Recommended Free Tools
iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Frame-dragging, also called the Lense–Thirring effect, is the general-relativistic effect in which a rotating mass changes the orientation of nearby local inertial frames. Earth’s spin therefore produces a minute gravitomagnetic twist in the spacetime around the planet. An orbiting gyroscope keeps pointing along its local inertial direction, but that direction slowly shifts relative to distant space.
Gravity Probe B (GP-B) measured this shift with four cryogenic gyroscopes in a nearly polar orbit 642 kilometres above Earth. NASA’s 2011 final result for the frame-dragging drift was −37.2 ± 7.2 milliarcseconds per year, close to Einstein’s predicted −39.2 milliarcseconds per year. The effect is real, but so small that isolating it required drag-free flight, magnetic shielding, cryogenic hardware and years of calibration.
What frame-dragging means in general relativity
Local inertial frames are the key idea
In everyday mechanics, an inertial frame is an ideal reference system that is not accelerating or rotating. A freely falling gyroscope provides a practical approximation: once set spinning, its axis tends to maintain its orientation unless an external torque acts on it.
General relativity changes what “not rotating” means. Mass and energy curve spacetime, and the local inertial directions defined by freely falling objects can vary from place to place. A rotating body adds another effect: its angular momentum slightly shifts those local directions. The result is called frame-dragging because the rotating body drags the local spacetime framework around with it. Stanford’s Gravity Probe B description calls it “the amount by which the rotating Earth drags its local spacetime around with it.”
#1 Best Overall
- Powerful Turbo Fan:CAGIWIRU Electric Air Duster have reached speed up to 130000RPM,Can efficient remove dust and debris.With LED light and Three Adjustable Speed to meet with different cleaning tasks.
- With Attached USB C Fasting Charging cable.Charing 3 hours,Enjoy up to 240 minutes of use on the lowest setting, For third speed can use for 25mins.with four charging options to meet with your needs.
- Wide Application: attached 5 different nozzles,making it suitable for a variety of scenes, such as car,pet, pc, keyboards, and other electronic devices. It also serves for office and home clean duster.
- Handy Design & Portable:Cordless air duster electric nozzle is Light weight and small size, design and comfortable to hold and space saving, convenient to carry around. You can put it in your room or inside the car without taking up space.
- Economical &Reusable: Built durable materials with a long-lasting battery,our CAGIWIRU air duster it's a sustainable alternative to disposable air cans.
It is not a whirlpool of material
Earth is not pulling nearby objects into a visible vortex, and spacetime is not a substance flowing around the planet. “Dragging” describes how the geometry used to define non-accelerating directions is altered by rotation. A gyroscope in orbit still follows its own freely falling path; the measurable change is the slow precession of its spin axis relative to a distant reference direction.
Why the effect has two names
Physicists Josef Lense and Hans Thirring derived the effect in 1918. Their names are therefore attached to the prediction: frame-dragging and the Lense–Thirring effect refer to the same relativistic phenomenon.
How Earth’s rotation twists nearby spacetime
Earth’s angular momentum creates the twist
Earth’s mass produces the ordinary gravitational curvature that governs orbits. Earth’s rotation superimposes a much weaker rotational component. The faster a central body spins and the more angular momentum it has, the stronger this rotational influence is in its surroundings. The signal also weakens with distance, so an experiment in low Earth orbit has a better chance of detecting it than one far away.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
For an orbiting gyroscope, the predicted consequence is a gradual turn of its spin direction. The shift is conventionally expressed as an angular drift per year. In the GP-B orbit the frame-dragging prediction was only about 39 milliarcseconds per year.
