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

I hoped Dark Energy would have called on the phone. "Hey, hello Sabine, it's me, Dark Energy. And you know what ? I'm a super-symmetric indeterministic cord vibrating in a 11 dimensions Calabi-Yau manyfold, but you will never be able to prove or disprove me. Mwahahahah !" Alas, it did not happen.

The sarcasm is strong with this one - I love it.

Now now, I've learned from science that if your phone hasn't detected a gravitino, it simply means you need to build a bigger phone! 😂

Very interesting, thank you. "the GDEM spacecraft will be placed on nearby elliptic heliocentric orbits", "Using the data about the Sun’s position and distance, our system-comprising satellites typically spaced 1,000 km apart and orbiting with a semi-major axis of 1 AU-shows capability to achieve a measurement precision approaching O(10−24 s−2)." Hopefully this answers some of the questions about where the spacecraft might be located in the solar system. I hope this project gets the funding it needs.

I thought MOND and these other hypotheses were competitor theories for dark matter rather than dark energy, so this video is surprising to me.

This is why I follow Sabine - one reason. Her picking up on this proposed new experiment and recognizing the value of the approach (search for raw evidence rather than supporting evidence of any particular speculative theory) is so on point. I share her enthusiasm even at the proposal stage.

Albert did his best. He had no tetrahedral spacecraft (which the aliens will yawn when they see, thinking we're showing carbon bonding again. _"How many times are those Earthlings going to show us that? Do they think they're special or something? We already played that record album they sent out after searching every museum in the quadrant for a player. It's like watching termites."_ ).

There's a strong assumption in measuring distances in deep space using spaceships: that the noise in measurement is an error in a Gaussian distribution. Consider, there is solar radiation, small deviations on how the spacecraft trajectory is measured, non-linear vibrations from the motor of the spacecraft, etc. In order to measure the distance between spacecraft, there has to be a filtering mechanism that depends upon that the noise is Gaussian and therefore, an averaging method -- say, a Fourier transform -- can distinguish between the measurement distance and the noise. I know almost nothing about spacecraft. I don't know if this is a trivial concern or it's an unknown that's going to prevent a successful experiment. But, if the noise is non-linear, there won't be a way to distinguish between a measurement error and noise.

I could've bet that when Sabine said the phone will ring when a gravitino comes by, Elon would call, telling her that he will send up three more of his Tesla's into outer space to make his own dark-matter experiment

Possible to combine the LISA gravity wave detector with this idea by adding a 4th LISA space craft?

"Well, the problem is we canxt directly interact with it." "I know, how about we directly interact with it!?" "BRILLIANT!"

This looks a lot like a gravity waves detector. If we measure often enough, we could use it for gravity waves detecting. That's would be a faster changing component. Then, the slower changing component would be used for gravity field testing. I hope it would be possible to kill two birds with one stone. (I don't hate birds, though)

So... A ligo in space that will find more gravitational waves and then call them dark influence😅

I do love watching your stuff. Very informative with just the right peppering of dry humor. Thank you for being dissatisfied with the academic career world because it sent you on a path that has made our every-day world much richer!

"yes you can" the funniest joke in the Sabine canon 😂😂

What you are proposing here is what we already have proposed with LIGO in space, because they were supposed to set up two different different experiments at right angles. The only true difference would be if you send these spaceships on elliptical orbits around the sun that would take them inside of mercury orbit, and then out to Jupiter or Neptune.

Priceless content! love you!

The fly in the ointment I think is that dark matter interacts so weakly with regular matter. The measurements would have to be more precise than I think can be done.

Looks like a promising experiment. Loved the phone joke.

Thank you for the video.

Thank you, Sabine. ❤

Thanks for spotting and reviewing this article, really appreciated! The idea of formations of several drag-compensated spacecraft to perform gravitational experiments is not new. I worked (in a previous working life) on Lisa Pathfinder (technology demonstrator for LISA) and I remember various configurations were assessed for LISA (Laser Interferometer Space Antenna, aiming to measure gravitation waves), besides the triangle which is current baseline. Among these was a tetrahedron like this one, and even a double tetrahedron (two tetrahedra located at different Langrange points, L4 and L5, if I remember well). But, indeed, the idea of using this concept for dark matter investigation, instead of "boring" gravitational waves measurement, is exciting. Also, the spacecrafts would fly much closer (~1000 km in this case, 2.5 million km for LISA) but in highly elliptical orbits, making the tetrahedron expand and collapse, in a sort of dance while revolving around the Sun... So cute! Maybe it's time for me to go back to some good old rocket science...

Thanks for tackling all these wonderful topics and presenting them in an engaging manner! I wonder if you would be interested in giving a talk on the laws of thermodynamics, enthalpy, entropy, and Gibbs free energy.

