• Hachem
    384
    Femtography and relay races.
    Imagine looking at racers who go as fast as the speed of light.
    The first racer starts running and reaches the position of the second racer who immediately takes off at his maximum speed. Both reach the third racer who reacts exactly the same way, until all racers cross the finish line at the same time.
    The only way an observer could see the light beam moving towards him would be if he could see the different phases of the race as they happened. He has to see the first racer while he is running towards the second, both towards the third, and so forth.

    But then, this observer would have to see something happening before the light coming from that location could ever reach him.
    The observer could be our admiral, or one of the observers on the Earth-Mars hand signals game.

    I asked Ramesh Raskar, the femotography specialist at M.I.T, if he were willing to do such an experiment, but that was a couple of weeks ago, and I am not holding my breath anymore.

    Too bad, because such an experiment would shut me up once and for all. That is, if we are unable to see the light beam growing towards us.
  • Hachem
    384
    Femtography and the Foundations of Physical Science

    Scientists take some ideas as being beyond any doubt, and they use these ideas to build their cosmological theories. Some of these ideas are:

    1) Light goes on indefinitely
    2) The universe is expanding
    3) When we look through a telescope, we are seeing the past.

    These ideas, and more, support each other and give each other meaning. They are all inextricably linked with each other and an attack on one is an attack on all,

    Femtography could give an empirical basis to all those beliefs, and silence any dissenting voice.

    Or it could usher a revolutionary era in physical science.

    I would propose the following experiment:

    Have a laser emit a pulse of a few nano or picoseconds in a vacuum.
    The pulse will remain of course invisible, except maybe for the reflections on the walls of the container. So maybe it should take place in empty space.

    Following the same methods advocated by femtography, one or more sensors should be placed in the path of the pulse some distance away.

    Those sensors should only be turned on after the laser has stopped emitting.

    As I see it, there are only two possibilities:

    1) The pulse is registered, and I would consider that as a confirmation of the contemporary physical theories where light is concerned.

    2) The pulse does not register, and then all bets are open.
  • Banno
    25.3k
    What is interesting, philosophically, is the way in which the ideas presented here fail to form a coherent argument; and yet it is apparent that Hachem quite honestly believes that they do.

    The only way an observer could see the light beam moving towards him would be if he could see the different phases of the race as they happened.Hachem

    This does not obviously follow, and is not argued for. It is a conclusion that is unsupported by the description provided. The light beam receives no mention before this sentence, and so is ambiguous. What could it mean to see a light beam, as opposed to seeing the runners? Yet Hachem apparently does not see these issues. Showing what is wrong with such an ambiguous thought experiment is impossible.

    Then there are the multiple references to other thought experiments. Suppose one showed that the runners was a misguided thought experiment; Hachem would simple move to the next, and the next; so that the effort involved in analysing each would wear down even the most strident critic.

    And the three scientific ideas that are beyond any doubt; these are not assumptions, but conclusions reached.

    IS the way of thinking employed here so different to that employed by idealists or Post modernists or anti-abortionists or second amendment advocates or even Trump supporters? This is why psychoceramics is of philosophical interest.
  • fishfry
    3.4k
    Oh, Femto! At first I thought this was another faux-feminist thread from the assembled sausagocracy. Nevermind.
  • Banno
    25.3k
    can we be sure it isn’t?
  • fishfry
    3.4k
    ↪fishfry can we be sure it isn’t?Banno

    I assume it's femto as in femtosecond, one quadrillionth second. In the US that's 10^(-15) seconds and in Great Britain it's 10^(-24) so your mileage may vary.

    [Edit. In GB a quadrillion is 10^(-24) seconds. But a femtosecond is 10^(-15) regardless].

    Imagine looking at racers who go as fast as the speed of light.Hachem

    This right here is a problem (sticky wicket, in British). Contemporary physics does not allow any such thing. A photon can go at the speed of light, but not a racer. You have to say what your assumptions are.

    * Is a "racer" a photon? Ok, we can work with that I think.

    * Or are you positing some future or alternative physics?



    Imagine looking at racers who go as fast as the speed of light.
    The first racer starts running and reaches the position of the second racer who immediately takes off at his maxi
    Hachem

    Immediately? So information (about the arrival of the first racer) is transmitted instantaneously to the second racer? Well ok, but that's only in some future or alternate physics. I'm not saying it couldn't happen. Only that it violates contemporary established physics. Information can not be transmitted faster than the speed of light. [Modulo this entanglement business, which is fascinating but mostly over my head].

    until all racers cross the finish line at the same time.Hachem

    In whose frame of reference? Simultaneity is not absolute. Another feature of modern physics.

