Using light as a barrier to block people without grilling them












2












$begingroup$


We know that light exerts pressure upon matter.



I'm imagining a hallway where an intense light source on one end shines towards the other end. The goal is to have the beam of light exert so much pressure that a human being cannot enter (or reach the end of) the hallway. Of course, we only want to deter the human, not to burn them to a crisp.



Would this be realistic?






science-based reality-check light radiation







share|improve this question









New contributor




user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$












  • $begingroup$
    Naw, fam. I'm not sure what the math looks like (someone will draft that and put it into an answer, I'm sure), but that would definitely kill the person you are trying to repel.
    $endgroup$
    – user49466
    2 hours ago
















2












$begingroup$


We know that light exerts pressure upon matter.



I'm imagining a hallway where an intense light source on one end shines towards the other end. The goal is to have the beam of light exert so much pressure that a human being cannot enter (or reach the end of) the hallway. Of course, we only want to deter the human, not to burn them to a crisp.



Would this be realistic?






science-based reality-check light radiation







share|improve this question









New contributor




user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$












  • $begingroup$
    Naw, fam. I'm not sure what the math looks like (someone will draft that and put it into an answer, I'm sure), but that would definitely kill the person you are trying to repel.
    $endgroup$
    – user49466
    2 hours ago














2












2








2





$begingroup$


We know that light exerts pressure upon matter.



I'm imagining a hallway where an intense light source on one end shines towards the other end. The goal is to have the beam of light exert so much pressure that a human being cannot enter (or reach the end of) the hallway. Of course, we only want to deter the human, not to burn them to a crisp.



Would this be realistic?






science-based reality-check light radiation







share|improve this question









New contributor




user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




We know that light exerts pressure upon matter.



I'm imagining a hallway where an intense light source on one end shines towards the other end. The goal is to have the beam of light exert so much pressure that a human being cannot enter (or reach the end of) the hallway. Of course, we only want to deter the human, not to burn them to a crisp.



Would this be realistic?






science-based reality-check light radiation




science-based reality-check light radiation






share|improve this question









New contributor




user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question









New contributor




user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question








edited 1 hour ago









Cyn

5,856935




5,856935






New contributor




user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 2 hours ago









user60406user60406

111




111




New contributor




user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.












  • $begingroup$
    Naw, fam. I'm not sure what the math looks like (someone will draft that and put it into an answer, I'm sure), but that would definitely kill the person you are trying to repel.
    $endgroup$
    – user49466
    2 hours ago


















  • $begingroup$
    Naw, fam. I'm not sure what the math looks like (someone will draft that and put it into an answer, I'm sure), but that would definitely kill the person you are trying to repel.
    $endgroup$
    – user49466
    2 hours ago
















$begingroup$
Naw, fam. I'm not sure what the math looks like (someone will draft that and put it into an answer, I'm sure), but that would definitely kill the person you are trying to repel.
$endgroup$
– user49466
2 hours ago




$begingroup$
Naw, fam. I'm not sure what the math looks like (someone will draft that and put it into an answer, I'm sure), but that would definitely kill the person you are trying to repel.
$endgroup$
– user49466
2 hours ago










3 Answers
3






active

oldest

votes


















2












$begingroup$

No, it won't be realistic.



The radiation pressure produced by an electromagnetic radiation of intensity, or better irradiance, $I_f$ impinging at an angle $alpha$ on a surface can be calculated according to



$P_{Inc}=$$I_f over c$$cdot cos^2 alpha$



where c is the speed of light.



You immediately see that, due to the c factor, you need huge irradiance to get meaningful pressures at human scale. Let's say you want to achieve $1 N/m^2$, you would need an irradiance of about $3 cdot 10^8 W/m^2$. That would char any human on which it impinges.






share|improve this answer









$endgroup$





















    1












    $begingroup$

    No



    It's true that light exerts a pressure, but photons have no mass. You're dealing with pressure created by a distribution of energy, which is miniscule.



    If you think about it, your skin burns on a beach — but you don't feel even the slightest pressure from the light that's burning you.



    Now increase the light such that you could feel the pressure. You'd flash into a fine ash before you could comprehend that you were feeling pressure.



    But!



