altmarius

cultură şi spiritualitate

Key Einstein principle survives quantum test



Equivalence of gravity, acceleration applies even for atoms in superposition of energy states

BY 
7:28AM, APRIL 28, 2017
warping space

EINSTEIN ENDURES  According to Einstein’s general theory of relativity, massive objects warp space (illustrated above), producing gravitational attraction. Scientists don’t understand how general relativity interfaces with quantum mechanics, but a pillar of general relativity, the equivalence principle, has withstood a new quantum test.

Particles with mind-bending quantum properties still follow a standard gravitational rule, at least as far as scientists can tell.

The equivalence principle — one of the central tenets of Einstein’s theory of gravity — survived a quantum test, scientists report online April 7 at arXiv.org.

In Einstein’s gravity theory — the general theory of relativity — gravity and acceleration are two sides of the same coin. According to the equivalence principle, the gravitational mass of an object, which determines the strength of gravity’s pull, is the same as its inertial mass, which determines how much an object accelerates when given a push (SN: 10/17/15, p. 16). As a result, two objects dropped on Earth’s surface should accelerate at the same rate (neglecting air resistance), even if they have different masses or are made of different materials.

One of the first reported tests of the equivalence principle — well before it was understood in the framework of general relativity — was Galileo’s apocryphal experiment in which he is said to have dropped weights from the Leaning Tower of Pisa. Scientists have since adapted that test to smaller scales, swapping out the weights for atoms. In the new study, physicists went a step further, putting atoms into a quantum superposition, a kind of limbo in which an atom does not have a definite energy but occupies a combination of two energy levels.

Manipulating rubidium atoms with lasers, scientists led by researchers from Italy gave the atoms an upward kick and observed how gravity tugged them down. To compare the acceleration of normal atoms with those in a superposition, the scientists split the atoms into two clouds, put atoms in one cloud into a superposition, and measured how the clouds interacted. These clouds of atoms behave like waves, interfering similarly to merging water waves. The resulting ripples depend on the gravitational acceleration felt by the atoms.

The scientists then compared the result of this test to one where both clouds were in a normal energy state. Gravity, the researchers concluded, pulled on atoms in a superposition at the same rate as the others — at least to the level of sensitivity the scientists were able to probe, within 5 parts in 100 million.

Quantum tests of the equivalence principle explore the murky realm where quantum mechanics and general relativity meet. The two theories don’t play well with one another. Scientists are currently struggling to unify the pair into one theory of quantum gravity, and some candidate theories predict that the equivalence principle breaks down at the quantum level.

The test “is a new way of confronting gravity with quantum physics,” says theoretical physicist Robert Mann of the University of Waterloo in Canada. “Any way that we can do that tells us something about how to put together gravity with quantum physics,” even if the test finds no violation, he says.

Guglielmo Tino, a study coauthor and physicist at the University of Florence, declined to comment on the work due to the policies of the journal where the paper has been accepted.

Scientists have previously tested the equivalence principle in atoms, comparing gravity’s effects on different types of atoms, for example. Because such tests deal with tiny particles, they also explore the nebulous territory between quantum physics and general relativity. But the new test is the first to study superposition, one of the weirdest properties of quantum mechanics.

“It’s a beautiful demonstration of the versatility of these quantum tests,” says physicist Ernst Rasel of Leibniz Universität Hannover in Germany.

Vizualizări: 153

Adaugă un comentariu

Pentru a putea adăuga comentarii trebuie să fii membru al altmarius !

Alătură-te reţelei altmarius

STATISTICI

Free counters!
Din 15 iunie 2009

200 state 

(ultimul: Micronesia)

Numar de steaguri: 264

Record vizitatori:    8,782 (3.04.2011)

Record clickuri:

 16,676 (3.04.2011)

Steaguri lipsa: 42

1 stat are peste 660,000 clickuri (Romania)

1 stat are peste 100.000 clickuri (USA)

1 stat are peste 40,000 clickuri (Moldova)

2 state au peste 20,000  clickuri (Italia,  Germania)

1 stat are peste 10.000 clickuri (Franta)

