Category: Science

Science is your friend (written August 13th, 2013)

On By Swarn GillIn Philosophy, Science7 Comments

A little while back I posted a quote from Carl Sagan about how we live in a world dependent on science and technology, but yet few people know very much about science and technology.  I wanted to say some more about the importance of science to kind of address some of the other things that worry me in regards to the attitude about science I’ve encountered in people.

First let me say that science is difficult but it is natural.  From a very young age we clearly have scientific principles within us that guide our learning.   You can watch young children play and manipulate objects and see that they are simply learning how those objects move, sound, feel, etc.  This is at the heart of experimentation.  Of course science in practice is far more sophisticated, but every child is a little scientist.  Of course every child is also a believer. A defenseless life form who is trying to survive and doesn’t know that it has the luxury of taking its time to think about things, the luxury to reason.  For even as safe as the world might be for some young humans it doesn’t know that.  And keep in mind for many humans even today it is not that safe.  So we have this scientific side that demands we pause, reflect, test and make conclusions based on this evidence.  Then there is the side of us that takes on face value what our parents or other authority figures tell us, we tuck it away and move on to something else.  Believing has evolutionary advantages because it’s quite simply faster.  Both types of thinking have their value up to a point, but in many ways the believer is most valuable to the self, where as the scientist is perhaps most valuable to the larger population and over a longer span of time.

Of course you actually don’t need to learn about science to survive.  One could argue that you don’t need to learn about science as a member of society if you simply accept that scientists are as right as they can be, based on the evidence that the community analyzes and thus trust the decisions and recommendations that they make.  This would work, except that, at least in the US, everybody still has an opinion about scientific issues and feel that it is of equal value to that of the scientist even when they are illiterate about the subject material and how science works.  No issue makes this clearer than when you look at the attitude of many towards climate change.  Though almost every researcher in the natural sciences find evidence of man-made climate change there are many who find the issue to be one of belief, bias and conspiracy.  So it’s not only a problem that few people know about science, but that many of these uninformed people will form an opinion based on pseudoscience, pundits, or even in some cases intellectuals who are not scientists, and then not support legislation that is based on the recommendation of the scientific community.  The issue of evolution in this country is another example, and it bothers me when people say the phrase “believe in evolution”, because evolution does not require belief.  It only requires an objective analysis of evidence and this is the natural conclusion that anyone would come to based on that evidence.

I have even learned that there are many people who don’t understand what evidence is.  What they consider evidence for something is not evidence and this is where math comes into the equation.  No pun intended.  Part of the reason why science is difficult is because math is at the heart of science.  And I don’t mean just complicated equations although sometimes to really understand a certain area of science it helps to understand some complicated equation.  The heart of math is logic.  Math is in fact cold, unemotional, and doesn’t care one iota about your passions.  This makes mathematics actually quite unique in our world which is actually why I’m passionate about it.  Math doesn’t care what you want, it’s there to tell you what is.  When you try to have a debate with someone about an issue you can see that most people don’t know how to make logical arguments.  Hey I make plenty of mistakes too, and logic, reasoning, math requires us also to be humble.  When someone points at an error in your logic it can be a blow to the ego.  Math may be perfect, but we are not. It’s something you have to get over if you want to continue to learn and grow in this world.  You are going to make mistakes, but you need to keep trying to understand where flaws in your reasoning might lie.  Often this is because you are missing pertinent information.  Logic is also dangerous because entire logical frameworks can be built on faulty premises.  The example I always use is the logical argument:

All A are B

All B are C

Therefore all A are C.

Few can argue here as this is a logical truth.  But let’s put actual information in there now.  All cats are black.  All black things are hats.  Therefore all cats are hats.  This is a silly example of course, but logic can lead us down a road when the premises we use to draw our conclusions are faulty.  However, we can test the truth of “All black things are hats” and “all cats are black” through careful observation and science.  As silly as this argument sounds it could be that any individual might come up with this conclusion if they really had not seen anything black other than a cat.  An authority figure in their life tells them now that “all black things are hats”.  You’ve never seen a hat, but you trust this adult.  So your brain makes the logical conclusion that all cats must also be hats.  The error is not your conclusion, but rather that you A) have seen only a small portion of the things that are black, and that you took at face value what the authority figure said about black things and hats.  Thus what the example actually shows is how easy it is to draw incorrect logical conclusions through having incomplete information about the world.  This person may even begin to argue with other people on the nature of cats and black things, but always remember to be humble and realize that you may not know as much as somebody else in regards to a particular subject.  This extreme example also demonstrates why religion fails to explain how the world works effectively because it generally suppresses the investigation into the truth of promises and relies heavily on simply trusting in what an authority figure as truth.  This is why religious texts have numerous contradictions and outdated information.  Any community which purports a text or set of guidelines that are not open to question, scrutiny, and testing that is a dangerous community.  That community is the exact opposite of a scientific community.