    What if you change your goal just a bit? What if the original intent of the light was to flash-burn anyone trying to get down the hall? Your protagonish knows this and dresses accordingly in attire that protects he/she from the burning properties of the light. And yet, as he/she walks down the hall, feels the pressure! pressure that's great enough to hinder progress! That would be a cool twist to the story.






    share|improve this answer









    $endgroup$





















      1












      $begingroup$

      Not with light pressure. You need 300 megawatts of radiation flux for each Newton of force on the object (equivalent to the force exerted by a ~100 gram weight).



      However, you can use microwaves as non-lethal deterrent. A moderate microwave flux is extremely painful on skin, well before it becomes damaging. This is the basis of several experimental crowd control weapons in real life, such as https://en.wikipedia.org/wiki/Active_Denial_System






      share|improve this answer









      $endgroup$













        Your Answer





        StackExchange.ifUsing("editor", function () {
        return StackExchange.using("mathjaxEditing", function () {
        StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
        StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
        });
        });
        }, "mathjax-editing");

        StackExchange.ready(function() {
        var channelOptions = {
        tags: "".split(" "),
        id: "579"
        };
        initTagRenderer("".split(" "), "".split(" "), channelOptions);

        StackExchange.using("externalEditor", function() {
        // Have to fire editor after snippets, if snippets enabled
        if (StackExchange.settings.snippets.snippetsEnabled) {
        StackExchange.using("snippets", function() {
        createEditor();
        });
        }
        else {
        createEditor();
        }
        });

        function createEditor() {
        StackExchange.prepareEditor({
        heartbeatType: 'answer',
        autoActivateHeartbeat: false,
        convertImagesToLinks: false,
        noModals: true,
        showLowRepImageUploadWarning: true,
        reputationToPostImages: null,
        bindNavPrevention: true,
        postfix: "",
        imageUploader: {
        brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
        contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
        allowUrls: true
        },
        noCode: true, onDemand: true,
        discardSelector: ".discard-answer"
        ,immediatelyShowMarkdownHelp:true
        });


        }
        });






        user60406 is a new contributor. Be nice, and check out our Code of Conduct.










        draft saved

        draft discarded


















        StackExchange.ready(
        function () {
        StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fworldbuilding.stackexchange.com%2fquestions%2f136612%2fusing-light-as-a-barrier-to-block-people-without-grilling-them%23new-answer', 'question_page');
        }
        );

        Post as a guest















        Required, but never shown

























        3 Answers
        3






        active

        oldest

        votes








        3 Answers
        3






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        2












        $begingroup$

        No, it won't be realistic.



        The radiation pressure produced by an electromagnetic radiation of intensity, or better irradiance, $I_f$ impinging at an angle $alpha$ on a surface can be calculated according to



        $P_{Inc}=$$I_f over c$$cdot cos^2 alpha$



        where c is the speed of light.



        You immediately see that, due to the c factor, you need huge irradiance to get meaningful pressures at human scale. Let's say you want to achieve $1 N/m^2$, you would need an irradiance of about $3 cdot 10^8 W/m^2$. That would char any human on which it impinges.






        share|improve this answer









        $endgroup$


















          2












          $begingroup$

          No, it won't be realistic.



          The radiation pressure produced by an electromagnetic radiation of intensity, or better irradiance, $I_f$ impinging at an angle $alpha$ on a surface can be calculated according to



          $P_{Inc}=$$I_f over c$$cdot cos^2 alpha$



          where c is the speed of light.



          You immediately see that, due to the c factor, you need huge irradiance to get meaningful pressures at human scale. Let's say you want to achieve $1 N/m^2$, you would need an irradiance of about $3 cdot 10^8 W/m^2$. That would char any human on which it impinges.






          share|improve this answer









          $endgroup$
















            2












            2








            2





            $begingroup$

            No, it won't be realistic.



            The radiation pressure produced by an electromagnetic radiation of intensity, or better irradiance, $I_f$ impinging at an angle $alpha$ on a surface can be calculated according to



            $P_{Inc}=$$I_f over c$$cdot cos^2 alpha$



            where c is the speed of light.



            You immediately see that, due to the c factor, you need huge irradiance to get meaningful pressures at human scale. Let's say you want to achieve $1 N/m^2$, you would need an irradiance of about $3 cdot 10^8 W/m^2$. That would char any human on which it impinges.






            share|improve this answer









            $endgroup$



            No, it won't be realistic.



            The radiation pressure produced by an electromagnetic radiation of intensity, or better irradiance, $I_f$ impinging at an angle $alpha$ on a surface can be calculated according to



            $P_{Inc}=$$I_f over c$$cdot cos^2 alpha$



            where c is the speed of light.



