In addition to the comments concerning the fact that there is nothing new at the LHC that wouldn't already be produced by cosmic rays in our atmosphere - there is an assumption in the paper: The production of small black holes at the LHC rests upon the assumption of "large" extra dimensions. There is no experimental evidence for this assumption. Therefore, there are many conclusions one could draw, a few that are consistent with the results of this paper are: There are no large extra dimensions. The parameter space they investigated is insufficient to characterize the real universe.
Have you heard the bitchin' news?! I reject your god because I don't need some elitist hipster cloud club. I've had my fill of standing in lines and getting judged at the door in this life, screw doing it again in the next. So, I bought my front-row ticket to the hottest show in Earth because all the good bands and fun people will be there.
You may be interested in my pamphlet, "So, you've decided to go to Hell."
The majority of the dose at airline altitudes is from neutrons (55%), with only a small component from photons (gammas are photons) - 5%. This is, of course, on average. I do not think anywhere in the preprint they claim to be able to measure anything but photons. Therefore, a cell phone will not do a great job of monitoring your radiation dose at airline altitudes.
However, there is a tool being developed by NASA which does a real-time calculation of your radiation dose along an airline trajectory. Check out NAIRAS
As AC said below - there is no funding to do this. In addition to no funding, there is no incentive. Speaking in generalized terms, scientists are judged on their research record. That is a combination of:
1. How much money they have brought in through grants.
2. How many papers they have published.
3. The prestige of the journals they have published in.
4. How many times their papers have been cited by other researchers.
So, if you keeping your job depends on those 4 things, where is the incentive to check the work of someone else? Especially large, difficult, and expensive experiments. At best, you get a quick "Comment on XYZ" paper that questions some findings and the authors reply with a "Reply to Comment on XYZ" telling you why your comment is rubbish and you didn't understand what they were saying.
This is nothing new. Paypal sucks when it comes to this stuff. If you still use it and this happens - you should have known better. Your own fault. Stop using them and maybe they will get the hint. Or maybe they will just go away.
While there certainly are some humanities students who get support - most of them do not receive full support from their institution. Typically, half time TA with no tuition coverage. This can also be the case for engineering PhDs at some institutions. Almost all science PhD students are typically guaranteed 2 years TA plus tuition even at the very smallest schools. In addition, non-STEM related PhDs take longer (about 1.5 years longer at the median). This leads to more student loan debt for non-STEM PhDs compared to STEM PhDs. Please see this study for a very nice comparison: The Price of a Science PhD
In addition, you make what I believe to be two assumptions by implication about Universities:
1. That professors are hired to teach.
2. That TAs will do a worse job teaching than professors.
Professors are NOT hired to teach - the exception is small private colleges without graduate programs. Professors are hired to bring research money into the University. The University takes in the region of 40-60% off the top of grants "for institutional research support." While this is not always the case (for some grants, the granting institution require the university to commit matching funds) it is more than the norm. Secondly, while professors are typically more knowledgeable in the subject and typically have more experience teaching (by virtue of spending the time as a TA during graduate school), that does not mean they are the better teachers. The best teachers I ever had were evenly split between professors and TAs. While not scientific, my colleagues experiences were similar.
No, I don't just mean Earth. All places outside the near vicinity of the sun, the storm is isotropic after initial onset. Also, it is all of them, not just low energy. As I have already explained it is the magnetic fields carried with the storm that causes this. However, SPE don't have the spectral hardness of GCR typically we only model them up to 1 GeV or so, but some events have had fluxes measured in the 10s of GeV energies.
It is isotropic - coming from every angle and direction. The spatial extent of the event is larger than the Earth and the particles rescatter many, many times off the magnetic fields carried with the storm. Those two factors create the isotropy. Sorry, after the initial shock, there is no directional dependence.
Your statement that you know the direction of solar cosmic rays is incorrect. The initial onset of a solar particle event maybe anisotropic, but soon after, the solar particle event is isotropic once it arrives. This is due to the internal magnetic field of the event that travels with the solar event.
Yes, the GCR does extend to those energies, however, the peak flux of GCR is at about 500 MeV. Which over a million times lower than LHC. This energy range is available all over the world.
Not quite. Cosmic rays are made up of mainly very energetic protons (compared to low energy alphas (helium nuclei) or betas (electrons)) which are very penetrating. For instance, the average range of a 500 MeV proton (near the peak in the cosmic ray spectrum) in aluminum (a common spacecraft pressure vehicle) is about 55 cm or almost 2 feet of aluminum. That is a huge amount of material to put into space.