Rank #2
- Screen Cleaner is Your Screen’s New Bestfriend! - EVEO is proud to present a screen cleaner that’s perfectly suited for your TV. Meet your new screen cleaner, computer screen cleaner, laptop cleaner, iPad cleaner, Macbook,tv cleaner or any other electronic device. Our screen cleaner spray and wipe along with the included plush microfiber cloth, easily removes dust, fingerprints & other smudges on the screen’s surface. Clean effectively for a streak-free screen
- Gentle on your Screens - Our screen cleaner spray and wipes is compatible to be used even for the most sensitive LCD, LED, CRT, and OLED screens in proper use. Be at ease knowing that this product is compatible with all the major brands: LG, SONY, Samsung, Sharp, iPad, iPhone, Android screens, Kindle, PC monitors - we’ve got you covered! Can be used as LCD screen cleaner, tv cleaner, smart tv screen cleaner, and more
- Premium Super Soft Plush Microfiber Cloth - Included in this efficient screen cleaning kit. This screen cleaner spray and wipe has our signature plush microfiber cloth specially designed to comply with screens and monitors and leave them streak-free. Has been shown to effectively absorbs stubborn stains, zero streaks, and no fiber shedding. Always use this together with our screen cleaner for the best results
- Easy-to-Use Screen Cleaner Kit + microfiber cleaning cloth - The EVEO Screen Cleaning Kit will easily be your new favorite tool when it comes to taking care of the things you love most, quick and easy solution for a streak-free screen. Simply screw on the sprayer gun on the screen cleaner bottle. Spray the cleaning liquid onto the microfiber cloth, then wipe the screen until desired cleanliness & shine is achieved.
- Quality Screen Care Kit Worth Purchasing - Enjoy a convenient Screen Cleaner anytime, anywhere you need it. Your satisfaction is our top priority. We stand behind the quality of our products and that’s why, you shouldn’t be worrying at all. We manufacture the Best Screen Cleaner. and can be used for laptop cleaning kit, laptop screen cleaner, tv screen cleaner for smart tv. MacBook screen cleaner, monitor cleaner or screen cleaner spray for electronic devices with microfiber cleaning cloth
Why people do not notice it on Earth
A milliarcsecond is one-thousandth of an arcsecond, and an arcsecond is one-three-thousand-six-hundredth of a degree. A few dozen milliarcseconds accumulated over a year is therefore an extraordinarily small angle. Stanford compared the GP-B frame-dragging angle with the apparent width of Pluto as seen from Earth. Ordinary gyroscopes, surveying equipment and uncorrected satellite motion cannot separate such a tiny relativistic drift from mechanical, thermal, magnetic and gravitational disturbances.
Frame-dragging versus geodetic precession
Two different general-relativistic precessions occur in an Earth-orbiting gyroscope. They are often discussed together because GP-B measured both, but their causes are different.
| Feature | Frame-dragging (Lense–Thirring) | Geodetic precession |
|---|---|---|
| Physical cause | Rotation of the central body and its angular momentum | An object’s motion through spacetime curved by mass |
| GP-B observable | East–west spin-axis drift in the mission’s analysis | North–south spin-axis drift in the mission’s analysis |
| Approximate Earth-orbit scale | About 39 milliarcseconds per year | About 6,606 milliarcseconds per year |
| Relative measurement challenge | Much smaller; especially vulnerable to spacecraft and rotor disturbances | Much larger and easier to distinguish |
Geodetic precession does not require the central body to rotate. It arises because the gyroscope is moving through the curved spacetime generated by mass. Frame-dragging does require rotation. In an actual orbit, the two drifts occur simultaneously, so the experiment must model and separate both components rather than treat every observed turn as evidence of frame-dragging.
PC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minuteHow Gravity Probe B tested the effect
The orbit and reference direction
NASA and Stanford built GP-B around a nearly polar orbit approximately 642 kilometres above Earth. The spacecraft repeatedly viewed the guide star IM Pegasi through a telescope. The star supplied a distant reference direction, while the gyroscopes supplied nearly torque-free inertial directions. Comparing those directions over time revealed how the gyroscope axes moved.
Rank #3
- 【Large size】：Measuring 800 x 300 mm/ 31. 5×12 inches, which is wider and taller than others. Large mouse pad can perfectly fit your keyboard and mouse of any size, and there is also ample space for peripherals such as phones, tablets, etc.
- 【LED backlight mouse pad】：Blade Hawks RGB mouse pad provides 7 static modes and 7 dynamic modes will give you the options you are looking for. Power-off memory function remembers the last lighting mode you selected. The super glow fiber Chroma will give you a colorful gaming setup that you want.
- 【Anti-slip rubber base】：Made from Natural rubber, this gaming mousepad will firmly grip your desktop, allowing you to enjoy the ultimate precision in the games you are most passionate about. It also comes with a texture that enhances this ability even further.
- 【Smooth and waterproof surface】: Micro-textured cloth surface, for extremely precise mouse control and a smooth movement. When liquid splashes on the gaming mouse pad, it forms water droplets and slides down. Will not delay your work or gameplay.
