Can you dodge Space Lasers?

iris printed lasers [Music] laser beam is slicing into the saucer section they're now looking lasers on us lasers yes sir not even penetrate down navigation shields don't they know that they're carving us up like a roast forward lasers so can you dodge lasers in space now Lisa's of course are made up of photons little packets of light the trouble really fast it's with speed of light in fact which is jolly fast nonetheless because space is big really really big he still takes quite a long time to get around so for instance it takes about seven minutes for light traveling from the Sun to get to the earth in fact what the hell you are now traveling from the Sun to the earth at the speed of light and I'm just gonna put that in one little corner cuz it's gonna take its time unlike of course he'd say for instance Star Trek well it takes a little more the time of a dramatic pause for not only for a missile to get to the Sun but for you to see the changes that it's caused there where is of course in reality you had a minute you would have time to get a cup of coffee or something before you would see any of the effects now I know it's gonna be shocking to some people even when it comes to Star Trek they occasionally allow the practicalities of telling a good story to take priority over scientific accuracy and the laws of physics some people will take that worse than others [Music] he's gone anyway where were we oh yes can a spaceship evade lasers or are they just wasting their time now there are some people who say these aren't lasers or photon based weapons of some sort and you know what you might be right because if they were photon based weapons you wouldn't be able to see them at all you see I can only see lasers when they scatter off particles or excite particles or something so you just get the random urge to do something interesting with three colored laser pointers and a snowstorm then we go up into the sky we're at a green and purple zoom right into that green purple converging affinity to feel this one right other than that the lasers are invisible when they're traveling through space but then again of course you ain't getting into that pew pew pew with the space lasers because sound can't travel in a vacuum either actually that's not entirely true because what sound is is it's compression waves in a medium what space is a very good vacuum there is still a very very low pressure of mostly hydrogen so sound will travel there is just it'll be really quiet and further the actual speed of sound in this near vacuum depends on the pressure and the temperature the practical upshot of which is the speed of sound in space is actually pretty similar to what it is here on earth so you would be waiting a very very long time before you would hear a very very faint puh-puh-puh after not seeing the lasers destroy something but we're interested in lasers right can you dodge space lasers well yes and no it all kind of depends on what sort of maneuvers your spaceship can do I mean if they close enough they can see each other as spaceships then targeting with lasers is a joke the time between when you fire the weapon and when it hits the target is basically instantaneous comically so so for instance spaceships in Star Trek are comparable in size to airliners you know within a factor of four or something so here's the enterprise next with jumbo jet which also has a space shuttle mounted on it the Space Shuttle enterprise interestingly the shuttle here was actually named after the TV series then this is all just so you have an idea of how big the vehicles are that we've put in space compared to the sci-fi spaceships now interestingly the Starship Enterprise was named out of the famous world war two carrier enterprise and we must succeed let's make sure history never forgets the name enterprise which is not this one this is the super courier enterprise and is a fascinating thing that the actual super carrier Enterprise had a significantly larger crew complement than the next generations enterprise now the next generation enterprise was about 650 meters long but for this for the I'm just gonna make the approximation it's about a kilometer long so it just Binks doing the mental numbers easier so if you were maybe say for instance 200 kilometers away from the enterprise mr. crusher keepers within 200 kilometers of enterprise see coming 2 2 1 7 mark and the enterprise-d is say one kilometer in length it would be tiny yeah those ships are maybe 10 kilometers apart tops not 200 kilometers apart so if you're close enough to see the spaceship as a spaceship its comically close maybe a few kilometers or miles that sort of thing and at that distance there's simply no maneuvers that the ship could do to dodge the laser that wouldn't kill all of the crew because light travels about 300 kilometers in a millisecond so even if the ships were 200 kilometers away it would take less than a millisecond to hit them with a laser so how far away would you have to be before you could dodge a laser well let's take the earth-moon distance as a yardstick coming the moon is a good one because people have actually been to the moon and when they were there there was about one second of lag between the people speaking and the other guys hearing it because the radio waves travel at the speed of light and the moon is about one light second away and for the moon landings were faked people know that two-second black is not evenly spread out over the recordings because all of the recordings were done on earth further for scale if you're on the moon looking at the earth America is about the size it's the full moon seen from Earth and the reason I bring this up is to give you an idea of what a reasonable sized spaceship might look like at one light-second away now remember we have that size comparison of the aircraft carriers and the spaceships and what turns out in Washington State there are actually some of those supercarriers moored up which you can see from Google Earth so if you zoom out to space and then to the distance of the moon you get an idea of the size that a big spaceship would look like at that sort of range cool so if someone was actually shooting at a spaceship going around the moon could you dodge the lasers well kind of you see lasers travel at the speed of light so there's no way you could see it coming in fact the first thing you would know that you were being actually shot at is when you got hit and makes dotting kind of tricky but let's just say you knew someone was shooting at you one second is the time of flight of the laser cool so the guys have to predict where your ship is going to be in about 1 seconds time and lead to target accordingly in fact complicate things further the image that they see of your ship is actually one second old so they actually have to lead the target by about two seconds to hit it now orbital velocity of the earth at the distance of the moon is about one kilometer per second and for comparison the speed of sound here on earth is about 1/3 of a kilometer