So, you are correct, stopping low energy particles, especially light low energy particles doesn't take a lot of material. But when the particles are protons and at much higher energies, then it is no longer that case that thin layers of material will stop them.
For high energy alphas, for instance, you also have to account for the nuclear interactions with the shielding material. The cosmic ray nuclei will collide with target nuclei in the shield and create giant sprays of secondaries that are more penetrating than the original particle, increasing the radiation dose received behind shielding.
Active shielding (as opposed to passive shielding that uses more mass of materials) is not a new idea [1]. The Rutherford Appleton Group every other year or so contacts NASA saying, look what we can do. Annoyingly, they do the contacting of NASA through the State department occasionally... NASA looks at their design, says "Uh huh, have you done a tech. demo yet?"
RAL says, "Yes, here are the results."
NASA says, "Yes, but this is for 10 MeV electrons. Which are not really part of the space radiation problem. Where are the higher energy proton and heavy ion results?"
RAL says, "..."
Space radiation protection is fundamentally different from terrestrial radiation protection. Space radiation is much higher energy and consists mainly of protons (but also heavy ions are important due to the Z^2 effect of radiation dose). And it is omnipresent - you cannot get away from space radiation - it is everywhere.
See, the problem with the unconfined magnetic field work is that the size and mass of the equipment to make a magnetic dipole against cosmic rays is prohibitive. The most recent analysis that I know of is by Paluzek [2] and needs a million kg in equipment with a diameter of 100 meters...
A nice review of the science and engineering aspects of active shielding can be found in Townsend (2005) [1].
[1] Townsend, L.W., "Critical analysis of active shielding methods for space radiation protection," Aerospace Conference, 2005 IEEE , vol., no., pp.724,730, 5-12 March 2005, doi: 10.1109/AERO.2005.1559364
[2] M. A. Paluszek, “Magnetic Radiation Shielding forPermanent Space Habitats,” in The Industrialization of Space: Proceedings of the Twenty-third Annual Meeting, American Astronautical Society,36 Part 1, 545-574, 1978.
Seems like this is something technology always deals with - cars and roads OR cell phones and cell towers - early adopters always have difficulties. How is this surprising?
I agree with you on the fact if it was only about oil, there are better pickings. However, oil had to be part of the equation, even it was just a nice cherry on top.
However, I am not sure about your notion that somehow taking Saddam out makes the US safer. Iran and Iraq are old enemies. It always seemed to me that keeping them pointed at each other was smart. However, claiming that there was an arms race that was just getting started seems odd. The arms race between those two nations has been a long standing "normal" in the Middle East. Do you have a reference for that? I would be interested in reading it.
Your analysis of NK is spot in, IMO. Thanks for the well reasoned post.
You do realize that you linked to a study on the perception of corruption of a given government, not an actual empirical measure of corruption. Those are two very different things. Your final statement, which I agree with, does not rest on the incorrect statement before it.
I truly mean anything with a lot of hydrogen. It attenuates the high-charge, high-energy radiation better (less secondary particle production). Water is good, liquid hydrogen is very good, polyethylene is also something that is often studied. I am ONLY talking about materials for radiation shielding here. Realistically, single function materials are not good for design engineers for space. The problem is actually things you want to build structures out of (space certified materials) don't tend to be high in hydrogen.
A small storm shelter can mean many things. One idea would be to have a region of the living compartment (say where ever sleeping quarters are) and have the sleeping quarters walls be always (or simply be able) to be filled with the drinking water from the long duration mission. In the case of emergency, the crew goes there. There have been studies using thick poly blankets where the crew needs to climb in bed during the storm. There was even a small study done of putting the crew's cabin surrounded by the hydrogen fuel tanks (done by Nealy et al. if memory serves). Fun to think about.
For the magnetic shielding, all that matters is the B-field strength. You need something strong enough to constantly deflect approximately 1 GeV protons and below. Don't forget that most realistic magnetic shielding schemes rely on a dipole. Just like on Earth, the "poles" of the dipole are the most susceptible will have to have some other sort of shielding since galactic cosmic rays are basically isotropic in the solar system. You are spot on when you say there are practical engineering issues with large B-fields.
Nothing has really changed in the state of the art of active shielding. They all fail miserably at even the theory stage or practical engineering stage.
You are not quite right. For this sort of radiation, lead is not so great. You want shielding that contains lots of low-Z nuclei. The more hydrogen the better. This is because you get a lot of secondary nuclear fragments and hydrogen minimizes these sort of interactions. For Mars, it actually isn't the solar storms that are worrying - it is the fairly constant galactic cosmic ray background that is more difficult to shield against. It is has a high energy tail that is quit penetrating.