- 【Plug and play】: This mouse and keyboard pad is powered by USB, plug and play, no driver required. One button control light modes. Press one time to change the lighting mode, press twice to change the brightness, press and hold about 3 seconds turn ON/OFF.
Four cryogenic gyroscopes
The payload contained four spherical gyroscopes. They were cooled to cryogenic temperatures so that their superconducting instruments and rotor systems could operate with extremely low noise. Using four units allowed the mission team to compare independent rotors, identify instrument-specific behavior and improve the estimate of a signal that was far smaller than many non-relativistic effects.
Keeping the spacecraft from pushing the result
Atmospheric drag at GP-B’s altitude, solar radiation pressure and other tiny forces could make the spacecraft accelerate. GP-B used drag-free control: the spacecraft sensed its motion around a freely falling proof mass and fired thrusters to follow that mass instead of allowing external forces to produce an apparent torque on the experiment.
Magnetic fields were another concern because the gyroscopes and their readout system could respond to magnetic interactions. The spacecraft therefore used magnetic shielding and extensive monitoring. Thermal changes, patch effects on rotor surfaces, suspension behavior and other non-relativistic torques were characterized through calibration and data modeling.
Extracting two tiny drifts
The analysis tracked the direction of each rotor’s spin axis relative to IM Pegasi. A component in the mission’s east–west coordinate corresponded primarily to frame-dragging, while the much larger north–south component corresponded primarily to geodetic precession. Separating the components required fitting the measured time series and accounting for known disturbances rather than simply reading a single change in pointing from one observation to the next.
Rank #4
- 【Softer and More Comfortable】Vaydeer wrist rest has unique diamond pattern, which is the combination of softness and aesthetics. The materials of wrist rest are improved into higher quality memory foam and covered with silky smooth lycra. The computer wrist rest makes you as comfortable and cushiony as like rest your wrists on clouds.
- 【Ergonomic Wrist Saver】The wrist rests for keyboard and mouse comes with a 17.32×3.15×0.83 inch keyboard wrist pad and a 5.94×3.15×0.83 inch mouse wrist support. Based on ergonomic design, the unique concave shape is the perfect fit for your wrist joints. The wrist rest pad fits most computer keyboards and laptops, improve hand and wrist posture, release your wrist and arm stress.
- 【Non-Slip Rubber Bottom】Featuring an anti-skid silicone base on the bottom, this wrist keyboard support stays firmly in place on your desk, preventing the padding from sliding around, ensuring stable and consistent wrist support during extended computer sessions.
- 【Better Experience & Pain Relief】Our keyboard arm rest is beneficial to alleviate the soreness caused by direct contact and friction between your arm and a hard desk surface, reducing the risk of wrist fatigue or carpal tunnel. The soft texture of memory foam can evenly distribute the pressure around your wrists and provide good support with just enough give.
- 【Helpful in Multiple Scenarios】Whether you're working, studying, writing, typing, gaming, this keyboard and mouse rest combo is an essential accessory to add comfort and support to your hands and wrists. It’s also a great gift for men, women, family, friend, coworker, gamer, teacher, etc.
What GP-B measured
NASA’s final 2011 analysis reported the following values:
| Effect | Measured drift | Einstein prediction |
|---|---|---|
| Frame-dragging | −37.2 ± 7.2 milliarcseconds per year | −39.2 milliarcseconds per year |
| Geodetic precession | −6,601.8 ± 18.3 milliarcseconds per year | −6,606.1 milliarcseconds per year |
The minus signs are part of the coordinate convention used for the reported drift directions; they do not mean that the effect is “negative gravity.” The uncertainty attached to the frame-dragging value is much larger in relative terms than the uncertainty on the geodetic result because the frame-dragging signal is the smaller component and is more easily imitated by spacecraft and rotor systematics.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Is frame-dragging real?
Within the stated experimental uncertainty, GP-B’s result was consistent with general relativity. The measured frame-dragging drift, −37.2 ± 7.2 milliarcseconds per year, overlaps the predicted −39.2 milliarcseconds per year. The same mission also obtained a geodetic result close to its prediction, providing a separate check on the relativistic behavior of a gyroscope in orbit.
“Consistent with” is the precise scientific conclusion. GP-B did not measure a large, visually obvious rotation of space, and its result is not an exact equality with the prediction. The experiment established a tiny drift at the expected scale after accounting for known sources of error. Its design and analysis were aimed specifically at making a frame-dragging measurement credible despite the signal’s small size.
