vacuum space

“If there is energy within the substance it can only come from without. This truth was so manifest to me that I expressed it in the following axiom: ‘There is no energy in matter except that absorbed from the medium…’ If all energy is supplied to matter from without then this all important function must be performed by the medium.”

“When radio-active rays were discovered their investigators believed them to be due to liberation of atomic energy in the form of waves. This being impossible in the light of the preceding I concluded that they were produced by some external disturbance and composed of electrified particles. My theory was not seriously taken although it appeared simple and plausible. Suppose that bullets are fired against a wall. Where a missile strikes the material is crushed and spatters in all directions radial from the place of impact. In this example it is perfectly clear that the energy of the flying pieces can only be derived from that of the bullets. But in manifestation of radio-activity no such proof could be advanced and it was, therefore, of the first importance to demonstrate experimentally the existence of this miraculous disturbance in the medium. I was rewarded in these efforts with quick success largely because of the efficient method I adopted which consisted in deriving from a great mass of air, ionized by the disturbance, a current, storing its energy in a condenser and discharging the same through an indicating device. This plan did away with the limitations and incertitude of the electroscope first employed and was described by me in articles and patents from 1900 to 1905. It was logical to expect, judging from the behavior of known radiations, that the chief source of the new rays would be the sun, but this supposition was contradicted by observations and theoretical considerations which disclosed some surprising facts in this connection.

“Light and heat rays are absorbed in their passage through a medium in a certain proportion to its density. The ether, although the most tenuous of all substances, is no exception to this rule.  Its density has been first estimated by Lord Kelvin and conformably to his finding a column of one square centimeter cross section and of a length such that light, traveling at a rate of three hundred thousands kilometers per second, would require one year to traverse it, should weigh 4.8 grams. This is just about the weight of a prism of ordinary glass of the same cross section and two centimeters length which, therefore, may be assumed as the equivalent of the ether column in absorption. A column of the ether one thousand times longer would thus absorb as much light as twenty meters of glass.  However, there are suns at distances of many thousands of light years and it is evident that virtually no light from them can reach the earth. But if these suns emit rays immensely more penetrative than those of light they will be slightly dimmed and so the aggregate amount of radiations pouring upon the earth from all sides will be overwhelmingly greater than that supplied to it by our luminary. If light and heat rays would be as penetrative as the cosmic, so fierce would be the perpetual glare and so scorching the heat that life on this and other planets could not exist.

“Rays in every respect similar to the cosmic are produced by my vacuum tubes when operated at pressures of ten millions of volts or more, but even if it were not confirmed by experiment, the theory I advanced in 1897 would afford the simplest and most probable explanation of the phenomena. Is not the universe with its infinite and impenetrable boundary a perfect vacuum tube of dimensions and power inconceivable? Are not its fiery suns electrodes at temperatures far beyond any we can apply in the puny and crude contrivances of our making? Is it not a fact that the suns and stars are under immense electrical pressures transcending any that man can ever produce and is this not equally true of the vacuum in celestial space? Finally, can there be any doubt that cosmic dust and meteoric matter present an infinitude of targets acting as reflectors and transformers of energy? If under ideal working conditions, and with apparatus on a scale beyond the grasp of the human mind, rays of surpassing intensity and penetrative power would not be generated, then, indeed, nature has made an unique exception to its laws.

"It has been suggested that the cosmic rays are electrons or that they are the result of creation of new matter in the interstellar deserts. These views are too fantastic to be even for a moment seriously considered. They are natural outcroppings of this age of deep but unrational thinking, of impossible theories, the latest of which might, perhaps, deal with the curvature of time. What this world of ours would be if time were curved…“

–Nikola Tesla

“The Eternal Source of Energy of the Universe, Origin and Intensity of Cosmic Rays.” October 13, 1932.
13 Reasons to Have an Out-of-This-World Friday (the 13th)

1. Not all of humanity is bound to the ground

Since 2000, the International Space Station has been continuously occupied by humans. There, crew members live and work while conducting important research that benefits life on Earth and will even help us eventually travel to deep space destinations, like Mars.

