during collisions.
Actually that is not really correct. Before use uranium fuel is only very mildly radioactive (the half life is in the billion year range) but is toxic whilst hydrogen is explosive if it mixes with air so both have their own hazards neither of which is really radioactivity before use. Both fission and fusion reactions produce radioactive products such as tritium from fusion depending on what you are reacting. The key difference is that fusion reactions produce light nuclei which, if they are radioactive, decay with short half-lives unlike the products of fission which have half-lives in the thousands or years or more.
Both types of reactor also produce lots of neutrons which activate the material around the reaction when they are absorbed. So really the two types of reactor are very similar the difference being the far short half-lives from fusion which make it far easier to deal with (just store the waste for a few years and it becomes safe) and the fact that the fuel in a fusion reactor is enough to last of order a second while a fission reactor's fuel can last for of order a year. This makes a fusion reactor far safer because all you have to do if anything breaks is wait a second (or less) for the reaction to stop plus you don't have a reactor which contains many months of radioactive decay products that need active cooling.
arsehole, B is for bastard, C is for...
It might be standard but I thought in most countries to be enforceable the agreement had to be made before purchase of the item. You can't sell the item to someone and then try to add a whole load of terms and conditions which were not readily visible on the outside of the box after you already agreed to the sale.
A guy who once left [grapevine.is] in the middle of a parliamentary session while answering questions because he had a craving for chocolate cake?
Leaving seems to be a thing with him: he apparently walked out of an interview when they asked him about his off shore accounts. Perhaps there was some more cake on offer.
David Cameron and George Osbourne are removing welfare that WORKING people need in order to work and be independent
What is wrong with this is not that they are removing it but that working people need welfare in order to work and be independent in the first place. Paying welfare to people who are in work just allows companies to pay lower wages increasing the profits for the fat cats at the top.
Thanks to regulations, American scientific inquiry by young people is limited to how to mod a vaper to volatilize hash oil.
Actually a far better sign of how bad things have become is that you think that both the video and your example are scientific inquiry.
Seriously, free webmail is unprofessional.
I am guessing that you are not aware that many universities use GMail for business under agreements where Google will actually manage the email for the university domain i.e. my university email address is essentially a GMail account that I can access through GMail on the web or via IMAP. We have an agreement with Google which means that they agree not to mine our email for advertizing and we don't get ads displayed on the Google pages. They also gave us unlimited Google Drive space as well although I suspect if I tried dumping petabytes of ATLAS LHC data there it might turn out to have a limit at some point.
If email is so important to you that you can lose your job if it does the wrong thing, then you should be using an email service with an SLA
I work at a university where we have an SLA agreement with Google (mainly to cover privacy issues) and are supposed, though not required, to use GMail for all official email. However it's also not the type of environment where you would ever get fired for something like this...although it might raise a few eyebrows!
You use the wind/solar instead of hydro when they're available. This preserves the Hydro as on-demand for peak times and/or when wind/solar are unavailable.
Modern hydro power stations use far smaller dams in order to reduce environmental impact and so cannot easily store large volumes of water for later use. Even for stations which do have large dams you cannot rapidly vary the water flow nor cut off the river entirely due to environmental impact: you cannot have some hiker downstream getting washed away simply because everyone turned their kettle on and you opened the flood gates to generate power.
if you can get 50% of your need from hydro then you can simply get the rest from wind + solar.
If you do that then what happens during a calm night when you only have half your power which comes from hydro?
I can't help but wonder what the accidental suicide rate will be for anyone who owns both.
Businesses aren't required to scan the notes' serial numbers, though.
True but that could easily change if a government wanted it to.
And for every Megawatt of Hydro-electric capacity you have you can match it with a megawatt of wind/solar and it doesn't matter how intermittent the wind / solar is because you have the hydro as back-up.
It's not really hydro power you need but pumped storage schemes to act as a backup for wind/solar. This is not the same as hydro because you need a lake at the bottom to pump the water out of when you are running the system in reverse to store energy. On the plus side you do not need to worry about water replenishment for the upper lake which means that you can have a larger height difference that with ordinary hydro. There is no point in backing wind/solar with ordinary hydro because you might as well just use the ordinary hydro and forget the wind/solar.
However this is still not enough. There was a study done a few years ago in the UK which showed that you would need to convert every body of water over a square mile in size in the UK into a pumped storage scheme to provide enough backup for the wind and solar stations that you would need to power the country....and even then you need to find sufficient area to build all the wind and solar stations you need and since there is not much solar in the UK that was a huge area (IIRC equal to Wales).
Wind and solar can certainly be improved and should be an important part of energy generation but if we really want to go carbon neutral then the only current technology which will let us do that is nuclear which comes with its own, but different risks.
It's too hard to install an electrical plug?!
It is if you want to install one which can charge your car rapidly. This is not just your standard wall socket and if you only plug it into a standard wall socket it you get 46km range per hour from Tesla's own figures (so that might be on the optimistic side) so if you ever forget to plug it in you will be 1-2 hours late for work. Even then the 240V socket only doubles the recharge rate.
The comparison of petrol stations to charging spots is also highly disingenuous. For a start a single petrol station has multiple pumps, typically 8-12, so you would need an order of magnitude more charging stations than petrol stations assuming the charging stations are for one car at a time. Then there is the time requirement. A typical tank of petrol will let a vehicle drive ~7-800km. So since most public stations only support the slow recharge rate (again a claim from Tesla's own website) what takes me ~5 minutes at a petrol station will take me 15 hours (=700/46) at a public charging station. Hence if each petrol station has 10 pumps then you need approximately 1,000 charging stations to be able to provide the same number of kilometres of range in the same amount of time.
Electric cars are the way of the future but there are still significant hurdles to overcome before they are ready for mainstream use. The most likely use-case at the moment is for a run-about-town vehicle but for that to happen the cost needs to drop to the ~$20-25k range. I doubt the next generation of "affordable" vehicles will be that cheap...but if they are I may be getting one!