            You immediately see that, due to the c factor, you need huge irradiance to get meaningful pressures at human scale. Let's say you want to achieve $1 N/m^2$, you would need an irradiance of about $3 cdot 10^8 W/m^2$. That would char any human on which it impinges.







            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered 2 hours ago









            L.Dutch♦L.Dutch

            79.3k26190387




            79.3k26190387























                1












                $begingroup$

                No



                It's true that light exerts a pressure, but photons have no mass. You're dealing with pressure created by a distribution of energy, which is miniscule.



                If you think about it, your skin burns on a beach — but you don't feel even the slightest pressure from the light that's burning you.



                Now increase the light such that you could feel the pressure. You'd flash into a fine ash before you could comprehend that you were feeling pressure.



                But!



                What if you change your goal just a bit? What if the original intent of the light was to flash-burn anyone trying to get down the hall? Your protagonish knows this and dresses accordingly in attire that protects he/she from the burning properties of the light. And yet, as he/she walks down the hall, feels the pressure! pressure that's great enough to hinder progress! That would be a cool twist to the story.






                share|improve this answer









                $endgroup$


















                  1












                  $begingroup$

                  No



                  It's true that light exerts a pressure, but photons have no mass. You're dealing with pressure created by a distribution of energy, which is miniscule.



                  If you think about it, your skin burns on a beach — but you don't feel even the slightest pressure from the light that's burning you.



                  Now increase the light such that you could feel the pressure. You'd flash into a fine ash before you could comprehend that you were feeling pressure.



                  But!



                  What if you change your goal just a bit? What if the original intent of the light was to flash-burn anyone trying to get down the hall? Your protagonish knows this and dresses accordingly in attire that protects he/she from the burning properties of the light. And yet, as he/she walks down the hall, feels the pressure! pressure that's great enough to hinder progress! That would be a cool twist to the story.






                  share|improve this answer









                  $endgroup$
















                    1












                    1








                    1





                    $begingroup$

                    No



                    It's true that light exerts a pressure, but photons have no mass. You're dealing with pressure created by a distribution of energy, which is miniscule.



                    If you think about it, your skin burns on a beach — but you don't feel even the slightest pressure from the light that's burning you.



                    Now increase the light such that you could feel the pressure. You'd flash into a fine ash before you could comprehend that you were feeling pressure.



                    But!



                    What if you change your goal just a bit? What if the original intent of the light was to flash-burn anyone trying to get down the hall? Your protagonish knows this and dresses accordingly in attire that protects he/she from the burning properties of the light. And yet, as he/she walks down the hall, feels the pressure! pressure that's great enough to hinder progress! That would be a cool twist to the story.






                    share|improve this answer









                    $endgroup$



                    No



                    It's true that light exerts a pressure, but photons have no mass. You're dealing with pressure created by a distribution of energy, which is miniscule.



                    If you think about it, your skin burns on a beach — but you don't feel even the slightest pressure from the light that's burning you.



                    Now increase the light such that you could feel the pressure. You'd flash into a fine ash before you could comprehend that you were feeling pressure.



                    But!



                    What if you change your goal just a bit? What if the original intent of the light was to flash-burn anyone trying to get down the hall? Your protagonish knows this and dresses accordingly in attire that protects he/she from the burning properties of the light. And yet, as he/she walks down the hall, feels the pressure! pressure that's great enough to hinder progress! That would be a cool twist to the story.







                    share|improve this answer












                    share|improve this answer



                    share|improve this answer










                    answered 53 mins ago









                    JBHJBH

                    41k590195




                    41k590195























                        1












                        $begingroup$

                        Not with light pressure. You need 300 megawatts of radiation flux for each Newton of force on the object (equivalent to the force exerted by a ~100 gram weight).



                        However, you can use microwaves as non-lethal deterrent. A moderate microwave flux is extremely painful on skin, well before it becomes damaging. This is the basis of several experimental crowd control weapons in real life, such as https://en.wikipedia.org/wiki/Active_Denial_System






                        share|improve this answer









                        $endgroup$


















                          1












                          $begingroup$

                          Not with light pressure. You need 300 megawatts of radiation flux for each Newton of force on the object (equivalent to the force exerted by a ~100 gram weight).