per second so you would have to aim at about two kilometers that ahead of the target to hit it that's actually quite a long way to lead the target by surely you could dodge that right but let's see the targeting system is pretty simple and just plot up your course and shoots where you will be in about two seconds time so you have to get your entire spaceship out of the way in which let's just say for ballpark numbers is a hundred metres or so and you better do that in about two seconds but let's not care too much about a factor or two it make the numbers easier let's just say you've got to get a hundred metres out of the way in one second so you're going to change your velocity by about a hundred meters per second in one second which is actually pretty tough I mean for ballpark numbers the speed of sound here on earth is about 300 meters per second so you'll hear a changing your horse speed from rest to about one third of the speed of sound in just one second now if you think that might actually be the sort of acceleration that would kill people you're about right it's getting there humans on earth just standing here have an acceleration of about 1g that's about 10 meters per second squared so your typical guy experiences weight here on earth of about a hundred kilos which is no big deal now you Jack that up to 3 G's 30 meters per second squared and you're into the shuttle takeoff type accelerations while your body is experiencing a weight of about 300 kilos which is getting pretty uncomfortable proximity danger proximity alert gravitational well detected who are now approaching the current system that alights you may want to hold on tight in case we've miscalculated and we hit something hey I can see my hoo from here and that was it traveling from the Sun to the earth at Lightspeed in real time now where were we ah yes 10 G's at 10 G's your body experiences a weight of about 1000 kilos about a ton which is yeah that's the subtle acceleration where we humans being fairly intolerant bags of mostly water start to die bags are mostly water an accurate description of humans sir you are over 90% water surrounded by a flexible container actually no we're about two-thirds water 65% I shall pass it on to Captain Picard my love is a fever longing still for that which longer NASA the disease Oh either that or humans have gotten a little wetter in the 23rd century I'm with Starfleet we don't lie shut up shut up shut up shut up [Applause] so I lied I'm with Starfleet we don't lie I bribed men to cover the crimes of other men [Music] I have an accessory to murder and if I had to do it all over again I would seriously by the pale moonlight is just one of the most awesome episodes ever ah sorry where were we oh yeah the accelerations that you need to dodge space lasers that is trying to dodge a laser being shot at you from this distance would likely kill everyone on this spaceship and this is of course assuming you can dodge effectively because the laser target err just has to guess randomly where your ship is gonna be in about two seconds time and it's only a matter of time before you get a hit that point is rather depressing when you consider I mean let's just say you're at the distance of the moon which is about 400,000 kilometers let's say you want to get another 400,000 kilometers away to get out of range and you're travelling about one kilometer per second which means it's gonna take about 100 hours four days of dodging and near-fatal accelerations to get out of range however there are three saving graces for everyone on that spaceship being shot at that means they probably don't have to worry too much the first is no one would be able to shoot a laser that accurately anyway cuz you see to target a laser the bare minimum you need to know is which direction to point the laser even with laser guns if you don't point them in the right direction you're not gonna hit anything have we ever hit anybody with these guns I hit a bird once so let's just say you're using the Hubble Space Telescope to target your laser and it's a decent telescope it's a maximum resolution when it's pointed towards the moon is about 50 meters so it's right on the limit of what one of the most advanced space telescopes could do and that's an intrinsically limit bear in mind you can't do any better without a bigger telescope you simply couldn't accurately target an object this small secondly of course lasers diffused by a mechanism that's not dissimilar to the factors that determine the resolution limit on telescopes there's so this actually has been done you may know the reason we know the exact distance to the moon is because when people went to the moon they left reflectors timing how long it takes the laser beam to go out and bounce back Peter can precisely calculate the distance to the moon so you can actually fire a laser at the moon and wait for about two seconds and a few laser photons of the right wavelength to come back again we may send out a thousand million billion photons whereas coming back coming back into the telescope might be ten and if you time that accurately you can get the distance to the moon and so how dispersed are the lasers they fire at the moon by the time they hit the moon about six kilometres and even at that it's technically challenging to hit this small area on the moon and they're simply talking about detecting a few photons coming back and not putting enough photons on the target to destroy it and of course as mentioned earlier laser spear no locking lasers on us lasers yes sir actually I hate to get all Star Trek on yeah but if Aliza's can't penetrate your navigational shields then you're either absorbing those photons and if your ships absorbing photons it would just appear black or it would be reflecting those photons and if your ships reflecting photons it would appear silver just say regulations to call for yellow alert hmm very old regulation lasers reflect quite well of nice shiny things like a via I've say for instance mirrors left on the moon the practical up shopping even if you had a laser powerful enough to destroy a ship going around the moon all you would have to do is make it a nice shiny ship [Music] [Music] the Woodworth let's say 90% of the visible light and you would have to get a later 10 times more powerful to destroy that ship ah yes mirrors the art enemy of the puh-puh-puh magic laser bolts the ship will self-destruct in 3 minutes the boldly go where no man has gone oh we are going to get so much crap for that [Music]

Channel: Thunderf00t

Views: 248,857

Rating: 4.8665638 out of 5

Keywords: space, laser, star, trek, star wars, fun, beam, dodge, moon, earth, sun, astronomy, science, win, enterprise, babylon 5, babylon, galactica

Id: GIYYFIKbByA

Length: 17min 33sec (1053 seconds)

Published: Tue Mar 20 2018

Reddit Comments

[u/mikeyrt16]

With regards to the star trek sun argument. It's not Earth. The distance from the Earth to the Sun is around 150Mkm. What's the say the alien planet they are on isn't 10x closer to their sun, which is 10x less hot?