How much dark matter passes through our body?

What if we told you that, One of the most  mysterious and abundant substances in our universe  is passing through our body every second.  You might have guessed it by now and yes it’s Dark Matter! The reality that we  see today– planets, stars, galaxies etc.


Make only 5% of the entire universe. The  rest is Dark Matter and Dark Energy. And it is passing through our bodies constantly.  But how much? Does it have any effect on us?


We will answer these questions  and more in this article!


If you are here watching this video, it means you  are passionately curious about human spaceflight and the mysteries of the universe.


We constantly  strive to make videos that excite a curious person like you, so subscribe now and press the  bell notification. Back to our Dark matter now!


Our universe, despite all the planets, galaxies,  stars and more doesn’t quite add up. If we look at our Galaxy, The Milky Way, it doesn’t have enough  mass to hold all star systems together in the form  of a spiral galaxy? But still it does, How so? The  same happens at the largest of scales, we find the same story everywhere we look. There isn’t enough  matter to account for the gravitational effects that we observe.


So what might be causing the  stars and planets in galaxies to stick together?  


To answer this scientists came  up with the term- Dark Matter.



What is dark matter?

‘Dark’ because we cannot see it, we are just  able to observe its effects. It is dark, which means it is not visible in the form of stars  and planets. Observations show that the universe contains far too little visible matter to account  for the 27 percent required by the observations.


Second, it is not in the form of dark clouds of  ordinary matter, which is composed of particles known as baryons. We know this because we  can detect baryonic clouds by measuring the absorption of radiation passing through them  and we have found that it doesn’t react with any  electromagnetic radiation.


Third, dark matter  is not antimatter because we do not see the distinctive gamma rays produced when antimatter  collides with matter.

Today we know that Dark  matter is present in almost all galaxies, and is  the explanation for the hidden matter in galaxies.  We have confirmed the presence of Dark matter  by a process called gravitational lensing.


Since Astronomers cannot directly see Dark  Matter, they detect its presence by observing how the gravity of massive galaxy clusters with  a large amount of dark matter, bends and distorts  the light of more distant galaxies located  behind them. Matter clumps together forming large galaxies, large galaxy clusters and eventually us.  Without dark matter we wouldn’t be here. Without


the presence of about five times as much matter as  protons, neutrons, and electrons can account for,  none of this would be possible. Our Universe  requires dark matter for proper functioning.


And if Dark matter is real, that means our milky  way also has a Dark matter halo, and some of that  matter should pass through the Solar System, earth  and even you. But how much? Let’s take a look.


In the early universe, everything was hot, dense  and more uniform than it is today. Back in the  young Universe, everything was hotter, denser,  and more uniform than it is today. Early on, there were areas of slightly higher-than-average  density, indicating a greater-than-average amount of matter. Gravitation works to  attract more matter into such a region, but radiation pushes that matter back out.  If only normal matter and its constituent


particles were to go with this radiation,  the galaxies and galaxy clusters that we see today would be extremely different from what we  observe today. If all we had was normal matter and its constituent particles to go with this  radiation, the galaxies and galaxy clusters that exist today would be vastly different from what  we observe.

Dark matter implies that every large structure in our universe, such as a galaxy or  a galaxy cluster, will be surrounded by a large, diffuse halo of dark matter. Normal matter will  congregate in the inner reaches of each galaxy, because normal matter can collide and  interact with both itself and radiation.


Dark matter, on the other hand, simply passes  through everything: itself, normal matter, photons, and so on. Dark Matter particles have  no way to lose the large momentum they start off with and only interact gravitationally. Each  dark matter particle may have passed through the galactic center only a dozen times till the  present day in the entire history of our Universe.


On the largest of scales, the Universe is  dominated by Dark Matter. But where we live, just 25,000 light years from the center of the  Milky way, normal matter is more dominant than Dark matter. That situation is considerably worse  here on Earth, in our Solar System, than it is in interstellar space.


The density of a human being  is equivalent to that of water: 1000 kilogrammes per cubic meter (kg/m3). If we take a look at  the most realistic simulations that we can come up with, the local density of Dark matter where we  are is even less: about 10-21 kg/m3. If we added up all the dark matter within all the people on  Earth at any given time, it would amount to less than a single nanogram.


If you added up all the  dark matter in the Solar System, all the way out to Neptune’s orbit, it would only amount to around  1017 kilograms: the mass of a moderately big asteroid. And because it doesn’t have interactions  like normal matter, it doesn’t move with the solar system. Not only that, it doesn’t orbit the  sun, doesn’t stay in a plane, doesn’t move around the other stars or the galactic center,  or even revolve around the Milky Way’s disk. Simply put, Dark Matter moves under the influence  of gravity, relative to earth at very high speeds! In other words, this matter moves  under the influence of gravity, relative to Earth, at pretty rapid speeds!


How much dark matter passes through you?


If you want to know how much dark matter passes through you in a given amount of  time, all you need are four numbers that you can multiply together.

They are:

  1. the density of dark matter,
  2. the surface area of a human being that the dark matter can hit,
  3. the speed of the dark matter,
  4. and the amount of time


you want to know the answer for. Once we’ve estimated the dark matter density — and we already have it, at  10-21 kg/m3 — we can get the answer right away. The surface area of a typical human is  1.7 square meters.


Since the dark matter comes in at a random angle, we can do a quick  calculation and find a good estimate for the area the dark matter “sees” is more like 0.6 m2. Our Solar System orbits the galactic center at speeds of around 200 km/s, but infalling dark  matter should be moving relatively quicker: closer to 350 km/s. All told, that  means dark matter moves, relative to a human on Earth, at a speed of around 400 km/s.


And we can do this for whatever times we want: every second, over the course of a year,  or over a typical (80 year) human lifetime. Even though, at any given instant, there’s only  around 10-22 kilograms of dark matter inside you, much larger amounts are  constantly passing through you.


Every second, you’ll experience  about 2.5 × 10-16 kilograms of dark matter passing through your body. Every year, approximately 10-8 kilograms of dark matter move through you. And over the course of a human lifetime, a total of just under 1 milligram of  dark matter has passed through you.


What might seem like a minuscule amount really  does add up over a long enough period of time. The fact that these numbers are as large  as they are not only teaches us something about our bodies and what’s in them, but how  we might dream of searching for dark matter. Whether it’s made of extraordinarily low-mass or  high-mass particles, we know the amount of dark matter mass that passes through not just a human,  but any detector of a given volume.


If we presume to know the mass of dark matter, we can calculate  the number of particles that go through anything. For decades, now, we’ve been building larger  and more sensitive detectors, attempting to probe whatever minuscule interactions might  exist between dark matter and normal matter.


The most advanced detectors today use atoms  with large nuclei in extremely large masses, looking for signs of a recoil or other  interaction. And so far, all the direct detection techniques have come up empty. Dark matter, to the best of our knowledge, is out there in all directions.


It may be invisible to  our eyes, but we can feel its gravitational force. It passes through all the matter in  the Universe, including human beings, as though it weren’t there at all.  There are, to the best of our knowledge, no collisions or interactions other  than its effects on curving spacetime. It doesn’t clump, cluster, or form  structure like dark atoms or molecules. And yet, if it has even the tiniest hint  of an ability to collide with either normal matter or radiation, we’ll be able to  detect it.


Over the course of your life, about a milligram of dark matter will have  passed through your body. If even one dark matter particle interacts with one proton or electron  in your body, we’ll have a chance. When it comes to dark matter — one of the Universe’s deepest  mysteries — it’s hard to ask for anything more.

Leave a comment

Your email address will not be published.