Best Value
- 【No Drill Mounted】Cable management tray can be assembled in as little as 3 minutes or less-simply. Side clips easily clampe the edge of desk, pass through the holes on the sides, and secure excess cables with baskets. Desk cable management supports inward or outward installation to meet your needs in different scenarios, and provides you with great convenience when collecting and organizing wires.
- 【Rubber Pad Protects Desk】Wire organizer under desk built-in soft rubber pads on the clamp protect your desk from scratches, so you will not damage your furniture or office.
- 【Sturdy and Beautiful】Cord management under desk is made of high-quality carbon steel and holds about 15 lbs. The wire basket has 2 holes on each side of the tray to enable your cables to pass freely. Cable baskets are suitable for desk thickness use from 0.4" to 2.4".
- 【Space Saving & Keep Organized】Desk cable management tray holds all your power cords, outlet strips, USB hubs and computer transformers hidden from your feet, and the data cables will not enter the vacuum cleaner to keep your desk clean and tidy. Desk wire organizer is also suitable for use in the kitchen and outdoors.
- 【Reduce Safety Risks】Cable tray under desk keeps all plugs away from your kids, no more worry about tripping. Using 2 holes wire tray saves extra space, helps you easily cabling and wire protection. The mesh design is not easy to accumulate dust, but avoids safety accidents caused by messy wires.
Why the experiment was so difficult
- Signal size: the predicted frame-dragging drift was only about 39 milliarcseconds per year.
- Competing relativistic signal: geodetic precession was roughly 6,606 milliarcseconds per year and had to be modeled separately.
- Environmental forces: atmospheric drag, solar pressure and other disturbances could alter the spacecraft’s motion.
- Magnetic effects: residual fields could interact with the gyroscopes or their readout.
- Thermal and mechanical behavior: temperature changes, rotor disturbances and suspension effects could mimic a slow drift.
- Long calibration: the experiment needed detailed characterization of non-relativistic torques before the relativistic residual could be trusted.
These requirements explain why a consumer-grade gyroscope or a short satellite observation cannot reproduce the measurement. The challenge was not merely detecting rotation; it was proving that the measured rotation came from Earth’s angular momentum rather than from the instrument or spacecraft.
What frame-dragging does—and does not—change
It changes inertial orientation, not Earth’s orbit around the Sun in an everyday way
Frame-dragging is a correction to the relativistic geometry governing motion. Near Earth, the correction is tiny compared with the Newtonian gravitational field and with the larger geodetic effect. It does not make the atmosphere visibly swirl, alter the length of a day in a detectable daily-life sense or pull satellites into the planet.
It affects more than gyroscopes in principle
Any sufficiently precise measurement of motion or orbital orientation can contain a Lense–Thirring contribution. Gyroscopes provide a particularly direct way to describe the effect because their spin axes act as inertial references. Other high-precision orbital experiments can also look for rotational corrections, but every method must control Earth’s uneven gravity field, non-gravitational forces and instrument biases.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →Why the effect is stronger near compact objects
Earth rotates, but its rotational influence is weak at the distances accessible to satellites. Much stronger frame-dragging signatures are expected near rapidly rotating compact objects, where gravity and angular momentum are concentrated in a much smaller region. Around such objects, relativistic effects can strongly influence the motion and orientation of nearby matter and light. Earth-orbit measurements remain valuable because they test the same theory in a comparatively gentle, controlled environment.
A practical way to remember the distinction
- Ask what supplies the cause. If the effect comes from the central body’s spin, it is frame-dragging.
- Ask what the gyroscope is moving through. Motion through mass-curved spacetime produces geodetic precession, even if the central body were not rotating.
- Compare the scale near Earth. GP-B’s frame-dragging signal was about 39 milliarcseconds per year, while its geodetic signal was about 6,606 milliarcseconds per year.
- Check the reference system. The reported direction and sign depend on the coordinate convention and the distant guide-star reference used by the experiment.
Bottom line
Earth does twist spacetime through its rotation. General relativity predicts that this twist slowly turns the local inertial frame around the planet, producing the Lense–Thirring effect. Gravity Probe B’s four cryogenic gyroscopes measured a frame-dragging drift close to Einstein’s prediction, while also measuring the much larger geodetic precession. The effect is genuine, but near Earth it is so small that only a carefully controlled space experiment can isolate it.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