    I don't doubt you have an interesting idea in there, but it would be helpful if you can put your ideas into context. Some of your suggestions violate known physical law. So you just have to tell us what your assumptions are.
  • Hanover
    13k
    IS the way of thinking employed here so different to that employed by idealists or Post modernists or anti-abortionists or second amendment advocates or even Trump supporters? This is why psychoceramics is of philosophical interest.Banno

    What do we say of those who can't see the flaw in lumping all who they disagree with into a single catagory of crackpottery and then identifying them with a poster child who they reject as wholeheartedly as you?

    This is why psychoceramics is of philosophical interest.
  • Banno
    25.3k
    Because I'm being self-critical, as well.

    What is it about crackpots that makes them crackpots?
  • fishfry
    3.4k
    What do we say of those who can't see the flaw in lumping all who they disagree with into a single catagory of crackpotteryHanover

    Yes I know. If you even ask questions about certain things, you get accused of agreeing with every crackpot theory on Youtube. I wonder if those kinds of people are secretly terrified of what they'll find if they allow themselves to ask questions. Asking questions is dangerous. Better to call the questioner a crackpot. That way they don't have to engage with the argument.
  • fishfry
    3.4k

    Very interesting site. Beautiful photos. I'm just starting to read their abstract. It does look very interesting.

    I do have one quibble. They write:

    The effective exposure time of each frame is two trillionths of a second and the resultant visualization depicts the movement of light at roughly half a trillion frames per second.

    Now it's funny, because my little anal-retentive streak that made me go look up the definition of a femtosecond earlier, turns out to be useful after all.

    Remember a femtosecond is 10^(-15) second. That's a decimal point with 14 zeros and a 1 to the right. [.1 = 10^(-1) has no zeros, .01 = 10^(-2) has one zero, etc. It's off by one].

    What's a trillionth of a second? Well a thousandth is 10^(-3), a millionth is 10^(-6), a billionth is 10^(-9), and a trillionth is 10^(-12). [This is American usage. Brits call billions trillions or vice versa. Apologize for being an uncouth yank. Didn't I get in trouble around here a while back on that very thing?]

    So they are about three orders of magnitude off. The title of the paper, "femto", is not backed up by the details. They are working at the scale of 10^(-12) but not 10^(15).

    That's not a knock on anything they're doing, which is impressive work. Just noting that the title may be a little bit hyped. I didn't read far enough to see if it's justified.

    I have heard about this work somewhere. They use statistical techniques I think, in other words they're not tracking a single photon. Rather they're looking at a lot of photons and looking at statistical models of where things are supposed to be. Kind of a computer strobe if my understanding is correct. That's a bit handwavy, I'll say more after I read the article, especially if I flagrantly mischaracterized their technology.

    Anyway yes this is a great experiment. But the stuff you are talking about is way beyond this. Your stuff is speculative physics not based on current physics. Do you agree or disagree with the specific points I made earlier?
  • fishfry
    3.4k
    In case anyone cares, I read the rest of the abstract and wanted to put the OP's linked paper into context.

    First, I was correct that they are not tracking individual photons, but rather putting together snapshots from many different experiments. They say:

    Direct recording of reflected or scattered light at such a frame rate with sufficient brightness is nearly impossible. We use an indirect 'stroboscopic' method that records millions of repeated measurements by careful scanning in time and viewpoints. Then we rearrange the data to create a 'movie' of a nanosecond long event.

    So this is impressive, but there's less here than meets the eye. There's a lot of software munging of a lot of data to put together a "track" of a photon.

    Secondly, about the name Femto. It turns out that they do femtosecond resolution in their measurements, but by the time they put together the software-adjusted pseudo track, they are viewing or modeling events across nanoseconds. So it's not really hype to call it Femto, but you have to read into the details to find out what's femto and what's nano.

    Finally, here is how they describe the significance of their experiment:

    Beyond the potential in artistic and educational visualization, applications include industrial imaging to analyze faults and material properties, scientific imaging for understanding ultrafast processes and medical imaging to reconstruct sub-surface elements, i.e., 'ultrasound with light'. In addition, the photon path analysis will allow new forms of computational photography, e.g., to render and re-light photos using computer graphics techniques.

    In other words there are no fundamental new understandings here. Rather this is a really impressive engineering feat that will lead to interesting applications. The authors do not claim this is any kind of theoretical breakthrough nor do they think this has any kind of metaphysical importance at all.

    It's the OP who has read about this interesting experiment, and extrapolated some unjustified conclusions about being able to control individual photons and line them up like race horses. Nothing in the experiment supports any such inferences. This is not a fundamental experiment. It's a terrific technological accomplishment but I think the OP is reading too much into it. In my opinion, at any rate.