Any individual scientist can also fall victim to his/her own gospel and this is of course why I don’t advocate that a society simply trust what scientists have to say, but rather is educated about science themselves.  Questions are what drive scientists, and any one scientist would easily admit that they may not have seen all the evidence, interpreted it correctly, or may be subject to bias.  This is where the value of community comes in.  The greater the volume of scientific literacy in a community the more likely we are to arrive at correct answers about how the world works and most likely more quickly.  Any researcher always faces some criticism from others in their field.  People who disagree with them and ask them questions that they may not have considered, which eventually makes them more careful researchers in the future.  Scientists make use of peer-review for their research, as well as the fact that numerous scientists may be working on a particular problem independently but attempting different methods at solving the problem.  This can reveal holes in an individual scientist’s research and this is extremely valuable because once again we can save time and energy by learning which methodologies are inefficient, which question shouldn’t be asked, and which questions we should ask.

Science is most successful when both old questions are re-asked, and new questions are asked.  A continued investigation of old questions that are attacked from new angles and with new information allow us to make sure the foundation in which we tackle new scientific problems are sound.  Science does this all the time, which is why occasionally you find out that something you learned in school may not be true anymore.  Science makes mistakes, but continually marches forward self-correcting along the way.  If you start trying to move forward on a faulty premise you find that you hit a wall. Forward progress can sometimes stall, sometimes even by the ego of a big scientist in the field, but eventually something that isn’t right will fail.

And even if you become scientifically literate are all your problems solved?  Certainly not.  There are a lot of things to know in the world and it is time consuming to be knowledgeable about the all.  There are plenty of areas of science I know little about.  Microbiology, organic chemistry, atomic physics are just a few.  So when I read something that a community of those scientists has said, I have two choices.  I can trust them.  Knowing how scientists work I can feel pretty confident that within their own community they are doing exhaustive and rigorous research to come to the conclusions they have.  However if I’m not satisfied, I can start learning.  I can start reading.  There is a lot of information on the web now so even the simplest of terms in a particular field I can find definitions for.  I could read a few books of course too.  All this takes time.  But perhaps it is worth it.  What seems surprising to me though is all the people who would argue against something like climate change having very little understanding of the subject and spouting off incorrect information from articles which actually prey on the scientific illiteracy of the reader to convince them to a certain point of view.

We live in an age of information.  But as a consequence there is also a lot of misinformation out there.   Science can be most powerful in just helping you understand the quality of the information that you are being given, and help you separate the bad from the good.  I see many people getting their information from terrible sources.  As a scientist here are some of the steps I take when trying to learn about something (this is also how good research is done):

  • Look for consensus.  Try to find independent sources that say similar things.  This can be hard on the internet as sometimes one person’s words get republished (and uncredited) on other sites.  But usually the wording will be very similar.
  • Try to find the author.  Who is he or she?  Do they even have a degree in the area of science they are writing about?  Many critics of something  like climate change do not come from people who actually are knowledgeable about the physics that apply to climate.
  • Does that author publish journal articles on their findings?  Before any science becomes mainstream it always first or at least simultaneously published in a journal.  But also important is the nature of that journal.  Does that journal have anonymous peer-review?  Does that journal seem to fit the subject of the article?  Is the journal regional, national, or international? Many weaker studies that represent bad science or relatively inconclusive findings will be published in small journals, journals without peer-review or in journals only loosely related to the subject area to avoid it being reviewed by other appropriate experts.
  • The best sources of information often site numerous studies and try to culminate those findings to build a logical narrative.

Finally it doesn’t hurt to try and read other contradictory articles, provided that those articles meet some or all of the criteria mentioned above.

