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









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  • $begingroup$
    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






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asked 3 hours ago









user60406user60406

111




111




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user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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user60406 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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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





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        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 1 hour 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 1 hour ago









                            tylisirntylisirn

                            30912




                            30912






















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










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