6 state au peste 5.000 clickuri (Olanda, Belgia, Marea Britanie, Canada, UngariaSpania )

10 state au peste 1,000 clickuri (Polonia, Rusia,  Australia, IrlandaIsraelGreciaElvetia ,  Brazilia, Suedia, Austria)

50 state au peste 100 clickuri

16 state au un click

Website seo score
Powered by WebStatsDomain

DE URMĂRIT

1.EDITURA HOFFMAN

https://www.editurahoffman.ro/

2. EDITURA ISTROS

https://www.muzeulbrailei.ro/editura-istros/

3.EDITURA UNIVERSITATII CUZA - IASI

https://www.editura.uaic.ro/produse/editura/ultimele-aparitii/1

4. PRINTRE CARTI

http://www.printrecarti.ro/

5. ANTICARIAT ALBERT

http://anticariatalbert.com/

6. ANTICARIAT ODIN 

http://anticariat-odin.ro/

7. TARGUL CARTII

http://www.targulcartii.ro/

8. MAGAZINUL DE CARTE

http://www.magazinul-de-carte.ro/

9. ANTICARIAT PLUS

http://www.anticariatplus.ro/

10. CARTEA DE CITIT

http://www.carteadecitit.ro 11. ANTICARIAT ON-LINE
http://www.carti-online.com/

12. ANTICARIATUL DE NOAPTE

 http://www.anticariatuldenoapte.ro/

13. ANTICARIATUL NOU

http://www.anticariatulnou.ro

14. ANTICARIAT NOU

https://anticariatnou.wordpress.com/

15. ANTICARIAT ALEPH

https://www.anticariataleph.ro/

16. ANTIKVARIUM.RO

http://antikvarium.ro

17.ANTIKVARIUS.RO

https://www.antikvarius.ro/

18. ANTICARIAT LOGOS

http://www.anticariat-logos.ro/

19. ANTICARIAT.NET

http://www.anticariat.net/informatii-contact.php

20. TIMBREE

www.timbree.ro

21. FILATELIE

 http://www.romaniastamps.com/

22 MAX

http://romanianstampnews.blogspot.com

23. STAMPWORLD

http://www.stampworld.com

24. LIBMAG

https://www.libmag.ro/oferta-carti-polirom/?utm_source=facebook-ads-7-99-polirom&utm_medium=banner-facebook&utm_campaign=7-99-polirom-facebook&utm_content=new-3

25. DAFFI'S BOOKS

https://www.daffisbooks.ro 26. MAGIA MUNTELUI

http://magiamuntelui.blogspot.com

27. RAZVAN CODRESCU
http://razvan-codrescu.blogspot.ro/

28.RADIO ARHIVE

https://www.facebook.com/RadioArhive/

29.NATIONAL GEOGRAPHIC ROMANIA

https://www.natgeo.ro/revista

30. SA NU UITAM

http://sanuuitam.blogspot.ro/

31. MIRON MANEGA
http://www.certitudinea.o

32. CERTITUDINEA

www.certitudinea.com

Anunturi

Licenţa Creative Commons Această retea este pusă la dispoziţie sub Licenţa Atribuire-Necomercial-FărăModificări 3.0 România Creativ

Note

Hoffman - Jurnalul cărților esențiale

1. Radu Sorescu -  Petre Tutea. Viata si opera

2. Zaharia Stancu  - Jocul cu moartea

3. Mihail Sebastian - Orasul cu salcimi

4. Ioan Slavici - Inchisorile mele

5. Gib Mihaescu -  Donna Alba

6. Liviu Rebreanu - Ion

7. Cella Serghi - Pinza de paianjen

8. Zaharia Stancu -  Descult

9. Henriette Yvonne Stahl - Intre zi si noapte

10.Mihail Sebastian - De doua mii de ani

11. George Calinescu Cartea nuntii

12. Cella Serghi Pe firul de paianjen…

Continuare

Creat de altmariusclassic Dec 23, 2020 at 11:45am. Actualizat ultima dată de altmariusclassic Ian 24.

© 2021   Created by altmarius.   Oferit de

Embleme  |  Raportare eroare  |  Termeni de utilizare a serviciilor