A democracy is only effective when its people are intelligent and well informed, and there are plenty of issues that are important to our future and future generation.  Climate change is only one of them.  Learn about biochemistry and understand more about vaccinations, diseases, stem cell research, genetically modified foods.   Learn about Earth Science and understand more about water quality, soil and water conservation, climate change, natural disasters, and pollution.  Learn about physics and understand important issues related to radiation, heating and cooling, lasers, and of course physics is such a fundamental science that it is the root for understand many other scientific disciplines.  Learn about biology and understand how life works such as: the similarities and differences among species, the human body, wildlife conservation, and evolution.  And don’t forget that scientific investigation is used to try to answer many questions in the social science.  Fields like sociology, psychology, education and communication.   For instance we can learn with science that if we want abortions to happen less and less than imposing one group’s morality is less effective than education, good health care, and easier access to birth control.  Learn about math and statistics so that you can understand when numbers are significant, what probabilities mean, and what uncertainties might be associated with a particular finding.

To conclude I would be remiss if I left out all the other amazing things that add color to this world.  In your quest for scientific literacy don’t forget about the humanities and arts.  Get lost in those things that inspire and excite the imagination.  Tell stories and listen to stories because there is insight interwoven into the narrative.  Learn about history and understand the process of discovery through the ages, learn about change, and the rise and fall of civilization so that we can learn well the lessons of the past for a better future.  Lose yourself in music, whether it is by dancing or just letting your mind and heart get carried away by the melody, or even just singing at the top of your lungs in the car.  I don’t expect everyone to get their sense of wonder from science, so make sure you are doing things that keep making you wonder about the world.

Religion and Models

On By Swarn GillIn Philosophy, ScienceLeave a comment

I was thinking today about models.  No, not supermodels, as a nerd I was thinking about computer models.  Computer models such as those that try to forecast the weather or forecast climate change take our understanding of how the world works and try to look at what is happening now and test that understanding by trying to predict what will happen later.  Then I thought about religion and how it is also a model.  I truly think that religions, at least at their inception, have the same intent as the models we use in science.  That is to look at what is happening now, to try and understand the world, and come up with an algorithm for how to live better lives.  To take way the unpredictability of life, which often causes great stress and fear, and replace it with a set of principles which, if followed, can help one feel more peaceful about the future.  That feeling alone can give great comfort and lead to even great success.

What is also similar is the fact that there are often numerous models that try to do the same thing.  If we look at general circulation models that try to forecast climate change we can see that there are several in use today.  They have many similarities as there is much we universally understand about the climate, but then there are different assumptions that different groups of scientists might make that lead to differences in the outcome of the model.  This is not too different from religion since religions all have many similarities, yet enough differences that each one does not necessarily produce the same results.  The main difference here is that in science when we look at the results and they do not seem to do a good job of representing a true understanding of the world we make adjustments.  We reevaluate our understanding and we make changes.  With religion however changes are general not made.  Instead brand new religions crop up, or denominations split off from one religion to produce a similar religion but with slight changes.  This may not be completely unlike computer models either to represent natural processes either, however if a model was made to the point where it was completely accurate, everyone would use it.  And overtime computer models do get more and more accurate as understanding increases and constant testing allows us to make appropriate adjustments.  Another important difference is that a computer model can only be a useful tool if it produces meaningful results.  Religious models can be used as a tool regardless of whether they are good or bad models, sometimes to terrifying consequences.

As I child I had a Christian mother, and a non-practicing Sikh father.  But much of his family and friends practiced, and what was clear to me is that there were good people on both sides, who grew up with completely different faiths.  Either both sides were right, or both sides were wrong; meaning that either two different stories were true, or that neither story was the whole story.  It seems to me that the latter must be the case.  If we look at religion as a model and test its validity based on its intent, which is often to rise up against repression and gain freedom in the way of life you choose, to give purpose, to give peacefulness, to act generously and compassionately to those around you, religion might do pretty well.  We all know religious people that are good people and if you pay attention you will see good people of many faiths.  Faith has been proven scientifically to be a good thing and we should all recognize the benefit for it in our life. It seems to me that if God is an explanation to the universe at all and it is the correct model for our existence and purpose then the model should converge.  However after 10,000 years of civilization convergence does not seem any closer.  Perhaps there are fewer religions in some way, but human history shows that religions have been more often forced on to others as nations have been conquered rather than people flocking to it because it looks like a better way to live and that it looks like a better explanation for our existence.  And in some ways even if there are fewer religions they are replaced by denominations and different groups of people pick and choose parts of the larger dogma that make more sense for their particular circumstance in their part of the world.  And we must also recognize that there are plenty of secular humanists, atheists, agnostics who are also good people, who don’t prescribe to any religion and yet manage to have compassion, kindness, and generosity, thus demonstrating that peacefulness and happiness are not contingent on using a religious model.

