Are we surrounded by dark energy? A spacecraft tetrad will look for it

astrophysicists say that 95% of the matter energy content of the universe is dark stuff either dark matter or dark energy it's supposedly all around us but we can't see feel or hear it yes you can shut up I'm not particularly excited about most of the experiments looking for this dark stuff but a few days ago I read about a new one that actually makes a lot of sense let's have a look so this new proposal comes from a team of NASA researchers and they're suggesting to use four small spacecraft that fly around in the solar system in the configuration of a tetrahedron the idea is fairly simple they want to very precisely measure the distances between the spacecraft to look for deviations from Einstein's theory of gravity right here around us this makes a lot of sense because you see we know from observations that this dark stuff makes itself notice ible on large distances galaxies Galaxy clusters the expansion of the entire universe whether it's really some sort of stuff or whether we have got something wrong with the law of gravity the differences kick in only at large distances and for some reason we can't detect it on our planet but somehow these two things have to fit together so nature must interpolate between this local einsteinian gravity and whatever's going on on out there in the cosmos this means that there should be an effect in the solar system it's just that it's so small that it's hard to measure this is why Precision tests of gravity in the solar system make a lot of sense if you look at the explanations that have been proposed for dark energy or dark matter like modified gravity they all need some sort of interpolation between Galactic and Earth scales they have a mechanism that makes those effects go away closed by the Sun but they never entirely shut down modified neonian Dynamics is somewhat awkward in that it doesn't tell you exactly how the modification shuts down it just has an arbitrary interpolation function but there are other ideas for example chameleon fields that could make up dark energy they have what's called a shielding mechanism that suppresses these fields near heavy objects like our planet or the Sun but they don't go away so you can measure them if you measure precisely enough but how before we talk about big space out there let's talk about your space with the Galaxy projector you can turn any room into a special place it creates a colorful display of stars and nebuli and I found it to be both relaxing and inspiring and not only that it's also a smart device let's look at some of the features first off it's RGB color brightness rotation speed onoff timers and many more are fully customizable and no need to get out of bed you can do it all from your phone better still you can use voice commands with Amazon Alexa or Google Assistant the Galaxy projector also comes with a selection of color themes that you can choose from and there's no need to worry about your electricity bill this device is super energy efficient the Galaxy projector is a neat modern device with solid hardware and software and it's just what science lovers like me and maybe you too need to chill if that sounds good make sure to get our special offer by clicking the link below and using the discount code zabina to get 15% off let's then talk a little more about this new proposal why do you need four spacecraft it's because if you have only three there's always a plane that goes through them if you have four that's a really three-dimensional configuration what you do then is that you precisely track the distances between the spacecraft by pinging back and forth laser signals this also allows you to measure the relative velocities and from the changes in the distances and velocities between the spacecraft and their relation to the distance to heavy objects mostly the sun you can then infer whether the law of gravity is as Einstein said or has subtle deviations Albert thinks that's a really cute idea this type of experiment will not detect dark matter at least not in the most common versions but it could pick up some type of super fluid dark matter which I've worked on for some time this isn't mentioned in the paper but the super fluid dark mattera also has a kind of screening mechanism which is that the super fluidity must go away near heavy objects the idea is that this happens because the gravitational pressure gets too large so in this model too you must have a crossover somewhere this is why I think this experiment is a really good idea because it looks for a generic effect does gravity in our solar system depend on the distance to the Sun as we expect we know that there can't be any large deviations because otherwise the orbits of planets would be weird but this experiment can look for subtle small deviations I think this is more promising than pretty much all of the dark mattera experiments that are popping up left and right these days I could talk about a new dark meta experiment every day if I wanted to like physicists are using everything as dark meta detectors now DNA rocks quantum computers I'm about to write a paper claiming that my phone is a dark meta detector you see if a gravitino comes by the phone will ring that's a negative result which will make for very interesting new bound on graval phone calls I'll submit this straightway to Nature thanks for watching see you tomorrow

Channel: Sabine Hossenfelder

Views: 139,405

Keywords: science without the gobbledygoook, hossenfelder, science, science news sabine, science news, science humor, astrophysics, space, dark energy, dark matter, tests of dark energy, tests of dark matter, space news, astrophysics news, physics news, modified gravity, is dark matter real, is dark energy real, Einstein wrong, testing Einstein's theory of relativity, relativity, general relativity test

Id: y81kQ_JEQkY

Length: 6min 16sec (376 seconds)

Published: Wed Apr 24 2024