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General relativity passes a range of precise tests set by pair of extreme stars

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Re: General relativity passes a range of precise tests set by pair of extreme stars

#11

Post by vlovich123 »

kanzenryu2 wrote: post #9

This does worry me, though https://en.wikipedia.org/wiki/Flyby_anomaly

> The analysis of the Juno flyby looked at analysis errors that could potentially mimic the flyby anomaly. They found that a high-precision gravity field of at least 50×50 coefficients was needed for accurate flyby predictions. Use of a lower-precision gravity field (such as a model with 10×10 coefficients, sufficient for launch analysis), would yield a 4.5 mm/s velocity error.

I buy this explanation as the most likely vs any other more esoteric explanation.

Re: General relativity passes a range of precise tests set by pair of extreme stars

#13

Post by treeman79 »

behnamoh wrote: post #10
mensetmanusman wrote: post #5

“ This cosmic laboratory known as the “Double Pulsar” was discovered by members of the team in 2003. It consists of two radio pulsars which orbit each other in just 147 min with velocities of about 1 million km/h. One pulsar is spinning very fast, about 44 times a second. The companion is young and has a rotation period of 2.8 seconds. It is their motion around each other which can be used as a near perfect gravity l…

My jaw (and my phone) dropped when I read the numbers. I feel like space is ruthlessly huge and these pulsars are brutally massive..

And the energy lost between Sum and Earth due to gravity waves is sufficient to power a small toaster oven.

Re: General relativity passes a range of precise tests set by pair of extreme stars

#15

Post by dotancohen »

behnamoh wrote: post #10
mensetmanusman wrote: post #5

“ This cosmic laboratory known as the “Double Pulsar” was discovered by members of the team in 2003. It consists of two radio pulsars which orbit each other in just 147 min with velocities of about 1 million km/h. One pulsar is spinning very fast, about 44 times a second. The companion is young and has a rotation period of 2.8 seconds. It is their motion around each other which can be used as a near perfect gravity l…

My jaw (and my phone) dropped when I read the numbers. I feel like space is ruthlessly huge and these pulsars are brutally massive..

Additionally, I love the challenge to language. These stars _are_ massive... but also tiny. Compare their 24 km radius to the 600,000 km radius of the sun. One of these objects would sit comfortably inside many Earth cities.

... at least for a milisecond before destroying it.

Re: General relativity passes a range of precise tests set by pair of extreme stars

#17

Post by ncmncm »

bmitc wrote: post #14

Neutron stars are just insane. > It is the only system of two radio pulsars known to date. The source, in a distance of 2400 light years What a find!

That is what astonishes me. I thought these things would have to be 24 million light years away, not just 24 hundred. That is practically our backyard.

Radiating away 8 million tons per second, and barely noticing the loss.

I marvel that these things aren't magnetars. We will be lucky if no magnetars are found within 500 ly, because a minor disturbance on one that close could end life on Earth. Life in a galaxy is a risky affair. Anybody capable would get far away from the galactic disc, as soon as possible, if they value life. It is no surprise they don't visit us. It is dangerous here.

Re: General relativity passes a range of precise tests set by pair of extreme stars

#18

Post by fmajid »

It's not as if anyone was expecting General Relativity to fail the test. Gravitational time dilation is a thing observed since the 1970s, atomic clocks have compensation for altitude and gravitational potential applied to them and that's part of the TAI and UTC standards we use every day, knowingly or not.

On the other hand, Einstein lost his vendetta against Quantum physics, badly, since Alain Aspect's 1980 experiment showing Bell's inequalities are violated.

Re: General relativity passes a range of precise tests set by pair of extreme stars

#19

Post by m4r35n357 »

fmajid wrote: post #18

It's not as if anyone was expecting General Relativity to fail the test. Gravitational time dilation is a thing observed since the 1970s, atomic clocks have compensation for altitude and gravitational potential applied to them and that's part of the TAI and UTC standards we use every day, knowingly or not. On the other hand, Einstein lost his vendetta against Quantum physics, badly, since Alain Aspect's 1980 experime…

Well he invented Quantum Physics, so hardly a loss!

Re: General relativity passes a range of precise tests set by pair of extreme stars

#20

Post by brabel »

dotancohen wrote: post #15
behnamoh wrote: post #10

Earlier quoted context omitted.

My jaw (and my phone) dropped when I read the numbers. I feel like space is ruthlessly huge and these pulsars are brutally massive..

Additionally, I love the challenge to language. These stars _are_ massive... but also tiny. Compare their 24 km radius to the 600,000 km radius of the sun. One of these objects would sit comfortably inside many Earth cities. ... at least for a milisecond before destroying it.

Now imagine that 24km object, something three times bigger than the biggest mountain on Earth, spinning 44 times a second!!! Of course, we can't even begin to imagine that this huge mountain also has the mass of the whole Earth, let alone the mass of the whole solar system (it's actually even more than that).

Just completely mind blowing.

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