It is proven, time and time again, that cooperation is what makes us better and more successful.  Therefore, we should be focusing on things that unify us as people and as a species.  Let’s not cling to what makes us different, but concentrate on what things make us similar.  Maybe we fear the loss of our individuality, but I submit that it will always be there.  Because successful cooperation might require some redundancy but it also works best when it is made up of a mosaic of people with different strengths and ways of thinking.   We can thus appreciate the differences that make us individuals, but take comfort and be peaceful in the things that bind us together.  I don’t believe this thought to be utopian in any way.  I don’t know what the future will look like or should look like.  I am no model.  I only recommend a direction or path; something new to try.  Who knows where It will lead, but it’s a pretty good direction to head in don’t you think?

My thoughts on guns (written July 20th, 2012)

On By Swarn GillIn Commentary, ScienceLeave a comment

So, the shooting in Colorado makes me angry and sad, as I am sure it does a lot of people.   It leaves us with many questions.  I think more so because we are in general a fairly orderly society and peaceful despite differences in ideologies, few of us would ever do something so heinous.  If this was South America where gun deaths happen so often we might still be angry and sad, but it still wouldn’t be too surprising.  I think after the many shootings that have taken place though now, even I have become less shocked by this.  As I read comments on articles, it also makes me angry because the argument erupts in to gun control.  I don’t know if this is the right answer, but what I do know is that faulty logic largely drives the debate; on both sides.  So I thought I would deal with some of the common errors in logic.

1.       Banning guns would end these types of incidences.

This of course is not true completely.  Guns can be obtained illegally.  Crazy people still exist, and often clever ones who can find different ways of ending a lot of lives if they so choose.  There is no denying this.  The correct solution to understanding these issues is not the knee jerk reaction but to understand why people like this exist.  What can be done to help them?  What are the warning signs?  Do they exist in other societies?  And in those societies does access to weapons of deadly force make them more likely to cause harm?  To my knowledge when these incidences have happened in the U.S. the media never really brings up these questions.  It always goes to gun control.  I can understand the knee jerk reaction though.  We all do it.  Let’s say you’re a parent and you can now start feeding your kid the food you eat and not just mashed up peas and carrots all the time.  So let’s say you give your child a soft taco with chicken, cheese, lettuce, onions, and tomato.  The kid likes it, but feels sick right after eating it.  The immediate reaction is to have your kid not eat anymore.  But this doesn’t mean he can never have a soft taco.  You’d start to say…hmm…do I feel sick…since you have a higher mass it might take longer for you to feel the effects and maybe the chicken was bad, not cooked enough.  Then you might take him/her to the doctor later to see whether they might be allergic to one of the ingredients because there were 5 foods in the taco that they had never had before.  So once again it comes to asking the right questions in the end, but knee-jerk reactions are natural.

2.        Banning guns is unconstitutional  because of the Second Amendment.

This line of reasoning is faulty on many levels.  For one, unless someone can provide me with more definitive resources there is debate as to the intention of the second amendment and this debate has yet to be resolved.  Pro-gun people will say it was so that we could defend ourselves against a tyrannical government and anti-gun say it was for development of militia.  If one imagines what life was like in the early days of the U.S. it makes sense that guns would be made a right, because population densities were very small, and law enforcement would have been extremely difficult.  And it clearly was on the American frontier.  Yet it is also quite handy when you have a tyrannical government, which I don’t think we’ve had in over 200 years as a nation.

What is often left out of this argument as well is that the 2nd Amendment says “Well regulated militia…”, because are a bunch of homeowners in the suburbs with guns a well regulated militia?