Solar storms are important, but a small storm shelter inside the craft can, in principal, handle this. Storms are typically short, so confining the crew to this area is typically reasonable.
They are not in the business of selling you apps - they want you to buy the hardware that runs that apps.
Then why do they charge you $99 per year for the privilege of making your own apps?
Your question has nothing to do with my statement.
It is like me saying the Sun is yellow and you respond with, why are trees green then?
What does charging developers have to do with it?
To answer your question naively, it is likely to create some semblance of quality by making sure a developer is serious about making an app and to provide an initial quality check. It probably also helps subsidize the whole app review process. Or maybe I am completely wrong... I actually know nothing about Apple app development.
You should see Dan Ariely speak. I didn't realize I had seen him previously until I read his bio on the linked website. He is really a great speaker and has a great amount of insight into irrational thinking. He gave a really great talk on 'cheating' that I saw earlier this year.
That being said, I think he has a point in his quick little blurb. But I also think it wouldn't fit into Apple's business plan to have all the apps cost something. They are not in the business of selling you apps - they want you to buy the hardware that runs that apps.
Servers are typically done outside the ODIN contract, so this is mainly for desktops and laptops. The question, and the one I see all of the top brass having issue with, is what will happen with their treasured iPhones when the contract switches over?
If you read the article you linked, the deal was with HP Enterprise Systems. Today's news is about splitting or selling HP Personal Systems Group.
Yes, I understand that. I guess you missed the point that they were using this contract to force NASA to buy HP hardware... sorry not buy but lease since NASA no longer is in the business of owning desktop hardware.
They were just awarded a huge NASA contract to provide HARDWARE and desktop support (the old Lockheed ODIN contract)... Seems odd.
http://www.hp.com/hpinfo/newsroom/press/2011/110428a.html
Since they are replacing all the Dells at NASA with HP (at HP's request when they started the contract) - why would they now be looking to get out of hardware?
Slashdot Mirror
In addition to the comments concerning the fact that there is nothing new at the LHC that wouldn't already be produced by cosmic rays in our atmosphere - there is an assumption in the paper: The production of small black holes at the LHC rests upon the assumption of "large" extra dimensions. There is no experimental evidence for this assumption. Therefore, there are many conclusions one could draw, a few that are consistent with the results of this paper are: There are no large extra dimensions. The parameter space they investigated is insufficient to characterize the real universe.
Have you heard the bitchin' news?! I reject your god because I don't need some elitist hipster cloud club. I've had my fill of standing in lines and getting judged at the door in this life, screw doing it again in the next. So, I bought my front-row ticket to the hottest show in Earth because all the good bands and fun people will be there.
You may be interested in my pamphlet, "So, you've decided to go to Hell."
This made me so very happy! Well done!
The majority of the dose at airline altitudes is from neutrons (55%), with only a small component from photons (gammas are photons) - 5%. This is, of course, on average. I do not think anywhere in the preprint they claim to be able to measure anything but photons. Therefore, a cell phone will not do a great job of monitoring your radiation dose at airline altitudes.
However, there is a tool being developed by NASA which does a real-time calculation of your radiation dose along an airline trajectory. Check out NAIRAS
References:
Cosmic Radiation @ skybrary
NAIRAS aircraft radiation model development, dose climatology, and initial validation
As AC said below - there is no funding to do this. In addition to no funding, there is no incentive. Speaking in generalized terms, scientists are judged on their research record. That is a combination of:
1. How much money they have brought in through grants.
2. How many papers they have published.
3. The prestige of the journals they have published in.
4. How many times their papers have been cited by other researchers.
So, if you keeping your job depends on those 4 things, where is the incentive to check the work of someone else? Especially large, difficult, and expensive experiments. At best, you get a quick "Comment on XYZ" paper that questions some findings and the authors reply with a "Reply to Comment on XYZ" telling you why your comment is rubbish and you didn't understand what they were saying.
This is nothing new. Paypal sucks when it comes to this stuff. If you still use it and this happens - you should have known better. Your own fault. Stop using them and maybe they will get the hint. Or maybe they will just go away.