2. We’re working to develop quieter supersonic aircraft that would allow you to travel from New York to Los Angeles in 2 hours

We are working hard to make flight greener, safer and quieter – all while developing aircraft that travel faster, and building an aviation system that operates more efficiently. Seventy years after Chuck Yeager broke the sound barrier in the Bell X-1 aircraft, we’re continuing that supersonic X-plane legacy by working to create a quieter supersonic jet with an aim toward passenger flight.

3. The spacecraft, rockets and systems developed to send astronauts to low-Earth orbit as part of our Commercial Crew Program is also helping us get to Mars

Changes to the human body during long-duration spaceflight are significant challenges to solve ahead of a mission to Mars and back. The space station allows us to perform long duration missions without leaving Earth’s orbit.

Although they are orbiting Earth, space station astronauts spend months at a time in near-zero gravity, which allows scientists to study several physiological changes and test potential solutions. The more time they spend in space, the more helpful the station crew members can be to those on Earth assembling the plans to go to Mars.

4. We’re launching a spacecraft in 2018 that will go “touch the Sun”

In the summer of 2018, we’re launching Parker Solar Probe, a spacecraft that will get closer to the Sun than any other in human history. Parker Solar Probe will fly directly through the Sun’s atmosphere, called the corona. Getting better measurements of this region is key to understanding our Sun. 

For instance, the Sun releases a constant outflow of solar material, called the solar wind. We think the corona is where this solar wind is accelerated out into the solar system, and Parker Solar Probe’s measurements should help us pinpoint how that happens.  

5. You can digitally fly along with spacecraft…that are actually in space…in real-time!

NASA’s Eyes are immersive, 3D simulations of real events, spacecraft locations and trajectories. Through this interactive app, you can experience Earth and our solar system, the universe and the spacecraft exploring them. Want to watch as our Juno spacecraft makes its next orbit around Juno? You can! Or relive all of the Voyager mission highlights in real-time? You can do that too! Download the free app HERE to start exploring.

6. When you feel far away from home, you can think of the New Horizons spacecraft as it heads toward the Kuiper Belt, and the Voyager spacecraft are beyond the influence of our sun…billions of miles away

Our New Horizons spacecraft completed its Pluto flyby in July 2015 and has continued on its way toward the Kuiper Belt. The spacecraft continues to send back important data as it travels toward deeper space at more than 32,000 miles per hour, and is ~3.2 billion miles from Earth.

In addition to New Horizons, our twin Voyager 1 and 2 spacecraft are exploring where nothing from Earth has flown before. Continuing on their more-than-37-year journey since their 1977 launches, they are each much farther away from Earth and the sun than Pluto. In August 2012, Voyager 1 made the historic entry into interstellar space, the region between the stars, filled with material ejected by the death of nearby stars millions of years ago.

7. There are humans brave enough to not only travel in space, but venture outside space station to perform important repairs and updates during spacewalks

Just this month (October 2017) we’ve already had two spacewalks on the International Space Station…with another scheduled on Oct. 20. 

Spacewalks are important events where crew members repair, maintain and upgrade parts of the International Space Station. These activities can also be referred to as EVAs – Extravehicular Activities. Not only do spacewalks require an enormous amount of work to prepare for, but they are physically demanding on the astronauts. They are working in the vacuum of space in only their spacewalking suit. 

8. Smart people are up all night working in control rooms all over NASA to ensure that data keeps flowing from our satellites and spacecraft

Our satellites and spacecraft help scientists study Earth and space. Missions looking toward Earth provide information about clouds, oceans, land and ice. They also measure gases in the atmosphere, such as ozone and carbon dioxide and the amount of energy that Earth absorbs and emits. And satellites monitor wildfires, volcanoes and their smoke.