The flawed logic though is holding to a 200 year old amendment like it was flawless.  Just like the bible which has things that pertain to the time it was written, so does the constitution.  Did the forefathers really think the constitution was perfect and timeless?  Undoubtedly no.  That’s what an amendment is.  The way society and technology has changed since then is immense.  It makes no sense why we should be held to a document that old.  We should in fact constantly be modifying it to help solve problems faced by our society.  When it was written the population was less than 1/100th of what it is today and the most dangerous weapon you could have was a musket, that took a few minutes to load, you got one shot, and it wasn’t overly accurate.  Would the founding fathers have made the second amendment if there were laser guided sights and semi-automatic weapons?  I don’t know, but I ask this question merely to point out that the logic one uses may depend on the times for which the decision was made.  Too many people in this country tend to hold to the constitution like it’s a bible and should be unchanging.  As a person who has become active in my faculty union on campus I see both the benefits and negatives of being bound to a document which is nearly as hard to change as the constitution.  It can be very binding in a way that doesn’t help solve problems that are different or new from when the contract was written.

The other faulty line of reasoning here is that the founding fathers were geniuses or something.  They were human, they made mistakes, and maybe some of them were brighter than others, but they fought, and came to compromises.  Now when a compromise is made it could be that both sides of an issue have merit, it could be that the other person was just plain wrong, but compromise was needed in order to just finish the thing and get an overall product that everyone would agree with.  The value we should take from the constitution is not so much its substance (although there is still a lot of great stuff in it) but the work ethic that was involved in putting it together; cooperation, idea exchange, and coming together to solve problems of the day.

3.       Gun deaths are higher in countries where guns are banned.

Nobody ever quotes some actual figures.  A very worthwhile site to go which has data collected by an international collaborative group, but based out of Australia is http://www.gunpolicy.org/

When you look at countries that have a lot of deaths by firearms and have restrictive policies, these are always third world countries with poor economies.  There is a huge educational gap, and a huge income gap.  United States has the highest murder rate and firearm death rate of any industrialized nation with a similar standard of living.  As a comparison between the UK and the US, there are about 4-5 times more homicides per capita in the U.S. than in the UK, and firearm homicides are 100 times more likely.  Now anti-gun people might excited by this statistic, but if firearms were the only thing to blame, we would expect the homicide rate per capita to also be about 100 times greater, but it’s only 4-5 times more likely.  So we cannot say that banning guns would make the homicide rate go down significantly in the U.S. Nevertheless if restricting firearms even reduce homicides by as little as 10% which is supported by figures from other countries similar in standard of living to the U.S., isn’t 10% a good thing?

4.        Banning guns only makes people look for them illegally because that’s what happens with drugs.

Comparing drugs and guns is difficult.  On one hand I do think that if guns are legal, all drugs should be too.    If it really does all come down to personal choice, then the same argument can be made for drugs.  Some drugs however are habit-forming.  Guns are not (well of course anything can be habit forming to a certain extent, but I’m talking about a physiological addiction).  However making drugs legal would save a ton of money that could be put into education.  The need for meth labs would probably disappear, because you could just buy a hit of something at the grocery store.  You’d probably have cleaner drugs that don’t poison your body quite as much also.  What the UK v. US comparison does show is that high gun restriction does not lead to a high amount of unregistered firearms.  There are only 6.7 per 100 people with guns in the UK, with 100 times less firearm homicides.  While there are still a high amount of homicides in the UK, it is clear that those wanting to murder aren’t going, “Bah I can’t get a gun legally, I’m going to get one illegally!”.  Comparing guns with drugs, or say that illegally obtained guns will rise in equal compensation in simply untrue.

5.       Studies show that homicides through other means increase when you ban guns, so nothing changes.

This is true, but only in part.  Of course if you take away a gun, and you really want to murder someone you can find a way.  So knife deaths increase, piano wire, the list goes on.  But there is a big difference killing someone with a gun as opposed to other methods.  You cannot just throw a knife into a crowd and expect to kill anyone.  It is also a lot easier to avoid being killed by a knife wound.  In general the person has to get close, it takes longer, and it’s brutal.  You have to listen to the person suffer, the blood will certainly spill on to your hands, perhaps more depending on whether you cut an artery.  If it wasn’t a fatal wound you may have to grapple with the victim.  Thus the size and strength of the victim compared to you is important.  With a gun you can stand at distance.  You can be behind them.  Size isn’t as important.  The psychology of the two acts is different.  It’s hard to rob a bank with a knife.