While there certainly are some humanities students who get support - most of them do not receive full support from their institution. Typically, half time TA with no tuition coverage. This can also be the case for engineering PhDs at some institutions. Almost all science PhD students are typically guaranteed 2 years TA plus tuition even at the very smallest schools. In addition, non-STEM related PhDs take longer (about 1.5 years longer at the median). This leads to more student loan debt for non-STEM PhDs compared to STEM PhDs. Please see this study for a very nice comparison: The Price of a Science PhD
In addition, you make what I believe to be two assumptions by implication about Universities:
1. That professors are hired to teach.
2. That TAs will do a worse job teaching than professors.
Professors are NOT hired to teach - the exception is small private colleges without graduate programs. Professors are hired to bring research money into the University. The University takes in the region of 40-60% off the top of grants "for institutional research support." While this is not always the case (for some grants, the granting institution require the university to commit matching funds) it is more than the norm. Secondly, while professors are typically more knowledgeable in the subject and typically have more experience teaching (by virtue of spending the time as a TA during graduate school), that does not mean they are the better teachers. The best teachers I ever had were evenly split between professors and TAs. While not scientific, my colleagues experiences were similar.
No, I don't just mean Earth. All places outside the near vicinity of the sun, the storm is isotropic after initial onset. Also, it is all of them, not just low energy. As I have already explained it is the magnetic fields carried with the storm that causes this. However, SPE don't have the spectral hardness of GCR typically we only model them up to 1 GeV or so, but some events have had fluxes measured in the 10s of GeV energies.
It is isotropic - coming from every angle and direction. The spatial extent of the event is larger than the Earth and the particles rescatter many, many times off the magnetic fields carried with the storm. Those two factors create the isotropy. Sorry, after the initial shock, there is no directional dependence.
Your statement that you know the direction of solar cosmic rays is incorrect. The initial onset of a solar particle event maybe anisotropic, but soon after, the solar particle event is isotropic once it arrives. This is due to the internal magnetic field of the event that travels with the solar event.
Yes, the GCR does extend to those energies, however, the peak flux of GCR is at about 500 MeV. Which over a million times lower than LHC. This energy range is available all over the world.
Not quite. Cosmic rays are made up of mainly very energetic protons (compared to low energy alphas (helium nuclei) or betas (electrons)) which are very penetrating. For instance, the average range of a 500 MeV proton (near the peak in the cosmic ray spectrum) in aluminum (a common spacecraft pressure vehicle) is about 55 cm or almost 2 feet of aluminum. That is a huge amount of material to put into space.
So, you are correct, stopping low energy particles, especially light low energy particles doesn't take a lot of material. But when the particles are protons and at much higher energies, then it is no longer that case that thin layers of material will stop them.
For high energy alphas, for instance, you also have to account for the nuclear interactions with the shielding material. The cosmic ray nuclei will collide with target nuclei in the shield and create giant sprays of secondaries that are more penetrating than the original particle, increasing the radiation dose received behind shielding.
Active shielding (as opposed to passive shielding that uses more mass of materials) is not a new idea [1]. The Rutherford Appleton Group every other year or so contacts NASA saying, look what we can do. Annoyingly, they do the contacting of NASA through the State department occasionally... NASA looks at their design, says "Uh huh, have you done a tech. demo yet?"
RAL says, "Yes, here are the results."
NASA says, "Yes, but this is for 10 MeV electrons. Which are not really part of the space radiation problem. Where are the higher energy proton and heavy ion results?"
RAL says, "..."
Space radiation protection is fundamentally different from terrestrial radiation protection. Space radiation is much higher energy and consists mainly of protons (but also heavy ions are important due to the Z^2 effect of radiation dose). And it is omnipresent - you cannot get away from space radiation - it is everywhere.
See, the problem with the unconfined magnetic field work is that the size and mass of the equipment to make a magnetic dipole against cosmic rays is prohibitive. The most recent analysis that I know of is by Paluzek [2] and needs a million kg in equipment with a diameter of 100 meters...
A nice review of the science and engineering aspects of active shielding can be found in Townsend (2005) [1].
[1] Townsend, L.W., "Critical analysis of active shielding methods for space radiation protection," Aerospace Conference, 2005 IEEE , vol., no., pp.724,730, 5-12 March 2005, doi: 10.1109/AERO.2005.1559364
[2] M. A. Paluszek, “Magnetic Radiation Shielding forPermanent Space Habitats,” in The Industrialization of Space: Proceedings of the Twenty-third Annual Meeting, American Astronautical Society,36 Part 1, 545-574, 1978.
Seems like this is something technology always deals with - cars and roads OR cell phones and cell towers - early adopters always have difficulties. How is this surprising?
I agree with you on the fact if it was only about oil, there are better pickings. However, oil had to be part of the equation, even it was just a nice cherry on top.