9. A lot of NASA-developed tech has been transferred for use to the public

Our Technology Transfer Program highlights technologies that were originally designed for our mission needs, but have since been introduced to the public market. HERE are a few spinoff technologies that you might not know about.

10. We have a spacecraft currently traveling  to an asteroid to collect a sample and bring it back to Earth

OSIRIS-REx is our first-ever mission that will travel to an asteroid and bring a sample of it back to Earth. Currently, the spacecraft is on its way to asteroid Bennu where it will survey and map the object before it “high-fives” the asteroid with its robotic arm to collect a sample, which it will send to Earth.

If everything goes according to plan, on Sept. 24, 2023, the capsule containing the asteroid sample will make a soft landing in the Utah desert.

11. There are Earth-sized planets outside our solar system that may be habitable

To date, we have confirmed 3,000+ exoplanets, which are planets outside our solar system that orbit a Sun-like star. Of these 3,000, some are in the habitable zone – where the temperature is just right for liquid water to exist on the surface.  

Recently, our Spitzer Space Telescope revealed the first known system of SEVEN Earth-size planets around a single star. Three of these plants are firmly in the habitable zone, and could have liquid water on the surface, which is key to life as we know it.

12. Earth looks like art from space

In 1960, the United States put its first Earth-observing environmental satellite into orbit around the planet. Over the decades, these satellites have provided invaluable information, and the vantage point of space has provided new perspectives on Earth.

The beauty of Earth is clear, and the artistry ranges from the surreal to the sublime.

13. We’re building a telescope that will be able to see the first stars ever formed in the universe

Wouldn’t it be neat to see a period of the universe’s history that we’ve never seen before? That’s exactly what the James Webb Space Telescope (JWST) will be able to do…plus more!

Specifically, Webb will see the first objects that formed as the universe cooled down after the Big Bang. We don’t know exactly when the universe made the first stars and galaxies – or how for that matter. That is what we are building Webb to help answer.

Happy Friday the 13th! We hope it’s out-of-this-world!

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Bonus (just sketchy, because I am a lazy human being) :

Alright! A lot of you asked for more Kuro’s small adventures - so I happily complied.

And since to me the Galra look like huge, ugly, purple space cats (and Kuro is at last half Galra) I made him a little more cat-like in his behaviour. At least that’d explain why he’s such a little shit sometimes.

So here and there he acts like a huge cat would - and did you ever see a cat that loves vacuum cleaners? No. (That one strange cat licking the vacuum doesn’t count. I’m sure that’s not a cat but an alien or something. seriously.) Space robot vacuums are no exeption!

Gonna add some more of these, soon. :D Oh and… Uh… I’ll add more Sheith to it, I guess? :3

So miss him. Send him some love and light every time you think about him, then drop it. You’re just afraid to let go of the last bits of him because then you’ll be really alone, and you’re scared to death of what will happen if you’re really alone. But here’s what you gotta understand. If you clear out all that space in your mind that you’re using right now to obsess about this guy, you’ll have a vacuum there, an open spot – a doorway. And guess what the universe will do with the doorway? It will rush in – God will rush in – and fill you with more love than you ever dreamed. So stop using that boy to block that door. Let it go.
—  Eat, Pray, Love (Elizabeth Gilbert)

Today, February 28, 2017 marks the 78th anniversary that Kars was defeated by Joseph Joestar; resulting in the last of the pillar men himself to be launched out of earth’s atmosphere, leaving him to float in the vacuum of space for all eternity. Kars has now been floating in space for 28,490 days. That’s 2,461,536,000 seconds or 41,025,600 minutes or 683,760 hours or 4070 weeks of endlessly drifting through the vast nothingness of space. 78 years and still going, never to return ever again(unless you read the novel, but thats non canon so who cares)

Happy National Techies Day!