"Gravitino phone calls"... hahahahaha....👏👏👏👏😂🤣😂🤣😂🤣🖖🖖🖖🖖🖖🖖

I think more than 4 should be used to account for the possibility of fractal dimensional spacetime. The more the better. Cheap minisats could work

Really interesting experiment indeed, Sabine! Thanks! 😊 Stay safe there with your family! 🖖😊

The search for gravitational waves started back in the late 1960's. It only took 50+ years to build equipment sensitive enough to find them. Take a guess on how many years before this new experiment will succeed.

I have been told that heated things have more mass than cold things? Well then, since the majority of matter in the universe is in a plasma state, dark matter might be either heated space/time or a temperature fluxed Higgs field? Either way, would isolating matter from the Higgs field create a hot or cold condition? I'll say that it would create a cold condition, somewhat akin to evaporation. Re-introducing said matter, incrementally, back and forth into the Higgs field would regulate gravity's effects thus making a thing lighter or heavier as it is manipulated in and out of the field. Also, as matter "falls" toward mass, might the movement of matter in and out of the Higgs field be used as a type of locomotion? Zoooom!

What is the distance between the vertices of the tetrahedron? Meters? Kilometers?

Why launch only 4... if one fails to function perfectly then it won't work. Would be better to launch like 6+

She nailed a perfect ending. What a natural talent!

That shut up was a perfect balance between annoyance and "this is the last god damn time"

looking forward to read your telephone paper on Nature.

Sabine Hossenfelder, I subscribed because your videos are super cool!

A gross oversimplification I know, but the experiment immediately made me think of the Michelson-Morley Experiment, seeking to detect and measure the hypothesized ether. Einstein, as I recall, was influenced by their results in formulating Special Relativity.

I think what creates all these illusions is time... we see galaxies spinning too fast than they should... because their time is different... they live in a faster world... for us... our watch sees all this quickly..... like flies that we can't hit, because they see us in slow motion

This idea of a screening mechanism is interesting to me. Are there any other physical examples of similar screening mechanisms that we know of?

You make me smile and laugh while learning. Thank you

I’m expecting that paper Sabine

We already found something when the Voyagers found far, far more magnetic field variation than ever predicted after the heliopause.

Our conventional understanding of space may require reexamination due to inherent limitations in human cognitive processes, particularly in interpreting non-existence or "negative" constructs. The human brain struggles with concepts that are fundamentally void or absent, such as the instruction to not think about a specific object, like a blue ball, or to avoid an action, like licking a frozen lamp post. This cognitive challenge extends to understanding spatial dimensions. If we consider the vacuum between celestial bodies-take, for example, the region between Earth and the Moon-it raises the question: if there is "nothing" in that intermediate space, does the concept of distance even apply? Our perceptual and cognitive limitations might be misleading us in understanding true spatial relationships and the nature of "empty" space. Thus, it is plausible that our current theories about space and distance might need rethinking to accommodate a framework that aligns more closely with these cognitive phenomena.

The "shut up" sent me 😅😂

Oddly enough, that phone does put an upper bound on the gravitino flux passing thru it: it must be less than what would be required to gravitationally pull the hammer into the bell.

If you are inside of a differential you cant measure something you are inside of. Try getting a pressure reading standing inside of a pressure differential or vessel using an instrument, you can not get a true or real reading. You may can observe the gases and concentrations but to know the true and real measure you will have to be outside the differential using a gauge.

A question for Sabine: Given that the differential equations of quantum mechanics are linear and the equations of general relativity are nonlinear, what can be said, if anything, about the differential equations of quantum gravity?

This sounds a lot like gravitational waves detection, where the smallest vibrations matter. It would be very really difficult to stabilize 4 moving spacecrafts relative to each other.

LISA is planned to have three satellites that measures via laser the precise distance to measure the gravitational waves, maybe extending that detector with a satellite more can allow not only detect GW on the LISA plane but also those micro differences in the gravitational field that this tetrahedron detector is supposed to see (and can be a feasible extension to have even more precision on the LISA detector). Just a brainstorm!

With gravitational influences permeating space, how would you maintain a tetrahedral relationship of the detectors. And how would you tell the difference between dark matter and gravitational influences?

The Galaxy Lamp is only available with an American standard plug and works with a Voltage of 120 Volts. If you apply 230 Volts you can simulate the Big Bang

I love your sense of humor.

Thanks!

Wow 😮 that could be interpreted a couple of different ways.

On the surface this theory sounds good but in reality I think it will fail as well. While this short video wasn't long enough to list all of the environmental variables I doubt that the folks behind this theory have taken everything into account. Our solar system doesn't exist in featureless space. Spatial phenomena from eons ago continue to effect the solar system everyday. Mostly in the form of galactic winds that carry everything from just plain simple gasses to dust to highly charged particles. Plus, and more importantly we pass thru different gravity waves and wells everyday. These waves come from every direction, have different amplitudes and pulses. They are not linear and you cannot sidestep them. Also, the same wave will have varying strengths and velocities along it depending on the phenomena the wave has encountered prior to it's arrival to the solar system and what it has encountered in the solar system prior to arriving to the Tetrad testing location. So all of this alone would throw lots of question marks into the reliability of any testing results from the Tetrad. Maybe too many!!!