However, I am not sure about your notion that somehow taking Saddam out makes the US safer. Iran and Iraq are old enemies. It always seemed to me that keeping them pointed at each other was smart. However, claiming that there was an arms race that was just getting started seems odd. The arms race between those two nations has been a long standing "normal" in the Middle East. Do you have a reference for that? I would be interested in reading it.
Your analysis of NK is spot in, IMO. Thanks for the well reasoned post.
You do realize that you linked to a study on the perception of corruption of a given government, not an actual empirical measure of corruption. Those are two very different things. Your final statement, which I agree with, does not rest on the incorrect statement before it.
Do not forget the chief component of acid rain and in gaseous form it is a greenhouse gas. Also, if inhaled at room temperature it is fatal.
I truly mean anything with a lot of hydrogen. It attenuates the high-charge, high-energy radiation better (less secondary particle production). Water is good, liquid hydrogen is very good, polyethylene is also something that is often studied. I am ONLY talking about materials for radiation shielding here. Realistically, single function materials are not good for design engineers for space. The problem is actually things you want to build structures out of (space certified materials) don't tend to be high in hydrogen.
A small storm shelter can mean many things. One idea would be to have a region of the living compartment (say where ever sleeping quarters are) and have the sleeping quarters walls be always (or simply be able) to be filled with the drinking water from the long duration mission. In the case of emergency, the crew goes there. There have been studies using thick poly blankets where the crew needs to climb in bed during the storm. There was even a small study done of putting the crew's cabin surrounded by the hydrogen fuel tanks (done by Nealy et al. if memory serves). Fun to think about.
For the magnetic shielding, all that matters is the B-field strength. You need something strong enough to constantly deflect approximately 1 GeV protons and below. Don't forget that most realistic magnetic shielding schemes rely on a dipole. Just like on Earth, the "poles" of the dipole are the most susceptible will have to have some other sort of shielding since galactic cosmic rays are basically isotropic in the solar system. You are spot on when you say there are practical engineering issues with large B-fields.
These have/are being looked into. See this review by Townsend from a few years ago: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1559364
Nothing has really changed in the state of the art of active shielding. They all fail miserably at even the theory stage or practical engineering stage.
You are not quite right. For this sort of radiation, lead is not so great. You want shielding that contains lots of low-Z nuclei. The more hydrogen the better. This is because you get a lot of secondary nuclear fragments and hydrogen minimizes these sort of interactions. For Mars, it actually isn't the solar storms that are worrying - it is the fairly constant galactic cosmic ray background that is more difficult to shield against. It is has a high energy tail that is quit penetrating.
Solar storms are important, but a small storm shelter inside the craft can, in principal, handle this. Storms are typically short, so confining the crew to this area is typically reasonable.
They are not in the business of selling you apps - they want you to buy the hardware that runs that apps.
Then why do they charge you $99 per year for the privilege of making your own apps?
Your question has nothing to do with my statement. It is like me saying the Sun is yellow and you respond with, why are trees green then? What does charging developers have to do with it? To answer your question naively, it is likely to create some semblance of quality by making sure a developer is serious about making an app and to provide an initial quality check. It probably also helps subsidize the whole app review process. Or maybe I am completely wrong... I actually know nothing about Apple app development.
You should see Dan Ariely speak. I didn't realize I had seen him previously until I read his bio on the linked website. He is really a great speaker and has a great amount of insight into irrational thinking. He gave a really great talk on 'cheating' that I saw earlier this year.
That being said, I think he has a point in his quick little blurb. But I also think it wouldn't fit into Apple's business plan to have all the apps cost something. They are not in the business of selling you apps - they want you to buy the hardware that runs that apps.
I am sure they went with the lowest bidder since federal requires that. But this was awarded before they announced their exit from the desktop market.
Servers are typically done outside the ODIN contract, so this is mainly for desktops and laptops. The question, and the one I see all of the top brass having issue with, is what will happen with their treasured iPhones when the contract switches over?
If you read the article you linked, the deal was with HP Enterprise Systems. Today's news is about splitting or selling HP Personal Systems Group.
Yes, I understand that. I guess you missed the point that they were using this contract to force NASA to buy HP hardware... sorry not buy but lease since NASA no longer is in the business of owning desktop hardware.
They were just awarded a huge NASA contract to provide HARDWARE and desktop support (the old Lockheed ODIN contract)... Seems odd. http://www.hp.com/hpinfo/newsroom/press/2011/110428a.html
Since they are replacing all the Dells at NASA with HP (at HP's request when they started the contract) - why would they now be looking to get out of hardware?