October 3 is National Techies Day…and here at NASA we have quite a few people who get REALLY excited about technology. Without techies and the technology they develop, we wouldn’t be able to do the amazing things we do at NASA, or on Earth and in space.

Our Techies

We love our techies! The passionate engineers, researchers and scientists who work on our technology efforts enable us to make a difference in the world around us. They are responsible for developing the pioneering, new technologies and capabilities needed to achieve our current and future missions.

Research and technology development take place within our centers, in academia and industry, and leverage partnerships with other government agencies and international partners. We work to engage and inspire thousands of technologists and innovators creating a community of our best and brightest working on the nation’s toughest challenges.

Technology Drives Exploration

Our investments in technology development enable and advance space exploration. We are continually seeking to improve our ability to access and travel through space, land more mass in more locations, enable humans to live and explore in space and accelerate the pace of discovery.

Techie Technology

Advanced Manufacturing Technologies

When traveling to other planetary bodies, each and every pound of cargo matters. If we can reduce the weight by building tools once we arrive, that’s less weight we need to launch from Earth and carry through space.

Additive manufacturing is a way of printing three-dimensional (3-D) components from a digital model. If you think of a common office printer, it uses a 2-D file to print images and text on a sheet of paper. A 3-D printer uses a 3D file to deposit thin layers of material on top of each other, creating a 3-D product.

Thanks to techies, we’re already using this technology on the International Space Station to print wrenches and other tools. Our Additive Construction for Mobile Emplacement (ACME) project is investigating ways to build structures on planetary surfaces using resources available at a given site.

Discover more about how our techies are working with advanced manufacturing HERE.

Technology Demonstrations

Our techies are always innovating and developing new cutting-edge ideas. We test these ideas in extreme environments both here on Earth and in space.  

Science missions in space require spacecraft propulsion systems that are high-performance, lightweight, compact and have a short development time. The Deep Space Engine project is looking to meet those needs. Our techies are currently testing a 100lbf (pound-force) thruster to see if this compact, lightweight, low-cost chemical propulsion system can operate at very low temperatures, which allows long duration storage capabilities.

Another technology in development is PUFFER, or the Pop-Up Flat Folding Explorer Robot…and it was inspired by origami! This robot’s lightweight design is capable of flattening itself, tucking in its wheels and crawling into places rovers can’t fit. PUFFER has been tested in a range of rugged terrains to explore areas that might be too risky for a full-fledged rover to go.

With our partners at Ball Aerospace & Technologies Corp., we’ve also collaborated on the Green Propellant Infusion Mission (GPIM), which will flight test a “green” alternative to the toxic propellant, hydrazine, in 2018. GPIM is the nation’s premier spacecraft demonstration of a new high-performance power and propulsion system — a more environmentally friendly fuel. This technology promises improved performance for future satellites and other space missions by providing for longer mission durations, increased payload mass and simplified pre-launch spacecraft processing, including safer handling and transfer of propellants.  

Find out more about our technology demonstrations HERE.

Aircraft Technology

What if you could travel from London to New York in less than 3.5 hours? Our techies’ research into supersonic flight could make that a reality! 

Currently, supersonic flight creates a disruptive, loud BOOM, but our goal is to instead create a soft “thump” so that flying at supersonic speeds could be permitted over land in the United States.

We’re conducting a series of flight tests to validate tools and models that will be used for the development of future quiet supersonic aircraft.

Did you know that with the ability to observe the location of an aircraft’s sonic booms, pilots can better keep the loud percussive sounds from disturbing communities on the ground? This display allows research pilots the ability to physically see their sonic footprint on a map as the boom occurs.

Learn more about our aircraft technology HERE.

Technology Spinoffs 

Did you know that some of the technology used in the commercial world was originally developed for NASA? For example, when we were testing parachutes for our Orion spacecraft (which will carry humans into deep space), we needed to capture every millisecond in extreme detail. This would ensure engineers saw and could fix any issues. The problem was,there didn’t exist a camera in the world that could shoot at a high enough frame rate – and store it in the camera’s memory – all while adjusting instantly from complete darkness to full daylight and withstanding the space vacuum, space radiation and water immersion after landing.