You don't need anything if the gravity waves themselves can produce nodes and anti-nodes, it's just ripples in the fabric of space itself displacing everything contained in the surrounding medium. It's like expecting something else to be causing ripples in a bucket while the water still hasn't settled from sloshing about.

I'd prefer to see you advertising some Taw Valley Cheddar.

Looks quite a lot like LISA. Then, since LISA plane stays the same on its orbit around the sun, wouldn't it relax the requirement to have tetrahedral configuration? Can't one just average data over a year of LISA observations instead, since the dark matter distribution should not change?

Would 4 satellites, equipped with LIGO capabilities make a good gravitational wave detector?

We're currently testing our Kinetic Mixing Detector. To date we've only managed to detect your phone. Please move Abert 1.07 meters from the device. Thank you.

Dear Sabine, will the precision of the measurements be of the same order as in the case of Ligo? So with corrections for the different gravitational effects of the planets and the Sun on individual ships, and also from one ship to another (third and fourth) and the pressure of the solar wind? - Is the entire project realistic due to the multitude of disturbing factors in space?

Finally 🎉with love from wales 🏴󠁧󠁢󠁷󠁬󠁳󠁿

What do you think? Should Sabine get her own version of Hecklefish ?

A question which comes to mind is. "In what units would dark energy be measured?

OK, well maybe no one else sees this but let me do this Imagine we have just a simple massive object, let’s say a neutron star, this way there are no large amounts of matter being shed, and the photon pressure is fairly minuscule. In essence a simple one body problem. I then add a tiny satellite way far away, still no problem. I then add two more satellites each spaced 120° relative to the dense central object. Communication by laser is hard, but let’s imagine that it can be done. So that the lasers form a perfect equilateral triangle. Still not to much of a problem. Now, just add one more satellite out of the plane of the other three. What happens? That forth objects orbit is inclined relative to the other three. Actually I have performed this set-up in KSP trying to dock a ship in orbit without correct from a north or south orientation in an otherwise equatorial orbit. Theoretically once you establish exact positioning, the orbits are identical they should collide, but instead they orbit each other. This is because zeroing the velocity of the one ship to the other at some distance exactly north is not exactly north because of the curvature of the isoquants (the same potential energy manifold in spacetime) in all three dimensions. And we can test this to make sure it’s true by performing the same maneuver but at a much much greater orbit and noting the two ships come much closer together at the minimum. So let’s create a real scenario, a tetrahedron in orbit around a massive object are not a fixture, the forces between them are subject to change because the true gravitational force is the tidal force. As we position these satellites outside of an equilateral triangle orbiting the sun and place them in reasonable orbits these effects become more noticeable. One satellite will have to be above or below the plane and still another in a different orbit. Thus the four satellites will always be moving (changing distance) with respect to each other. One could try putting them in a Lagrange point between say the Sun and Jupiter, but then now you are using to gravimetric objects to reduce the wandering of satellites, when the goal of the satellites is to take measurements away from massive objects. I suppose one could put them at the L2 of Neptune getting them as far away from the sun as possible, but then what is their power supply, and have we ever managed to orbit the sun anywhere that far away _And_ how long would it take (very long), and how much energy would be required (A lot more than we have ever imparted, you have to correct the orbit at L2 of a very eccentric orbit).

Light MUST indeed travel at the speed of light C. When distance is stretched light must travel that distance in the time determined by C. That means the light is traveling faster as perceived by us in a more contracted frame of reference. Add to that the fact that a second passes by faster away from the center of mass which increases the speed light MUST travel even more. It’s not complicated. It’s so simple. It’s the very reason things appear to be moving faster than the speed of light moving away from the center of the galaxy because they are moving faster yet without exceeding the speed of light. I don’t know why that is so hard to understand.

Wouldn't various minor forces and variations in solar winds affect their velocities and distances?

A space array is the obvious next step for large scale detection.

Sabine gets better and better !!

I wish they would fly a sensor away from Earth and check to see if the Casimir force is noticeably different than here on Earth. Seems like that would be interesting to know about the quantum vacuum.

Wouldn't a gravity wave also alter the scale of whatever is being used to measure distance, effectively disguising the effect of the wave?