6.       Guns are necessary to protect us from people who come in to our homes/person with the intent to cause harm.

How often does this actually happen?  According to www.fbi.gov the number of violent crimes (murder, forcible rape, robbery, and aggravated assault) in the U.S. for 2010 totaled 1.2 million.  If we assume that all these crimes were committed by a different person (which is likely not true) but it’s a reasonable assumption to make, given that we must take into account violent crime that may not have been reported, that means about 0.35% of the population of the U.S. are those who would commit violent crimes.  Not a high percentage, but let’s say any percentage is too high.  And remember that compared to other countries with a similar economy and standard of living the U.S. is the highest, then the 88.7 guns owned/100 people don’t seem to be making much of a difference.  The high number of firearms is not a deterrent at all to violent crime, and yet we are told that we are safer with one.  And of course the percentage is not uniform across the states…it is highly regional, so the idea that we are always in danger if someone assaulting us, robbing us, raping us, etc with the threat of force is pure fear mongering when you look at it statistically.

7.        Guns are necessary to protect us against our government.

This is the worst bit of fear mongering.  Once again we look at www.gunpolicy.org and see that there are many countries (again comparing only to ones with strong economies and a comparable standard of living and education) that have restrictive gun laws and the government has yet to start massacring their people.  The UK government hasn’t.  In 2001 Belarus passed legislation to increase restrictions on firearms.  Guns there are only for military or law enforcement.  Citizens cannot own handguns or revolvers, and to get a gun you need to show you need it for hunting.  Homicides went down by 50% since 2000 and firearm homicides by 80%.   The Belarus government has yet to show any signs of enslaving its people.  Yes this is not a comprehensive list of examples and my point here is that there are plenty of counter examples to the claims pro-gun people say, and so their logic does not even follow in general and then few rarely do their own research in order to come to any conclusions.   Think what you will of Michael Moore, but his thesis in Bowling for Columbine that we live in a “culture of fear” seems to be spot on.

8.   Automobiles cause more deaths every year so we should make automobiles illegal too.

There are many other anologies of this sort including the use of spoons, because people get fat and die of heart attacks, soda, etc.  For better or for worse it took me awhile to spot the flaw in this type of analogy even though I know it was a false analogy.  The reason has to do with the intention of the object.  Automobiles and spoons were not created as objects to commit crime, acts of violence, or to kill.  An extreme analogy might be to say that life is the chief cause of death, so we should not make babies.  The gun was invented to kill.  To kill from a distance, to kill quickly.  It struck me as ironic that pro gun arguments would use this logic and ignore intention.  Since much of their arguments involve the intention of the writer’s of the 2nd Amendment.  Showing that intention is pretty important to them.  Laws have intentions, as do objects.  Why create an object if it has no use?  Automobiles, spoons, guns all have uses and their inventor had an intention for those objects.  Only one out of 3 of those has the intention of deadly force.

9. Criminals don’t obey laws so what’s the point in making a gun law.  If criminals always break laws, then what is the point of having laws?  Nobody who is pro-gun has been able to answer this for me yet. If we always adopted the attitude that laws do not deter criminal behaviour, then all laws have no value.

Well if you’ve read this far, perhaps you are willing to read a bit further.  Yes, I’m a liberal atheist and I know facebook friends who are going to argue with me, but I know many who own guns and am not scared for my life at all.  But because I refuse to give in to fear is also the reason I don’t own a gun.  I am much more interested in the psychology.  I also know myself and I know that shooting a man dead who just wanted to steal my computer so he could afford his next cocaine fix is not something I could easily live with if I did that.  I try to be a good man, and yes even good men die too, but I don’t feel like a gun significantly helps increase my chances of protecting myself against the low probability of being effected by a violent crime.  And yes I do lean towards stronger legislation.  I don’t think anybody who passes a background check should be able to get an AK-47.  Stronger restrictions to firearms might not prevent all of these senseless deaths, but if it stops even one crazy person gunning down 12 people a year.  I feel it’s worth it.  But that doesn’t mean that we shouldn’t keep trying to stop them all together, and that is going to take investigation and understanding beyond banning guns.  They are in our world and they are not leaving, so we do have to understand ourselves better so that we don’t need to use them.  Firearm homicides in general are decreasing in the U.S. and in general the world is less violent than it has been in the past.  May we continue on this trend.  Peace out all.