Oh…and it had to be small, lightweight, and run on low power. Luckily, techies built exactly what we needed. All these improvements have now been incorporated into the camera which is being used in a variety of non-space industries…including car crash tests, where high resolution camera memory help engineers get the most out of testing to make the cars we drive safer.

Learn about more of our spinoff technologies HERE.

Join Our Techie Team

We’re always looking for passionate and innovative techies to join the NASA team. From student opportunities to open technology competitions, see below for a list of ways to get involved:

NASA Solve is a gateway for everyone to participate in our mission through challenges, prize competition, citizen science and more! Here are a few opportunities:

Vascular Tissue Challenge 

The Vascular Tissue Challenge, a NASA Centennial Challenges competition, offers a $500,000 prize to be divided among the first three teams that successfully create thick, metabolically-functional human vascularized organ tissue in a controlled laboratory environment. More information HERE.

For open job opportunities at NASA, visit:

For open internship opportunities at NASA, visit:

Stay tuned in to the latest NASA techie news, by following  @NASA_Technology on Twitter, NASA Technology on Facebook and visiting

Happy National Techies Day!

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The Ones BTS Would Fall For

J-Hope: Angel girl. For real probably walks on water. Always bakes cookies. Probably a bit of a mom friend. Completely wholesome. Tells surprisingly dirty jokes from time to time. Longest eyelashes. Such a little cutie pie and probs doesn’t know it. Undeniable social butterfly that children love. 

Rap Mon: Ooooh mama. V spicy. Sexy and open minded. Knows how to articulate opinions well. A bit intimidating but passionate. Good at knowing how people are truly feeling. Eyeliner wings so sharp you could commit murder with them. The turner of heads. 

Suga: Introverted, quiet, thoughtful. Always gives 110010% towards everything. Laughs quietly, pretty eye smile. Mutters some seriously funny shit under their breath. Blushes easily. Some sort of artist, probably. Likable, but only maintains a few close friends. Buys colorful clothes and then ends up wearing the same 3 black shirts anyways. 

Taehyung: Puppy in human form. Excited for no reason. Feels every emotion to the extreme. Dances in public anytime there is music. Carries all the groceries in one trip. Super fun, bold, life of the party. Has no enemies. Tries too often to walk backwards. Wants to see the world. Unstoppable force of nature. 

Jin: Probably won Prom Queen. Highlight is always poppin’. Holds up peace signs in selfies. Can make any outfit work. Literal deity that descended to the mortal realm. Trendy, knows too much about fashion. Such a good cook, Gordon Ramsey approves.  

Jimin: So loud. Laugh fills up the vacuum of space. Owns the coolest sunglasses always. Borrows everyone’s clothes. Looks like the embodiment of summertime. Bright smile. Screams a lot for no reason. Hits you when talking excitedly. V indecisive. Ready to fight anyone. Knows all the constellations, for whatever reason. 

Jungkook: Talk. About. A. Meme. Queen. Internet culture 101. Always knows whats happening. Dances like a dad at a bbq. Pulls stupid faces at small children and gets awkward when the parents look. Waves to people that aren’t waving at them all the time. Optimistic outlook, almost always in a good mood. 

Tough as a Tardigrade

Without water, a human can only survive for about 100 hours. But there’s a creature so resilient that it can go without it for decades. This one millimeter animal can survive both the hottest and coldest environments on Earth, and can even withstand high levels of radiation. This is the tardigrade, and it’s one of the toughest creatures on Earth, even if it does look more like a chubby, eight-legged gummy bear. 

Most organisms need water to survive. Water allows metabolism to occur, which is the process that drives all the biochemical reactions that take place in cells. But creatures like the tardigrade, also known as the water bear, get around this restriction with a process called anhydrobiosis, from the Greek meaning life without water. And however extraordinary, tardigrades aren’t alone. Bacteria, single-celled organisms called archaea, plants, and even other animals can all survive drying up.