Could you make a video on how hypotheses not involving dark matter explains the gravitational lensing results typically attributed to dark matter? That seems to be the strongest indicator for there being an invisible matter-like thing interacting with gravity and I've often heard that MOND and other modified gravity theories can't account for that, although I wouldn't expect that to actually be the case since no serious scientist would keep on working on those lines of research if they had such a massive flaw.

such an interesting question

If the deviation isn't interpolating but only happens after a certain threshold is achieved, that would actually be a much more puzzling and therefore interesting result. But could well be explainable considering that the quantum world behaves in a similar way.

Not a lot here except an advert for a lamp.

these instruments could be added to any number of future interplanetary probes thus inexpensively forming a grid larger even than four and no need for specialized craft

With something like this you have to mention how well gravity has already been measured with Mercury and other solar system bodies as well as Pioneer/Voyager/other deep space probes. For example we have gravity down to x significant digits just using what we know of the solar system, but this experiment will add another three digits and that is enough to find some of these anomalies.

superfluid dark matter...? Ticks a lot of boxes. Topologicaltastic.

Dark Energy is my favorite Parliament tribute band!

I am not sure how four space craft can do this. Is each space craft producing a different color light and the other space craft is reflecting it back to the original’s sensor? Can spacecraft be so precisely aligned in space? How do the spacecraft calculate the distance from the sun and other big objects? Does there need to be another laser on earth or the moon? How is mass measured if they use propellant?

I don’t know much but I consider if background gravitational waves would be a form of “noise”. What would be the expected signal to noise ratio? The laser “links” between the ships could be in the form of (a few) interferometers.

I like those protector toys. I want to know how many times I can get hit in the eye with a green laser before it it starts damaging my retinas :)

But how will we account for minuscule perturbations that are caused by one of those spacecraft passing by an object the presence of which might not be known to us, such as Elon's astro-Tesla...?

Nice subject. I would have appreciate more technical details about the spaceships, the distance between them, the direction they will go, the release date, or simply the name of this project :-)

Put in for a research grant to develop and test the phone gravitino detector ;) > Ok, on a more serious note. Do flying saucers offer a more accurate result over triangular space craft/detectors?

If we assume that >99% of stuff is dark, can we evaluate where it is interacting more based on the way that non-dark stuff misbehaves? ie, along galactic radii

I reproduced the gravitino experiment's negative result.

I'll keep my eyes open for it as well. I'll let you all know if I see it 🥰

Why can’t this apparent dark energy be explained by photons emitted from stars pushing on other bodies when they hit them? Like solar sails everywhere basically.

2:58 I like how they fake the protection onto itself in a lot of scenes, like there's mirrors everywhere.

A fun second step for this experiment could be putting a fourth ship in the middle and a new set of lasers to measure distances to it. Changing the masses of the ships would be cool too.

I came up with this idea years ago. But I "only" have a degree in physics, electronics and computer science, so the establishment ignored me.

Is there a pre print for the phone paper available?

Imagine trying to measure the pressure of the air in the room using a differential against a floor of bubbles also in the room, not realizing the bubbles also contained air as well. The answers may be hiding in plain sight underneath what we already know, we’ve just unwittingly taken certain things for granted enough to not bridge the connection🤔…

The tetrad if configured by masses of the spacecraft and distances should have a center of gravity somewhere in the volume. I would think that each craft would have a clocking mechanism as well to look for deviation. I'm not sure if the interpretation would mean much other than spacetime points exhibit extremely slightly different values.

Hehe, perhaps one could equip the central spacecraft within the postulated Tetrad fleet of dark matter detection spacecraft to run on the quantum propulsion neutron spewing Queller Drive which emits oodles of highly concentrated phantasmal dark energy bundled within amplitudinally intense oscillatory pockets of short burst gravity waves, causing the other spacecraft in its vicinity to vacillate drastically in acute bouts of molecular bond breaking vibrations & blow up into smithereens like so as featured in this Space 1999 episode. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0voS3FxoSuU.htmlsi=bHhMCRvsTqDFgxOX (trailer) ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-fIPlPhg5ii4.htmlsi=NPIoukGK0QovvOx8 (check out excerpted segment of episode from 47:27 - 49:42)

'Kein schwein ruft mich ANNN...' *singt(den Physiker-Blues)

What if the deviations are smaller than the system can measure? On a Universe scale the deviations could be minutely small and only count in the absolute aggregate. Plus there is always the plus or minus factor in any measurement system. The deviation could be contained within the accuracy of the measuring system.

Don't you know our little part of the galaxy is in an area called "Cruel Space". The rest of the galaxy is normal and the extra energy/matter that we scientists don't know that is is called the rest of the galaxy calls Axiom.

Graviton-based phone calls ought to be possible, you just need a supply of black hole pairs to merge at timed intervals, and a really sensitive phone to receive the signals.

What do you think of John Moffat's gravity theory?

Watch it turn out to be something simple like, in the absence of matter space time expands. Space time simply pushes space time, but we can never really measure that since we typically need matter as a reference for measurements.