    Well that's my two cents on this. I do recommend that people give this article a click, the pictures alone are worth it.

    http://web.media.mit.edu/~raskar/trillionfps/
  • Hachem
    384
    It's the OP who has read about this interesting experiment, and extrapolated some unjustified conclusions about being able to control individual photonsfishfry

    This is a very narrow reading of my posts. Maybe you should take the videos where one or more objects are gradually illuminated, and imagine that the camera is not on the side as it is on all the videos but at the end of the path of the beam. Nothing needs to be changed further to the experiments, and instead of my racers arriving all at once or not, the question becomes:

    Will we see the whole scene enlightened at once, or will we see each object getting lit by the beam as the beam (or rather pulse) progresses?
  • fishfry
    3.4k
    This is a very narrow reading of my posts.Hachem

    Agreed. Narrow. But not IMO unfair.

    You still haven't responded to my specific concerns regarding the violations of known physical law in your thought experiment.

    You understand we are not seeing a "beam" but rather a statistical interpretation of a beam. Perhaps you should just explain your idea in terms of photons and not reference this experiment at all, which seem to be about something else entirely.

    Also I believe you are referencing other posts you've made, but I haven't read them. In this post you talked about "racers" that can communicate at faster than light speed. I'm perfectly justified in asking you to put that in context.
  • Hachem
    384
    I have indeed extrapolated from the experiments as presented in femtography. I am not advocating any new physics. You should be able to answer the question easily enough without any further reference to any of my posts:

    What would the sensors register if the camera or cameras were placed at the end of the trajectory, instead of on the side?

    That is the only relevant question, the rest is presentation details that may or may not be important.
  • fishfry
    3.4k
    What would the sensors register if the camera or cameras were placed at the end of the trajectory, instead of on the side?Hachem

    I have no idea. Maybe you can explain this to me. How am I supposed to know what are "presentation details" that "may or may not" be important? I responded to the post you wrote. How am I supposed to know what you consider important? Your post has at least three specific violations of contemporary physics. You might consider writing a post that's more clear.

    Like I said, you may well have something interesting to say. But I don't think you've said it.
  • Hachem
    384


    Then you shouldn't bother any further.
  • Hanover
    13k
    It's a fair question. The crackpottery of the OP lies not in its incoherence. Plenty of normals skip steps in their explanations. The problem lies in the inability to accept that failure and in defending the irrational as if it were rational.

    Your examples were not necessarily all examples of crackpots, but were instead a listing of those conclusions you simply disagreed with. It therefore appeared simply as an arrogant display of personal rightness, and not as a true analysis of crackpottery. I tell you this because you noted you wished to self-evaluate.

    I'd place conspiracy theorists, anti-scientists, and half-brains under the crackpot umbrella. A half-brain is a Hanoverian term that describes someone who has mastered academic lingo but only halfway understands what they mean. This person lures a full brain into a conversation that quickly ends in disappointment when the half brain says something revealing.

    A crackpot example: I recall a long conversation I had once with a poster who insisted that American jurisprudence was doomed from its inception due to its adherence to the philosophy of J.S. Mill. Not only did he misinterpret Mill, he didn't view the fact that Mill was born after the Constitution was long since written and signed as problematic to his position.

    If you get drawn in and pissed off, you are dealing with a crakpot extraordinaire as they say in France. The PoMo movement is healthy in France by the way.
  • Hachem
    384

    You are a really poor excuse of a moderator and editor. Instead of name calling why don't you try presenting arguments for your convictions? Or is all you can do is hide behind insults and your status?
  • fishfry
    3.4k
    I'd place conspiracy theorists, anti-scientists, and half-brains under the crackpot umbrellaHanover

    I'll take the bait. Question. If I say the following: "The 9/11 commission spent $15M. They spent $40M on Bill Clinton's blowjob. There are many inconsistencies and outright impossibilities presented as fact in the commission report. I would like to see a proper investigation done. I would like to see at least a blowjob's worth of investigation on what was the crime of the millennium."

    If I said that, would you regard me as a crackpot?

    Do you think that anyone who even questions the government narrative of a public event is automatically to be labelled a crackpot and dismissed? "Remember the Maine?" The Gulf of Tonkin? Saddam's WMDs? When the government lies us into war is one a conspiracy theorist for asking for a thorough and comprehensive investigation?

    I really want to hear this.
  • Hanover
    13k
    To your questions, in order: No, no, yes, not really well, yes, no.

    Saying, I want a more comprehensive report about 9/11 is different than the crackpot conclusion that GW orchestrated it.