For many tardigrades, this requires that they go through something called a tun state. They curl up into a ball, pulling their head and eight legs inside their body and wait until water returns. It’s thought that as water becomes scarce and tardigrades enter their tun state, they start synthesize special molecules, which fill the tardigrade’s cells to replace lost water by forming a matrix. 

Components of the cells that are sensitive to dryness, like DNA, proteins, and membranes, get trapped in this matrix. It’s thought that this keeps these molecules locked in position to stop them from unfolding, breaking apart, or fusing together. Once the organism is rehydrated, the matrix dissolves, leaving behind undamaged, functional cells.

Beyond dryness, tardigrades can also tolerate other extreme stresses: being frozen, heated up past the boiling point of water, high levels of radiation, and even the vacuum of outer space. This has led to some erroneous speculation that tardigrades are extraterrestrial beings.

While that’s fun to think about, scientific evidence places their origin firmly on Earth where they’ve evolved over time. In fact, this earthly evolution has given rise to over 1100 known species of tardigrades and there are probably many others yet to be discovered. And because tardigrades are so hardy, they exist just about everywhere. They live on every continent, including Antarctica. And they’re in diverse biomes including deserts, ice sheets, the sea fresh water, rainforests, and the highest mountain peaks. But you can find tardigrades in the most ordinary places, too, like moss or lichen found in yards, parks, and forests. All you need to find them is a little patience and a microscope.

Scientists are now to trying to find out whether tardigrades use the tun state, their anti-drying technique, to survive other stresses. If we can understand how they, and other creatures, stabilize their sensitive biological molecules, perhaps we could apply this knowledge to help us stabilize vaccines, or to develop stress-tolerant crops that can cope with Earth’s changing climate. 

And by studying how tardigrades survive prolonged exposure to the vacuum of outer space, scientists can generate clues about the environmental limits of life and how to safeguard astronauts. In the process, tardigrades could even help us answer a critical question: could life survive on planets much less hospitable than our own?

From the TED-Ed Lesson Meet the tardigrade, the toughest animal on Earth - Thomas Boothby

Animation by Boniato Studio

  • Galra Soldier: My prince, I'm afraid the asteroids will not allow us to follow the Altean castle.
  • Lotor: I’m sorry, but I do not know much about the asteroids. Can you explain something to me?
  • Galra Soldier: Of course, my prince.
  • Lotor: Do the asteroids command this ship?
  • Galra Soldier: Um, I'm afraid I don't understand.
  • Lotor: You said the asteroids would not allow us to follow. Do the asteroids command this ship?
  • Galra Soldier: No, my prince.
  • Lotor: And if I were to have you thrown out into the cold vacuum of space, would the asteroids think twice about smashing into you?
  • Galra Soldier: ...No, my prince.
  • Lotor: Well, then, maybe you should worry less about the asteroids who’ve already made up their mind about killing you, and worry more about me, who’s still mulling it over.

seattledawg69  asked:

What was the hardest part in training to go to space?

One of the most challenging parts of space training was learning how to use the space suit.  We weigh over 400 pounds in the space suit, and since it is pressurized, each movement of your hands is like working against an exercise ball.  Since the suit needs to be quite bulky in order to protect us from the environment of space (vacuum, radiation, micrometeoroids, extreme temperature) while doing a spacewalk, it makes body movements a bit awkward.  Dexterity is quite compromised with the bulky gloves as well.  Although it is challenging, however, it is likely also the most rewarding, because, well, you are in a SPACE SUIT!!!  Hopefully I’ll get to do a spacewalk and look down on the our planet from above on a mission to the International Space Station in a few years. 