                          However, you can use microwaves as non-lethal deterrent. A moderate microwave flux is extremely painful on skin, well before it becomes damaging. This is the basis of several experimental crowd control weapons in real life, such as https://en.wikipedia.org/wiki/Active_Denial_System






                          share|improve this answer









                          $endgroup$
















                            1












                            1








                            1





                            $begingroup$

                            Not with light pressure. You need 300 megawatts of radiation flux for each Newton of force on the object (equivalent to the force exerted by a ~100 gram weight).



                            However, you can use microwaves as non-lethal deterrent. A moderate microwave flux is extremely painful on skin, well before it becomes damaging. This is the basis of several experimental crowd control weapons in real life, such as https://en.wikipedia.org/wiki/Active_Denial_System






                            share|improve this answer









                            $endgroup$



                            Not with light pressure. You need 300 megawatts of radiation flux for each Newton of force on the object (equivalent to the force exerted by a ~100 gram weight).



                            However, you can use microwaves as non-lethal deterrent. A moderate microwave flux is extremely painful on skin, well before it becomes damaging. This is the basis of several experimental crowd control weapons in real life, such as https://en.wikipedia.org/wiki/Active_Denial_System







                            share|improve this answer












                            share|improve this answer



                            share|improve this answer










                            answered 53 mins ago









                            tylisirntylisirn

                            30912




                            30912






















                                user60406 is a new contributor. Be nice, and check out our Code of Conduct.










                                draft saved

                                draft discarded


















                                user60406 is a new contributor. Be nice, and check out our Code of Conduct.













                                user60406 is a new contributor. Be nice, and check out our Code of Conduct.












                                user60406 is a new contributor. Be nice, and check out our Code of Conduct.
















                                Thanks for contributing an answer to Worldbuilding Stack Exchange!


                                • Please be sure to answer the question. Provide details and share your research!

                                But avoid …



                                • Asking for help, clarification, or responding to other answers.

                                • Making statements based on opinion; back them up with references or personal experience.


                                Use MathJax to format equations. MathJax reference.


                                To learn more, see our tips on writing great answers.




                                draft saved


                                draft discarded














                                StackExchange.ready(
                                function () {
                                StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fworldbuilding.stackexchange.com%2fquestions%2f136612%2fusing-light-as-a-barrier-to-block-people-without-grilling-them%23new-answer', 'question_page');
                                }
                                );

                                Post as a guest















                                Required, but never shown





















































                                Required, but never shown














                                Required, but never shown












                                Required, but never shown







                                Required, but never shown

































                                Required, but never shown














                                Required, but never shown












                                Required, but never shown







                                Required, but never shown







                                -

                                Popular posts from this blog

                                Accessing regular linux commands in Huawei's Dopra Linux

                                Image
                                4 Backstory: I have a Huawei HG8245 router in my house and I want to change the default username/password. I've tried following this guide but the config file always gets reset. My ISP isn't helping either so I'm looking for other ways to accomplish this. The router has telnet access so this seems like a way to change the credentials. The first shell I gain access to looks like this: WAP> Pressing "?" gives me a list of available commands which I've pasted here, the two interesting ones are "su" and "shell". I can't seem to get su access, even after logging in as root (challenge password prompt, and then nothing happens), but shell gives me a proper linux shell. WAP>shell BusyBox v1.18.4 (2017-12-26 17:06:34 CST) built-in shell (ash) Enter 'hel...
                                Read more

                                Can't connect RFCOMM socket: Host is down

                                Image
                                up vote 3 down vote favorite I have bluez 5.4.3 and I am attempting to communicate with a ble device through minicom. These two deceives (my computer and a bluno nano) are alreadt paired and this has been my method so far. #bluetoothctl # pair xx:xx:xx:xx:xx:xx # exit Everything is working well so far then... #sudo rfcomm connect /dev/rfcomm0 xx:xx:xx:xx:xx:xx 1 & [1] 3665 Can't connect RFCOMM socket: Host is down Does anyone know how to resolve this issue? Any help would be very much appreciated. bluetooth bluez share | improve this question asked Feb 9 '17 at 18:46 Brandon Knape 46 2 ...
                                Read more

                                Kernel panic - not syncing: Fatal Exception in Interrupt

                                Image
                                0 Every day this error occured on my pc, kernel panic error on interrupt, what will be the problem? linux-mint share asked 6 mins ago Vinod Selvin Vinod Selvin 1 1 New contributor Vinod Selvin is a new contributor to this site. Take care in asking for clarification, commenting, and answering. Check out our Code of Conduct. add a comment ...
                                Read more