    Wanting reasonable allocations of money for investigations is reasonable . Wanting the same allocation of money for what you think was unreasonable for something that you think reasonable isn't reasonable. Unreasonable decisions ought not be used as binding precedent. If you insist that it should, you're unreasonable.
  • Hanover
    13k
    My criticism was that I didn't know what you were talking about and neither do you. I'm sure of the former, but I'll admit that the latter may be false because of the former, although I am sure the problem of the former lies with you.
  • Hachem
    384

    you are full of it, so excuse me if I do not take you seriously. You are unfit to be a moderator, your prejudices are blinding you.
  • fishfry
    3.4k
    Saying, I want a more comprehensive report about 9/11 is different than the crackpot conclusion that GW orchestrated it.Hanover

    You say that here. But anyone who questions anything is generally labelled a crackpot. If you say "I want a better investigation" you get labeled as someone who believes Cheney personally picked up the phone and said "Go!" And tell me something. What is your evidence he didn't? You think he's too nice a person? LOL. Maybe you never heard of the report of PNAC, the Project for a New American Century, in which Cheney and others specifically called for a "new Pearl Harbor" to make Americans willing to go to war in the Middle East and destabilize seven specific countries. If I'm a conspiracy theorist it's because I've read the published plans of the conspirators.

    When you ask questions, you get labelled a crackpot. Are you following this Las Vegas shooting story? Even people who aren't usually conspiracy nuts are saying this story stinks to high heaven. But "reputable" news outlets label anyone who questions this a conspiracy nut or a lunatic.

    That is a technique to keep people from asking questions or using their own judgment and common sense. I choose to push back. It's more vital than ever to question the government's account of virtually everything that happens. The US has been at war in half a dozen countries since 9/11. The exact countries named in the PNAC document. We're not supposed to ask questions?

    Ok I've said my piece. I wish you'd rethink who you regard as beyond the pale for doubting and questioning what the government says. They lied us into the Vietnam war, they lied us into the wars in Iraq and Afghanistan, and now nobody even knows all the wars we're involved in. Those four guys who got killed in Niger, did you even know the US was at war in Niger?

    The American people have gotten numb to the government's war machine. We dare not ask questions. If we do, our friends and neighbors label us "conspiracy theorists."

    Try to think for yourself.
  • Hanover
    13k
    I admit to having certain prejudices. Please tell me you're not Dutch.
  • Hanover
    13k
    You greatly misstate my position. Questioning is not the same as arriving at unsupported and outlandish theories.
  • fishfry
    3.4k
    You greatly misstate my position. Questioning is not the same as arriving at unsupported and outlandish theories.Hanover

    I think Cheney not only ordered it. I think he personally flew the planes. That's my Lone Hijacker theory. Now you can call me a nut if you like. By the way I quite agree with you that theories should be supported by evidence. But are you aware that the government's own 9/11 story is an unsupported and outlandish theory? The commission's co-chairs said publicly that the commission was set up to fail. But we should believe it anyway? Why? What is the epistemological principle according to which we should believe the account of the 9/11 commission, which is riddled full of bad logic, unsupported claims, shoddy investigative work, and outright impossibilities? That has no credibility even with the people who authored it?

    Why should we believe it? If we are rational people who demand evidence and logic, we must in fact reject the report of the 9/11 commission. That makes us conspiracy theorists. Crackpots. Crazies.

    So where do you draw the line? What questions may be asked and what theories are too outlandish? 19 Arabs with boxcutters because they hate our freedoms. Now that's outlandish.
  • Hanover
    13k
    Yep, you're a crackpot under my definition.
  • Hachem
    384
    Please respect the thread's topic.
  • fishfry
    3.4k
    crackpotHanover

    By what epistemological principle should I accept the findings of the government's 9/11 commission? What filter or principle of reasoning should I apply?

    Say it's 1964 and Lyndon Johnson tells me that a US ship was attacked by North Vietnamese in the Gulf of Tonkin, therefore we must dramatically escalate the war in Vietnam?

    What principle should I use to believe or disbelieve it?

    Why do you think I'm a crackpot?
  • Hanover
    13k
    This isn't complicated. If you have a reasonable basis to reject an account (including believing the source isn't credible), then you should reject it. You don't then get to make up something else.

    Not believing the official US 9/11 report and declaring that Cheney ordered the attacks are two different things and that I have to point that out indicates an irrational element in your reasoning.
bold
italic
underline
strike
code
quote
ulist
image
url
mention
reveal
youtube
tweet

Welcome to The Philosophy Forum!

Get involved in philosophical discussions about knowledge, truth, language, consciousness, science, politics, religion, logic and mathematics, art, history, and lots more. No ads, no clutter, and very little agreement — just fascinating conversations.