Rings Of The Cosmos

That title is just the coolest way I could think of to sum up this idea

So basically I just read through a literal Shit ton of the humans are space orcs stuff and I got to thinking all the aliens already are in contact with eachother before they find us right so here is my theory as to why this is

The closer to the Center you get the more inhabitable planets you find all these dudes found eachother really quickly and were like “let’s become homies” (friendly reminder that these guys are from REALLY mineraly rich plants so war to them is a foreign policy) they keep on doing this eventually have to fight some wars and gather a military

Eventually they start to notice that the further out they go the more dangerous planets get and consequently the tougher the inhabitants get. so they do some math and are like “Kay so intelligent cannot be found this distance away from the Center” this place becomes known as the Dead Zone

They get proven wrong a bunch of times the first time they find a creature in the Dead Zone it’s a zaxxo (I just made that name up give me a break) which are essentially a really fucking big single cell organism they survive on sunlight and can adapt to anything except temperature which is fine for them as they live in THE FUCKING VACUUM OF SPACE.

Anyways language barriers were a Bitch with these guys but eventually a solution was reached

So then people start going “hey if one thing can live in the Dead Zone why can’t another”
Which is pretty sound logic you know

So then they find the drakeks (look I’m bad with names okay) which are these super tall armor plated motherfuckers with poisonous spikes emitting from every orifice I mean sure they’re not the smartest but they don’t need to when they can survive the gravity of their planet which is only THE SIZE OF OUR SUN yeah they’re fucking op. eventually peaceful contact is established and most of them are enrolled into the military (tho there is one REALLY popular drakek musician)

They keep on exploring for maybe a thousand more years and then everyone goes “okay that’s it we already going
Found two species capable of jumping from one planet to another (turns out that if you put a drakek on a normal planet they’re even more terrifying, what gives?)”

it’s a bit after the Dead Zone exploration program is shut down that humans show up and there’s the normal “OH MY DEROG THESE FUCKERS CAN’T BE KILLED” then after ages and ages humans are kinda normalised and integrated like they’re still REALLY fucking handy to have around and really cute and all the other goodness that is associated with the humans are space orcs stuff.

This is the setting for an idea of mine that I may or may not end up posting I honestly don’t know if you read to the end of this I love you. Bye

  • Admiral Piett: My lord, I'm afraid the asteroids will not allow us to follow the Millennium Falcon.
  • Darth Vader: I’m sorry, Admiral Piett, but I do not know much about the asteroids. Can you explain something to me?
  • Admiral Piett: Of course, my lord.
  • Darth Vader: Do the asteroids command this ship?
  • Admiral Piett: Um, I'm afraid I don't understand.
  • Darth Vader: You said the asteroids would not allow us to follow. Do the asteroids command this ship?
  • Admiral Piett: No, my lord.
  • Darth Vader: And if I were to have you thrown out into the cold vacuum of space, would the asteroids think twice about smashing into you?
  • Admiral Piett: No, my lord.
  • Darth Vader: Well, then, maybe you should worry less about the asteroids who’ve already made up their mind about killing you, and worry more about me, who’s still mulling it over.

Ask Ethan: Does Light Always Move At The Same Speed?

“Does light always move at the same speed? If it is slowed down by something, will is stay slower after it is no longer being slowed down? Will [it] speed back up to the speed of light?”

Throughout the entire Universe, there’s a fundamental law that governs the motions of all particles: Einstein’s relativity. It states that all particles with mass can never attain the speed of light, no matter how much energy you put into it. Additionally, all massless particles only move at the speed of light, no matter what you do to either them or to the device/person observing them. No matter what reference frame you’re in, the speed of light in a vacuum is a constant. But light isn’t always in a vacuum!  From air to quartz to acrylic to glass to many other media, light can pass through transparent material, and when it does, it slows down. Not only that, but light of different energy slows down by different amounts. In what ways is the speed of light always the same, and in what ways can it change?

And most importantly, what do the known properties of light mean for the rest of the Universe? Find out on this edition of Ask Ethan!