# Mystery of strange radio bursts from space

1. Apr 2, 2015

### Garth

DISCRETE STEPS IN DISPERSION MEASURES OF FAST RADIO BURSTS

(emphasis mine)

And no, this wasn't published in April 1st!

Link to New Scientist article: Is this ET? Mystery of strange radio bursts from space.

Garth

Last edited: Apr 2, 2015
2. Apr 2, 2015

### Chronos

It certainly is ... interesting. It is difficult to resist concluding some pretty exotic technology is required to fine tune coordination between signals.

3. Apr 2, 2015

### wabbit

Had a quick look - does it say substantially more w.r.t. the thread title than "we haven't looked very much into possible causes and we just don't know what this could be, so E.T. is one possibily we can entertain" ?

Last edited: Apr 2, 2015
4. Apr 2, 2015

### Garth

I think it is saying a bit more than that, even though we have to remain sceptical until proven otherwise.

It would seem to be difficult to find a natural explanation, particularly because to the correlation of the dispersion measures with exact multiples of 187.5cm-3.

The only other possibility IMHO, as described in the paper, is that the signal is terrestrial "perytons" - wait we have a picture:-
- sorry, wrong kind of peryton!

Garth

Last edited: Apr 2, 2015
5. Apr 2, 2015

### marcus

Garth, I looked up an elementary explanation of the dispersion measure (DM) of pulsar signals and found this:
http://astronomy.swin.edu.au/cosmos/P/Pulsar+Dispersion+Measure

It explains why the DM can be quoted in parsecs per cubic cm, as in your article.

My impression was that the authors were leaning towards an artificial (terrestrial) origin. Particularly as almost all the instances were picked up at one observatory (Parkes), and because of the correlation with the Earthly time standard.
==quote==
As perytons are thought to be produced on Earth, this would imply that FRBs are also Earthly noise. Indeed, why would both perytons and FRBs show arrival times with a strong correlation to Earth’s integer second?

This hints at some man-made device, such as mobile phone base stations. The device needs to keep (or sync) the time to sub-second precision, ...

5. CONCLUSION

...
...
...
Failing some observational bias, the suggestive correlation with terrestrial time standards seems to nearly clinch the case for human association of these peculiar phenomena...
==endquote==

Last edited: Apr 2, 2015
6. Apr 2, 2015

### Wizzyman

Hey guys,

Let me preface this by saying that I'm not a scientist, or a mathematician, in fact I'm pretty terrible at maths, but I have noticed a pattern between these 187.5 steps and π - is this something that is known already?

I thought I would query this before I go any further so as not to embarrass myself with my lack of understanding!

7. Apr 2, 2015

### wabbit

Which pattern ?

In any case if any, it would then if not a coincidence (most likely, 3 or 4 digits only plus a range of possible pattern making transformations) perhaps point to a terrestrial origin from someone who knew in what unit DM would be measured - a practical joke on the observers ?

Last edited: Apr 2, 2015
8. Apr 2, 2015

### Wizzyman

Like I say, I don't have a understanding of the underlying principals, so I could be doing something stupid - but here is what I saw:

FRBs step in 187.5cm
Hydrogen Line 21cm

187.5 / 21 = 8.928
(2*Pi)* 1420.40 (Hydrogen line MHZ) = 8924.63 / 1000 = 8.924

375 / 21 = 17.857
(4*Pi)* 1420.40 (Hydrogen line MHZ) = 17849.27 / 1000 = 17.849

562/21 = 26.761
(6*Pi)* 1420.40 (Hydrogen line MHZ) = 26773.909/ 1000 = 26.773

750/21 = 35.714
(8*Pi)* 1420.40 (Hydrogen line MHZ) = 35698.54/ 1000 = 35.698

If I am doing something silly then please forgive my ignorance (and feel free to have a laugh at my expense!)

9. Apr 2, 2015

### Garth

Sorry Wizzyman - no "Hydrogen times Pi"

The wavelength and frequency of a transmission are related by $\lambda\nu = c$ so in your calculations you have used the fact that $2 \pi c = 2 \pi \lambda \nu = 188.365 \times10^9 cm.s^{-1}$ and this coincidentally is near the numerical value of the DM step of 187.5 cm-3 pc (not cm as you quote - in any case the units are all wrong).

A mistaken near coincidence!

Garth

Last edited: Apr 2, 2015
10. Apr 2, 2015

### Garth

Thank you for that link Marcus, but note that one signal was picked up at Arecibo.

Garth

Last edited: Apr 2, 2015
11. Apr 2, 2015

### Wizzyman

I'll just pretend that I understood all of that, back away slowly to the back of the class and put on the cap of shame. Thanks for setting me straight!

12. Apr 10, 2015

### Garth

Another clue in today's physics arXiv Identifying the source of perytons at the Parkes radio telescope.

A reminder:
Identified:
Somebody was cooking supper!!

However note:
Curiouser and curiouser!!

Garth

13. Apr 10, 2015

### Staff: Mentor

A microwave oven telescope!
"Hey, could you check if my lunch is ready?"
Okay, but with just one event the timing structure is meaningless.

14. Apr 10, 2015

### wabbit

Maybe manufacturers should now put a warning sign on microwaves "beware of perytons - do not open during cooking" : )

15. Apr 10, 2015

### OmCheeto

Katie Mack @AstroKatie · 12 hours ago
Fact Sheet: Perytons vs. Fast Radio Bursts (see http://arxiv.org/abs/1504.02165 ) #FRB #perytons

Thank you for clearing it up.

I was somewhat confused.

---------------------------------
Katie Mack
@AstroKatie
(a.k.a. Dr Katherine J Mack) astrophysicist, occasional freelance science writer, connoisseur of airplane food
Melbourne, Australia, or not
www.astrokatie.com

16. Apr 17, 2015

### Garth

According to this paper: Identifying the source of perytons at the Parkes radio telescope -
Perytons that have been observed are caused by a microwave. However at least one signal FRB 010724 was not such a peryton, which they still claim could be extraterrestrial.

Garth

17. Apr 17, 2015

### wabbit

I don't know if this applies at all to 010724, but I just saw this in another thread :
He proposes an interesting candidate for some FRBs (121102 is the one quoted).

18. Apr 17, 2015

### Garth

Yes, at last a natural explanation for non-terrestrial FRBs!

I found the FRB eprint/papers a bit confusing as to which signals might be non-terrestrial and which might be someone's microwaved supper!

If they are 'Planck stars', which is assuming such stars exist in the first place, then you still have to explain the 1875 multiples.

Garth

19. Apr 17, 2015

### wabbit

Ah I thought this concerned only the microwave perytons. As you say one needs to read closely to sort them out...
For Planck stars, if they (Rovelli & al.) can determine some unique enough signature of Planck star signals (didn't see that in the slides, only that FRBs could have the right wavelength - but from their earlier papers it seems the signal received from a Planck star should have a characteristic magnitude, spectrum, decay shape, etc., depending on just mass of star and distance) and if that does match some FRBs, this would be pretty big news.

20. Apr 17, 2015

### Jimster41

Is there no sense in which the FRB's are directional. Like is there any pattern to where they are coming from? Or is that not a meaningful notion in practical radio astronomy...? Or did I just miss it.